>> I am looking at the performance of my code, and have found that rather a lot
>> of time is spent in [NSBitmapImageRep getBitmapDataPlanes]. This is rather
>> disappointing because I had assumed this was a 'trivial' way of getting a
>> pointer to the actual data store itself in the case of ras
Hi all,
I have been reading up on an area unfamiliar to me - fullscreen drawing and
display refresh rates. This is for a scientific application - we have a third
party external pixellated device which presents itself as a second monitor over
DVI, but with an unusually high refresh rate (about 2
>> I am encountering what I believe to be a spurious compiler warning. I wonder
>> whether this is a clue that I am doing something differently to how I
>> "should" do it. The problem comes if I define a protocol containing a
>> property and then define that property in a base class that does NO
I am encountering what I believe to be a spurious compiler warning. I wonder
whether this is a clue that I am doing something differently to how I "should"
do it. The problem comes if I define a protocol containing a property and then
define that property in a base class that does NOT conform to
>>> I now think that what I am seeing is a minor parsing sort of issue within
>>> the compiler (gcc 4.2) when mixing id with blocks.
>> The more fundamental problem is that gcc C++ does not fully support blocks,
>> period.
> Indeed, as soon as it gets a sniff of c++ near a block things start to
On 8 Nov 2010, at 20:11, Greg Parker wrote:
>> I now think that what I am seeing is a minor parsing sort of issue within
>> the compiler (gcc 4.2) when mixing id with blocks.
> The more fundamental problem is that gcc C++ does not fully support blocks,
> period.
Indeed, as soon as it gets a snif
> On Mon, Nov 8, 2010 at 10:53 AM, Jonny Taylor wrote:
>>// Both these have errors: "request for member 'frameNumber'
>> in 'm', which is of non-class type 'objc_object* const'"
>>// when compiled as Ob
> I'm new at this too, so perhaps I am completely off here. My guess is that it
> isn't the const that is messing this up, but the non-class type. The problem
> I see is that "frame" is a pointer to an objc_object and objc_objects aren't
> the same as NSObjects (but, like I said, I'm new, so may
Thankyou everybody for your help (and patience!) with this one. I have indeed
been making some wrong assumptions and as I result much of what I was writing
was incorrect. From the various helpful replies I have received, I have (I
hope!) got a much clearer understanding of what is and isn't goin
010, at 16:53, David Duncan wrote:
> My question is why do you need to have a 'const' pointer.
>
> On Nov 8, 2010, at 8:37 AM, Jonny Taylor wrote:
>
>> I'm afraid I'm not sure if I understand exactly what you're asking. I would
>> like to be able
ary
> to ensure the semantics that you desire.
>
> On Nov 8, 2010, at 4:59 AM, Jonny Taylor wrote:
>
>> I have encountered what I presume is a common newcomer's problem, but I
>> haven't had any luck with google (maybe I'm using the wrong search terms?).
>
I have encountered what I presume is a common newcomer's problem, but I haven't
had any luck with google (maybe I'm using the wrong search terms?). Suppose I
have a const id, e.g. "const id frame". If I attempt to call a
getter for the object I get the following compiler error:
request for membe
>> One workaround is to include explicit casts like I have shown. However this
>> leaves me wondering whether it goes against convention and/or
>> recommendations to have two init methods with the same name but different
>> parameter types, even for two unrelated different classes (hard to enfor
Apologies for a very basic question, but unfortunately one that I don't really
know what keywords to search for an answer about.
Suppose I have two separate classes with init methods that have the same name,
but which take different types. MyClassA has:
-(id)initForCamera:(QICamera*)cam
and MyCl
ven though it was posted through the main thread's default
queue and the main thread is still running). That sort of thing should probably
put me off using them for many of the things I currently do...
On 2 Nov 2010, at 18:44, James Bucanek wrote:
> Jonny Taylor <mailto:j.m.tay..
ny
On 2 Nov 2010, at 15:21, James Bucanek wrote:
> Jonny Taylor <mailto:j.m.tay...@durham.ac.uk> wrote (Tuesday, November 2,
> 2010 3:01 AM -):
>
>> So, can anybody comment on all this? It seems like pretty bad news. Is this
>> what the release notes are saying
I'm reviving an old thread I posted (sorry, I can't remember who the people
were who replied, but thanks again...) because I've just read something that
rather alarmed me and would appreciate peoples comments.
