To illustrate this question, I gisted a very small Xcode project on Github (two classes, 11kb download). Have a look at the gist here or use git clone git#gist.github.com:93982af3b65d2151672e.git.
Please consider the following scenario. A custom view of mine, called 'container view', contains two little squares. Illustrated in this screenshot:
The blue square is a 22x22 pt UIView instance and the red square is a 22x22 pt CALayer instance. For purposes of this question I want the two squares to 'stick' to the bottom right corner of the outer view, while I animate the frame of that outer view.
I change the container view's frame within a UIView's class method animateWithDuration:delay:options:animations:completion:, with a non-default easing parameter of type UIViewAnimationCurveEaseOut.
[UIView animateWithDuration:1.0 delay:0
options:UIViewAnimationCurveEaseOut
animations:^{ _containerView.frame = randomFrame; }
completion:nil];
Note: Both the blue UIView's and the red CALayer's frame are set in the overridden setFrame: method of the container view, but results would have been the same if I had set the blue UIView's autoresizingMask property to UIView flexible left and top margins.
In the resulting animation, the blue square 'sticks' to the corner just the way I intended it, but the red square completely disregards both timing and easing of the animation. I assume this is because of the implicit animation feature of Core Animation, a feature that has helped me in many occasions before.
Here are a few screenshots in the animation sequence that illustrate the asynchronicity of the two squares:
On to the question: Is there a way to synchronize the two frame changes so that the red CALayer and the blue UIView both move with the same animation duration and easing curve, sticking to each other as if they were one view?
P.S. Of course the required visual result of the two squares sticking together could be achieved in any number of ways, for example by having both layers become either CALayers or UIViews, but the project that the real issue is in has a very legit cause for the one to be a CALayer and the other to be a UIView.
I'm assuming that you got the end position correct and that after the animation that the view and the layer are aligned. That has nothing to do with the animation, just geometry.
When you change the property of a CALayer that isn't the layer of a view (like in your case) it will implicitly animate to its new value. To customize this animation you could use an explicit animation, like a basic animation. Changing the frame in a basic animation would look something like this.
CABasicAnimation *myAnimation = [CABasicAnimation animationWithKeyPath:#"frame"];
[myAnimation setToValue:[NSValue valueWithCGRect:myNewFrame]];
[myAnimation setFromValue:[NSValue valueWithCGRect:[myLayer frame]]];
[myAnimation setDuration:1.0];
[myAnimation setTimingFunction:[CAMediaTimingFuntion functionWithName: kCAMediaTimingFunctionEaseOut]];
[myLayer setFrame:myNewFrame];
[myLayer addAnimation:myAnimation forKey:#"someKeyForMyAnimation"];
If the timing function and the duration of both animations are the same then they should stay aligned.
Also note that explicit animations doesn't change the value and hat you have to both add the animation and set the new value (like in the sample above)
Yes, there are a number of ways to achieve the same effect. One example is having the view and the layer be subviews of the same subview (that in turn is a subview of the outer frame).
