Re: Cocoa bug? release/removeObserver from inside observeValueForKeyPath

[Kai]

On 30.5.2008, at 00:53, Hamish Allan wrote:

On Thu, May 29, 2008 at 11:15 PM, Geoff Schmidt <[EMAIL PROTECTED] 
> wrote:


3) If this is already known, is there a customary pattern for  
avoiding the

problem? "Never release from observeValueForKeyPath" is a bit harsh!


I don't know if it's known, but you could try [obj
performSelector:@selector(release) withObject:nil afterDelay:0]
instead of [obj release]


Or use [obj autorelease] instead of [obj release] which should be  
pretty much the same with less typing. Again, you probably need to be  
able to handle the extra observeValueForKeyPath:


(My guess is that when A receives observeValueForKeyPath:, it is  
already too late to still remove B from the list of objects which will  
be notified. Most likely some kind of copy is made of the list of  
objects to notify internally by Cocoa.)


Kai


if you don't mind getting the extraneous
observeValueForKeyPath:... for that obj (it could have an "about to be
released" flag which would cause it to ignore the
observeValueForKeyPath:...)

Hamish
___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/kai%40granus.net

This email sent to [EMAIL PROTECTED]


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: Problems with a Layer backed NSView in a NSScrollView

[Kai]

Hi,

I am not sure whether this is relevant for your problem, but it might  
be useful to know that the content view of a scroll view gets a  
CATiledLayer instead of a normal CALayer via [setWantsLayer:YES].


The reasoning is that the content view can be potentially large and  
easily exceed the max size of OpenGL textures. Besides being tiled,  
CATiledLayer updates its contents lazily and in some background  
thread, if I remember correctly. In any case, it is different.


Best
Kai

On 19.6.2008, at 19:54, Moray Taylor wrote:


Thanks for the reply...

I've tried

[[[self pageScrollView] contentView] setWantsLayer:YES];

This results in a still flipped display, and very badly corrupted,  
lots of artifacts etc


[[self pageScrollView] setWantsLayer:YES];

Nice display, but still flipped.

The transform that used to work before I tried the above line makes  
no difference if I set the scrollview to be layer backed.


Any ideas?


--- On Thu, 19/6/08, Scott Anguish <[EMAIL PROTECTED]> wrote:


From: Scott Anguish <[EMAIL PROTECTED]>
Subject: Re: Problems with a Layer backed NSView in a NSScrollView
To: [EMAIL PROTECTED]
Date: Thursday, 19 June, 2008, 5:50 PM
have you tried just setting the contentview of the scroll
view to
layer backed?

otherwise you can remvoe the extra transofrm you added to
the view
itself.


On Jun 19, 2008, at 11:38 AM, Moray Taylor wrote:


Hi there!

I've been tearing my hair out trying to figure

this out, so

hopefully someone will take pity!

Basicaly, I've a CALayer-backed custom view, which

works pretty

great, I use a transform to flip it, and it works

fine, the problem

happens when I put it in a NSScrollView

If I put it in the scrollview, and set the

scrollview's

setWantsLayer to YES,  then it works good, very fast

and smooth

scrolling, BUT, it's completely upside down!

If I setWantsLayer to NO, then it's the right way

up, but jerky and

generally doesn't work (i.e. the scroll bar

doesn't do anything in

the scrollview)

I've tried flipping and unflipping the view,

applying a transform to

the CALayer (I had a transform to begin with, removed

it, no

difference), nothing I do will flip it back!

Please help!

Thanks

Moray




__

Sent from Yahoo! Mail.
A Smarter Email

http://uk.docs.yahoo.com/nowyoucan.html

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator

comments to the list.

Contact the moderators at

cocoa-dev-admins(at)lists.apple.com


Help/Unsubscribe/Update your Subscription:


http://lists.apple.com/mailman/options/cocoa-dev/scott%40cocoadoc.com


This email sent to [EMAIL PROTECTED]



 __
Sent from Yahoo! Mail.
A Smarter Email http://uk.docs.yahoo.com/nowyoucan.html
___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/kai%40granus.net

This email sent to [EMAIL PROTECTED]


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: PDFKit guidance

[Kai]

On 20.6.2008, at 13:47, Torsten Curdt wrote:



On Jun 20, 2008, at 13:09, Antonio Nunes wrote:


On 20 Jun 2008, at 11:07, Torsten Curdt wrote:


you can't go wrong by reading the "Cocoa
Drawing Guide."


Surely will read through that. Because frankly speaking I didn't  
think this was Quartz related.


Well, you need to know how to generally draw in Cocoa, and you need  
to know how to take advantage of PDFKit, so both John Calhoun and  
Joel Norvell provided useful pointers.


The scaling is done when a PDFPage needs to be drawn, so you need  
to implement it in your subclass's drawWithBox: method. Use an  
affine transform set up to serve your needs and apply it to the  
current graphics context within the drawWithBox: method before  
drawing the page.


Right. The point though is - I don't really want to display it. So I  
did not look into the drawing side of things. But I guess I just  
read up on the Quartz stuff and then get back to you guys (if  
needed). I assume one could also draw in memory - without  
displaying. Just didn't know that's the right direction.


You just should be aware that Quartz rewrites the PDF from scratch  
when using this approach. That is, while still showing the same  
grafics, the result is a completely new PDF file with potentially very  
different structure. Plus, since Quartz is about displaying, some non- 
display properties of the original PDF may be lost. Its a while ago  
that I last checked (Tiger, I think), but I would be surprised if  
Quartz became perfect in this respect in the meantime.


Depending on your application, this may be between no problem and  
inacceptable.


Greetings
Kai

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: Newbie question: error in creating a NSData object using handle (Resource Management)

[Kai]

Hi,

"I GOT AN ERROR HERE" may be a little too unspecific. Perhaps you can  
elaborate: crash, exception, nil return, Console entry, what else?


That said, you should use GetHandleSize (dataHandle) instead of  
GetResourceSizeOnDisk(dataHandle). GetResourceSizeOnDisk() can return  
values which are too large (see documentation).


Ah, and I just see that you combinded CountResources with  
Get1IndResource, that’s probably wrong. You should use CountResources  
with GetIndResource or Count1Resources with Get1IndResource.


Neither of this directly explains the difference between using NSData  
and the direct copy. But since you potentially access non existing  
bytes or data, that may be coincidence.


Best
Kai


Hi folks,I'm a newbie to Cocoa.
Recently, I'm working on a project relating to Resource Management.
In my project, there's a part that I'm reading through the resources  
in a

resource file.
I'm using:
int count = CountResources( typeName );
to get all resource that has the type "typeName", then loop through  
this

resource list to take resource data out.

for (n = 1; n <= count; n++)
{
  Handle dataHandle = Get1IndResource( type1, n);
  
  NSData *data = [NSData dataWithBytes: *dataHandle length:
GetResourceSizeOnDisk(dataHandle)];  // I GOT AN ERROR HERE
  //using data
  struct A_STRUCT aStruct;

  memcpy(& aStruct,[data bytes], [data length]);
}
After several times looping through the list, I got an error in the  
line

above.
But if I use data directly, like the following code, there is no error
occurred.
 memcpy(&pgControlRes,*dataHandle, GetResourceSizeOnDisk(dataHandle));
Any suggestions for my problem.
I highly appreciate all your helps.
___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/kai%40granus.net

This email sent to [EMAIL PROTECTED]


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: Newbie question: error in creating a NSData object using handle (Resource Management)

[Kai]

On 25.6.2008, at 10:42, Tran Kim Bach wrote:


Thanks Ken and Kai for your very very quick responses
This is my first post in the list, I'm sorry for not clarifying my  
problem.


Actually, the program stopped at the mentioned line.
In console, it said something like:
objc[2144]: FREED(id): message release sent to freed object=0x17d1d0


Ok, this looks like a standard overrelease problem. You posted too  
little code to include the problematic point.


Best to read up on Cocoas Memory Management Rules and make sure, that  
your Objective-C objects are not overreleased. Enabling Zombies can  
help if you can’t find it in source.


(Note: retain counts are the same concept as AddRef and Release in  
Microsofts COM, which you may know.)


Unless you have exceptionally many or large resources, I’d say you  
won’t need to worry about running out of memory in the loop on todays  
machines.


Best
Kai

PS: In case you have more questions about old-style resource access,  
you’d better take them to Apples Carbon list. People there are  
probably more understanding about the need to use time proven but no  
longer fancy APIs. ;-)



This GDB was configured as "i386-apple-darwin"
(Error from the debugger) /users/...path_to_my_exe_file: No such  
file or directory.


But I checked the exe file and it's absolutely there(in the bundle).
I tried an autorelease pool inside the loop, disposing of  
datahandle.etc, but still got the same problem.

Now, when I confirmed the *dataHandle, it returned NULL
but I don't know why?

--Bach

On Wed, Jun 25, 2008 at 3:36 PM, Ken Thomases <[EMAIL PROTECTED]>  
wrote:

On Jun 25, 2008, at 1:19 AM, Tran Kim Bach wrote:

Hi folks,I'm a newbie to Cocoa.
Recently, I'm working on a project relating to Resource Management.
In my project, there's a part that I'm reading through the resources  
in a

resource file.
I'm using:
int count = CountResources( typeName );
to get all resource that has the type "typeName", then loop through  
this

resource list to take resource data out.

for (n = 1; n <= count; n++)
{
 Handle dataHandle = Get1IndResource( type1, n);
 
 NSData *data = [NSData dataWithBytes: *dataHandle length:
GetResourceSizeOnDisk(dataHandle)];  // I GOT AN ERROR HERE

What do you mean "GOT AN ERROR"?  What error?  How did it manifest?




 //using data
 struct A_STRUCT aStruct;

 memcpy(& aStruct,[data bytes], [data length]);
}
After several times looping through the list, I got an error in the  
line

above.
But if I use data directly, like the following code, there is no error
occurred.
 memcpy(&pgControlRes,*dataHandle, GetResourceSizeOnDisk(dataHandle));
Any suggestions for my problem.
I highly appreciate all your helps.

You don't show if you're:

1) Checking if dataHandle is NULL
2) Checking if *dataHandle is NULL
3) If (1) or (2), checking ResError()
4) Disposing of dataHandle with ReleaseResource()

Also, in the pseudo-code you provide, the NSData objects will  
accumulate in the autorelease pool until some point after your "for"  
loop.  You can try using an autorelease pool inside the loop so that  
the NSData objects are released after each iteration.  You may just  
be exhausting memory.  For the case where you're not using NSData,  
the memory exhaustion might not happen since you're not storing the  
data twice in memory (once in the handle, once in the NSData), but  
would if there were twice as many resources.


Cheers,
Ken



___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: Newbie question: error in creating a NSData object using handle (Resource Management)

[Kai]

On 27.6.2008, at 05:00, Tran Kim Bach wrote:


Wow, thanks Ken a lot.
About the endian issues, I have a compatible swap function to  
convert data to Big-endian (and vice verse).

Then, I will correct big-endian issues.
I may know where the problem is.
When I read to your suggestion,

On Fri, Jun 27, 2008 at 6:11 AM, Ken Thomases <[EMAIL PROTECTED]>  
wrote:



data = [NSData dataWithBytes:*dataHandle length:sizeLong ];

  resID = [NSNumber numberWithShort:resIDShort];

if((type2 =='PREC')&&([resID intValue]== 302))

{

  struct PGControlRes pgControlRes;

memcpy(&pgControlRes,[data bytes], [data length]);

Have you tested that the resource size is the same as the structure  
size?


I found out something.
Actually, I'm just trying to make a prototype in one fixed size of  
the same resource type.
I used to test on the same resource files with this fixed resource  
structure.
but in reality, in my application, the resource size for this  
type(PREC) is various for each resource file(.rsrc).
So, I think the struct caused my problem ( I never thought of it  
before).
By the way, I have a lot of structs of the same resource type(PREC  
for example) written in C,

Is there any way to still take advantage of them in Objective-C?


