I'm trying to scale an image down, change the image, then scale it back up.
CABasicAnimation* shrink = [CABasicAnimation animationWithKeyPath:#"transform.scale"];
shrink.toValue = [NSNumber numberWithDouble:0];
shrink.duration = 1;
shrink.delegate = self;
[myImageView.layer addAnimation:shrink forKey:#"shrink"];
makes the shrink, then when it completes, I change the image, and start the grow:
- (void)animationDidStop:(CAAnimation *)theAnimation finished:(BOOL)flag
{
myImageView.image = [images objectAtIndex:image];
CABasicAnimation* grow = [CABasicAnimation animationWithKeyPath:#"transform.scale"];
grow.toValue = CGAffineTransformMakeScale(1,1);
grow.delegate = self;
grow.duration = 1;
[myImageView.layer addAnimation:grow forKey:#"grow"];
}
This works great on the simulator, but on the device, when the shrink completes, I get a flash of the full-size, old image, then the grow animation begins with the new image.
Any idea how to get rid of that flash?
(I've tried "removedOnCompletion = NO;" and attempted setting the affineTransform equal to the scaled down size after the first completion, but didn't have much luck.)
Any tips appreciated.
kb
Edit:
Excellent! Setting the following:
shrink.fillMode = kCAFillModeForwards;
shrink.removedOnCompletion = NO;
Removed the flashing. Thanks, Ben!
Try setting your animation's fillMode to kCAFillModeForwards. That should leave the item as it was at the end of the animation, rather than before.
I've had the same problem when I tried to create another CAAnimation in the animationDidStop method. I suggest using CAKeyframeAnimation.
Related
I'm animating UIImageView using iOS core animation "CABasicAnimation", all works fine for me but the only problem is when i animate to the position, after completeing animation it comes back to original position where it was. how can i overcome this? i need to keep UIImageView in moved position.
NOTE : I've seen few questions with success answers regarding this, but i have no idea why mine is not working like they say.
After rotating a CALayer using CABasicAnimation the layer jumps back to it's unrotated position
Here is my sample code,
CGPoint endPt = CGPointMake(160, 53);
CABasicAnimation *anim5 = [CABasicAnimation animationWithKeyPath:#"position"];
[anim5 setBeginTime:CACurrentMediaTime()+0.4];
anim5.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
anim5.fromValue = [NSValue valueWithCGPoint:imgRef.layer.position];
anim5.toValue = [NSValue valueWithCGPoint:endPt];
anim5.duration = 1.5;
anim5.speed = 2;
[imgRef.layer addAnimation:anim5 forKey:#"position"];
//this is what other answers ask to do
[anim5 setFillMode:kCAFillModeForwards];
[anim5 setRemovedOnCompletion:NO];
BTW [imgRef.layer setPosition:CGPointMake(160, 53)]; won't help me since i'm delaying animation with 4 milliseconds.
The root cause is that the animation just transitions the property between two values, it doesn't actually change the ending value. You need to change the ending value when the animation completes, there are three ways to do that.
1) Use the delegate property on the CAAnimation superclass to be notified of when the animation completes. At that point you can set the property to it's end value. See: https://developer.apple.com/library/mac/#documentation/GraphicsImaging/Reference/CAAnimation_class/Introduction/Introduction.html#//apple_ref/occ/cl/CAAnimation The animationDidStop:finished: is the method you'll need to implement on the delegate.
2) Set a completion block on the surrounding CATransaction. You'll need to manually start the CATransaction rather than having CABasicAnimation do that automatically for you. See: Objective-C - CABasicAnimation applying changes after animation?
3) See OMZ's comment below...
The right answer is to set the layer's position property, but as you've pointed out, it makes it more difficult because you're wanting a 0.4 second delay prior to the position change. Is there any reason you couldn't perform the delay first and then do the animation? Something like this:
- (IBAction)didTapMove:(id)sender
{
[self performSelector:#selector(animate) withObject:nil afterDelay:0.4];
}
- (void)animate
{
CGPoint endPt = CGPointMake(160, 53);
CABasicAnimation *anim5 = [CABasicAnimation animationWithKeyPath:#"position"];
anim5.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
anim5.fromValue = [NSValue valueWithCGPoint:_imageView.layer.position];
anim5.toValue = [NSValue valueWithCGPoint:endPt];
anim5.duration = 1.5;
anim5.speed = 2;
[_imageView.layer addAnimation:anim5 forKey:#"position"];
[_imageView.layer setPosition:CGPointMake(160, 53)];
}
Noticed I've removed your begin time from the animation since the delay is occurring in the perform selector call.
