I am learning Core Animation and as per my task I have to expand/collapse a layer in y-axis linearly I have following piece of code
CABasicAnimation *shrinkAnimation;
shrinkAnimation = [CABasicAnimation animationWithKeyPath:#"transform"]; //use transform instead of bounds.size
shrinkAnimation.repeatCount = 1;
shrinkAnimation.autoreverses = NO;
[shrinkAnimation setDuration:1.5];
shrinkAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
shrinkAnimation.toValue = [NSValue valueWithCATransform3D:CATransform3DScale(myView.layer.transform, 1, 0.1, 1.0)];
[myView.layer addAnimation:shrinkAnimation forKey:#"bounds.size"];
but the problem here is the layer contracts/expands from both the ends simultaneously, can you help me to get it expand/collapse in one direction.
Thanks in advance
Regards
Ankit
set the anchor point of your layer to 0,0 or 1,1 or some other values, to make the edge you want won't move.
myView.layer.anchorPoint = CGPointMake(0,0);
Related
I've used CAKeyframeAnimations to animate a layer's transform.rotation and transform.translation.x properties, but I'm having trouble animating the transform property implicitly. I have a layer that must animate between two states and CABasicAnimation's default interpolation is totally incorrect and doesn't follow the path I want. CAKeyframeAnimation to the rescue, or so I thought. Any attempt to animate transform using a CAKeyframeAnimation results in the view immediately snapping to the final transform while the other animations run. If I remove the first half of the following function and let my "transform" events use the CABasicAnimation on the bottom, it animates just fine - albeit with incorrectly interpolated transforms along the way.
My layer delegate has implemented the following:
- (id <CAAction>) actionForLayer:(CALayer *)layer forKey:(NSString *)event
{
if ([event isEqualToString:#"transform"])
{
CGSize startSize = ((CALayer *)self.layer.presentationLayer).bounds.size;
CGSize endSize = self.layer.bounds.size;
CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:event];
animation.duration = 0.25;
NSMutableArray *values = [NSMutableArray array];
int stepCount = 10;
for (int i = 0; i < stepCount; i++)
{
CGFloat p = i / (float)(stepCount - 1);
CGSize size = [self interpolateBetweenSize:startSize andSize:endSize percentage:p];
CATransform3D transform = [self transformForSize:size];
[values addObject:[NSValue valueWithCATransform3D:transform]];
}
animation.values = values;
return animation;
}
// All other animations use this basic animation
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:event];
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
animation.removedOnCompletion = YES;
animation.fillMode = kCAFillModeForwards;
animation.duration = 0.25;
return animation;
}
My transform is a translation followed by a rotate, but I think a group animation with separate keyframe animations animating through a translation AND a rotate would result in crazy town. I've confirmed that size & transform are correct for all values of p that I pass though, and p strictly ranges from 0 to 1.
I've tried setting a non-default timing function, I've tried setting an array of timing functions, I've omitted the keyTImes, I've set a repeatCount of 0, removedOnCompletion=YES, and a fillMode of forwards and that had no effect. Am I not creating the transform keyframe animation correctly?
This technique worked back in iOS 3 but seemed to be broken in iOS 5.0.
5.1 'magically' fixed this, it seemed to be a bug in iOS 5.0. I'd file a radar, but it is now working in 5.1.
#Gsnyder: Some background: I am experimenting with Clear-like UI (for something completely unrelated to Clear) and came up with this: http://blog.massivehealth.com/post/18563684407/clear. That should explain the need for a rotate & translate.
I've since created a shutter transition that subdivides a view into N layers (instead of just 2) that looks like this when viewed from the side: /////.
My code is not animating the bounds, it is using the size at each step to determine the necessary transform.
#Paul.s: Implicit allows me to keep this abstraction within the layer class itself without polluting the view controller that owns it. The view controller should just be changing the bounds around and the layer should move appropriately. I'm not a fan of view controllers having dozens of custom animations when the views themselves can handle it.