Absolutely. Objective-C is a superset of C, so you can use all C you’d  
ever like to use.


Code of you like
NSNumber* resID =   [NSNumber numberWithShort:resIDShort];
and later
[resID intValue]
is pretty unnecessary - unless you are going to use resID with some  
Cocoa message which expects an NSNumber.


Another tip: Handle locking (HLockHi, HUnlock) is a no op under Mac OS  
X and can be skipped.


Best
Kai

(I mean if I can use these C structs in Objective-C?, don't have to  
rewrite them using Objective-C language).

Thank you for your supports.

---(Bachtk


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: Calculating accurate bounds of stroked paths

[Kai]

Hi,

have you checked CGContextReplacePathWithStrokedPath (CGContextRef  
c) ? This together with CGRect CGContextGetPathBoundingBox  
(CGContextRef c) might do the trick for you.


Best,
Kai

On 8.7.2008, at 14:16, Graham Cox wrote:

I need to know a rect within which all pixels will be painted for a  
given path and stroke width. I'd prefer not to make this rect any  
larger than it really needs to be. To compute this, I have to factor  
in all sorts of bits and pieces such as the angles of the line  
joins, miter limits and so on. It's getting so complicated I feel  
there has to be an easier way. Surely there's something in Quartz  
that can do this?


A close second best would be a rect that was the worst case bounds  
for a given stroke width (it wouldn't need to know the actual path,  
just its basic bounds), which thus assumed that all angles were  
acute enough to trigger the mitre conversion. Even that is proving  
hard to figure, as I'm probably not really understand the miter  
limit calculation. The docs state:


"The miter limit helps you avoid spikes at the junction of two line  
segments connected by a miter join (NSMiterLineJoinStyle). If the  
ratio of the miter length—the diagonal length of the miter join—to  
the line thickness exceeds the miter limit, the joint is converted  
to a bevel join. The default miter limit value is 10, which converts  
miters whose angle at the joint is less than 11 degrees."


So what *is it*? A value in degrees? Or a ratio of two sides of a  
triangle? What triangle, exactly? How can I tell just how far out I  
need to outset the rect to make sure I'm always just outside the  
edge of any mitred corner?


thanks for any insight into this, it's getting frustrating. I'm  
pretty OK at trig generally, but the definition is a bit vague, so  
I'm not sure what I should be using as my starting points (I  
possibly mean that literally!).


cheers, Graham___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/kai%40granus.net

This email sent to [EMAIL PROTECTED]


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: Any good advice for naming parameters of init methods?

[Kai]

On 11.7.2008, at 04:59, William Xu wrote:


Jens Alfke <[EMAIL PROTECTED]> writes:

With any naming convention, the possible problem is a conflict with  
a name in a
superclass.  Apple's Cocoa frameworks tend to use a "_" prefix for  
both ivars

and private method names.


How about using "_" as postfix then? Like `this_one_'.  I find google
c++ guide suggests that:

 http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml#Variable_Names

Looks good to me.


The only disadvantage of this approach is that KVC’s direct access to  
your ivars_ will no longer work. KVC knows about the _ivar convention  
(because it is used by Apple ;-) ) and matches an _ivar to the key  
"ivar". It won’t for ivar_. But than again it is better anyway to have  
explicit accessors, I’d say.


Kai

PS and OT: _ivar is not (any more) considered portable C++ either  
because all names beginning with _ are reserved for compiler/library  
use by the standard.





--
William

http://williamxu.net9.org

... I think I'd better go back to my DESK and toy with a few common
MISAPPREHENSIONS ...
___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/kai%40granus.net

This email sent to [EMAIL PROTECTED]


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: Cleaning up my Data Model

[Kai]

Yes, there is: IB 3.1 (coming with Xcode 3.1) lists all "Referencing  
Bindings" pointing to an object under the "Connections" tab.


Hope this helps.
Kai


On 25.7.2008, at 18:06, Richard Gutierrez wrote:


Thanks for the response...

Ultimately what I am trying to do is determine which objects are  
bound to which array controllers. I understand that if I delete an  
array controller, all of the bindings associated with that array  
controller will be removed, but I need to know which items are  
associated with that array controller so I can re-bind them to the  
new array controllers that I am creating.


Basically, I am re-structuring my data model to get myself better  
organized. I need to transfer the bindings for my objects from my  
old array controllers to my new array controllers without leaving  
any objects that were bound to my old array controllers "unbound"  
when I delete the old array controllers.


My problem is that I cannot see which items are bound to my old  
array controllers without going through them one by one, which can  
take forever with the amount of objects I have. Is there an easier  
way to see all bound objects to an array controller?

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/kai%40granus.net

This email sent to [EMAIL PROTECTED]


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: Design Question: Pro & Cons of KVC/KVO

[Kai]

Oleg,

by all means, go ahead with what you started and spend more time  
learning about KVC/KVO.


Yes, this is used in many many projects and I personally would really  
miss it if it wouldn’t be there. Actually, as you described yourself,  
if it wouldn’t be there, you’d had to brew something similar yourself.  
Which I did, coincidental, like 15 years ago under Mac OS 7 or so.  
Only that Apple can spend a lot more resources than you (I guess) or  
me (I’m sure) in making this "right". And they did.


Yes, it has a learning curve. And yes, it is sometimes unfortunate  
that the inner workings are a black box and can not be looked at with  
the debugger. Nevertheless, these are minor disadvantages in  
comparison to the whole thing.


Amin already mentioned all the advantages of KVC/KVO as provided by  
Apple, including the integration with other Cocoa technologies, which  
a home-brewn solution could never provide.


Concerning Core Data: it is equally great - inside its specs. Just  
take the build-in multi-level undo and redo support. Another great  
reason to use KVC/KVO, by the way: when Core Data undoes something,  
KVO is the way to get notified about these changes. Done consistently,  
this works simply beautiful.


And I wouldn’t restrict Core Data to database+forms apps. You can  
certainly use it for a drawing application. Whether it is the best  
solution for this kind of application depends - as always - on many  
details.


Hope this helps a little
Kai


On 21.8.2008, at 16:41, Oleg Krupnov wrote:


Thanks Amin for responding.

You are correct that there's no need to reinvent the wheel, and that's
exactly what I'd like to avoid, that's why I am now re-reading about
KVC/KVO and reconsidering it.

So, does everybody really always use KVC/KVO for implementing MVC, in
all projects? Is this the recommended best practice?

BTW does anyone use Core Data? I've watched the video tutorial and it
looks like too much magic. I would never guess how to make Core Data
work for a drawing application like the Sketch. Is Core Data rather
for database+forms apps?

Thanks.
___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/kai%40granus.net

This email sent to [EMAIL PROTECTED]


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: Strange Strange Bug

[Kai]

Steve,

looks like the debugger tries to inspect your uninitialized string  
pointers. And it happens that the stack location assigned to the 6th  
string pointer still contains the address of a now deallocated object  
left there when another method exited.


So this is a debugger-only problem and completely harmless without  
debugger (if I am not mistaken, of course).


To fix it, assign nil to the string pointers when you declare them:

NSString *gAsOf = nil;
etc..

Or, better yet, do not declare the variables before using them (that  
is, not all together at the start of the method). (Note that this  
style may be only possible with certain C dialects. I use Objective C+ 
+, therefore I’m not sure).


Hope this helps.
Kai


On 5.9.2008, at 09:04, Steve Cronin wrote:


Folks;

OK this behavior has me a little spooked...
This behavior occurs the first time through the method!
I have a breakpoint set at the first line of a method, which happens  
to be a NSLog(@"Ready");
As is normal I have my local variable declarations at the beginning  
of the method:

NSArray *myKeys, *workingValues;
	NSString *gAsOf, *gAsOfDate,  *gDataMask, *gDataMaskName, *gID,  
*gIDName, *gVersion, *gVersionName;
	gAsOfDateName = [[NSUserDefaults standardUserDefaults]  
stringForKey:@"groupAsOfDatePropertyName"];
	gDataMaskName = [[NSUserDefaults standardUserDefaults]  
stringForKey:@"groupDataMaskPropertyName"];


Nothing surprising or complicated...

However, the console window will show at least two of these messages:.
2008-09-05 00:56:45.101 XYZ[345:813] *** -[CFString _cfTypeID]:  
message sent to deallocated instance 0x16d1db80
2008-09-05 00:56:45.563 XYZ[345:813] *** -[CFString _cfTypeID]:  
message sent to deallocated instance 0x16d1db80
2008-09-05 00:56:46.776 XYZ[345:813] *** -[CFString _cfTypeID]:  
message sent to deallocated instance 0x16d1db80


If I scroll the variables display at the upper right in the debugger  
window, the console will add more of these messages.
One of the strings in the variable display will have its 'Value'  
shown as the instance id shown in these messages.
For this string variable the 'Summary' will be empty as opposed to  
all other 'Summary' which have 'Invalid'
The debugger is paused several lines above the declaration of this  
variable...


If I merely switch the positions of the variables I can change which  
variable has the 'bad' instance id.

It is always the 6th declared string variable.
I can mix up the order of variables, change the actual variable  
names, or interleave NSArray declarations, it doesn't matter...the  
6th string exhibits this behavior.
Hovering over the variable it displays the 'yellow help ribbon' with  
'NSZombie_CFString', whereas all the others are 'NSString'

Commenting out the declarations and use and compiling works fine.
Uncommenting brings back the exact behavior.

Note:  If I take out the breakpoint then the console does NOT show  
these messages even though I have left log messages in the method so  
I know the method is being executed


I have restarted XCode as well as the system (Intel 10.5.4, XC3.1)  
no change


What in the heck is going on?  Should I be worried? How can I shed  
this anomaly?


Thanks,
Steve

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/kai%40granus.net

This email sent to [EMAIL PROTECTED]


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: Strange Strange Bug

[Kai]

On 6.9.2008, at 02:10, Steve Cronin wrote:


Kai;

OK That seems reasonable but:

why do I not see this behavior anywhere else?


Yes, it surprised me a little, too, that I had never seen something  
like this. Now if I am right, this occurs only if such a variable  
happens to be at a location where another object pointer has  
previously been, which has been deallocated in the meantime. And if  
zombies are enabled, if I interpret your findings correctly. That may  
explain it.



why have I never seen it before now?


Zombies not enabled? Pure luck?



why if I restart XCode does the 'bad' instance fall on exactly the  
same string?


Because your program behaves reproducible and always does the same  
things on the stack before calling the method in question.


Again, I am not 100% sure about this.

Kai




Thanks,
Steve
On Sep 5, 2008, at 4:11 AM, Kai wrote:


Steve,

looks like the debugger tries to inspect your uninitialized string  
pointers. And it happens that the stack location assigned to the  
6th string pointer still contains the address of a now deallocated  
object left there when another method exited.


So this is a debugger-only problem and completely harmless without  
debugger (if I am not mistaken, of course).


To fix it, assign nil to the string pointers when you declare them:

NSString *gAsOf = nil;
etc..

Or, better yet, do not declare the variables before using them  
(that is, not all together at the start of the method). (Note that  
this style may be only possible with certain C dialects. I use  
Objective C++, therefore I’m not sure).


Hope this helps.
Kai


On 5.9.2008, at 09:04, Steve Cronin wrote:


Folks;

OK this behavior has me a little spooked...
This behavior occurs the first time through the method!
I have a breakpoint set at the first line of a method, which  
happens to be a NSLog(@"Ready");
As is normal I have my local variable declarations at the  
beginning of the method:

NSArray *myKeys, *workingValues;
	NSString *gAsOf, *gAsOfDate,  *gDataMask, *gDataMaskName, *gID,  
*gIDName, *gVersion, *gVersionName;
	gAsOfDateName = [[NSUserDefaults standardUserDefaults]  
stringForKey:@"groupAsOfDatePropertyName"];
	gDataMaskName = [[NSUserDefaults standardUserDefaults]  
stringForKey:@"groupDataMaskPropertyName"];


Nothing surprising or complicated...