I'm using a rotation animation created with CABasicAnimation. It rotates a UIView over 2 seconds. But I need to be able to stop it when the UIView is touched. If I remove the animation the view is in the same position as before the animation started.
Here's my animation code:
float duration = 2.0;
float rotationAngle = rotationDirection * ang * speed * duration;
//rotationAngle = 3*(2*M_PI);//(double)rotationAngle % (double)(2*M_PI) ;
CABasicAnimation* rotationAnimation;
rotationAnimation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.z"];
rotationAnimation.toValue = [NSNumber numberWithFloat: rotationAngle ];
rotationAnimation.duration = duration;
rotationAnimation.cumulative = YES;
rotationAnimation.removedOnCompletion = NO;
rotationAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
rotationAnimation.fillMode = kCAFillModeForwards;
rotationAnimation.delegate = self;
[self.view.layer addAnimation:rotationAnimation forKey:#"rotationAnimation"];
How can I stop the UIView's rotation right where it is, when it's touched? I know how to manage the touch part, but I can't figure out how to stop the view at the animation's current angle.
Solution:
I solved the problem by getting the angle of the presentation layer, removing the animation and setting the view's transform. Here's the code:
[self.view.layer removeAllAnimations];
CALayer* presentLayer = self.view.layer.presentationLayer;
float currentAngle = [(NSNumber *)[presentLayer valueForKeyPath:#"transform.rotation.z"] floatValue];
self.view.transform = CGAffineTransformMakeRotation(currentAngle);
Good question! For this, it's helpful to know the Core Animation architecture.
If you check out the diagram in the Core Animation Programming Guide that describes the Core Animation Rendering Architecture, you can see that there's three trees.
You have the model tree. That's where you set the values of what you want to happen. Then there's the presentation tree. That's what is pretty much happening as far as the runtime is concerned. Then, finally is the render tree. That's what the user sees.
In your case, you want to query the values of the presentation tree.
It's easy to do. For the view that you have attached the animation, get the layer and for that layer, query the presentationLayer's values. For example:
CATransform3D myTransform = [(CALayer*)[self.view.layer presentationLayer] transform];
There's no way to "pause" an animation mid flow. All you can do is query the values, remove it, and then re-create it again from where you left off.
It's a bit of a pain!
Have a look at some of my other posts where I go into this in a bit more detail, e.g.
Restoring animation where it left off when app resumes from background
Don't forget also that when you add an animation to a view's layer, you aren't actually changing the underlying view's properties. So what happens? We'll you get weird effects where the animation stops and you see the view in it's original position.
That's where you need to use the CAAnimation delegates. Have a look at my answer to this post where I cover this:
CABasicAnimation rotate returns to original position
You need to set the rotation to the rotation of the presentationLayer and then remove the animation from the layer. You can read about the presentation layer in my blog post about Hit testing animating layers.
The code to set the final rotation would be something like:
self.view.layer.transform = [(CALayer*)[self.view.layer presentationLayer] transform];
[self.view.layer removeAnimationForKey:#"rotationAnimation"];
I've hit a wall here. I know how to move an Image using "CGAffineTransformMakeTranslation" and I also know how to scale an image using"CGAffineTransformMakeScale" but for the life of me, I can't seem to get one Image to do both of these and stay that way. It scales to the desired size for about a split second and then immediately reverts to its original size and moves to the desired location. What I need is for the image to get big, STAY big, and then move to a new location (while permanently staying its new size).
Here is what I've got going on in my .m file:
-(IBAction)PushZoomButton {
[UIWindow animateWithDuration:1.5
animations:^{
JustinFrame.transform = CGAffineTransformMakeScale(2.0, 2.0);
JustinFrame.transform = CGAffineTransformMakeTranslation(10.0, 10.0);}];
[UIWindow commitAnimations];}
Any help with this would be appreciated!
you can use CGAffineTransformConcat, for instance:
JustinFrame.transform = CGAffineTransformConcat(CGAffineTransformMakeScale(2.0, 2.0), CGAffineTransformMakeTranslation(10.0, 10.0));
You may need to adapt the translation to (5, 5) since you have doubled the scale
The second transform you set overrides the first one. You need to concat both transform actions into one, as Luis said. Another way of writing that would be:
CGAffineTransform transform = CGAffineTransformMakeScale(2.0, 2.0);
transform = CGAffineTransformTranslate(transform, 10, 10);
JustinFrame.transform = transform;
You may need to look into CoreAnimation, basically what UIView animation is controlling under the hood. If you set up a CAAnimation, then what you want to achieve is done with the fillMode property of the animation.
