On Dec 30, 2010, at 06:13 PM, colo <[email protected]> wrote:
I can get it to compile just fine now but I can't get the button to
show up at all.
Perhaps I am sending the addSubview to the incorrect place? NSView
*superview = [window contentView];
I thought contentView was the top.
@implementation WVShapesView
-(BOOL) isFlipped { return YES;}
- (id)initWithFrame:(NSRect)frame {
self = [super initWithFrame:frame];
if (self) {
// Initialization code here.
NSView *superview = [window contentView];
NSRect frame = NSMakeRect(10, 10, 200, 100);
NSButton *button = [[NSButton alloc] initWithFrame:frame];
[button setTitle:@"arrrrggg"];
[superview addSubview:button];
[button release];
}
return self;
}
The immediate answer to your question is that your init method is the wrong
place to do this. The view is in the process of being created, so it doesn't
belong to any window yet. Try doing this in awakeFromNib. See the
documentation for awakeFromNib for more info.
Related points that will make your life easier:
(1) Use the debugger and/or NSLog statements. This is the kind of thing where
you should use the debugger to confirm the code is going through the steps you
think it is. In this case I would have stepped through initWithFrame: to
confirm the button is being created and does become a subview of the window's
content view. I'm pretty sure if you do this you will find the window is nil.
You could also have discovered this by adding NSLog statements. Messages sent
to nil don't do anything, so the button you created never gets added as a
subview of anything.
(2) Use nibs. Setting up view hierarchies is exactly the kind of thing nib
files (also known as xib files) are for. You can create your WVShapesView and
your button within your window, and you can easily do some of the things you
left out in your code. For example, it just takes a couple of clicks to
specify how your button should reposition itself when the window resizes. Also
in the code above you never set an action for the button to perform when it is
clicked; you would typically do this with a simple drag in Interface Builder.
The overwhelming majority of Cocoa UIs are constructed with Interface Builder,
especially where it's just a couple of subviews within a window.
(3) Separation of concerns. The design of WVShapesView is flawed if it's
adding a button to its own window; it's not even adding the button to itself.
Suppose you create a window containing two WVShapesViews? They will both put a
button in the window. The existence of the button is no concern of the
WVShapeView, and the view shouldn't muck with the view hierarchy outside of
itself. Better to create your layout in a nib file and create a view
controller and/or window controller that loads the nib. See NSViewController
and NSWindowController.
Hope this helps,
--Andy
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