However, the console window will show at least two of these  
messages:.
2008-09-05 00:56:45.101 XYZ[345:813] *** -[CFString _cfTypeID]:  
message sent to deallocated instance 0x16d1db80
2008-09-05 00:56:45.563 XYZ[345:813] *** -[CFString _cfTypeID]:  
message sent to deallocated instance 0x16d1db80
2008-09-05 00:56:46.776 XYZ[345:813] *** -[CFString _cfTypeID]:  
message sent to deallocated instance 0x16d1db80


If I scroll the variables display at the upper right in the  
debugger window, the console will add more of these messages.
One of the strings in the variable display will have its 'Value'  
shown as the instance id shown in these messages.
For this string variable the 'Summary' will be empty as opposed to  
all other 'Summary' which have 'Invalid'
The debugger is paused several lines above the declaration of this  
variable...


If I merely switch the positions of the variables I can change  
which variable has the 'bad' instance id.

It is always the 6th declared string variable.
I can mix up the order of variables, change the actual variable  
names, or interleave NSArray declarations, it doesn't matter...the  
6th string exhibits this behavior.
Hovering over the variable it displays the 'yellow help ribbon'  
with 'NSZombie_CFString', whereas all the others are 'NSString'

Commenting out the declarations and use and compiling works fine.
Uncommenting brings back the exact behavior.

Note:  If I take out the breakpoint then the console does NOT show  
these messages even though I have left log messages in the method  
so I know the method is being executed


I have restarted XCode as well as the system (Intel 10.5.4, XC3.1)  
no change


What in the heck is going on?  Should I be worried? How can I shed  
this anomaly?


Thanks,
Steve

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/kai%40granus.net

This email sent to [EMAIL PROTECTED]






___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

NSXMLParser and character entities?

[Kai]

When NSXMLParser hits a character entity like ä (-> German umlaut  
'ä'), it sends parser:resolveExternalEntityName:systemID: to its  
delegate and if this is not implemented or returns nil,  
parser:parseErrorOccurred: is called with  
NSXMLParserUndeclaredEntityError.


Am I supposed to resolve all these character entities myself? And if  
so, what should the NSData object returned by  
parser:resolveExternalEntityName:systemID: contain? Unicode? Which  
Unicode encoding?


But this can’t be, can it? I must be missing something simple.

Thanks for any hints
Kai



___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: NSXMLParser and character entities?

[Kai]

On 14.9.2008, at 10:45, Nathan Kinsinger wrote:



On Sep 12, 2008, at 3:56 PM, Kai wrote:

When NSXMLParser hits a character entity like ä (-> German  
umlaut 'ä'), it sends parser:resolveExternalEntityName:systemID: to  
its delegate and if this is not implemented or returns nil,  
parser:parseErrorOccurred: is called with  
NSXMLParserUndeclaredEntityError.


Am I supposed to resolve all these character entities myself? And  
if so, what should the NSData object returned by  
parser:resolveExternalEntityName:systemID: contain? Unicode? Which  
Unicode encoding?


But this can’t be, can it? I must be missing something simple.

Thanks for any hints
Kai



The main problem is that entities like ä are defined by HTML  
and have nothing to do with XML or NSXMLParser.


Understood.



I haven't dealt with this problem myself but I was curious so I  
tried a few things.




My first attempt was using NSAttributedString to convert the HTML  
entity to a UTF8 string.


- (NSData *)parser:(NSXMLParser *)parser resolveExternalEntityName: 
(NSString *)entityName systemID:(NSString *)systemID

{   
	NSAttributedString *entityString = [[[NSAttributedString alloc]  
initWithHTML:[[NSString stringWithFormat:@"&%@;", entityName]  
dataUsingEncoding:NSUTF8StringEncoding] documentAttributes:NULL]  
autorelease];


NSLog(@"resolved entity name: %@", [entityString string]);

	return [[entityString string]  
dataUsingEncoding:NSUTF8StringEncoding];

}

This works, parser:foundCharacters: gets the ä but for some reason  
parser:parseErrorOccurred: is still being called with the same error  
you received: "Operation could not be completed.  
(NSXMLParserErrorDomain error 26.)"


The parser does continue and parse the file correctly (with the ä),  
it just makes it hard to tell when you have real errors. I'm really  
curious as to why this doesn't work (running 10.5.4 on Intel). And  
the fact that the parser keeps parsing after the error, when the  
documentation says it will stop, is odd too.


That’s indeed odd behavior. Guess I’ll better file a bug.





Another option is to add an XHTML DocType DTD to the file and set  
setShouldResolveExternalEntities: to YES (default is NO). This works  
with no errors because the DTD defines the entities.


However NSXMLParser will download the DTD (over the net) every time  
you parse a file. So you probably want to copy one of the DTD's (say http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd 
 ) locally. Although I didn't try it, you could copy the entity  
definitions into your own DTD to make the file smaller and parsing  
it faster.


That should work well, thanks for the hint.





Of course if the content really is XHTML you should really be using  
an HTML parser and not an XML one.


No, it isn’t. Just needs some way to encode all German characters.  
I’ll have to investigate whether simply using utf8 encoding is an  
option, though.



--Nathan


Thanks a lot for your very helpful answer
Kai___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: NSXMLParser and character entities?

[Kai]

On 15.9.2008, at 22:24, Nathan Kinsinger wrote:



On Sep 15, 2008, at 1:45 PM, Kai wrote:



Of course if the content really is XHTML you should really be  
using an HTML parser and not an XML one.


No, it isn’t. Just needs some way to encode all German characters.  
I’ll have to investigate whether simply using utf8 encoding is an  
option, though.



--Nathan


Thanks a lot for your very helpful answer
Kai


Someone who knows more about unicode can correct me if I'm wrong,  
but I don't think ä is an utf8 (or any other string) encoding.  
The point I was trying to make is that ä and such are  
specifically defined by HTML.


XML supports utf8 so you can just use german text without the HTML  
entities. Or rather it can, if you use encoding="UTF-8"?> as your XML declaration (this is typically the  
default). NSXMLParser will parse it correctly.


This was exactly what I meant. Sorry for the unclear wording.

Kai




--Nathan





___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Core Animation Caching Resolution

[Kai]

Hi,

I am having a CALayer with a scale-down transform and many sub layers.  
It seems to be the case that these sub layers cache their contents  
with 1 unit to 1 pixel, that is they ignore the (outer) transform  
until it comes to draw to the screen.


Is there a suggested way to work around this? What I want is to have  
the cache at screen resolution to keep memory usage controlled.


Thanks for any hints
Kai

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: Which language to get started with cocoa development?

[Kai]

Achim:

I can’t answer your questions concerning the scripting languages, but  
given your background I’d suggest to go ahead with ObjC. It won’t  
really be a new language for you since it is but an extension of C.  
Granted, the bracket notation for message sending needs a little  
getting used to, but that’s about it, syntax wise.


The by far larger part of the learning curve is getting used to the  
Cocoa design patterns, which you’ll have to do anyway. And since ObjC  
is the "native language" of Cocoa, approching it from this side  
probably has some obstacles less, which may be introduced by bridiging  
to other languages.


Have fun!
Kai


On 31.12.2008, at 09:22, Achim Domma wrote:


Hi,

I develop software for a living and want to get started with cocoa  
development just for fun. I'm good at python, C, C++ and C# and have  
some Ruby knowledge. Now I'm asking myself, which language I should  
use to get started with cocoa development:


- ObjC looks interesing, but would be a new language to learn. I  
like to learn new languages, but I also prefer to do one step after  
another. So learning Cocoa and Obj-C toghether could be frustrating.
- I like dynamic scripting languages like python and ruby, but I  
would like to ship my apps to other users. And they should not care  
about the language I have used. Can pyObjC or RubyCoca be bundled  
with my app, so that the enduser will not recognize that python/ruby  
is shipped with my app?
- As far as I understand, GUIs are usually build with the interface  
builder of XCode. That tools is tuned to be used with ObjC. How good  
is the integration with scripting languages?
- How up to date are bindings to "non ObjC" languages usually? If I  
will like cocoa development, I want to have a look at core data and  
core animations. Are these also available for ruby and python?
- What about Mono/Cocoa#? Looks like Mono is not an good option, if  
I want to distribute my app as small download via the web. Or am I  
wrong?


I would be very happy to hear some opinions of experienced cocoa  
developers about these topics. Any feedback would be very appreciated.


cheers,
Achim
___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/kai%40granus.net

This email sent to k...@granus.net


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: Problems when putting a window between desktop and desktop icons

[Kai]

On 28.10.2008, at 08:27, Markus Amalthea Magnuson wrote:


On Mon, Oct 27, 2008 at 21:45, Karl Goiser <[EMAIL PROTECTED]> wrote:


Dear Markus and others,

This is a problem that I have had with an application of mine,  
iCalViewer,

which displays a window on the desktop.

What happens is that you can find a window level which draws the  
window
under the desktop icons and over the desktop itself.  However, at  
that
level, that window captures the mouse events as if it was _over_  
the desktop

icons.

My only solution was to disable mouse interaction with my window.

I raised this as a bug with Apple, bug number 3521992 on 5 January,  
2004 -

coming up to 5 years ago!

Regards,
Karl


Thanks for your reply, good to hear it's not just me, on the other
hand not so good because it obviously can't be done :)


Hm, you could try to detect mouse events for the icons yourself and if  
such an event is detected repost it to the Finder using some low level  
event posting in Core Graphics. I’m not sure though whether you can  
post events for a specific app or even for a specific window.


Or (maybe easier) turn it around: set your window to ignore mouse  
events and use a low level event tap to catch those mouse events you  
are interested in.


Best luck!
Kai




Time to come up with an entirely different solution then.
--
Markus Amalthea Magnuson

http://konstochvanligasaker.se
http://nattlek.se

"Life... is like a grapefruit. It's orange and squishy, and has a few
pips in it, and some folks have half a one for breakfast."
– Douglas Adams
___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/kai%40granus.net

This email sent to [EMAIL PROTECTED]


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: Question about NSThread?

[Kai]

It depends...

You may well just be lucky that it seems to work (or unlucky, this  
again depends...).


If your worker thread is only reading any data shared with other  
threads, it will indeed never disturb these other threads (probably  
just the main thread in your case). But if the main thread modifies  
this data, your worker thread may get inconsistent values. Like  
reading the width, then the main thread modifies the size (both width  
and height), then the worker thread reads the height.


The simplest approach would be to give the worker thread the complete  
info it needs at once when it is started, thus avoiding any shared data.


NSOperation and NSOperationQueue might be of help here. You would  
create a sub class of NSOperation which knows all the info your worker  
thread needs and off you go.


Best luck
Kai


On 19.11.2008, at 22:37, Jean-Nicolas Jolivet wrote:


Mmm I see

Well, right now I would say my worker thread is pretty much just  
reading values (size of image to generate etc)... but it's not  
"modifying" anything... it doesn't change any variables etc... just  
reads the info it needs to generate the images and ...well,  
generates the images...


If my worker thread doesn't have to "write" in any variables/objects  
whatever, shared with the UI, can I assume that it's safe to leave  
it like it is?



On 19-Nov-08, at 4:32 PM, Stefan Sinclair wrote:


In a word, yes :)

If you are accessing a piece of memory across threads, you should  
be making sure you are synchronizing any access to that memory  
which could occur across threads. For simple primitives (such as  
possibly your work progress number) just using an atomic integer  
would suffice. For more complicated access, you will want better  
protection (such as using locks around any APIs which can access  
your data). You're probably getting away with it now b/c your UI  
thread (the main thread) is only reading data (the work progress  
value - I'm guessing a single integer or floating point value which  
can be read/written in a single instruction) while the worker  
thread is modifying it. But it doesn't hurt to use proper thread- 
safe access patterns for data shared between threads even for small  
things like this.


