CABasicAnimation Problem

So, I have read in the docs, that use of blocks like

beginAnimation
commitAnimation

is discouraged from os4.0.

So I have开发者_C百科 tried to get my code to work by using CABasicAnimation. I want to achieve, that an image's frame is resized from its thumbnail size, somewhere within my view, to a full width position e.g. (0, 120, 320, 240) - on my iPhone.

What I have so far:

[CATransaction begin];
[CATransaction setValue:[NSNumber numberWithFloat:1.0] forKey:kCATransactionAnimationDuration]; 

CABasicAnimation *scalingAnimation;
scalingAnimation = [CABasicAnimation animationWithKeyPath:@"transform"];
scalingAnimation.duration=1.0/2;
scalingAnimation.autoreverses=YES;
scalingAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
scalingAnimation.fromValue=[NSValue valueWithCATransform3D:CATransform3DMakeScale(1.0, 1.0, 1.0)];
scalingAnimation.toValue=[NSValue valueWithCATransform3D:CATransform3DMakeScale(4, 4, 1)];

[b.layer addAnimation:scalingAnimation forKey:@"scaling"];

[CATransaction commit];

My nextstep would be to first try to move the image to a centered position then scale it to the correct size. However, I doubt I'm doin it the right way. Can anyone comment on my code/approach.... is there a better way?

---

Am pretty sure you have solved this by now, but in any case.

You shouldn't need the [CATransaction begin]; and [CATransaction commit]; The simplest way that I have found to do this kind of thing is to use CAAnimationGroup and and add the animations one by one.

An example would be

CABasicAnimation *scaleX = [CABasicAnimation animationWithKeyPath:@"transform.scale.x"];
//this is not used, as the group provides the duration
scaleX.duration = duration;
scaleX.autoreverses = NO;

scaleX.toValue = [NSNumber numberWithFloat:1.0];
scaleX.fromValue = [NSNumber numberWithFloat:scaleFrom]; 
scaleX.fillMode = kCAFillModeForwards;
scaleX.removedOnCompletion = NO;

CABasicAnimation *scaleY = [CABasicAnimation animationWithKeyPath:@"transform.scale.y"];
//this is not used, as the group provides the duration
scaleY.duration = duration;
scaleY.autoreverses = NO;

scaleY.toValue = [NSNumber numberWithFloat:1.0];
scaleY.fromValue = [NSNumber numberWithFloat:scaleFrom]; 
scaleY.fillMode = kCAFillModeForwards;
scaleY.removedOnCompletion = NO;

//add in the translation animations

NSMutableArray* animationsArray = [NSMutableArray arrayWithObjects:scaleX,
                                                                   scaleY, 
//and any other animations you want in the group
                                       nil];

CAAnimationGroup *animationGroup = [CAAnimationGroup animation];
animationGroup.duration = 1.0/2;
animationGroup.timingFunction = [CAMediaTimingFunctionfunctionWithName:kCAMediaTimingFunctionEaseIn];
animationGroup.animations = animationsArray;
animationGroup.delegate = self;
animationGroup.removedOnCompletion = YES;
animationGroup.fillMode = kCAFillModeForwards;
[animationGroup setValue:@"imageTransform" forKey:@"AnimationName"];
[b.layer addAnimation:animationGroup forKey:@"imageTransform"];

There are a few gotchas though. Animations are purely visual, so before running the animations, set your eventual view frame.

You will notice that the scales end at 1, this is to ensure that you dont end up with a scaled image layer. Instead we start it scaled and bring it back to normal.

Translations should be done in the same way.

Hope this helps

---

//in Event Method Copy Below code to place the image to the center

    CABasicAnimation* positionAnimation;
    positionAnimation = [CABasicAnimation animationWithKeyPath:@"position"];
    positionAnimation.fromValue = [NSValue valueWithCGPoint:imageView.layer.position];
    positionAnimation.toValue = [NSValue valueWithCGPoint:centerPointofView];
    positionAnimation.duration = 2.0;
    positionAnimation.fillMode = kCAFillModeForwards;
    positionAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
    positionAnimation.removedOnCompletion = NO;
    positionAnimation.delegate = self;
    [imageView.layer addAnimation:positionAnimation forKey:@"positionAnimation"];

// For Scale After image is in center copy below code

    - (void)animationDidStop:(CAAnimation *)theAnimation finished:(BOOL)flag{
    CAAnimation *animation = [imageView.layer animationForKey:@"positionAnimation"];
    if (animation == theAnimation) 
    {
        CABasicAnimation* scaleAnimation;
        scaleAnimation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
        scaleAnimation.fromValue = [NSNumber numberWithFloat:1];
        scaleAnimation.toValue = [NSNumber numberWithFloat:4.0];
        scaleAnimation.duration = 2.2;
        scaleAnimation.fillMode = kCAFillModeForwards;
       scaleAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
        scaleAnimation.removedOnCompletion = NO;
        scaleAnimation.delegate = self;
        [imageView.layer addAnimation:scaleAnimation forKey:@"scaleAnimation"];
    }
    else 
    {
        //if you want changes to image should remain forever 
        //place your code for scale & transform here
        ....................
        //now simple remove animation from layer
        [imageView.layer removeAllAnimations];
    }
}

---

Cant you use

[UIView animateWithDuration:2.0
                        animations:^{ 
                            //animations
                        } 
                        completion:^(BOOL finished){
                           // completion methods
                        }];