I need to move object (UIImageView) from point A to point B, then rotate image at point B by 180 degrees to face the opposite direction and move object from B to A (backwards).
I have the code below which moves from A to B. I also know how to rotate UIImageView. But how to know when object has reached point B and how to apply rotation action considering there are many objects on the screen?
CAKeyframeAnimation *pathAnimation = [CAKeyframeAnimation animationWithKeyPath:#"position"];
pathAnimation.duration = speed;
pathAnimation.calculationMode = kCAAnimationPaced;
pathAnimation.fillMode = kCAFillModeForwards;
pathAnimation.removedOnCompletion = NO;
CGMutablePathRef pointPath = CGPathCreateMutable();
CGPathMoveToPoint(pointPath, NULL, rect.origin.x, rect.origin.y);
CGPathAddLineToPoint(pointPath, NULL, x, y);
pathAnimation.path = pointPath;
CGPathRelease(pointPath);
[imageView.layer addAnimation:pathAnimation forKey:[NSString stringWithFormat:#"pathAnimation%#",objId]];
[imageView release];
Set a delegate on the CAAnimation object, and in the delegate implement the animationDidStop:finished: method.
OTOH, the animation you described sounds like it could be done easily enough with UIView's animation support. See Animating Views with Blocks if you're targeting 4.0 and up, or Animating Views if you're still targeting earlier versions.
You can use the CAAnimation delegate method
-(void)animationDidStop:(CAAnimation *)theAnimation finished:(BOOL)flag
Related
I am developing a small game in iphone... Game concept is place an object in top of the bar...Rotating a bar using accelerometer. When bar rotating , i need to move an object with respect to bar. How to implement this concept...Any examples or references?
Rotating both img:
barImg,objImg //UIImageView
barImg.transform = CGAffineTransformMakeRotation(Ypos);
objImg.transform=CGAffineTransformMakeRotation(Ypos);
So for rotating 360 Degree with animation:
CABasicAnimation *rotationAnimation;
rotationAnimation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.z"];
rotationAnimation.toValue = [NSNumber numberWithFloat:-M_PI * 2.0]; // full rotation*/ * rotations * duration ];
rotationAnimation.duration = 1;
rotationAnimation.cumulative = YES;
rotationAnimation.repeatCount = MAXFLOAT;
[rotatingTelIamgeview.layer addAnimation:rotationAnimation forKey:#"rotationAnimation"];
you can play with toValue for changing the angle.
For moving an object:
CGPoint startPoint = CGPointMake(lvMessageInputBar.animationBubbleImageView.layer.frame.origin.x+lvMessageInputBar.animationBubbleImageView.layer.frame.size.width/2
, lvMessageInputBar.animationBubbleImageView.layer.frame.origin.y +lvMessageInputBar.animationBubbleImageView.layer.frame.size.height/2 );
CGPoint endPoint = CGPointMake(endPoint.origin.x+Endpoint.size.width/2, bubleRect.origin.y+bubleRect.size.height/2);
CGPoint middlePoint = // any point between start and end corrdinates
CGMutablePathRef path = CGPathCreateMutable();
CGPathMoveToPoint(path, NULL, startPoint.x, startPoint.y);
CGPathAddQuadCurveToPoint(path, NULL,middlePoint.x, middlePoint.y,endPoint.x,endPoint.y);
CAKeyframeAnimation *pathAnimation = [CAKeyframeAnimation animationWithKeyPath:#"position"];
pathAnimation.delegate = self;
pathAnimation.removedOnCompletion = NO;
pathAnimation.path = path;
[pathAnimation setCalculationMode:kCAAnimationCubic];
[pathAnimation setFillMode:kCAFillModeForwards];
pathAnimation.duration = 0.3;
[lvMessageInputBar.animationBubbleImageView.layer addAnimation:pathAnimation forKey:nil];
The above example moves the layer of the object over a path.but CGPathAddQuadCurveToPoint makes the path not diagonal rather circular path (curve).
you can use CGPathAddPath if you do not want this effect.