-Stefan

> From: [EMAIL PROTECTED]
> To: cocoa-dev@lists.apple.com
> Date: Wed, 19 Nov 2008 15:57:44 -0500
> Subject: Question about NSThread?
>
> I have an app that generates a bunch of images... the process can  
be
> long so I wanted to start it in a separate thread so that the UI  
can

> be responsive etc...
>
> basically the only thing I did was:
>
> [NSThread detachNewThreadSelector:@selector(doLongProcess)
> toTarget:self withObject:nil];
>
> and I added
>
> NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
>
> at the beginning of my doLongProcess method, and [pool release]  
at the

> end...
> Now the weird part is that... it appears to be working... the  
images

> are created...the UI stays responsive..my status textfield gets
> updated (it wasn't getting updated when the long process was not  
in a

> separate thread)...
>
> Am I wrong to think that it should've been much more complex than
> that? (With NSLocks and whatnot...) Maybe I should just shut up  
and be

> happy that it work, but somehow this doesn't seem right...
>
> Jean-Nicolas Jolivet
> [EMAIL PROTECTED]
> http://www.silverscripting.com
>
> ___
>
> Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)
>
> Please do not post admin requests or moderator comments to the  
list.

> Contact the moderators at cocoa-dev-admins(at)lists.apple.com
>
> Help/Unsubscribe/Update your Subscription:
> http://lists.apple.com/mailman/options/cocoa-dev/stefan_sinclair%40hotmail.com
>
> This email sent to [EMAIL PROTECTED]


Proud to be a PC? Show the world. Download the “I’m a PC” Messenger  
themepack now. Download now.


Jean-Nicolas Jolivet
[EMAIL PROTECTED]
http://www.silverscripting.com

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/kai%40granus.net

This email sent to [EMAIL PROTECTED]


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: Magnify anything on the screen?

[Kai]

Hi,

if you’re on Leopard only, you can use the new screen capturing APIs  
to capture the screen area you need (look for the SonOfGrab sample  
code). I’d say magnifying the captured pixels is left to you. Some  
carefully chosen scale factor during drawing together with disabled  
anti-aliasing might work.


Kai

On 23.11.2008, at 17:03, Tim Andersson wrote:


Hi guys.

I'm currently working on my own custom color picker, and it's all  
going well. However, I need to replicate the magnifying function  
found in a NSColorPanel. I think I've figured out how to capture  
mouse-events anywhere on the screen, but I don't know how I would go  
about to "magnify" what's beneath the cursor. Any help is greatly  
appreciated.


Kind regards,
Tim
___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/kai%40granus.net

This email sent to [EMAIL PROTECTED]


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Re: Adding an associated reference is memory expensive (was: Adding an observer is memory expensive)

[Kai Brüning]

On 12.9.2009, at 00:35, Greg Parker wrote:

We have your earlier report rdar://7212101. Thanks, Torsten. (Ken  
didn't see it because the bug didn't pass through his group's hands  
on its way to my group.)


This is a bug in the associated reference machinery. That code keeps  
a C++ std::hash_map per augmented object, mapping associated keys to  
associated values. std::hash_map uses an std::vector internally, and  
the default hash_map constructor pre-allocates 100 entries for that  
vector.


Which are then raised to 193 by __stl_next_prime() in hashtable.h.  
Times the 64 bit pointer size makes 1544 bytes, which GC seems to  
round up to the 2k seen by the OP.


This is overkill for associated objects usage. The fix is to use a  
non-default constructor that specifies a much smaller initial  
hash_map size.


Unfortunately constructing the std::hash_map with a small capacity  
will lower the number of preallocated bucket slots only to 53 (-> 424  
bytes under 64 bits), because this is the smallest number returned by  
__stl_next_prime(). (I deduced this from the stl source in the 10.6  
sdk, so I may be mistaken.)


Still a lot for the probably predominate case of a single association.  
Especially if the OP is right with his observation that this memory is  
scanned by the collector, which adds time overhead to the space  
overhead.


Kai





On Sep 11, 2009, at 2:25 PM, Ken Ferry wrote:


Hi Torsten,
Please file as a bug if you haven't already.  That clearly needs to  
be

looked into.

For your KVO issue, you can probably work around it by implementing

- (void)setObservationInfo:(id)observationInfo;

- (id)observationInfo;

on the object that you are observing.  This provides the storage,  
and KVO

won't have to use associated references.

Note that the observation info is typed id despite being typed void  
* in the
headers.  KVO needs strong storage here to implement the feature  
described
in "Automatic Removal of Finalized Key-Value Observers" in the  
release
notes.  KVO assumes you are providing strong storage if the method  
is typed
id, which can be introspected out of the runtime.  If you aren't,  
it'll have

to use an associated reference to keep things alive.

-Ken
Cocoa Frameworks

On Fri, Sep 11, 2009 at 3:13 AM, Torsten Radtke >wrote:


Is this when the first observer is added to each of the 100k  
objects?




Yes, it happens for the first observer I add.

But I expressed the problem not good enough. Adding an observer is  
realized
by adding an associated reference (with objc_addAssociatedObject 
(), new in
Snow Leopard) to the observed object. So the main problem is that  
adding a
single associative reference to an object results in an allocation  
of 2048
byte block. If I do this to my 100.000 objects, about 200MB are  
allocated
(in comparison to about 3MB for the objects). These blocks seem to  
be

scanned memory, as I also noticed significant delays as the garbage
collector scanned and collected.

This amount of memory seems to be allocated on purpose (see  
the ::reserve
method on top of the stack trace shown below) but seems way too  
high for the

general case of adding a single associative reference!

0 libauto.dylib  
std::vector<__gnu_cxx::_Hashtable_node
const, void*> >*,
Auto::AuxAllocator<__gnu_cxx::_Hashtable_nodeconst, void*>

*> >::reserve(unsigned long)

1 libauto.dylib Auto::Zone::set_associative_ref(void*, void*, void*)
2 AssociativeReferences -[Object setName:]
3 AssociativeReferences main
4 AssociativeReferences start

The Object class is implemented as follows:

static char name_key;

@implementation Object

- (NSString*)name {
 return objc_getAssociatedObject(self, &name_key);
}

- (void)setName:(NSString*)aName {
 objc_setAssociatedObject(self, &name_key, aName,
OBJC_ASSOCIATION_COPY);
}

@end

Torsten







___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/kenferry 
%40gmail.com


This email sent to kenfe...@gmail.com


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/gparker%40apple.com

This email sent to gpar...@apple.com


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com

Re: Undo architecture advice needed

[Kai Brüning]

Hello Dave,

undo/redo is a model operation and should be handled inside the model.  
That is, I wouldn’t pick your suggestions 1) or 2), because they both  
do not observe (in a general case, not KVO) the model to generate undo  
information.


If I understand you correctly, the phase objects are your model. If  
this is correct, the changes do go through your code: when they arrive  
at the phase object (typically in a setter). And this is the place to  
record the information needed for undoing the change.


Hope this makes any sense
Kai

On 9.10.2009, at 19:53, David Hirsch wrote:


Hello list-
	I have a document-based application.  Each document has a NSArray  
of phases.  Phases is an NSArrayController created in IB and bound  
to FIle's Owner.phases.  When a given phase is selected in the  
NSTableView (bound to phase controller), then its properties show up  
in a set of text fields, check boxes, color wells, popup menus,  
etc., through bindings similar to "Phases.selection.size".


	Here is my question:  what is the best way to implement undo/redo  
here?  I'd like to enable undo of changes to the settings (like  
size) that the user makes in the text fields, but they don't go  
through my code - they are just bound directly to the array.  (Note  
that I do understand that the field editor has its own undo that  
operates during text editing; that is not what I'm talking about.)   
Here are some potential avenues I'm considering:
	1) Make the document the delegate for all these fields.  Then I can  
get a controlTextDidChange: notification, figure out the current  
phase, get the object and the value, and post an undo.  However,  
this requires me to implement a whole bunch of setters in my  
NSDocument subclass that duplicate setters in my phases class, which  
seems inelegant, to say the least.  Also, I don't see an obvious way  
to do something similar for, say checkboxes.
	2) Try to set up KVO (from my document subclass, I guess?) on the  
NSArrayController to watch for changes, and then register undo  
operations in the observing method.  I would have to be careful not  
to get into a loop when re-doing the undo operations, though, since  
I would observe any changes I made during undo.
	3) I'm sure there are other ways, but I'm not smart enough to think  
of them.


Thanks in advance,
Dave


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/lists%40kai-bruening.de

This email sent to li...@kai-bruening.de


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: Snow Leopard: unsupported PointerFunctions configuration was requested

[Kai Brüning]

On 10.10.2009, at 13:56, Chris Idou wrote:




Below is the RegexKit code that causes the Snow Leopard error. After  
reading the doco, I don't feel very enlightened about what the  
unsupported configuration is, or what the solution might be. Can  
anyone give me a clue?


Sure: replace NSPointerFunctionsIntegerPersonality by  
NSPointerFunctionsIntegerPersonality | NSPointerFunctionsOpaqueMemory.


Best
Kai




+ (void)load
{
 RKAtomicMemoryBarrier(); // Extra cautious
 if(RKCacheLoadInitialized== 1) { return; }

 if(RKAtomicCompareAndSwapInt(0, 1, &RKCacheLoadInitialized)) {
   if((cacheMapKeyCallBacks= dlsym(RTLD_DEFAULT,  
"NSIntegerMapKeyCallBacks")) == NULL) { cacheMapKeyCallBacks= dlsym 
(RTLD_DEFAULT, "NSIntMapKeyCallBacks"); }


#ifdef ENABLE_MACOSX_GARBAGE_COLLECTION
   id garbageCollector = objc_getClass("NSGarbageCollector");

   if(garbageCollector != NULL) {
 if([garbageCollector defaultCollector] != NULL) {
   id pointerFunctions = objc_getClass("NSPointerFunctions");

   RKCacheIntegerKeyPointerFunctions = [pointerFunctions  
pointerFunctionsWithOptions:NSPointerFunctionsIntegerPersonality];
   RKCacheIntegerKeyPointerFunctions.acquireFunction =  
intPointerFunctionsAcquire;
   RKCacheIntegerKeyPointerFunctions.descriptionFunction =  
intPointerFunctionsDescription;
   RKCacheIntegerKeyPointerFunctions.hashFunction=  
intPointerFunctionsHash;
   RKCacheIntegerKeyPointerFunctions.isEqualFunction =  
intPointerFunctionsIsEqual;
   RKCacheIntegerKeyPointerFunctions.relinquishFunction  =  
intPointerFunctionsRelinquish;
   RKCacheIntegerKeyPointerFunctions.sizeFunction=  
intPointerFunctionsSize;


   RKCacheObjectValuePointerFunctions = [pointerFunctions  
pointerFunctionsWithOptions:(NSPointerFunctionsZeroingWeakMemory|  
NSPointerFunctionsObjectPersonality)];


   [[garbageCollector defaultCollector]  
disableCollectorForPointer:RKCacheIntegerKeyPointerFunctions];
   [[garbageCollector defaultCollector]  
disableCollectorForPointer:RKCacheObjectValuePointerFunctions];

 }
   }
#endif // ENABLE_MACOSX_GARBAGE_COLLECTION
 }
}






From: Bill Bumgarner 
To: Chris Idou 
Cc: cocoa-dev@lists.apple.com
Sent: Thu, 24 September, 2009 12:36:04 PM
Subject: Re: Snow Leopard: unsupported PointerFunctions  
configuration was requested


On Sep 23, 2009, at 7:09 PM, Chris Idou wrote:
Very early in application startup, even before main() is called, I  
get the following error:


2009-09-24 12:07:11.462 MyApp[5534:a0f] *** An unsupported  
PointerFunctions configuration was requested, probably for use by  
NSMapTable, NSHashTable, or NSPointerArray.  The requested  
configuration fails due to integer personality not using opaque  
memory


It happens twice on startup, and below are the stack traces when it  
happens:


What does it all mean?