I need to use a keyframe animation because the default animation between layer transforms / and _ animate through incorrect angles so the ///\ layers do not line up throughout the transform. The keyframe animations ensure the edges all line up correctly while they all animate.
I'm considering this closed, this seems to be a bug in iOS 5.0 and has since been fixed. Thanks everyone.
(void)animateViewWith3DCurrentView:(UIView *)currentView withPoing:(CGPoint)movePoint
{
//flip the view by 180 degrees in its place first.
currentView.layer.transform = CATransform3DRotate(currentView.layer.transform,myRotationAngle(180), 0, 1, 0);
//set the anchor point so that the view rotates on one of its sides.
currentView.layer.anchorPoint = CGPointMake(0.5, 0.5);
//Set up scaling
CABasicAnimation *resizeAnimation = [CABasicAnimation animationWithKeyPath:kResizeKey];
//we are going to fill the screen here. So 423,337
[resizeAnimation setToValue:[NSValue valueWithCGSize:CGSizeMake(423, 337)]];
resizeAnimation.fillMode = kCAFillModeForwards;
resizeAnimation.removedOnCompletion = NO;
// Set up path movement
UIBezierPath *movePath = [UIBezierPath bezierPath];
//the control point is now set to centre of the filled screen. Change this to make the path different.
// CGPoint ctlPoint = CGPointMake(0.0, 0.5);
CGPoint ctlPoint = CGPointMake(1024/2, 768/2);
//This is the starting point of the animation. This should ideally be a function of the frame of the view to be animated. Hardcoded here.
// Set here to get the accurate point..
[movePath moveToPoint:movePoint];
//The anchor point is going to end up here at the end of the animation.
[movePath addQuadCurveToPoint:CGPointMake(1024/2, 768/2) controlPoint:ctlPoint];
CAKeyframeAnimation *moveAnim = [CAKeyframeAnimation animationWithKeyPath:kPathMovement];
moveAnim.path = movePath.CGPath;
moveAnim.removedOnCompletion = YES;
// Setup rotation animation
CABasicAnimation* rotateAnimation = [CABasicAnimation animationWithKeyPath:kRotation];
//start from 180 degrees (done in 1st line)
CATransform3D fromTransform = CATransform3DMakeRotation(myRotationAngle(180), 0, 1, 0);
//come back to 0 degrees
CATransform3D toTransform = CATransform3DMakeRotation(myRotationAngle(0), 0, 1, 0);
//This is done to get some perspective.
CATransform3D persp1 = CATransform3DIdentity;
persp1.m34 = 1.0 / -3000;
fromTransform = CATransform3DConcat(fromTransform, persp1);
toTransform = CATransform3DConcat(toTransform,persp1);
rotateAnimation.toValue = [NSValue valueWithCATransform3D:toTransform];
rotateAnimation.fromValue = [NSValue valueWithCATransform3D:fromTransform];
//rotateAnimation.duration = 2;
rotateAnimation.fillMode = kCAFillModeForwards;
rotateAnimation.removedOnCompletion = NO;
// Setup and add all animations to the group
CAAnimationGroup *group = [CAAnimationGroup animation];
[group setAnimations:[NSArray arrayWithObjects:moveAnim,rotateAnimation, resizeAnimation, nil]];
group.fillMode = kCAFillModeForwards;
group.removedOnCompletion = NO;
group.duration = 0.7f;
group.delegate = self;
[group setValue:currentView forKey:kGroupAnimation];
[currentView.layer addAnimation:group forKey:kLayerAnimation];
}
I hope to make 3d transition between two pictures just like the slideshow 3d transition in app 'photos'.
For 2d transition, I can use CATransition.
Is there any 3D api for this?
Welcome any comment
Yes, there is 2.5d animation in the iphone which is basiclly simulated 3d environment. you can do it by doing a 3dtransform to a layer and mov it in the Z Axis.
