Re: how do I put a subview in a superview with color
Re: how do I put a subview in a superview with color
- Subject: Re: how do I put a subview in a superview with color
- From: John Joyce <email@hidden>
- Date: Thu, 30 Dec 2010 20:09:44 -0600
On Dec 30, 2010, at 7:44 PM, colo wrote:
> On Thu, Dec 30, 2010 at 6:50 PM, aglee <email@hidden> wrote:
>> On Dec 30, 2010, at 06:13 PM, colo <email@hidden> 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
>>
>
> Hey Andy I totally appreciate every last word you wrote there. I was
> trying it all from a hacking approach in just trying to get something
> working. But you were totally correct on the awakefromnib being part
> of the issue.
> I will slow down now and try to build things correctly from all of that advice.
>
> Thank you very much.
> _______________________________________________
>
You may want to consider using windowControllerDidLoadNib in document based apps.
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