#00x7fff84b342f7 in NSLog
#10x7fff84ac84d1 in +[NSConcretePointerFunctions  
initializeSlice:withOptions:]
#20x7fff84aea796 in -[NSConcretePointerFunctions  
initWithOptions:]
#30x7fff84aea74d in +[NSPointerFunctions  
pointerFunctionsWithOptions:]

#40x10004b633 in +[RKCache load]


One change to the NSPointerFunction based collection classes (which  
support a number of things that NSArray & the like do not) between  
Leopard and Snow Leopard was to tighten up the validation of the  
pointer function validation such that a handful of non-sensical  
configurations are detected that weren't before.


I.e. RKCache is trying to create a set of pointer functions that  
doesn't make sense (and for whose behavior is undefined).


As someone else pointed out, RK is most likely RegexKit and, thus,  
the source is available and can be fixed.  Given the relatively  
common use of RK*, please provide a patch to the author so it can be  
fixed upstream.


b.bum


  
__

Get more done like never before with Yahoo!7 Mail.
Learn more: http://au.overview.mail.yahoo.com/
___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/lists%40kai-bruening.de

This email sent to li...@kai-bruening.de


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: Appropriate dealloc and finalize actions

[Kai Brüning]

Hi Karolis,

I’d say your pattern is absolutely correct. I assume those two objects  
do not retain each other, they just need to know about the other one.  
And they should be allowed to die separately, while cleaning up the  
otherwise dangling pointer in the other object.


The good news is that GC has support for this: weak references. Simply  
declare the connection ivar as weak: __weak MyClass* connection. GC  
does the rest. No dealloc, no finalizer, no dangling pointer. And it’s  
even thread safe.


Best
Kai


On 12.10.2009, at 04:44, Karolis Ramanauskas wrote:



If you want to do something that doesn't break encapsulation, then  
you
should simply release the one ivar connection.  That will let the  
receiving
object perform its own actions, by itself, on its own behalf, as  
appropriate

to its own affairs.



Thanks, however, I do not see how to accomplish my purpose. I'm  
confused.

Help ;)

I have object1 that has a connection to object2, (object1.connection =
object2). And at the same time object2.connection = object1:

O1 -> O2
O2 -> O1

If one of these objects gets deallocated how should I make sure the  
other
object is not pointing to the now deallocated object without doing  
what I

did:

- (void)dealloc {

if (self.connection) {

self.connection.connection = nil;

}

[super dealloc];

}

Thanks

On Sun, Oct 11, 2009 at 6:11 PM, Greg Guerin   
wrote:



Karolis Ramanauskas wrote:

- (void)dealloc {


  if (self.connection) {

  self.connection.connection = nil;

  }

  [super dealloc];
}




Why would you do this?  You're making one object responsible for the
internals of another object.  This is a bad idea.  It breaks the  
individual

encapsulation of each object.

One of the cardinal points of good object-oriented design is that an
object's responsibilities are circumscribed.  It should manage  
itself and
the things it directly references, nothing else.  For any objects  
it DOES
reference, each of those objects also has its own responsibilities,  
and so
on recursively.  Objects shouldn't poke their noses into another  
object's

business.

If you want to do something that doesn't break encapsulation, then  
you
should simply release the one ivar connection.  That will let the  
receiving
object perform its own actions, by itself, on its own behalf, as  
appropriate

to its own affairs.

-- GG


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/lists%40kai-bruening.de

This email sent to li...@kai-bruening.de


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: Appropriate dealloc and finalize actions

[Kai Brüning]

On 12.10.2009, at 13:42, Roland King wrote:



On 12-Oct-2009, at 7:26 PM, Karolis Ramanauskas wrote:


Thanks, Kai, Greg, Jens,

It's generally a bad idea to have two objects each retain the  
other. It
produces a reference loop, which means neither object can be  
deallocated

without manually releasing each side of the relationship.



As was stated in my original email these are all weak references:

@property (readwrite, assign) MyClass * connection;

I am not retaining the other object. In fact I couldn't really do  
it because

I'm pointing to the object of the SAME class.


yes you could - nothing stops you in retain/release mode from  
retaining an object of the same class, or even yourself, multiple  
times.




MyClass 1 > MyClass 2
MyClass 2 > MyClass 1

If I made a property to retain the value it would automatically  
mean that I

get a retain cycle.


indeed you would one you would have to break.



So whenever either an input or output is deleted I have to nil the
connection of the object pointing to the soon to be deallocated  
object:



self.connection.connection = nil;



Yes that looks like it would work, you explicitly remove the pointer  
to yourself as you go away. That's fine. Of course it means you  
aren't managing the lifetimes of the objects between each other,  
their lifetimes are totally dependent on external factors, but if  
that's what you want, that's good.





Thanks, Kai, for pointing this out:


The good news is that GC has support for this: weak references.  
Simply
declare the connection ivar as weak: __weak MyClass* connection.  
GC does the
rest. No dealloc, no finalizer, no dangling pointer. And it’s even  
thread

safe.





No. Under GC you don't have this problem at all. You don't need weak  
references or anything else funky, it just works. MyClass1 pointing  
to MyClass2 and back with ordinary object references/assign  
properties does create a cycle yes, however GC can manage that  
perfectly well. Once there are no references to either MyClass1 or  
MyClass2 from the *ROOT* objects, even though they point to each  
other, they are subject to collection. GC is able to deal with these  
reference loops quite happily.


Of course you’re right, you do not need weak references under GC to  
break reference count cycles - these are a non-issue under GC. I made  
the implicit assumption (bad bad!) that these objects should not keep  
each other alive. This is what __weak is good for: it marks a  
reference which does not keep the target alive and is auto-niled when  
the target dies. Depends on what you need.


And there’s no need to conditionalize __weak in any way. It’s simply  
ignored under non-GC.


Best
Kai



___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/lists%40kai-bruening.de

This email sent to li...@kai-bruening.de


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: GC and atomic getters/setters

[Kai Brüning]

On 17.10.2009, at 17:38, BJ Homer wrote:

In the Garbage Collection Programming Guide: Architecture [1], an  
example is
given of a set of non-GC getters and setters which use @synchronized 
(self)

to control the access to the ivar, and in the setter to protect the
releasing of the old object and retaining of the new.  Then, a GC  
example is
given in which the getters and setters have no synchronization; the  
getter

simply returns the value, and the setter simply assigns the new value.
I understand why the setter is so much simpler under GC; no retain/ 
release

fiddling is necessary.  However, I'm confused about the lack of
synchronization in the GC examples.  I know there's lots of  
skepticism as to
whether synchronization at the getter/setter level is even useful  
(hence the
general recommendation to make properties nonatomic).  But assuming  
that you
wanted it there in the first place, why does the GC version not need  
the
synchronization?  Is it simply because the setter is doing less, and  
thus

the getter wouldn't ever catch the setter halfway through its setting?
(After releaseing the old value, but before retaining the new, for
example.)


Basically yes.

Another way to look at it is that assignment to a GC-controlled  
pointer variable must be thread safe anyway (because GC is running in  
a separate thread and because there are things like weak references),  
so there is no need to put extra synchronization around it.


By the way, this thread safety feature of GC is another big reason to  
use GC over managed memory besides the automatic memory management.


Kai

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: how to make cocoa application run as a command line tool?

[Kai Brüning]

The clean solution for this is to refactor your application into a  
framework, a Cocoa application and a command line tool.


The framework contains all the document logic (the model part of the  
MVC pattern). Both the Cocoa application and the command line tool use  
the framework.


The tricky part is probably to find the right border between framework  
and application/tool. I haven’t done it myself yet, therefore I am for  
instance not sure whether NSDocument sub classes can/should be part of  
such a framework.


Others may know whether it is possible/feasible at all to run a Cocoa  
application faceless.


Good luck
Kai


On 20.10.2009, at 11:58, XiaoGang Li wrote:


Greetings,
   I have created an document-based cocoa application, now I  
need to

provide a command line interface for my users.
for example, users input this into the terminal:
./myApplication.app/Contents/MacOS/myApplication -c --srcFolder "A/B/ 
C"

--dstFolder "A/B/D";
I can get the argument information through [[NSProcessInfo  
processInfo]

arguments] in the init method of the application
delegate, and parse the arguments, then step by step.
My question is that, I don't want the window and other document be  
displayed

on the screen, even the menu.
I want all the action be processed  without user's interventio.
Maybe, this feature seems odd. anyway, however, user can open my  
application

in the Finder, and open a document to edit it. but they
also can run it like a shell command utility to do some other  
faceless work,

like convert the type the document to another type.

I don't know whether I have a detailed description for my issue, but  
I will

be very appreciated for your feedback.
___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/lists%40kai-bruening.de

This email sent to li...@kai-bruening.de


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: xml object memory issue

[Kai Brüning]

On 30.10.2009, at 08:36, Roland King wrote:

Autoreleased objects are only autoreleased when the pool is drained.  
It is more than likely that the XMLDocument initWithContentsOfURL  
makes a lot of temporary objects which end up on the autorelease  
pool but they won't actually be released until the end of your loop.


Put another pool alloc at the start of your loop before the NSURL  
alloc and then drain it after you release the xmlDocument - that  
will ensure all temporaries created during the parse are destroyed.


Or switch to garbage collection. By far the better alternative unless  
you must support Tiger or iPhone.


Kai



XiaoGang Li wrote:

The piece of code I want to discuss is followed:
#import 
int main (int argc, const char * argv[]) {
   NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
   for(int i=0;i<5000;i++)
   {
   NSURL *inAbsoluteURL = [[[NSURL alloc]  
initFileURLWithPath:@"the

path to one xml file"] autorelease];
   NSError *error = NULL;
   NSXMLDocument *xmlDocument = [[NSXMLDocument alloc]
initWithContentsOfURL:(NSURL*)inAbsoluteURL
options:0
error:&error];
   //hande my Xpath, and do check work. will not cosume the  
memory.

   [xmlDocument release];
   }
   [pool drain];
   return 0;
}
I used the Instruments to detect the objects created but still live  
until
the application quit, I also use top command to check the memory  
usage.
I found a lot of node, element, and other children object still  
live after

the xmlDocument do release.
I found that the memory usage of this application is increasing  
rapidly.
Can any one give me a guilde to force the system to dealloc the  
memory
during the for loop. I need to batch handle a lot of xml files. But  
after

the application runs for a while,
the system will crash because of no memory.
___
Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/rols%40rols.org
This email sent to r...@rols.org

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/lists%40kai-bruening.de

This email sent to li...@kai-bruening.de


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: Should I learn CoreData for this project?

[Kai Brüning]

Hi David,

this question is most definitely on topic :-)

So, lets see, what would Core Data give you:

- Scalability, fast incremental loads and saves for big data sets.
I don’t think you’ll need this. Loading and saving 500 items each time  
will be fast enough.


- A data model modeler.
That’s actually more valuable then it may seem on first glance. I  
often look at my Core Data models when thinking about algorithms and  
want to recap how the object graph looks.


- Automatic and semi-automatic version migration.
Depends on the lifecycle of your application. When needed, it’ll save  
you tons of time.


- Object graph consistency management.
A big one. Core Data automatically updates inverse relationships as  
needed. A lot of work to do manually, and always a source of subtle  
bugs.


- Automatic undo support.
Big

- Disadvantage: Core Data does not support ordered relationships. That  
is, it uses sets instead of arrays. If you need an order, you have to  
manage this yourself. Not hard, but sometimes an annoyance (the reason  
for this "shortcoming" are hard technical problems).


That’s it out of my head. I’m sure I forgot something.