Heres a code sample
First you should set the vision point or the "Camera" by doing this :
CATransform3D perspective = CATransform3DIdentity;
perspective.m34 = -0.001;
self.view.layer.sublayerTransform = perspective;
then you just add BasicAnimation to your layer and change the y property
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.y"];
animation.toValue = [NSNumber numberWithFloat:M_PI];
animation.duration = 10;
[imageView.layer addAnimation:animation forKey:#"Transform"];
this sample code will make a 3d rotation to the image
I've been trying to understand what is wrong with my animation and I still haven't figure it out. I think it should be really straight forward, but there is probably something I'm missing, even after reading lot of examples and documentation.
My problem comes originally form the fact that on the iPhone, you cannot resize layers automatically (with the view). The documentation says otherwise but there is no autoresizeMask for the layer in the SDKs. So I decided to make a little workaround and animate the layer myself.
I've got this simple piece of code that should do a simple resize animation. The values are good and I even set the delegate in order to trace if the anim start/end.
// I've got a property named layerImage (which is a CALayer)
- (void)animateTestWithFrame:(CGRect)value {
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"layerImage.frame"];
animation.duration = 1;
animation.fromValue = [NSValue valueWithCGRect:self.frame];
animation.toValue = [NSValue valueWithCGRect:value];
animation.removedOnCompletion = YES;
animation.delegate = self;
[self.layer addAnimation:animation forKey:#"layerImage.frame"];
}
So, any ideas? (This view that contains the code is the subview of a subview of the window if that could make a difference)
--- EDIT ---
It seems that frame is not animatable via CABasicAnimation and the named property "frame". When using bounds, I've got some strange result, but at least I'm getting something. Will continue investigating on this.
So it's good that you've figured things out here, but your answer to your own question has some inaccuracies. Let me correct a few things:
The frame property can be animated--just not with explicit animation. If you do the following to a layer other than the root layer of a view, the frame will animate just fine:
[CATransaction begin];
[CATransaction setAnimationDuration:2.0f];
[animationLayer setFrame:CGRectMake(100.0f, 100.0f, 100.0f, 100.0f)];
[CATransaction commit];
Remember that setting a property on a layer will animate that property change by default. In fact you have to disable animations on a property change if you don't want it to animate. (Of course this is only true if you are animating a layer other than the root layer of a view.) You are correct in animating both position and bounds if you need to use an explicit animation.
You can animate the frame on a UIView using implicit animation:
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:3.0f];
[[self view] setFrame:CGRectMake(45.0f, 45.0f, 100.0f, 100.0f)];
[UIView commitAnimations];
This will animate from the view's current frame (bounds and position) to x = 45.0, y = 45.0, w = 100.0, h = 100.0.
It seems you may also be misunderstanding the difference between an animation and a layer. You add animations to layers, but adding an animation to a layer does not automatically set the property that you're animating.
CALayers are model objects. They contain information about the layer that eventually gets rendered to screen. You must set a layer's property if you want that property to actually have that value. If you simply animate the property, it will only be a visual representation and not actual--which is to say this is why the value snaps back to the original value of the layer because you never actually changed it.
Which leads me to the next point. You said:
Use "animation.removedOnCompletion =
NO; animation.fillMode =
kCAFillModeForwards;" to ensure that
the values are not reseted at the end
of the animation
This is not exactly right. These two values simply cause the animation to remain at it's final position visually, however, the layer's actual values have not changed. They are still the exact same values they were when you started the animation. In general (with a few exceptions) you don't want to use these two parameters because they are visual only. What you want is to actually set the layer value for the property you're animating.
Say, for example, that you want to animate the position of your layer using an explicit animation. Here is the code you want:
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"position"];
[animation setFromValue:[NSValue valueWithCGPoint:CGPointMake(70.0f, 70.0f)]];
[animation setToValue:[NSValue valueWithCGPoint:CGPointMake(150.0f, 150.0f)]];
[animation setDuration:2.0f];
// Actually set the position on the *layer* that you want it to be
// when the animation finishes.