Edit
You can't easily group the UIView-animation with an explicit animation. Neither can you use an animation group (since you are applying them to different layers) but yo can use a CATransaction:
[CATransaction begin];
[CATransaction setAnimationDuration:1.0];
[CATransaction setAnimationTimingFunction:[CAMediaTimingFuntion functionWithName: kCAMediaTimingFunctionEaseOut]];
// Layer animation
CABasicAnimation *myAnimation = [CABasicAnimation animationWithKeyPath:#"frame"];
[myAnimation setToValue:[NSValue valueWithCGRect:myNewFrame]];
[myAnimation setFromValue:[NSValue valueWithCGRect:[myLayer frame]]];
[myLayer setFrame:myNewFrame];
[myLayer addAnimation:myAnimation forKey:#"someKeyForMyAnimation"];
// Outer animation
CABasicAnimation *outerAnimation = [CABasicAnimation animationWithKeyPath:#"frame"];
[outerAnimation setToValue:[NSValue valueWithCGRect:myNewOuterFrame]];
[outerAnimation setFromValue:[NSValue valueWithCGRect:[outerView frame]]];
[[outerView layer] setFrame:myNewOuterFrame];
[[outerView layer] addAnimation:outerAnimation forKey:#"someKeyForMyOuterAnimation"];
[CATransaction commit];
If you want David Rönnqvist's snippet in Swift 3.0, here you have it:
CATransaction.begin()
CATransaction.setAnimationDuration(1.0)
CATransaction.setAnimationTimingFunction(CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseOut))
// Layer animation
let myAnimation = CABasicAnimation(keyPath: "frame");
myAnimation.toValue = NSValue(cgRect: myNewFrame)
myAnimation.fromValue = NSValue(cgRect: myLayer.frame)
myLayer.frame = myNewFrame
myLayer.add(myAnimation, forKey: "someKeyForMyAnimation")
// Outer animation
let outerAnimation = CABasicAnimation(keyPath: "frame")
outerAnimation.toValue = NSValue(cgRect: myNewOuterFrame)
outerAnimation.fromValue = NSValue(cgRect: outerView.frame)
outerView.layer.frame = myNewOuterFrame
outerView.layer.add(outerAnimation, forKey: "someKeyForMyOuterAnimation")
CATransaction.commit()
Related
I have a UIView. I applied the animation to its CALayer.
[view.layer addAnimation:groupAnimation forKey:name];
I want the final state of the layer to be the state of the UIView after the animation. Let's say I rotated by 45degrees and moved to a new position using the layer; is it possible for my view to be in that state after the animation? Because right now, after the animation, it goes back to the original state of the UIView. I hope to receive some help with this. Thanks.
The thing to understand is that layer animation is just animation; it's merely a kind of temporary "movie" covering the screen. When the animation ends, the "movie" is removed, thus revealing the true situation. It is up to you to match that situation with the final frame of the movie.
UIView animation does this for you, to a great extent. But layer animation leaves it entirely up to you.
Thus, let's say you animate a position change; doing something so that the layer or view actually is where you animated to is completely up to you.
The usual thing is to perform the changes yourself as a separate set of commands. But be careful not to do anything that might trigger implicit layer animation, as this will conflict with the animation you are trying to perform explicitly.
Here's example code (not related to yours, but it does show the general form):
CAAnimationGroup* group = // ...
// ... configure the animation ...
[view.layer addAnimation:group forKey:nil];
// now we are ready to set up the view to look like the final "frame" of the animation
[CATransaction setDisableActions:YES]; // do not trigger implicit animation by mistake
view.layer.position = finalPosition; // assume we have worked this out
When animating a CALayer or using a CAAnimationGroup, the following properties must be set, e.g.:
groupAnimation.removedOnCompletion = NO;
groupAnimation.fillMode = kCAFillModeForwards;
See also: After Animation, View position resets
Also note that it may be helpful to apply animations directly to the view itself, rather than by accessing the view's layer. This is accomplished using animation blocks, which I have found to be very useful.
Block style animations can be customized in many ways, but here's a basic example, which could be invoked within a function when your view needs to animate:
- (void) animateMyView
{
CGRect newViewFrame = CGRectMake(x,y,w,h);
[UIView animateWithDuration:0.5
delay:0
options: (UIViewAnimationOptionCurveLinear )
animations:^{
self.myView = CGAffineTransformMakeRotation (45);
[self.myView setBounds:newViewFrame];
}
completion:NULL];
}
For more information, see Apple's documentation on View Animation.
I have a NSTextField as a label, showing a string.
I want to animate this label from right to left, if the content of it is too large to be displayed at once.
I've done this with an NSTimer so far, it works, but it's just not a very good solution.
The labels are displayed in an NSTextFieldCell, in a Table View.
They often get out of sync, and I guess it's just eating up a lot of CPU/GPU resources.