The learning effort? Hard to say. Core Data is well documented and  
works (almost always) as advertised. So it depends on how well you  
learn new abstractions.


One unrelated advice: by all means use garbage collection. It makes  
object graph management (and a lot of other things) so much easier, no  
matter whether you use Core Data or not.


Good luck!
Kai

On 4.11.2009, at 05:22, David Hirsch wrote:

So, I'm hearing folks sing the praises of CoreData, which I have not  
yet learned.  It seems like a long uphill climb, but if life will be  
spectacular afterwards, I'll do it.  I am a semi-casual programmer;  
I've just finished a couple of small programs that do not use  
CoreData, and I can see the advantage in gaining open/save and undo/ 
redo for free, but I'm concerned about the work I'll have to put in  
to learn it.  I've read a bunch of the CoreData intro documentation,  
but it doesn't give a feel for how difficult it will be to learn,  
nor how big the advantages are if I do.


Here's the next project I'm going to work on, for which I'm  
considering CoreData:


A simulated annealing code for class scheduling.  The CoreData part  
would lie in managing all the lists involved: classes, rooms,  
instructors, preferences, conflict cost weights, etc.  I estimate  
that I will have about 500 items spread over about 10 arrays.  I  
would not expect to have a complex object graph (if that's the right  
term) - just a lot of items in lists, items that need to be managed,  
displayed, saved, loaded, etc.  I could use NSArrays for all these,  
which I currently understand.


Does this sound like it's worth learning CoreData for?

Thanks,
Dave

S.A.: I hope this is on topic; I think it is.

Those recent projects I mentioned:
http://almandine.geol.wwu.edu/~dave/research/code/ModeMaker/
http://almandine.geol.wwu.edu/~dave/research/code/ModeQuiz/



Dave Hirsch
Associate Professor
Department of Geology
Western Washington University
persistent email: dhir...@mac.com
http://www.davehirsch.com
voice: (360) 389-3583
aim: dhir...@mac.com
vCard: http://almandine.geol.wwu.edu/~dave/personal/DaveHirsch.vcf




___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/lists%40kai-bruening.de

This email sent to li...@kai-bruening.de


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: Should I learn CoreData for this project?

[Kai Brüning]

On 4.11.2009, at 11:33, Ruotger Skupin wrote:


more disadvantages to mention:

1. schema updates with every model change if you use an sql store  
(you have to make a mapping for every single from version/ to  
version combination you need to support)


In Snow Leopard Core Data does this automatically for "simple" cases.  
For non-simple cases you would have to write code for migration of non- 
Core Data documents, too.


2. multithreaded core data is very hard to get right (multiple  
contexts, data merges)


Isn’t this true for multi threaded code in general?
Seriously, the documentation explains how to structure multi threaded  
use of Core Data. This might even save you some pitfalls compared with  
a "naive" approach to multi-threading a model.


3. performance tuning of core data often means making your schema  
more complex (see also point 1)


Probably irrelevant for the task at hand.

4. debugging core data can be hard (most bugs only get to the  
surface when you try to save your data).


Sure, you have more black box behavior compared to a hand crafted  
model. Helps to go by the recommendations in the documentation and  
avoid anything which smells like a hack.


5. core data throws exceptions all over the place so you may end up  
with a try-catch block with every data access in your code


Not my experience. As with the whole of Cocoa, exceptions in Core Data  
indicate programmer errors, which should be fixed before releasing.




If your data set fits in memory and you don't mind loading it all at  
once, stay away from core data.


my two cents
Ruotger

On 04.11.2009, at 08:54, Kai Brüning wrote:


Hi David,

this question is most definitely on topic :-)

So, lets see, what would Core Data give you:

- Scalability, fast incremental loads and saves for big data sets.
I don’t think you’ll need this. Loading and saving 500 items each  
time will be fast enough.


- A data model modeler.
That’s actually more valuable then it may seem on first glance. I  
often look at my Core Data models when thinking about algorithms  
and want to recap how the object graph looks.


- Automatic and semi-automatic version migration.
Depends on the lifecycle of your application. When needed, it’ll  
save you tons of time.


- Object graph consistency management.
A big one. Core Data automatically updates inverse relationships as  
needed. A lot of work to do manually, and always a source of subtle  
bugs.


- Automatic undo support.
Big

- Disadvantage: Core Data does not support ordered relationships.  
That is, it uses sets instead of arrays. If you need an order, you  
have to manage this yourself. Not hard, but sometimes an annoyance  
(the reason for this "shortcoming" are hard technical problems).


That’s it out of my head. I’m sure I forgot something.

The learning effort? Hard to say. Core Data is well documented and  
works (almost always) as advertised. So it depends on how well you  
learn new abstractions.


One unrelated advice: by all means use garbage collection. It makes  
object graph management (and a lot of other things) so much easier,  
no matter whether you use Core Data or not.


Good luck!
Kai

On 4.11.2009, at 05:22, David Hirsch wrote:

So, I'm hearing folks sing the praises of CoreData, which I have  
not yet learned.  It seems like a long uphill climb, but if life  
will be spectacular afterwards, I'll do it.  I am a semi-casual  
programmer; I've just finished a couple of small programs that do  
not use CoreData, and I can see the advantage in gaining open/save  
and undo/redo for free, but I'm concerned about the work I'll have  
to put in to learn it.  I've read a bunch of the CoreData intro  
documentation, but it doesn't give a feel for how difficult it  
will be to learn, nor how big the advantages are if I do.


Here's the next project I'm going to work on, for which I'm  
considering CoreData:


A simulated annealing code for class scheduling.  The CoreData  
part would lie in managing all the lists involved: classes, rooms,  
instructors, preferences, conflict cost weights, etc.  I estimate  
that I will have about 500 items spread over about 10 arrays.  I  
would not expect to have a complex object graph (if that's the  
right term) - just a lot of items in lists, items that need to be  
managed, displayed, saved, loaded, etc.  I could use NSArrays for  
all these, which I currently understand.


Does this sound like it's worth learning CoreData for?

Thanks,
Dave

S.A.: I hope this is on topic; I think it is.

Those recent projects I mentioned:
http://almandine.geol.wwu.edu/~dave/research/code/ModeMaker/
http://almandine.geol.wwu.edu/~dave/research/code/ModeQuiz/



Dave Hirsch
Associate Professor
Department of Geology
Western Washington University
persistent email: dhir...@mac.com
http://www.davehirsch.com
voice: (360) 3

-[NSDateFormatter dateFormatFromTemplate:options:locale:] does not work as expected

[Kai Brüning]

Hi,

I am having problems using -[NSDateFormatter 
dateFormatFromTemplate:options:locale:] (new in 10.6.). It’s a great API which 
makes world-savvy custom date formats possible.

Unfortunately it does not seem to work. Examples of wrong results are:

- Hour format templates like "h a" (12 Hour with AM/PM) are converted to format 
"H" (24 Hour) under US locale. Other combinations ("ha ", "h", "H" under US or 
German locale) also always return "H".

- The template "EEyMd" is converted to format "EE, -M-d" under German 
locale. This is completely wrong, expected would be "EE, d.M.".

I filed a bug under rdar://7803429.

Does anybody have similar experiences with this method? Any work around to make 
it work?

- Kai

-

Test code:

The following code:

NSLocale* usLocale = [[NSLocale alloc] initWithLocaleIdentifier:@"en-US"];
NSLocale* germanLocale = [[NSLocale alloc] 
initWithLocaleIdentifier:@"de-DE"];

NSString* format = [NSDateFormatter dateFormatFromTemplate:@"h a" options:0 
locale:usLocale];
NSLog (@"Template “h a” with US local results in �...@”", format);

format = [NSDateFormatter dateFormatFromTemplate:@"H" options:0 
locale:usLocale];
NSLog (@"Template “H” with US local results in �...@”", format);

format = [NSDateFormatter dateFormatFromTemplate:@"h" options:0 
locale:usLocale];
NSLog (@"Template “h” with US local results in �...@”", format);

format = [NSDateFormatter dateFormatFromTemplate:@"h a" options:0 
locale:germanLocale];
NSLog (@"Template “h a” with German local results in �...@”", format);

format = [NSDateFormatter dateFormatFromTemplate:@"H" options:0 
locale:germanLocale];
NSLog (@"Template “H” with German local results in �...@”", format);

format = [NSDateFormatter dateFormatFromTemplate:@"EEyMd" options:0 
locale:germanLocale];
NSLog (@"Template “EEyMd” with German local results in �...@”", format);

gives me this output:

Template “h a” with US local results in “H”
Template “H” with US local results in “H”
Template “h” with US local results in “H”
Template “h a” with German local results in “H”
Template “H” with German local results in “H”
Template “EEyMd” with German local results in “EE, -M-d”

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

How to parse multipart/form-data?

[Kai Cao]

Hi,

I'm using CocoaHTTPServer to upload files from computer to iOS devices. But the 
result NSData received from the browser is multipart form data, which is really 
hard to parse manually. I know I can write a parser from scratch, however, it's 
time consuming and bug prone. I'm wondering wether there's a sophisticated 
library/framework for this. Any help would be appreciated. Thanks in advance. 

Best regards,

Kai
nonamel...@me.com

sent from Mobile Me
___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: My try/catch block isn't catching exceptions on 10.6

[Kai Brüning]

On 28.11.2009, at 13:57, Gwynne Raskind wrote:

> On Nov 28, 2009, at 4:25 AM, Greg Parker wrote:
>> Here's a fun idiom for handling both C++ and Objective-C exceptions in the 
>> same place (on iPhone and 64-bit Mac).
>> 
>>   @try {
>>   // do stuff
>>   } @catch (NSException *e) {
>>   // NSException
>>   } @catch (id e) {
>>   // Other Objective-C exception
>>   } @catch (...) {
>>   // Non-ObjC exception
>>   // Decode it by rethrowing it inside a C++ try/catch.
>>   try {
>>   @throw;
>>   } catch (std::bad_cast& e) {
>>   // C++ failed dynamic cast to reference type
>>   } catch (...) {
>>   // Other C++ exception
>>   // or non-ObjC non-C++ foreign exception
>>   }
>>   }
> 
> 
> I apologize if this is a dense question, but can't you just go like this?
> 
>   @try {
>   // do stuff
>   } @catch (NSException *e) {
>   // NSException
>   } @catch (id e) {
>   // Other Objective-C exception
>   } @catch (std::bad_cast& e) {
>   // C++ failed dynamic cast to reference type
>   } @catch (...) {
>   // Other C++ exception
>   // or non-ObjC non-C++ foreign exception
>   }

No - there’s a syntactically subtle but important difference above between 
@try/@catch and try/catch, the further being the Objective-C variant, the later 
C++.

Kai

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: Migrating changed objects between contexts

[Kai Brüning]

On 2.12.2009, at 18:27, Jim Thomason wrote:

>> It shouldn't deadlock. The doc for -lock says: "If you lock (or successfully 
>> tryLock) a managed object context, the thread in which the lock call is made 
>> must have a retain until it invokes unlock. If you do not properly retain a 
>> context in a multi-threaded environment, this will result in deadlock." Did 
>> you heed it?
> 
> It didn't matter one way or the other. Incidentally, I've seen that
> warning too, but in this case I was sharing the [document
> managedObjectContext] across threads, so it was guaranteed to exist as
> long as the window was open.
So I take it that you have code in place that postpones window closing while 
your background thread works with the context?
> What was the need to retain it in that
> case, anyway?
To safe writing above code.
> 
> Sigh. Nevermind, I'm an idiot. My worker thread that refreshes my
> graph does 3 different things in it. 1 is fairly old and has been
> around for months, the other 2 things are newly added.
> 
> The original one ended up calling rearrangeObjects on an array
> controller, and since that's not threadsafe (right?) I dispatched the
> call to the main thread, and helpfully set waitUntilDone:YES. That was
> fine originally, since the app was guaranteed not to be looking at the
> context in the main thread, and basically I got lucky and could get
> away with it.
> 
> But now, due to additional processing in the main thread, it was
> looking at the context. So my worker thread would happily chug along
> until it reached the rearrangeObjects call. It'd hand it off to the
> main thread and wait for it to finish. But the main thread was paused
> since my worker thread had the lock on the context. And blamo.
> Deadlock.
> 
> Solution? Disturbingly easy to see now 12 hours into trying to fix it.
> Just do the rearrangeObjects on the main thread as before, but set
> waitUntilDone:NO. All problems miraculously fixed.