[animationLayer setPosition:CGPointMake(150.0f, 150.0f)];
// Add the animation for the position key to ensure that you
// override the animation for position changes with your animation.
[animationLayer addAnimation:animation forKey:#"position"];
You may also want to consider animation grouping. With an animation group, you can group several animations together and then control how they relate to each other. In your case the duration for your bounds and position animations are the same and so what you are trying to do will work fine without a group, but if you wanted to offset the start of the animations, for example you didn't want the position animation to start until a second or two into the frame animation, you could stagger them by setting the beginTime value of the position animation.
Finally, I would be curious to know why you couldn't use the implicit animations available on UIView. I use these in the vast majority of the Core Animation code I write and can't see why this wouldn't work for your situation.
Best regards.
The key path should only be the key path of the property, not the name of the object as well.
Use this
[CABasicAnimation animationWithKeyPath:#"frame"]
instead of this
[CABasicAnimation animationWithKeyPath:#"layerImage.frame"]
And just BTW, when you add animation to a layer, the key doen't mean the key property to animate. Just the key (name) that you want this animation to have (this refers to the last line your code)
So, the solution was to animate the #"bounds" and the #"position" of the layer because frame is not animatable on iPhone. It took me some time to understand that the position was the center of the layer and the resize of the bounds was extending from the center, but that was the easy part.
So, what I did in resume was:
In the setFrame, create 2 animations with the bounds and position property.
Use "animation.removedOnCompletion = NO; animation.fillMode = kCAFillModeForwards;" to ensure that the values are not reseted at the end of the animation
Register the delegate to self in order to implements "animationDidStop:finished:". It seems that you still need to set the values: "layerImage.bounds = [animation.toValue CGRectValue]; layerImage.position = [animation.toValue CGPointValue];".
I wasn't able to use the UIView animation system directly because it wasn't doing what I wanted on the layers.
Thanks tadej5553 for pointing me out the layer problem I had with the "addAnimation". So here is the code for those who would like to see what it looks like.
- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag {
CABasicAnimation *animation = (CABasicAnimation*)anim;
if ([animation.keyPath isEqualToString:#"bounds"]) {
layerImage.bounds = [animation.toValue CGRectValue];
} else if ([animation.keyPath isEqualToString:#"position"]) {
layerImage.position = [animation.toValue CGPointValue];
}
}
- (void)setFrame:(CGRect)value {
CGRect bounds = CGRectMake(0, 0, value.size.width, value.size.height);
if ([UIView isAnimationStarted]) {
// animate the bounds
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"bounds"];
animation.duration = [UIView animationDuration];
animation.fromValue = [NSValue valueWithCGRect:layerImage.bounds];
animation.toValue = [NSValue valueWithCGRect:bounds];
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;
animation.timingFunction = [UIView animationFunction];
animation.delegate = self;
[layerImage addAnimation:animation forKey:#"BoundsAnimation"];
// animate the position so it stays at 0, 0 of the frame.
animation = [CABasicAnimation animationWithKeyPath:#"position"];
animation.duration = [UIView animationDuration];
animation.fromValue = [NSValue valueWithCGPoint:layerImage.position];
animation.toValue = [NSValue valueWithCGPoint:CGPointMake(bounds.size.width / 2, bounds.size.height / 2)];
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;
animation.timingFunction = [UIView animationFunction];
animation.delegate = self;
[layerImage addAnimation:animation forKey:#"PositionAnimation"];
} else {
layerImage.frame = bounds;
}
[super setFrame:value];
}
I am trying to perform some kind of animation of a layer in my iPhone application. It does not matter what I do I always get the same results: after the animation is done it jerks back into it's original position. Even though I set removedOnCompletion to false there is no difference.
What am I missing here?
Thanks in advance!
