how to build in and build out a layer? - ios

I want to build in a layer and build out it after 5 seconds. but I don't know how to assign the final value to the layer. my code is as following:
-(CABasicAnimation *) buildIn{
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"opacity"];
animation.duration = 2.0f;
[animation setFromValue:[NSNumber numberWithFloat:0.0f]];
[animation setToValue:[NSNumber numberWithFloat:1.0f]];
[animation setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]];
return animation;
}
-(CABasicAnimation *) buildOut{
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"opacity"];
animation.duration = 2.0f;
animation.beginTime = CACurrentMediaTime() + 5;
[animation setFromValue:[NSNumber numberWithFloat:1.0f]];
[animation setToValue:[NSNumber numberWithFloat:0.0f]];
[animation setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]];
return animation;
}
- (IBAction)startAnimation:(id)sender {
[self.textView.layer addAnimation:[self buildIn] forKey:#"transparent"];
self.textView.layer.opacity = 1.0f;//I need to set the opacity to 1 after buildIn animation
[self.textView.layer addAnimation:[self buildOut] forKey:#"transparent"];
self.textView.layer.opacity = 0.0f;//ERROR: this is the final layer value, but I need to assign it after the build out animation, not here.
}
I think I can use a completion block to do it, but I can't find it.

If you set a delegate on your buildIn animation, then when it is finished the -animationDidStop:finished: message will be sent to the delegate. Then you can start your buildOut animation.
CAAnimation delegate reference

Related

Delay start of a CATransition

It's possible to delay the animation of a CATransition? I tried with startProgressbut it doesn't make any difference.
This is how I'm making the transition:
CATransition *animation = [CATransition animation];
[animation setType:kCATransitionPush];
[animation setSubtype:kCATransitionFromLeft];
[animation setDuration:0.25];
[animation setTimingFunction:[CAMediaTimingFunction functionWithName:
kCAMediaTimingFunctionEaseInEaseOut]];
[animation setRemovedOnCompletion:YES];
[self.tabBarController.view.layer addAnimation:animation forKey:#"pushAnimation"];
Please read this: http://wangling.me/2011/06/time-warp-in-animation.html
It's a good article about additional timing properties of animatios.

