core-animation

问题 I am trying to animate a custom property on a CALayer with an implicit animation: [UIView animateWithDuration:2.0f animations:^{ self.imageView.myLayer.myProperty = 1; }]; In -actionForKey: method I need to return the animation taking care of interpolating the values. Of course I have to tell somehow the animation how to retrieve the other parameters for the animation (i.e. the duration and the timing function ). - (id<CAAction>)actionForKey:(NSString *)event { if ([event isEqualToString:@

问题 I have some CGPath (a poly with two circle) carried out on a CAShapeLayer . Can I trim/subtract paths like this? 回答1: Instead of do the math, the result can be achieved at drawing time using kCGBlendModeClear . // Create the poly. CGContextBeginPath(context); CGContextMoveToPoint (context, a_.x, a_.y); CGContextAddLineToPoint (context, b_.x, b_.y); CGContextAddLineToPoint (context, c_.x, c_.y); CGContextAddLineToPoint (context, d_.x, d_.y); CGContextClosePath(context); // Draw with the

问题 Here I found how to animate UIButton 's title change using now-deprecated beginAnimations:context: method: UIBUtton title animation for iPhone How to do the same thing using current APIs? Update: I've tried to use block-based animations: NSTimeInterval animationDuration = animated ? 1.f : 0.f; [UIView animateWithDuration:animationDuration delay:0.f options:UIViewAnimationOptionBeginFromCurrentState | UIViewAnimationOptionAllowUserInteraction animations:^{ [button setTitle:newTitle forState

问题 Here I found how to animate UIButton 's title change using now-deprecated beginAnimations:context: method: UIBUtton title animation for iPhone How to do the same thing using current APIs? Update: I've tried to use block-based animations: NSTimeInterval animationDuration = animated ? 1.f : 0.f; [UIView animateWithDuration:animationDuration delay:0.f options:UIViewAnimationOptionBeginFromCurrentState | UIViewAnimationOptionAllowUserInteraction animations:^{ [button setTitle:newTitle forState

问题 I would like to create a masking effect over a UIView in order to accomplish the following. I will display a sealed box in the screen and the user will be able to touch (scratch) the screen in order to reveal whats behind that image(UIView). Something similar to those lottery tickets where u r suppose to scratch some cover material thats on top of the results.. If someone could point me in the right direction would be awesome, I'm not sure how to start doing this... thanks 回答1: Sorry I'm late

问题 I have a UIImageView which i want to rotate 180 degrees, taking up 1 second, then i want to wait 1 second at this position, then rotate 180 degrees back to the original position taking up 1 second. How do i accomplish this? I've tried a 100 approaches and it keeps snapping back instead of rotating back EDIT: I forgot to add i need this to repeat indefinitely 回答1: You can perform the second animation in the completionHandler presented on UIView.animate let duration = self.transitionDuration

问题 Is there a way to control the brightness of the OS X desktop programmatically using Cocoa or Core Animation? 回答1: In case you were actually interested in doing a fade-out or fade-in of the whole screen, here is a link describing how to do that. The linked document contains examples for how to fade all displays (or a single display) to black (you can change the color), capture the display (where you can display what you'd like), and then fade back. This uses CGAcquireDisplayFadeReservation()

问题 I am trying to animate the drawing of a UIBeizerPath (in my example a triangle) in a UIView subclass. However, the entire subview is animating instead of the shape. Is there something I am missing with the animation? - (void)drawRect:(CGRect)rect { CAShapeLayer *drawLayer = [CAShapeLayer layer]; drawLayer.frame = CGRectMake(0, 0, 100, 100); drawLayer.strokeColor = [UIColor greenColor].CGColor; drawLayer.lineWidth = 4.0; [self.layer addSublayer:drawLayer]; UIBezierPath *path = [UIBezierPath

问题 I want to perform an infinite 360 degrees rotation animation, so I coded: - (void)rotate { __weak typeof(self) weakSelf = self; [CATransaction begin]; [CATransaction setDisableActions:NO]; [CATransaction setCompletionBlock:^{ [weakSelf rotate]; }]; [CATransaction setAnimationDuration:1.0]; [CATransaction setAnimationTimingFunction: [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]]; self.squareLayer.transform = CATransform3DRotate(self.squareLayer.transform, M_PI, 0

问题 How to shift shape (from oval to rect and vice versa) animated? Dirty code: UIBezierPath *roundedRectBezierPath = [UIBezierPath bezierPathWithRoundedRect:newRect cornerRadius:10]; UIBezierPath *ovalBezierPath = [UIBezierPath bezierPathWithOvalInRect:newRect]; CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"path"]; animation.duration = 3; animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]; if (isRect) { self.shapeLayer