Here's some example code to make a UIView look like it's opening like a door (copy pasted some code I have, but perhaps you could modify it and find it useful):
- (void) pageOpenView:(UIView *)viewToOpen duration:(NSTimeInterval)duration pageTurnDirection:(PageTurnDirection) p{
// Remove existing animations before stating new animation
[viewToOpen.layer removeAllAnimations];
// Make sure view is visible
viewToOpen.hidden = NO;
// disable the view so it’s not doing anythign while animating
viewToOpen.userInteractionEnabled = NO;
float dir = p == 0 ? -1.0f : 1.0f; // for direction calculations
// create an animation to hold the page turning
CABasicAnimation *transformAnimation = [CABasicAnimation animationWithKeyPath:#"transform"];
transformAnimation.removedOnCompletion = NO;
transformAnimation.duration = duration;
transformAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
CATransform3D startTransform = CATransform3DIdentity;
if (p == NEXT_PAGE) {
// orig values
startTransform.m34 = 0.001f;
}else {
// orig values
startTransform.m34 = -0.001f;
}
// start the animation from the current state
transformAnimation.fromValue = [NSValue valueWithCATransform3D:startTransform];
// this is the basic rotation by 90 degree along the y-axis
CATransform3D endTransform = CATransform3DMakeRotation(3.141f/2.0f,
0.0f,
dir,
0.0f);
// these values control the 3D projection outlook
if (p == NEXT_PAGE) {
endTransform.m34 = 0.001f;
endTransform.m14 = -0.0015f;
}else {
endTransform.m34 = -0.001f;
endTransform.m14 = 0.0015f;
}
transformAnimation.toValue = [NSValue valueWithCATransform3D:endTransform];
// Create an animation group to hold the rotation
CAAnimationGroup *theGroup = [CAAnimationGroup animation];
// Set self as the delegate to receive notification when the animation finishes
theGroup.delegate = self;
theGroup.duration = duration;
// CAAnimation-objects support arbitrary Key-Value pairs, we add the UIView tag
// to identify the animation later when it finishes
[theGroup setValue:[NSNumber numberWithInt:[(BODBookPageView *)viewToOpen pageNum]] forKey:#"animateViewPageNum"]; //STEPHEN: We set the tag to the page number
[theGroup setValue:[NSNumber numberWithInt: p] forKey:#"PageTurnDirection"];
[theGroup setValue:[NSNumber numberWithBool:YES] forKey:#"isAnimationMidpoint"]; // i.e. is this the first half of page-turning or not?
// Here you could add other animations to the array
theGroup.animations = [NSArray arrayWithObjects:transformAnimation, nil];
theGroup.removedOnCompletion = NO; // THIS LINE AND THE LINE BELOW WERE CRUCIAL TO GET RID OF A VERY HARD TO FIND/FIX BUG.
theGroup.fillMode = kCAFillModeForwards; // THIS MEANS THE ANIMATION LAYER WILL STAY IN THE STATE THE ANIMATION ENDED IN, THEREBY PREVENTING THAT ONE FRAME FLICKER BUG.
// Add the animation group to the layer
[viewToOpen.layer addAnimation:theGroup forKey:#"flipViewOpen"];
}
This is my first question her so please be gentle:
I have followig animation code running smoothly on the simulator as well as on the real device (I am testng on iPhone 3GS 3.1.2).
Animation is a simple transition between the 2 views, something like book page flipping.
One diffrence betwen simulator an real device (The problem I cannot investigate - solve) is that on real device when animation finishes - after rotation has been done animated view blink (show for a split of second) for a moment before it goes hidden. On the simulator this 'unexpected' blink does not happen.