Two animations on one layer

I have a CALayer, and I want to show it and then hide.
CALayer *layerOne = [CALayer layer];
[layerOne addSublayer:textOne];
layerOne.frame = CGRectMake(0, 0, size.width, size.height);
[layerOne setMasksToBounds:YES];
layerOne.opacity = 0.0;
CABasicAnimation *animationOne = [CABasicAnimation animationWithKeyPath:#"opacity"];
[animationOne setDuration:0];
[animationOne setFromValue:[NSNumber numberWithFloat:0.0]];
[animationOne setToValue:[NSNumber numberWithFloat:1.0]];
[animationOne setBeginTime:3];
[animationOne setRemovedOnCompletion:NO];
[animationOne setFillMode:kCAFillModeForwards];
[layerOne addAnimation:animationOne forKey:#"animateOpacity"];
This code work successfully, layerOne appear after 3 seconds.
But I want to hide this layer, so I add this:
CABasicAnimation *animationTwo = [CABasicAnimation animationWithKeyPath:#"opacity"];
[animationTwo setDuration:0];
[animationTwo setFromValue:[NSNumber numberWithFloat:1.0]];
[animationTwo setToValue:[NSNumber numberWithFloat:0.0]];
[animationTwo setBeginTime:6];
[animationTwo setRemovedOnCompletion:NO];
[animationTwo setFillMode:kCAFillModeForwards];
[layerOne addAnimation:animationTwo forKey:#"animateOpacity"];
And it doesn't work. layerOne not appear after 3 seconds. Its just flashed in second 6 and disappear. Its seems like the second animation blocking the first one and only the second animation is going on.
What I do wrong?
Well, for one thing since the second animation has the same key, when you add it to the layer, the original animation will be removed. When the animation is removed, it's long-term effect (setting opacity = 1.0) will also be removed so the animation will be immediately hidden.
For something like this, the normal process to show the layer is:
// set the final result you want to persist forever
layerOne.opacity = 1.0;
// set up your animation here
CABasicAnimation *animationOne = [CABasicAnimation animationWithKeyPath:#"opacity"];
animationOne.fromValue = #(0.);
animationOne.toValue = #(1.);
animationOne.duration = 3.;
animationOne.beginTime = 0.;
animationOne.removedOnCompletion = true;
animationOne.fillMode = kCAFillModeRemove; // for clarity, this is the default
[layerOne addAnimation:animationOne forKey:#"animateOpacity"];
And then when you want to hide the layer just reverse the process:
// Set the final animation state
layerOne.opacity = 0.0;
// set up your animation here
CABasicAnimation *animationTwo = [CABasicAnimation animationWithKeyPath:#"opacity"];
animationTwo.fromValue = #(1.);
animationTwo.toValue = #(0.);
animationTwo.duration = 3.;
animationTwo.beginTime = 0.;
animationTwo.removedOnCompletion = true;
animationTwo.fillMode = kCAFillModeRemove; // for clarity, this is the default
[layerOne addAnimation:animationTwo forKey:#"animateOpacity"];
If you're wanting to run the whole process as a single event, you should put both animations into a single animation group:
// set up your animation here
CABasicAnimation *animationOne = [CABasicAnimation animationWithKeyPath:#"opacity"];
animationOne.fromValue = #(0.);
animationOne.toValue = #(1.);
animationOne.duration = 3.;
animationOne.beginTime = 0.;
animationOne.fillMode = kCAFillModeForwards;
// set up your animation here
CABasicAnimation *animationTwo = [CABasicAnimation animationWithKeyPath:#"opacity"];
animationTwo.fromValue = #(1.);
animationTwo.toValue = #(0.);
animationTwo.beginTime = 6.;
animationTwo.duration = 3.;
animationOne.fillMode = kCAFillModeForwards;
// set up the animation group
CAAnimationGroup* group = [CAAnimationGroup new];
group.beginTime = 0.;
group.duration = 9.;
group.animations = #[ animationOne, animationTwo ];
[layerOne addAnimation:group forKey:#"animateOpacity"];

Flipping the UILabel

I want to use the CABasicAnimation to flip the UILabel. Animation will repeat forever and will change the text of UILabel between two different values.
- (void)animateLabel
{
[self.myLabel.layer addAdnimation:[self labelAnimation] forKey:#"flip"];
}
- (CAAnimation*)labelAnimation
{
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"transform"];
[animation setRepeatCount:NSIntegerMax];
[animation setAutoreverses:YES];
[animation setDuration:2.0];
[animation setDelegate:self];
CATransform3D transform = CATransform3DMakeRotation(M_PI_2, 1, 0, 0);
[animation setToValue:[NSValue valueWithCATransform3D:transform]];
return animation;
}
Now, I tried using the delegate but the delegate method is only when the animation first begins. Rather I need to be able to know the the label completes one cycle. Is there some convenience method or way to do it with CALayer or do I have to use CADisplay link or timer ? I would like to thank you before hand for helping me.
To get notified on each cycle, setRepeatsCount to 1. You'll then get notified in the delegate animationDidStop:finished. You would then simply add the same animation again.
- (void)animateLabel
{
[self.myLabel.layer addAdnimation:[self labelAnimation] forKey:#"flip"];
}
- (void)animationDidStop:(CAAnimation *)theAnimation finished:(BOOL)flag
{
[self animateLabel];
// do other stuff
}
- (CAAnimation*)labelAnimation
{
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"transform"];
[animation setRepeatCount:1];
[animation setAutoreverses:YES];
[animation setDuration:2.0];
[animation setDelegate:self];
CATransform3D transform = CATransform3DMakeRotation(M_PI_2, 1, 0, 0);
[animation setToValue:[NSValue valueWithCATransform3D:transform]];
return animation;
}
No, this is the way you're supposed to do it according to the documentation.
Setting this property to HUGE_VALF will cause the animation to repeat forever.