And an important lesson learned: blocking or waiting in any way while holding a 
lock is a dangerous thing to do.

Kai

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: App works when launched from Xcode, not from Finder

[Kai Brüning]

Great you found this issue.

But according to the log output, it seems that you do have a serious 
threading-related problem. I wouldn’t ignore this, it may raise its head any 
time in the future and bite you badly.

Good luck
Kai

On 18.12.2009, at 03:26, PCWiz wrote:

> Thanks, will do.
> 
> And regarding Jeremy's note about the 2 libraries can't be loaded, those are 
> Input Manager plugins that have nothing to do with my app.
> 
> But I'm happy to say that I eventually found the cause of my problem. One of 
> the frameworks I was using was compiled using "i386 ppc" set as the 
> architecture. Setting this to "Standard (32-bit/64-bit Universal)" and 
> recompiling the framework fixed it. Xcode seems to launch the app in 32 bit 
> mode whether its in Debug or Release (because I have the Active Architecture 
> set to i386). When launched from Finder, the app launches in 64 bit mode, and 
> since that framework was not compiled with the x86_64 architecture it screwed 
> up the app.
> 
> Hope this helps anyone else that runs into this issue.
> 
> Independent Cocoa Developer, Macatomy Software
> http://macatomy.com
> 
> 
> On 2009-12-17, at 9:55 AM, Jens Alfke wrote:
> 
>> 
>> On Dec 16, 2009, at 10:04 PM, PCWiz wrote:
>> 
>>> I'm not using NSLock or NSRecursiveLock directly. I'm using @synchronized 
>>> on an object that multiple threads acess, to allow only one thread to 
>>> access the object at a time.
>> 
>> The fact that the description of the lock is " 
>> '(null)'" makes me suspect that you're synchronizing on a nil pointer, i.e. 
>> that when you call
>>  @synchronized(foo) { ... }
>> the value of foo is nil. I'm pretty sure that's illegal, and I would have 
>> thought it would throw an exception, but maybe not. Try putting a check 
>> above the block, something like
>>  NSAssert(foo!=nil, @"no foo");
>> 
>> —Jens
> 
> ___
> 
> Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)
> 
> Please do not post admin requests or moderator comments to the list.
> Contact the moderators at cocoa-dev-admins(at)lists.apple.com
> 
> Help/Unsubscribe/Update your Subscription:
> http://lists.apple.com/mailman/options/cocoa-dev/lists%40kai-bruening.de
> 
> This email sent to li...@kai-bruening.de

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: App works when launched from Xcode, not from Finder

[Kai Brüning]

On 18.12.2009, at 15:54, PCWiz wrote:

> Yeah I definitely need to squash this bug. But as Greg Parker said, 
> @synchronized (which I'm using) has nothing to do with NSRecursiveLock. And 
> the only other threading related classes I'm using are NSOperationQueue and 
> NSInvocationOperation. Would one of these classes use NSRecursiveLock?

Possibly in Leopard, but very unlikely under Snow Leopard: NSOperationQueue is 
now based on Grand Central.

> I am positive that I'm not directly using NSRecursiveLock or NSLock anywhere 
> in my project.

Have you tried to break on [NSRecursiveLock alloc]? Or on one of the init 
methods?

Kai

> 
> Independent Cocoa Developer, Macatomy Software
> http://macatomy.com
> 
> 
> On 2009-12-18, at 12:07 AM, Kai Brüning wrote:
> 
>> Great you found this issue.
>> 
>> But according to the log output, it seems that you do have a serious 
>> threading-related problem. I wouldn’t ignore this, it may raise its head any 
>> time in the future and bite you badly.
>> 
>> Good luck
>> Kai
>> 
>> On 18.12.2009, at 03:26, PCWiz wrote:
>> 
>>> Thanks, will do.
>>> 
>>> And regarding Jeremy's note about the 2 libraries can't be loaded, those 
>>> are Input Manager plugins that have nothing to do with my app.
>>> 
>>> But I'm happy to say that I eventually found the cause of my problem. One 
>>> of the frameworks I was using was compiled using "i386 ppc" set as the 
>>> architecture. Setting this to "Standard (32-bit/64-bit Universal)" and 
>>> recompiling the framework fixed it. Xcode seems to launch the app in 32 bit 
>>> mode whether its in Debug or Release (because I have the Active 
>>> Architecture set to i386). When launched from Finder, the app launches in 
>>> 64 bit mode, and since that framework was not compiled with the x86_64 
>>> architecture it screwed up the app.
>>> 
>>> Hope this helps anyone else that runs into this issue.
>>> 
>>> Independent Cocoa Developer, Macatomy Software
>>> http://macatomy.com
>>> 
>>> 
>>> On 2009-12-17, at 9:55 AM, Jens Alfke wrote:
>>> 
>>>> 
>>>> On Dec 16, 2009, at 10:04 PM, PCWiz wrote:
>>>> 
>>>>> I'm not using NSLock or NSRecursiveLock directly. I'm using @synchronized 
>>>>> on an object that multiple threads acess, to allow only one thread to 
>>>>> access the object at a time.
>>>> 
>>>> The fact that the description of the lock is " 
>>>> '(null)'" makes me suspect that you're synchronizing on a nil pointer, 
>>>> i.e. that when you call
>>>>@synchronized(foo) { ... }
>>>> the value of foo is nil. I'm pretty sure that's illegal, and I would have 
>>>> thought it would throw an exception, but maybe not. Try putting a check 
>>>> above the block, something like
>>>>NSAssert(foo!=nil, @"no foo");
>>>> 
>>>> —Jens
>>> 
>>> ___
>>> 
>>> Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)
>>> 
>>> Please do not post admin requests or moderator comments to the list.
>>> Contact the moderators at cocoa-dev-admins(at)lists.apple.com
>>> 
>>> Help/Unsubscribe/Update your Subscription:
>>> http://lists.apple.com/mailman/options/cocoa-dev/lists%40kai-bruening.de
>>> 
>>> This email sent to li...@kai-bruening.de
>> 
> 

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: Program not working under Snow Leopard

[Kai Brüning]

On 28.12.2009, at 13:07, Quincey Morris wrote:

> On Dec 27, 2009, at 07:23, insanely...@mac.com wrote:
> 
>> I'm working on a program that manages file downloads via NSURLConnection.  I 
>> was developing under Leopard and the program was working just fine. I've 
>> switched to a new computer running Snow Leopard with the latest Xcode.  My 
>> program now crashes with the ever popular EXEC_BAD_ACCESS error at seemingly 
>> random points.  At first it was consistently crashing when I was attempting 
>> to reference the value in an NSDate variable (via NSLog).  So I commented 
>> that line out and then it crashed with the same error on a different 
>> variable.  Also, I can run the program just fine in the debugger with it set 
>> to Debug.  Once it's set to Release it crashes.  I've confirmed the settings 
>> are identical for Debug/Release.  And as I said, this code worked fine in 
>> Leopard.
> 
> No one can say the cause without further evidence. However, given the 
> symptoms, the *high probability* is that:
> 
> 1. You have a memory management bug in your code.
> 
> 2. It never showed up under Leopard by pure luck.

Since you switched computers together with the OS, there’s another possibility: 
is your old computer by chance single-core? And do you have any threading in 
your code? If so, threading bugs tend to be much worse under multi-core because 
you are introducing real parallelism.

Good luck
Kai

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: Why is [NSArray arrayWithObjects:] failing for me?

[Kai Brüning]

On 4.1.2010, at 13:44, Charles Jenkins wrote:

> Thank you to all who offered your expertise!
> 
> Whatta dumb mistake! I thought all objects were retained once when created, 
> not auto-released. Gah!
> 
> I've been programming for 20+ years--mostly with C++ and C#. Cocoa-ObjC has 
> the steepest learning curve of any programming I have ever done.

Strange that you feel so. I’d say C++ is way more complex - although I did 20+ 
years of C++ coding and only 2 of ObjC/Cocoa.

But in any case you can take the whole retain/release problem out of your 
learning curve by switching to GC - unless you are targeting the iPhone.

> It makes me feel like an idiot, so you can certainly expect to see more of 
> these noobish questions from me... Thanks in advance for your help and 
> patience!

Kai___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: Why is [NSArray arrayWithObjects:] failing for me?

[Kai Brüning]

On 4.1.2010, at 13:58, Charles Jenkins wrote:

> On 2010-01-03 00:08, Eric Smith wrote:
>> Correct, do not release the array.  If you don't create it with "init", or 
>> retain it, then you should not release it.
>>   
> Eric, thank you for stating that rule. It should be easy enough to remember 
> and help me avoid this problem in the future.
> 
> In my defense, there seems to be a bug in the latest XCode, which make 
> strings stored in NSArrays look like garbage when inspected during debugging. 
> So the elements of pnl appeared to be trashed immediately upon creation. 
> That's why I was looking for the bug in the wrong place.

Yes, the data formatters in the debugger do not always work. Typing "po 
" (e.g. po [pnl objectAtIndex:0]) normally works. "po" stand for "print 
object".
> 
> Does anyone else find XCode extremely buggy?

Not at all. For me Xcode is extremely robust and a lot of fun to use. I use the 
latest version under Snow Leopard, but it was mostly the same under Leopard, 
too. My impression was that Xcode gained a lot of robustness when it was 
switched to GC.

> I have to continually close and reopen my editing window because the code 
> display gets trashed and appears to scramble my code. It doesn't really 
> change the source code file; it just makes it look as if I've randomly gone 
> through the file deleting stuff, and when I see that happen, I immediately 
> save, close, and reopen the window, and everything is fine.

Sounds scary, i’ve never seen this.
> 
> Mac software is usually first class, stable, and beautiful. How do folks 
> write such great software when they're stuck with such a sub-par IDE? :-)

They aren’t. There must be something very special with your setup.

Best
Kai


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: Use NSDocument as a variable of another NSDocument

[Kai Brüning]

On 18.1.2010, at 23:17, Jarod Wen wrote:

> Good points guys! In my application the table data depends on the movie it 
> comes from. And also, there will be several tables for one movie (for 
> example, one is for the video information and the other is about the audio 
> information). 
> 
> The reason why I want to select the document architecture is because all the 
> table data can be edited by the user, and finally, these data should be able 
> to save onto the disk as text for further usage. Maybe a wrapped file for 
> both the movie and the tables will be a better choice? In this way I think a 
> NSDocument for the movie and then a list of table controllers will be better?

I’d say you are starting to approach it from the right side now: consider how 
your application should be structured document-wise as the user sees it. After 
you got a clear picture, mapping this to AppKit concepts is the second step. 
Concerning NSDocument, this is very much tied to what the user sees as a 
document: something visible in the Finder which can be double-clicked, edited, 
saved again and so on.

So you’ll have to decide whether your tables are documents in their own right 
or whether the "save onto the disk as text for further usage" is an export. In 
the later case you would have a single document which is able to export tables 
as text files (or Excel or Numbers or HTML, you name it).