An extract from the original thread is below, and here is the code I wrote
based on
Thanks for your answers Bill, that has cleared up some of my confusion.
> In the manual case, 'atomic' only has meaning if you make it meaningful. I'd
> be interested in knowing why you need an atomic property in this case as
> atomicity at the property level rarely contributes to thread safety
I currently have a property declared as follows:
@property(atomic, readwrite, retain) MyFrame* latestFrame;
When the value is set, I would like to broadcast a notification on the main
thread, and one way of doing that would be to write my own custom setter that
sets the value and then broadcasts
Is there a way of forcing an autoreleased object to be released right now? I am
encountering problems in my image processing code where I am receiving (and
later discarding) a lot of large blocks of autoreleased memory in a loop. This
is not getting cleaned up until the end of the loop (when I d
Thankyou for peoples patience with my recent very basic conceptual cocoa
questions. I have another where I am trying to understand the best way of
handling some persistent data storage.
My app is a workstation for a type of microscope, which from the point of view
of the software consists of se
Thanks for your replies Ken.
>> I have a modal dialog which, among other things, contains a number of file
>> paths. There are "set..." buttons to set which files these are pointing to.
> You should probably by using NSPathControl instead of displaying paths and
> having "set" buttons.
Ah, I had
I have a modal dialog which, among other things, contains a number of file
paths. There are "set..." buttons to set which files these are pointing to. I
feel that with bindings I should be able to set things up automatically in
InterfaceBuilder so that when that button is clicked a nav dialog is
> Quincey Morris wrote:
>> You're kind of mixing up two different tasks here. The Camera object is
>> (likely) part of your data model (in the MVC paradigm). A window controller
>> is a ... controller. For your settings window, you'll have least heartache
>> if you make the NIB's File's Owner a
>> I am trying to understand the right way of dealing with a "settings" window
>> in my application. I have a "Camera" object that wraps a Firewire video
>> camera. I would like to bring up an NSPanel that enables various settings of
>> the camera to be modified. I do not need to override any pa
I am trying to understand the right way of dealing with a "settings" window in
my application. I have a "Camera" object that wraps a Firewire video camera. I
would like to bring up an NSPanel that enables various settings of the camera
to be modified. I do not need to override any particular beh
> First, the objects are retained by dispatch_async as others have mentioned.
> Second, I'm not sure why you used 2 queues for the tasks in your code, seems
> overly complex. Async queues are serialized, which means that you can
> continue to add to the queue and the jobs will be done in order
> [theImage release] is really suspicious.
Suspicious in what way? Are you saying I am using the wrong sort of
implementation for my [frame GetNSImage], and I shouldn't be returning
something that requires an explicit release? Because I can certainly confirm
that in its current state it leaks me
Thanks for your reply Jean-Daniel.
>> I can see two ways of working around this - either implement placeholder
>> methods in the base class (that raise an exception or something) in order to
>> make the base class conform to the protocol (knowing that in practice they
>> should always be overri
I've just been looking back at some code that has been working fine for me for
a while, and as far as I can see it shouldn't actually work! I'd be interested
for peoples' comments. The code is as follows:
dispatch_async(queue1,
^{
NSImage *theImage = [frame GetNSImage];
NSData *t
I am still getting to grips with objective C, coming from a C++ background, and
I'm stuck on a particular aspect of the base class/subclass model that I hope
somebody can help me with.
I need an object representing a video camera plugged into the mac, a camera
which may be one of several models
>>> - I could try acquiring the NSNotificationQueue for the main thread, but
>>> there does not appear to be a standard way of doing that. I have seen this
>>> suggested as a strategy elsewhere, but I think I have also read that one is
>>> not meant to post to queues other than that of the curre
Hi all,
I have been programming on the mac for many years but have only just started
trying to get the hang of cocoa. I have a particular question about
NSNotification that I hope somebody will be able to help with.
My code works with a firewire video camera, and receives callbacks from the
ca
33 matches
Mail list logo