Animate UIView using Core Animation?

I am having a little trouble getting a UiView to animate properly using core animation. Here is my code:
CABasicAnimation* animation = [CABasicAnimation animationWithKeyPath:#"position"];
[animation setFromValue:[NSValue valueWithCGPoint:self.view.layer.position]];
[animation setToValue:[NSValue valueWithCGPoint:CGPointMake(250, self.view.layer.position.y)]]; //I want to move my UIView 250 pts to the right
[animation setDuration:1];
[animation setDelegate:self]; //where self is the view controller of the view I want to animate
[animation setRemovedOnCompletion:NO];
[self.view.layer addAnimation:animation forKey:#"toggleMenu"]; //where self.view returns the view I want to animate
I have also implemented the following delegate method:
-(void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag{
if(flag)
[self.view.layer setTransform:CATransform3DMakeTranslation(250, 0, 0)]; //set layer to its final position
}
I am trying to make it so that the UIView moves 250 points to the right. However, when the animation is triggered, my view starts to move but the animations seems to end before the view moves 250 points to the right, resulting in the UIView 'teleporting' to its final position. I can't seem to figure out what is causing this behavior.
I have also tried using the UIView method +(void)animateWithDuration:animations: and this approach works perfectly. However, I am trying to achieve a subtle 'bounce' effect and I'd much rather achieve it using the setTimingFunction:functionWithControlPoints: method rather than having multiple callbacks.
Any help and suggestions are appreciated.
Try like this
CABasicAnimation *rotationAnimation;
rotationAnimation = [CABasicAnimation animationWithKeyPath:#"position"];
rotationAnimation.fromValue=[NSValue valueWithCGPoint:CGPointMake([view center].x, [view center].y)];
rotationAnimation.toValue=[NSValue valueWithCGPoint:CGPointMake([view center].x+250, [view center].y)];
rotationAnimation.duration = 1.0+i;
rotationAnimation.speed = 3.0;
rotationAnimation.cumulative = YES;
rotationAnimation.repeatCount = 1.0;
rotationAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
[view.layer addAnimation:rotationAnimation forKey:#"position"];
If you are aiming to move your view, your code should go like this:
CABasicAnimation* animation = [CABasicAnimation animationWithKeyPath:#"position"];
[animation setFromValue:[NSValue valueWithCGPoint:self.view.layer.position]];
CGPoint p = self.view.layer.position;
p.x += 250;
self.view.layer.position = p;
[animation setDuration:1];
[animation setRemovedOnCompletion:NO];
[self.view.layer addAnimation:animation forKey:#"toggleMenu"];
You should really change your view's(layer's) position. Otherwise, your view will stay still at its previous position when your animation removed. That's a difference between UIView Animation and Core Animation.
CABasicAnimation* animation = [CABasicAnimation animationWithKeyPath:#"position"];
[animation setFromValue:[NSValue valueWithCGPoint:view.layer.position]];
CGPoint newPosition = CGPointMake(200, 300);
view.layer.position = p;
[animation setDuration:0.5f];
[animation setRemovedOnCompletion:NO];
[group setFillMode:kCAFillModeForwards];
[[view layer] addAnimation:animation forKey:#"position"];

Fade-transition a rect in a UIView

So I want to redraw a rectangle in a view and then transition to it with a fade. This is what I'm using now:
[self setNeedsDisplayInRect:changedRect];
CATransition *animation = [CATransition animation];
[animation setDuration:0.25];
[animation setType:kCATransitionFade];
[[self layer] addAnimation:animation forKey:nil];
This however fades the entire layer. How can I go about fading just changedRect?
Thanks,
Alec

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