Here is the animation code:
-(void)flip{
UIView *animatedView;
// create an animation to hold the page turning
CABasicAnimation *transformAnimation = [CABasicAnimation animationWithKeyPath:#"transform"];
transformAnimation.removedOnCompletion = NO;
transformAnimation.delegate = self;
transformAnimation.duration = ANIMATION_TIME;
transformAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
// this is the basic rotation by 90 degree along the y-axis
CATransform3D endTransform = CATransform3DMakeRotation(3.141f/2.0f,
0.0f,
-1.0f,
0.0f);
// these values control the 3D projection outlook
endTransform.m34 = 0.001f;
endTransform.m14 = -0.0015f;
// start the animation from the current state
transformAnimation.fromValue = [NSValue valueWithCATransform3D:CATransform3DIdentity];
transformAnimation.toValue = [NSValue valueWithCATransform3D:endTransform];
animatedView = screenShot;
// Create an animation group to hold the rotation and possibly more complex animation in the future
CAAnimationGroup *theGroup = [CAAnimationGroup animation];
// Set self as the delegate to receive notification when the animation finishes
theGroup.delegate = self;
theGroup.duration = ANIMATION_TIME;
// CAAnimation-objects support arbitrary Key-Value pairs, we add the UIView tag
// to identify the animation later when it finishes
[theGroup setValue:[NSNumber numberWithInt:animatedView.tag] forKey:#"animated"];
// Here you could add other animations to the array
theGroup.animations = [NSArray arrayWithObjects:transformAnimation,nil];
theGroup.removedOnCompletion = NO;
// Add the animation group to the layer
if (animatedView.layer.anchorPoint.x != 0.0f)
{
animatedView.layer.anchorPoint = CGPointMake(0.0f, 0.5f);
float yy = animatedView.center.x - (animatedView.bounds.size.width / 2.0f);
animatedView.center = CGPointMake(yy, animatedView.center.y);
}
if(![animatedView isDescendantOfView:self.view])[self.view addSubview:animatedView];
screenShot.hidden = NO;
animatedView.hidden = NO;
[animatedView.layer addAnimation:theGroup forKey:#"flip"];
}
- (void)animationDidStop:(CAAnimation *)theAnimation finished:(BOOL)flag {
screenShot.hidden = YES;
}
Try setting theGroup's and / or transformAnimation's fillMode to kCAFillModeForwards:
theGroup.fillMode = kCAFillModeForwards;
This should cause your animation to persist once its active duration has completed. I've used this to remove an end-of-animation flicker before.
Not sure I understand completely what you are seeing but it's possible you're seeing something caused by the speed difference between the device and the simulator. The simulator is considerably faster than the device so something that "blinks" very quickly might do so too fast for the human eye to catch on the simulator.
Oof. That's annoying. I think it is that there's a split-second between when animation stops and when that line of code executes. If only there were an animationWillStop: method! You might try, instead of screenShot.hidden = YES, screenShot.alpha = 0. I doubt it will make any difference speed-wise, but it might be worth a shot? You could also fade out the view as part of the animation, but I don't think you want to do that.
The only other thing I can think of is to setup an NSTimer with an interval just under your animation time. Something like:
[NSTimer scheduledTimerWithTimeInterval:(ANIMATION_TIME - .001) target:self selector:#selector(hideTheView) userInfo:nil repeats:NO];
And then implement that hideTheView method, of course.
I am trying to create a falling coin. The coin image is a CALayer with 2 CABasicAnimations on it - a falling down and a rotation one. When the falling down animation gets to its end, it stays there. The rotation animation though, which is supposed to be random and end up in a different angle every time, just pops back to the original CALAyer image.
I want it to stay in the angle it finished the animation on. Is it possible? How do I do it?
Code:
//Moving down animation:
CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:#"transform.translation.y"];
anim.duration = 1;
anim.autoreverses = NO;
anim.removedOnCompletion = YES;
anim.fromValue = [NSNumber numberWithInt: -80 - row_height * (8 - _col)];
anim.toValue = [NSNumber numberWithInt: 0];
//Rotation Animation:
CABasicAnimation *rota = [CABasicAnimation animationWithKeyPath:#"transform.rotation"];
rota.duration = 4;
rota.autoreverses = NO;
rota.removedOnCompletion = NO;
rota.fromValue = [NSNumber numberWithFloat: 0];
rota.toValue = [NSNumber numberWithFloat: 2.5 * 3.15 ];
[cl addAnimation: rota forKey: #"rotation"];
[cl addAnimation: anim forKey: #"animateFalling"];
Have you set the removedOnCompletion property of the rotation animation to NO, e.g.,
rota.removedOnCompletion = NO;
That should leave the presentation layer where it was when the animation finished. The default is YES, which will snap back to the model value, i.e., the behavior you describe.
The fillMode should also be set, i.e.,
rota.fillMode = kCAFillModeForwards;
I was trying to rotate an arrow back and forth, like the Twitter/Facebook "Pull to Refresh" effect.
The problem is, I was doing the rotation back and forth on the same UIView, so after adding
rotation.removedOnCompletion = NO;
rotation.fillMode = kCAFillModeForwards;
The forward animation war working OK but the backwards animation was not working at all.
So I added the last line suggested by yeahdixon, and in addition set the view's transform to the animation's completed state: (rotation by 180 degrees)
[myview.layer removeAllAnimations];
myView.transform = CGAffineTransformMakeRotation(M_PI);
For the 'restore' animation (backwards) I do this on completion:
myView.transform = CGAffineTransformMakeRotation(0);
...and it works fine. Somehow it doesn't need the removeAllAnimations call.
I found that by setting : removedOnCompletion = NO;
did not produce a visible leak in instruments, but did not get deallocated and was accumulating a small amount of memory. IDK if its my implementation or what, but by adding removeAllAnimations at the end of the animation seemed to clear out this tiny bit of residual memory.
[myview.layer removeAllAnimations];