Is there another way with Core Animation to do this?
I have tried it with layers, as you can see right here:
CALayer and drawRect
but I didn't get it working either.
I would really appreciate your help.
You can simply animate the position of NSTextField with animator like
[[textField animator] setFrameOrigin:NSMakePoint(x,y)];
you can also embed it in "CATrancation" code like this:
[CATransaction begin];
[CATransaction setAnimationDuration:0.5];
[CATransaction setAnimationTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut]];
[[textField animator] setFrameOrigin:NSMakePoint(x,y)];
[CATransaction commit];
if you need animation delegate, you can use CABasicAnimation
CABasicAnimation* animation = [CABasicAnimation animation];
animation.delegate = self;
NSDictionary *animations = [NSDictionary dictionaryWithObjectsAndKeys:animation,#"frameOrigin",nil];
[textField setAnimations:animations];
[[textField animator] setFrameOrigin:NSMakePoint(x,y)];
Delegate methods are
- (void)animationDidStart:(CAAnimation *)theAnimation;
- (void)animationDidStop:(CAAnimation *)theAnimation finished:(BOOL)flag;
If you need to mask your text field, just embed it in other NSView.
First, animate the label using one of the functions offered in the other answers.
Then, if you want to display another view on the sides without overlapping, you can:
Insert the label in a subview with the limits you wish
Use bringSubviewtoFront: or sendSubviewToBack: to make sure your label stays in the back
I've created my own transition animation between views. I animate two properties, the position and the transform, to provide a cube-like transition between views. The frame uses CABasicAnimation while the transform uses a "2-stage" CAKeyframeAnimation. Everything works fine except for one small detail I can't seem to figure out. In my transition I apply a CATransform3DScale on the middle key frame to create a zoom-in/zoom-out effect. That works fine except the animation looks slightly jerky. It's animating the between the key frames in a linear fashion, and I would like to smooth that out. Now CAKeyframeAnimation has a way to do that using calculationMode, but it doesn't seem to work for transforms. I've tried setting it to kCAAnimationCubic and kCAAnimationCubicPaced with no effect.
Here is the code that animates one view's transform (a similar block of code animates the other view):
CAKeyframeAnimation *aTransform = [CAKeyframeAnimation animationWithKeyPath:#"transform"];
CATransform3D transform1 = RotateOnX(toView, M_PI_4);
transform1 = CATransform3DScale(transform1, RotationalZoom, RotationalZoom, RotationalZoom);
[aTransform setValues:Array([NSValue valueWithCATransform3D:RotateOnX(toView, M_PI_2)],
[NSValue valueWithCATransform3D:transform1],
[NSValue valueWithCATransform3D:RotateOnX(toView, 0)])];
[toView.layer addAnimation:aTransform forKey:#"transform"];
Note: RotateOnX(UIView *, CGFloat) is a block that returns a transform for a view rotated on X by the desired Radians.
As you can see I only set a scaling transform on the middle key frame. Also, the rotation of the view is perfectly smooth, it's only the scaling that appears to 'jerk' as it changes direction.
Does anyone have any ideas on how to smooth out the scaling/zooming?
Try the timingFunctions property. Since you have 3 keyframes, you need 2 timing functions: one for the animation from keyframe 0 to keyframe 1, and another for the animation from keyframe 1 to keyframe 2.
aTransform.timingFunctions = [NSArray arrayWithObjects:
[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInOut],
[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInOut],
nil];
I have a method in which a bunch of layers are positioned, and a single "activated" layer (basically a layer that the user has clicked on) is both positioned and resized at the same time. All the layers, including the activated layer are sublayers of a larger layer. Here is my method:
[CATransaction begin];
[CATransaction setValue:[NSNumber numberWithFloat:0.7]
forKey:kCATransactionAnimationDuration];
}];
for (CALayer *layer in self.inactiveLayers) {
... do some positioning ...
