Re: Problem with CALayer delegate

FROM : Francois-Jean De Brienne
DATE : Sat Feb 23 07:21:04 2008

I am calling those methods but my drawLayer method still is not 
getting called.

On 23-Feb-08, at 1:01 AM, Bob Van Osten wrote:

> Try calling [mainLayer setNeedsDisplay] or [mainLayer display].  You 
> need to call one of those to get layers to update properly.
>
> On Feb 22, 2008, at 9:48 PM, Francois-Jean De Brienne wrote:
>

>> thanks, but this did not help. I'm still not getting drawLayer: 
>> inContext to be called.
>>
>>
>>
>> On 23-Feb-08, at 12:41 AM, Vinay Prabhu wrote:
>>

>>> Instead of creating CALayer object using,
>>> mainLayer = [[[CALayer alloc] init] retain];
>>>
>>> try creating the CALayer this way,
>>> mainLayer = [[CALayer layer] retain];
>>>
>>> -Vinay
>>>
>>> On Feb 23, 2008, at 10:50 AM, Matt Long wrote:
>>>

>>>> You could try creating your own CALayer derived class that 
>>>> overrides
>>>>
>>>> - (void)drawInContext:(CGContextRef)ctx
>>>>
>>>> drawLayer simply allows your delegate to override that same 
>>>> method externally.
>>>>
>>>> -Matt
>>>>
>>>>
>>>> On Feb 22, 2008, at 9:52 PM, Francois-Jean De Brienne wrote:
>>>>

>>>>> Hello everyone,
>>>>>
>>>>> I'm a very new cocoa developer (I switched two months ago) but 
>>>>> an experienced (15+ years) developer.
>>>>>
>>>>> I'm struggling trying to get a CALayer delegate method, 
>>>>> specifically drawLayer being called. I am trying to host the 
>>>>> CALayer inside an NSView that would be the delegate for the 
>>>>> CALayer.
>>>>>
>>>>> The CALayer is an attribute of my custom NSView called mainLayer.
>>>>>
>>>>> Here is the initWithFrame method for my custom NSView:
>>>>>
>>>>> -(id) initWithFrame: (NSRect) frameRect
>>>>> {
>>>>>     self = [super initWithFrame:frameRect];
>>>>>     
>>>>>     if (self)
>>>>>     {
>>>>>         mainLayer = [[[CALayer alloc] init] retain];
>>>>>         
>>>>>         [mainLayer setDelegate:self];
>>>>>         [self setLayer:mainLayer];
>>>>>         [self setWantsLayer:YES];
>>>>>     }
>>>>>     
>>>>>     return self;
>>>>> }
>>>>>
>>>>> Then, the custom NSView declares a drawLayer method as such 
>>>>> (that I'd want to be called from my mainLayer):
>>>>>
>>>>> -(void)drawLayer:(CALayer*) layer inContext:(CGContextRef)ctx
>>>>> {
>>>>>     NSLog (@"Entered drawLayer");
>>>>> }
>>>>>
>>>>> Now, whenever I send the setNeedsDisplay message to mainLayer, I 
>>>>> assume that drawLayer would be called. It is not.
>>>>>
>>>>> drawLayer is also declared in the .h for the custom NSView (if 
>>>>> that makes any difference).
>>>>>
>>>>> If I override and define drawRect for my NSView, I can verify 
>>>>> that it does enter that method:
>>>>>
>>>>> - (void)drawRect:(NSRect)rect
>>>>> {
>>>>>     NSLog (@"Entered drawRect");
>>>>> }
>>>>>
>>>>>
>>>>> What am I doing wrong?
>>>>> _______________________________________________
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>>>>
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>>>

>>
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>