Hope this helps a little
Kai


> 
> Thanks!
> 
> On Jan 18, 2010, at 1:59 PM, Jeffrey Oleander wrote:
> 
>>> At Mon, 2010/01/18 15:19, Quincey Morris  
>>> wrote:
>>> On 2010 Jan 18, at 10:48, Jarod Wen wrote: 
>>>> Is it a proper design to use a NSDocument as a
>>>> variable of another NSDocument? 
>>>> 
>>>> I am now working on an application which generates
>>>> some information from a movie. The information
>>>> generated will be showed as a table, and the
>>>> information in the table can be saved/opened.
>>>> Multiple types of information are possible
>>>> so for one movie there may be several tables. 
>>>> 
>>>> I used the NSDocument architecture for the movie
>>>> document, and I am a little bit confused about
>>>> the hierarchy...
>> 
>>> The question isn't whether one document object
>>> can contain a reference to another document
>>> object. The question is what's supposed to
>>> happen later when the derived (table)
>>> document is re-opened.
>>> 
>>> If the table refers to information in the
>>> original (movie) document, you'll need to
>>> open the movie document too.
>> 
>> That depends on what you mean by "refers to".
>> 
>> I can refer to the Encyclopedia Brittanica 
>> without opening it.  I can say "this is
>> related to the movie 'Blah' whose screen-
>> play was written by Blurp, was direced
>> by Blorp, and produced by Bloop" without 
>> having to open up that movie file.
>> 
>> It just depends on what Jarod Wen wants
>> to do.
>> 
>> If he wants the extracted data which he
>> displays in tables to be mostly independent
>> of the original movie, then he will need
>> that to be in a document with its own
>> hierarchy.  The original movie would be
>> one document with its own data,
>> and the extracted data for that movie might
>> be a separate document with its own,
>> independent data hierarchy.  If he does
>> that, then the 2 files can diverge, and
>> he might have to consider how to control
>> proliferation of related data files, 
>> each derived from the same movie file.
>> 
>> So, his question becomes, what object
>> owns each document type?  What object
>> owns the movie?  What object owns the
>> derived data that he displays as tables?
>> Or, should he just keep only the movie
>> document and extract/generate at run-
>> time the data to display in table views 
>> as "views of the movie".
>> 
>> 
>> 
>> ___
>> 
>> Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)
>> 
>> Please do not post admin requests or moderator comments to the list.
>> Contact the moderators at cocoa-dev-admins(at)lists.apple.com
>> 
>> Help/Unsubscribe/Update your Subscription:
>> http://lists.apple.com/mailman/options/cocoa-dev/jarodwen%40gmail.com
>> 
>> This email sent to jarod...@gmail.com
> 
> --
> J.W.
> 
> 
> 
> 
> ___
> 
> Cocoa-dev mailing 

-[NSBundle preferredLocalizations]

[Kai Brüning]

Hi,

Apple’s documentation states about -[NSBundle preferredLocalizations]: "The 
localizations in the array are not returned in any particular order."

This makes no sense, I’d expect this to be true for -[NSBundle localizations], 
why I’d expect -[NSBundle preferredLocalizations] to be implemented similar to 
the following:

- (NSArray*) preferredLocalizations
{
  return [NSBundle preferredLocalizationsFromArray:self.localizations];
}

and the docu of -[NSBundle preferredLocalizationsFromArray:] says: "These 
strings are ordered in the array according to the current user's language 
preferences".

Could somebody with insight confirm whether this is a documentation bug?

(Sure, I could check the actual order. But if the documentation is correct, the 
result would be meaningless for the future.)

Thanks
Kai



___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: -[NSBundle preferredLocalizations]

[Kai Brüning]

Done: rdar://7637393
Kai


> 
> On Feb 10, 2010, at 5:52 AM, Kai Brüning wrote:
> 
>> Could somebody with insight confirm whether this is a documentation bug?
> 
> This is indeed an error in the documentation.  Please file a bug against the 
> documentation with the information you have provided.
> 
> Douglas Davidson

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: #define and if statements

[Kai Brüning]

A tip for the next time you have problems with macros: use Xcode’s Preprocess 
command (in the Build menu) to see your macros resolved. Helps a lot in such 
cases.

Kai

On 27.2.2010, at 07:37, Adam Gerson wrote:

> Thanks! I can't believe I missed that. Its 1:35am here and its been a long 
> day.
> 
> Adam
> 
> 
> On Sat, Feb 27, 2010 at 1:24 AM, Dave DeLong  wrote:
>> #define's are basically a simple find and replace, so if you do:
>> 
>> #define IsDemo NO;
>> 
>> and then do:
>> 
>> if (IsDemo) { ... }
>> 
>> It's going to become:
>> 
>> if (NO;) { ... }
>> 
>> See the problem?  You've got a semicolon in there.  Generally, you don't end 
>> a #define with a semicolon unless you want a semicolon in the place where 
>> the #define will be used.
>> 
>> Dave
>> 
>> On Feb 26, 2010, at 11:22 PM, Adam Gerson wrote:
>> 
>>> I have the following constant set up. I have tried all three of these
>>> variations and none of them work in an if statement in cocoa. I get
>>> error: expected `)' before ';' token
>>> 
>>> #define IsDemo NO;
>>> #define IsDemo false;
>>> #define IsDemo 0;
>>> 
>>> 
>>> if (IsDemo) {
>>>  bla...
>>> }
>>> 
>>> Same problem, when I try:
>>> #define FreeUpdateDaysAllowed 180;
>>> if (daysSoFar > FreeUpdateDaysAllowed)
>>> 
>>> 
>>> What am I doing wrong? Whats the right way to have a bool or int constant?
>>> 
>>> Thanks,
>>> Adam
>>> ___
>>> 
>>> Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)
>>> 
>>> Please do not post admin requests or moderator comments to the list.
>>> Contact the moderators at cocoa-dev-admins(at)lists.apple.com
>>> 
>>> Help/Unsubscribe/Update your Subscription:
>>> http://lists.apple.com/mailman/options/cocoa-dev/davedelong%40me.com
>>> 
>>> This email sent to davedel...@me.com
>> 
>> 
> ___
> 
> Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)
> 
> Please do not post admin requests or moderator comments to the list.
> Contact the moderators at cocoa-dev-admins(at)lists.apple.com
> 
> Help/Unsubscribe/Update your Subscription:
> http://lists.apple.com/mailman/options/cocoa-dev/lists%40kai-bruening.de
> 
> This email sent to li...@kai-bruening.de

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: Short-circuit evaluation

[Kai Brüning]

On 23.6.2009, at 17:14, Kyle Sluder wrote:

On Tue, Jun 23, 2009 at 7:47 AM, Graham Cox  
wrote:
I'd like to if I could - unfortunately in this case the method in  
question
is -validateMenuItem: which is designed to have intentional side- 
effects,
like setting the item's state or title, as well as returning a  
boolean value
for the enable state. The API might have been better if it returned  
nothing
and made you handle the enable state directly also, but it wasn't  
so I'm

stuck with it.


There is no reason you can't do this:

BOOL a = [foo bar];
BOOL b = [baz quux];
return a || b;


Or, different style:

BOOL a = NO;

if ([foo bar])
   a = YES;
if ([baz quux])
   a = YES;

return a;

Kai

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: How to share Cocoa classes?

[Kai Brüning]

On 6.7.2009, at 20:30, Alexander Bokovikov wrote:


Thank you for the reply,

It looks like your case is just what I'd like to have, though my  
situation is simpler, as my shared code is the same for different  
projects (though different projects may include other different  
pieces). Therefore the problem of code stripping (which you  
described) should not appear for me.


Nevertheless, I'd appreciate it highly, if you'll guide me through  
the XCode project settings adjustment, as it sounds foggy for me,  
how to make static library to rebuild itself when main project is  
built. What particular settings should I add to the main project?


Also it's not clear, where to put that "common" header file? What is  
the correct location for that? Am I correct in my understanding,  
that placing this .h file into the right place I'll have the ability  
to include my classes (stored in static library) by single  
#import ? If yes, then it is just, what I'd  
like to get! The same question is about static library itseklf --  
where it should be located? Should I create my own directory system  
or is it better to use some standard (system) directories for that?  
If I must use my own directories, then where should I add a path to  
them to avoid the necessarity to add this path to every new XCode  
project manually?


Besides the suggestions of other, an additional method to handle this  
are Xcode source trees. You can define paths to source trees in Xcode  
preferences (that is, per machine), and then use these definitions to  
set paths in projects relative to a defined source tree. This frees  
you from the need to have the exact same directory setup on each  
computer which uses the project.


Kai

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

NSView.alphaValue without Core Animation Layer?

[Kai Brüning]

Hi,

the documentation for -[NSView setAlphaValue:] states:

"Sending this message to a view that is not managing a Core Animation layer 
causes an exception."

But experiment under 10.6 shows that not only no exception is thrown, setting 
the alpha value on views without Core Animation layer even works just fine.

Is this a feature of Snow Leopard we can dependent upon? We were not able to 
find it documented, not even in the AppKit release notes for 10.6.

Thanks
Kai

___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: image transition while dragging

[Kai Brüning]

Hi Rajesh,

as far as I know Cocoa has no provision for this at least up to  
Leopard. (If I remember correctly, you could do this easily with  
Carbon ;-) )


If you absolutely want this behavior, I can think of two ways to  
persuade:


- Return no or an empty image from dragImageForRowsWithIndexes:, track  
the mouse yourself and move a temporary window with an image of your  
chosing around on the screen. Should be doable, but probably not in a  
single afternoon.


- Read about Cocoa hacking and look for some private API IB might be  
using for its dragging. Usual caveats apply, like Apple might break  
your code with any update etc.


Best success
Kai


On 23.4.2009, at 13:23, rajesh wrote:


Hi All,

I am working on dragging table row (not for re-ordering or deleting)  
onto a NSView

I am returning an processed image (for dragImage) in
- (NSImage *)dragImageForRowsWithIndexes:(NSIndexSet *)dragRows  
tableColumns:(NSArray *)tableColumns
  event:(NSEvent *)dragEvent offset: 
(NSPointPointer)dragImageOffset

{
//
 return doctoredImage;
}

I want to change the dragged image with smooth transition to another  
image, whenever it reaches its destination(NSView) or when drag  
moves out of the source(NSTableView)   just like the effect to the  
drag image in interface builder tool when items from palette are  
dragged out of it.


Any pointers or ideas is appreciated.

Thanks
Rajesh.
___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/kai%40granus.net

This email sent to k...@granus.net


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com

Re: Drawing 1 pixel line with zoom change

[Kai Brüning]

On 12.5.2009, at 06:23, Graham Cox wrote:



On 12/05/2009, at 12:44 AM, Sahana A wrote:

We have a feature in our application wherein we have to draw a 1  
pixel line.  This drawing also varies relative to  the zoom factor  
of our view. For example
if we are drawing at a zoom factor of 200% we draw 0.5 pixel line.  
( basically: 1/zoomfactor width of line; 1 if  the zoomfactor <  
100 ).


For most of the times we succeed in drawing the 1 pixel line.  
However after we change the zoom factor, our drawing fails. Our 1  
pixel

line is now drawn in 2 pixels.
For example: On changing the zoom values from say 100% to 300% and  
back to 100% again, the single pixel line sometimes draw in 2 pixels.
Even if the stroke width is set to 0.0 or 1.0, the stroked line  
will draw 2 pixels.



It's not just a case of setting the line width, but also of placing  
the line where you want it. Strokes are placed so that they are  
centred on the co-ordinate, so half the line is above and half below  
the integral co-ordinate position. This is true even if you suppress  
anti-aliasing, which make matters worse since the lightening of the  
line is disabled and it'll draw as a solid 2 pixel line.


You need to truncate the line's co-ordinates to a whole number then  
add or subtract 0.5 so that the line is drawn on the pixel, not on  
the co-ordinate.


This goes into the right direction, but things are a little more  
involved. Basically you need to convert to device coordinates first,  
to the correct rounding, convert the result back and then draw.


The 10.5-only NSView methods convertPointToBase: and friends are quite  
helpful for this.


For more details see Apples "Resolution Independence Guidelines".

Kai




--Graham


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/kai%40granus.net

This email sent to k...@granus.net


___

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to arch...@mail-archive.com