}
CGRect newFrame = activeLayer.frame;
newFrame.origin.x = 50.0;
newFrame.origin.y = 50.0;
newFrame.size.width = 100.0;
newFrame.size.height = 100.0;
activeLayer.frame = newFrame;
[CATransaction commit];
The problem I'm experiencing is really weird. Using the code above, none of the animations run (not even the animations for the inactive layers). But as soon as I comment out the lines that set the size and width of the new frame, the animations magically start working again.
Is there any reason this should be happening?
Figured out the problem, I had a layout manager set on the superlayer of the layers I was trying to animate, and the layout code (which reset the sizes of the layers) was being called when the layer bounds changed. Disabling the layout manager for the duration of the animation solved the issue.
It is because the frame property of a CAlayer is not animatable. Use the bounds property instead and the position animation will run without a hitch.
I have two circles which move around the screen. The circles are both UIViews which contain other UIViews. The area outside each circle is transparent.
I have written a function to create a CGPath which connects the two circles with a quadrilateral shape. I fill this path in a transparent CALayer which spans the entire screen. Since the layer is behind the two circular UIViews, it appears to connect them.
Finally, the two UIViews are animated using Core Animation. The position and size of both circles change during this animation.
So far the only method that I have had any success with is to interrupt the animation at regular intervals using an NSTimer, then recompute and draw the beam based on the location of the circle's presentationLayer. However, the quadrilateral lags behind the circles when the animation speeds up.
Is there a better way to accomplish this using Core Animation? Or should I avoid Core Animation and implement my own animation using an NSTimer?
I faced a similar problem. I used layers instead of views for the animation. You could try something like this.
Draw each element as a CALayer and include them as sublayers for your container UIVIew's layer. UIViews are easier to animate, but you will have less control. Notice that for any view you can get it's layer with [view layer];
Create a custom sublayer for your quadrilateral. This layer should have a property or several of properties you want to animate for this layer. Let's call this property "customprop". Because it is a custom layer, you want to redraw on each frame of the animation. For the properties you plan to animate, your custom layer class should return YES needsDisplayForKey:. That way you ensure -(void)drawInContext:(CGContextRef)theContext gets called on every frame.
Put all animations (both circles and the quad) in the same transaction;
For the circles you can probably use CALayers and set the content, if it is an image, the standard way:
layer.contents = [UIImage imageNamed:#"circle_image.png"].CGImage;
Now, for the quad layer, subclass CALayer and implement this way:
- (void)drawInContext:(CGContextRef)theContext{
//Custom draw code here
}
+ (BOOL)needsDisplayForKey:(NSString *)key{
if ([key isEqualToString:#"customprop"])
return YES;
return [super needsDisplayForKey:key];
}
The transaction would look like:
[CATransaction begin];
CABasicAnimation *theAnimation=[CABasicAnimation animationWithKeyPath:#"customprop"];
theAnimation.toValue = [NSValue valueWithCGPoint:CGPointMake(1000, 1000)];
theAnimation.duration=1.0;
theAnimation.repeatCount=4;
theAnimation.autoreverses=YES;
theAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
theAnimation.delegate = self;
[lay addAnimation:theAnimation forKey:#"selecting"];
[CATransaction setValue:[NSNumber numberWithFloat:10.0f]
forKey:kCATransactionAnimationDuration];
circ1.position=CGPointMake(1000, 1000);
circ2.position=CGPointMake(1000, 1000);
[CATransaction commit];
Now all the draw routines will happen at the same time. Make sure your drawInContext: implementation is fast. Otherwise the animation will lag.
After adding each sublayer to the UIViews's layer, rememeber to call [layer setNeedsDisplay]. It does not get called automatically.
I know this is a bit complicated. However, the resulting animations are better than using a NSTimer and redrawing on each call.
If you need to find the current visible state of the layers, you can call -presentationLayer on the CALayer in question, and this will give you a layer that approximates the one used for rendering. Note I said approximates - it's not guaranteed to be fully accurate. However it may be good enough for your purposes.