layer.anchorPoint won't animate

dimaco · 05-12-2009, 04:55 PM

Hello everyone,
I'm a newbie Iphone Developer and I came here with a question, which I've been googling all day for an answer.

Consider the following code:

Code:

[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:10];
pageBack.layer.position = CGPointMake(320.0, 460.0);
pageBack.layer.anchorPoint = CGPointMake(0.0, 1.0);
pageBack.layer.opacity = 0.0;
[pageBack.layer setValue:[NSNumber numberWithFloat:[self degrees2Radians:90.0]] forKeyPath:@"transform.rotation.z"];
[UIView commitAnimations];

Everything works just fine except for one property of the layer: anchorPoint. It looks like it directly jumps to the CGPoint with no animation. Event with a very slow duration (I've set it to 10) the layer instantly gets that anchorPoint with no transition. It's driving me crazy. Am I doing something stupid there? Apple Documentation says that property is animatable!

Thanks in advance for any help/explanation.
Giorgio

ivico92 · 05-13-2009, 07:18 AM

Hi, I don't know for your non-transition problem cuz I have the same problem.
Did you find the reason ?
(I have a scale transform coupled with a translate transform animation, and the scale jumps cut directly to the final value...)

sukumar_77 · 05-13-2009, 08:02 AM

Hi Dimaco,

You will have to animate the anchor point too. Below is an updation to your code. Hope it will solve your problem.

Code:

[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:5];
pageBack.layer.position = CGPointMake(320.0, 460.0);

// Animate the anchor point	
CABasicAnimation *theAnimation = [CABasicAnimation animationWithKeyPath:@"anchorPoint"];
theAnimation.duration = 1.0;
theAnimation.fromValue = [NSValue valueWithPoint:NSMakePoint(pageBack.layer.anchorPoint.x, pageBack.layer.anchorPoint.y)];	
theAnimation.toValue = [NSValue valueWithPoint:NSMakePoint(0.0, 1.0)];
[pageBack.layer addAnimation:theAnimation forKey:@"anchorPoint"];
pageBack.layer.anchorPoint = CGPointMake(0.0, 1.0);
// end
	
pageBack.layer.opacity = 0.0;
[pageBack.layer setValue:[NSNumber numberWithFloat:[self degrees2Radians:90.0]] forKeyPath:@"transform.rotation.z"];
[UIView commitAnimations];

dimaco · 05-13-2009, 01:33 PM

Quote:

Originally Posted by sukumar_77

Hi Dimaco,
You will have to animate the anchor point too. Below is an updation to your code. Hope it will solve your problem.

Code:

[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:5];
pageBack.layer.position = CGPointMake(320.0, 460.0);
// Animate the anchor point	
CABasicAnimation *theAnimation = [CABasicAnimation animationWithKeyPath:@"anchorPoint"];
theAnimation.duration = 1.0;
theAnimation.fromValue = [NSValue valueWithPoint:NSMakePoint(pageBack.layer.anchorPoint.x, pageBack.layer.anchorPoint.y)];	
theAnimation.toValue = [NSValue valueWithPoint:NSMakePoint(0.0, 1.0)];
[pageBack.layer addAnimation:theAnimation forKey:@"anchorPoint"];
pageBack.layer.anchorPoint = CGPointMake(0.0, 1.0);
// end	
pageBack.layer.opacity = 0.0;
[pageBack.layer setValue:[NSNumber numberWithFloat:[self degrees2Radians:90.0]] forKeyPath:@"transform.rotation.z"];
[UIView commitAnimations];

thank you for the code
would you please tell me what library I've got to include? I get the following error:

Code:

Undefined symbols:
  "_NSMakePoint", referenced from:
      -[PageController cancelAnimation] in PageController.o
      -[PageController cancelAnimation] in PageController.o
  ".objc_class_name_CABasicAnimation", referenced from:
      literal-pointer@__OBJC@__cls_refs@CABasicAnimation in PageController.o
symbol(s) not found
collect2: ld returned 1 exit status
Build failed (2 errors, 3 warnings)

Still I have included the whole QuartsCore
#import <QuartzCore/QuartzCore.h>;

Thank you very much for your time!
Giorgio

sukumar_77 · 05-14-2009, 12:24 AM

Just check for Foundation framework.

sukumar_77 · 05-14-2009, 08:26 AM

This is just an update to my own post.

Please use the following updated code. The api used previously are not available in iPhone OS.

Code:

[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:5];
imgView.layer.position = CGPointMake(320.0, 460.0);
	
CABasicAnimation *theAnimation = [CABasicAnimation animationWithKeyPath:@"anchorPoint"];
theAnimation.duration = 1.0;
	
CGPoint fromPoint = CGPointMake(imgView.layer.anchorPoint.x, imgView.layer.anchorPoint.y);
CGPoint toPoint = CGPointMake(0.0, 1.0);
	
theAnimation.fromValue = [NSValue valueWithBytes:&fromPoint objCType:@encode(CGPoint)];	
theAnimation.toValue = [NSValue valueWithBytes:&toPoint objCType:@encode(CGPoint)];
[imgView.layer addAnimation:theAnimation forKey:@"anchorPoint"];
imgView.layer.anchorPoint = CGPointMake(0.0, 1.0);
	
	
imgView.layer.opacity = 0.0;
[imgView.layer setValue:[NSNumber numberWithFloat:90.0*(M_PI/180)] forKeyPath:@"transform.rotation.z"];
[UIView commitAnimations];

dimaco · 05-14-2009, 05:33 PM

Quote:

Originally Posted by sukumar_77

This is just an update to my own post.
Please use the following updated code. The api used previously are not available in iPhone OS.

Hi sukumar,
thanks again for your replies
Unfortunately, even with your second code I get the following error:

Code:

".objc_class_name_CABasicAnimation", referenced from:
      literal-pointer@__OBJC@__cls_refs@CABasicAnimation in PageController.o
ld: symbol(s) not found
collect2: ld returned 1 exit status

I tried, as you suggested, to include <Foundation/Foundation.h> but it didn't help...
There is any other library I should include?
Thank you very much
I appreciate your patience!

Giorgio

sukumar_77 · 05-14-2009, 11:48 PM

When you create a new Xcode project, the template include three frameworks viz. Foundation, UIKit and CoreGraphics.

I have just added QuartzCore and nothing more. This time error might be coming due to one of the missing header file. Don't know what exactly is happening.

Alexander · 06-16-2009, 04:18 AM

Quote:

Originally Posted by dimaco

Hi sukumar,
thanks again for your replies
Unfortunately, even with your second code I get the following error:

Code:

".objc_class_name_CABasicAnimation", referenced from:
      literal-pointer@__OBJC@__cls_refs@CABasicAnimation in PageController.o
ld: symbol(s) not found
collect2: ld returned 1 exit status

Giorgio

You need to add QuartzCore.framework (/System/Library/Frameworks/QuartzCore.framework) into your project in Xcode.

sukumar_77 · 06-16-2009, 09:41 AM

Quote:

Originally Posted by Alexander

You need to add QuartzCore.framework (/System/Library/Frameworks/QuartzCore.framework) into your project in Xcode.

The correct path is /Developer/Platforms/YOUR_PLATFORM(SIMULATOR/IPHONE)/Developer/SDKs/YOURSDK(2.0/2.1/2.2/3.0)/System/Library/Frameworks/QuartzCore.framework.

Just do not get confuse with System (Mac OS X) path.