Hi,
On 11/12/2017 20:10, Quincey Morris wrote:
I made my own text field class according to this (in NSTableCellView's doc) :
I think you’re still kinda Doing It Wrong™. The standard (and, I believe,
recommended) way to do this is to create an instance of
NSTableCellView, which has the “objectValue” property, along with other
potentially useful behaviors for cell views (such as
identifiers that allow the NSTableView to cache and manage cell views).
I know it's wrong, or at least bad, but NSTextView and NSButton are the
controls I kind of master right now...
I really don't need a textview, as I'm just trying to reproduce the
"Combattant" example.
I still can't get the names to display with NSTableCellView.
Here (at the bottom of the page) :
https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/TableView/PopulatingViewTablesWithBindings/PopulatingView-TablesWithBindings.html
it says :
"""
When you make the connection to the table view’s Content binding, the objectValue property of the NSTableViewCell used as the cell
for the table column is configured such that for each item in the model array, the table updates the objectValue property to the
current row’s Person object
1) Select the text field in the table column cell and create the binding.
All bindings of subviews in the cell are made to the objectValue.
Configure the textField instance’s value binding.
Binding field | Value
-----------------------------------
Bind to: | Table Cell View
Model key path | objectValue.name
"""
So I have this in my NSTableView's delegate, which is my interpretation of the
above :
- (NSView *)tableView:(NSTableView *)tableView
viewForTableColumn:(NSTableColumn *)tableColumn
row:(NSInteger)row
{
#if 0 // this shows the names
cTextView* view = [[cTextView alloc] init]; // cTextView is my custom
NSTextView with just an added objectValue property
[view bind: @"value" toObject: tableView withKeyPath:
@"objectValue.name" options: 0]; // wrong, but works
//[view bind: @"value" toObject: view withKeyPath: @"objectValue.name"
options: 0]; // right, works
#else // this doesn't show the names
NSTableCellView* view = [[NSTableCellView alloc] init];
//[[view textField] setBackgroundColor: [NSColor redColor]]; // just to
be sure to see it when empty... nada
//[[view textField] bind: @"value" toObject: tableView withKeyPath:
@"objectValue.name" options: 0]; // wrong, doesn't work
[[view textField] bind: @"value" toObject: view withKeyPath:
@"objectValue.name" options: 0]; // right?, but doesn't work
#endif
return view;
}
Note that I bind the NSTextView to tableView, while the doc says "the objectValue property of the NSTableViewCell", not of the
tableview... but it works, and I don't understand why... I don't like it when I don't understand what's happening.
It also works when binding to the view, which is expected (I first bound it to
tableView by mistake...).
It's still weird (to me) to bind an object's binding to one of it's own
properties.
I guess it's more or less by chance that it displays the names, and that some
changes in my model won't get correctly propagated...
In the case of NSTableCellView, neither binding works... I don't get any exception or crash, but nothing is displayed inside my
table view (although it's size suggests the four rows are there).
But setting the backgroud of the textfield to red doesn't show any red on the
screen...
(Trying to the set the cell's background gives me a "may not respond to message" warning, and obviously nothing gets red on the
screen).
Something in the "big scheme of things" escapes me, and Apple's doc was not
very helpful until now.
In a very unusual or complex case, you might subclass NSTableCellView to add
properties or behaviors to it, but it’s normally not
necessary. Custom properties, for example, can be carried around by the object
referred to by “objectValue”, and custom behaviors
can sometimes be implemented as part of the delegate.
Instead of using a cell view other than a NSTableCellView or subclass, it’s
usual to *add subviews* for things like text fields
and buttons. That separates the behavior of the cell *as a cell* (such as being
cached for the table view) from the view hierarchy
represented by the cell. However, if your cell just needs to contain a text
field, you don’t need to add one yourself,
because NSTableCellView already contains a NSTextField subview that you can
just *use*. It also contains NSImageView subview that
you can use or ignore.
How do you "ignore" what you don't need in an NSTableCellView ?
And when I add a subview to one, how do I arrange (layout) it's content, so it works with the way the 'free' NSTextField and
NSImageView are arranged (which I ignore) ?
NSTableCellView's doc is rather scarce.
Now I can see all the names :)
One reason to use a NSTableCellView instead of a control sum as a text field is
that the cell view’s size is *forced* to the
dimensions required by the table view row. That means you have no control of
the placement of the contents relative to the row.
For a text field, for example, you have no direct way of controlling the
margins surrounding the text. This approach also limits
the use of autolayout, which may or may not be an issue in your project.
- (NSView *)tableView:(NSTableView *)tableView
viewForTableColumn:(NSTableColumn *)tableColumn row:(NSInteger)row {
NSTextView* view = [[NSTextView alloc] init];
…
You say “text field” everywhere, but you actually create a text view. I don’t
get a sense of which one you really want to use, but
using a separate NSTextView for each row of the table could end badly, and
subclassing NSTextView is probably a code smell.
I'm using an NSTextView, but just because I can make it kind of work...
Calling them text fields is a bad habit of mine (especially since there IS an
NSTextField), sorry.
Thanks for your efforts.
Eric M.
--
Keep intel OUTSIDE my Mac !
Hiii !!! I can see Intel chips creeping around my G5 !
Eric M.
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