EDIT: Really need help with this one guys. I am creating animations with CAKeyframeAnimation and CABasicAnimation objects, then adding them to a CAAnimationGroup which I in turn att to the layer. The animation works as predicted except that it always snaps back to it's original state. This is the case even though I set removedOnCompletion = NO; on all animation-objects and the animation group.
Some one please point me in the right direction! I you live in the Stockholm area I will buy you a coffe. =) New code posted below:
CABasicAnimation *leveloutLeafAnimation = [CABasicAnimation animationWithKeyPath:#"transform"];
leveloutLeafAnimation.removedOnCompletion = NO;
leveloutLeafAnimation.duration = 1.0;
leveloutLeafAnimation.repeatDuration = 20;
CATransform3D transformLeafToRotation = CATransform3DMakeRotation(0.0, 0.0, 0.0, 1);
CATransform3D transformLeafFromRotation = CATransform3DMakeRotation([self _degreesToRadians:270.0], 0.0, 0.0, 1);
leveloutLeafAnimation.fromValue = [NSValue valueWithCATransform3D:transformLeafFromRotation];
leveloutLeafAnimation.toValue = [NSValue valueWithCATransform3D:transformLeafToRotation];
//Create an animation group to combine the animations.
CAAnimationGroup *theAnimationGroup = [CAAnimationGroup animation];
//The animationgroup conf.
theAnimationGroup.delegate = self;
theAnimationGroup.duration = animationDuration;
theAnimationGroup.removedOnCompletion = NO;
theAnimationGroup.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
theAnimationGroup.animations = [NSArray arrayWithObjects:leveloutLeafAnimation, leafMoveAnimation, nil];
// Add the animation group to the leaf layer.
[leafViewLayer addAnimation:theAnimationGroup forKey:#"animatLeafFalling"];
Not sure if this is helpful, but this guy seems like he was having a similar problem.
You might have to set the transform property of the layer while the animation is running to transformLeafToRotation.
Good luck!
I have a case where i'm drawing shapes, e.g. a Triangle (Points A, B, C). Now i want to animate it so that Points A, B, C move towards Point X, Y, Z. (Lets just say on button click)
I'm using a drawRect: method in my custom view for drawing. I don't want my view to move, i rather want my drawing to move (because i have multiple drawings).
Any pointers? Any relative articles?
Regards,
Mustafa
Core Animation is a good solution for this type of thing. You have CAShapeLayer that allows you to draw shapes according to a path and you can animate using a basic animation or a keyframe animation. You can do something like this in your button click:
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"position"];
[animation setFromValue:[NSValue valueWithCGPoint:CGPointMake(0.0, 0.0)]];
[animation setToValue:[NSValue valueWithCGPoint:CGPointMake(320.0, 480.0)]];
[animation setDuration:2.0f];
[shapeLayer addAnimation:animation forKey:#"positionAnimation"];
This will animate the layer from point 0.0, 0.0 (upper left hand corner) to 320.0, 480.0 (lower right hand corner) over the course of two seconds. When you add the animation to your layer, it will start playing immediately. If you are looking to rotate the animation (wasn't sure from the post), you can do this:
CABasicAnimation *rotationAnimation;
rotationAnimation = [CABasicAnimation
animationWithKeyPath:#"transform.rotation.z"];
[rotationAnimation setFromValue:DegreesToNumber(0)];
[rotationAnimation setToValue:DegreesToNumber(360)];
[rotationAnimation setDuration:2.0f];
[rotationAnimation setRepeatCount:10000]; // keep spinning
[shapeLayer addAnimation:rotationAnimation forKey:#"rotate"];
The DegreesToNumber is a helper function that converts degrees to radians and returns an NSNumber object:
CGFloat DegreesToRadians(CGFloat degrees)
{
return degrees * M_PI / 180;
}
NSNumber* DegreesToNumber(CGFloat degrees)
{
return [NSNumber numberWithFloat:
DegreesToRadians(degrees)];
}
There are lots of articles on the web about Core Animation, but this should get you started. Let me know if you need clarification.