If you are new to iPhone I would start with layer tutorial to get the idea behind CALayer and then take a look CALayer animations
CALayers introduction:
https://www.raywenderlich.com/3096-calayers-tutorial-for-ios-introduction-to-calayers
CALayer Animation documentation of from Apple:
https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/CoreAnimation_guide/Introduction/Introduction.html
You can also watch Session 424 (Core Animation in Practice, Part 1) and 425 (Core Animation in Practice, Part 2) of WWDC 2010:
https://developer.apple.com/videos/archive/
I move my UIImageView with layer around the screen. When at some point I'm trying to retrieve x and y coordinates of a moved imageView using imageView.frame.origin.x I receive original coordinates not the new ones after the move. How to get X and Y correctly?
Here is my code:
UIImageView *imageView = [[UIImageView alloc] initWithFrame:rect];
imageView.animationImages = [NSArray arrayWithArray:imgNameArr];
imageView.animationDuration = 2;
imageView.animationRepeatCount = 0;
[imageView startAnimating];
[self.view addSubview:imageView];
CAKeyframeAnimation *pathAnimation = [CAKeyframeAnimation animationWithKeyPath:#"position"];
pathAnimation.duration = speed;
pathAnimation.calculationMode = kCAAnimationPaced;
pathAnimation.fillMode = kCAFillModeForwards;
pathAnimation.removedOnCompletion = NO;
CGMutablePathRef pointPath = CGPathCreateMutable();
CGPathMoveToPoint(pointPath, NULL, rect.origin.x, rect.origin.y);
CGPathAddLineToPoint(pointPath, NULL, x, y);
pathAnimation.path = pointPath;
CGPathRelease(pointPath);
[imageView.layer addAnimation:pathAnimation forKey:[NSString stringWithFormat:#"pathAnimation%#",objId]];
[imageView release];
Per the UIView documentation for the frame property:
Warning: If the transform property is not the identity transform, the
value of this property is undefined and therefore should be ignored.
The frame property also becomes undefined if you adjust that view's layer's transform or affineTransform properties (which are actually what the UIView alters when you set its transform). In Cocoa Touch transforms are applied at the time of compositing by the compositor. At present what you seem to get when a transform is applied is the original frame as though there were no transform, but as the docs say it's undefined so don't rely on that.
If you're just moving the view around with no other transformation, I recommend you use the view's center property rather than applying a transform. That will update your frame correctly. Based on empirical evidence, UIKit also seems smart enough that just adjusting the centre doesn't have any performance downside compared to applying a transform.
I want to crossfade between two different UIImages but for a reason i cannot figure out my first UIImage stays when the second one fades in.
Here is the sourcecode of my animation (it does a lot more than just crossfading, but the crossfading is my only problem right now).
I need all of the three animations listed below to be executed at the same time.
CGMutablePathRef thePath = CGPathCreateMutable();
CGPathMoveToPoint(thePath,NULL,startPoint.x, startPoint.y);
CGPathAddLineToPoint(thePath, NULL, endPoint.x, endPoint.y);
CAKeyframeAnimation *positionAnimation =[CAKeyframeAnimation animationWithKeyPath:#"position"];
positionAnimation.path=thePath;
positionAnimation.duration=ti_duration;
positionAnimation.repeatCount=0;
positionAnimation.delegate = self;
positionAnimation.autoreverses=NO;
positionAnimation.fillMode=kCAFillModeForwards;
positionAnimation.removedOnCompletion = NO;
[self.layer addAnimation:positionAnimation forKey:s_direction];
CABasicAnimation *crossFade = [CABasicAnimation animationWithKeyPath:#"contents"];
crossFade.duration = ti_duration;
crossFade.fromValue = (id)img_startImage.CGImage;
crossFade.toValue = (id)img_transferImage.CGImage;
[self.iv_image.layer addAnimation:crossFade forKey:#"animateContentsToTransferState"];
[self.iv_image setImage:img_transferImage];
CAAnimationGroup *theGroup = [CAAnimationGroup animation];
theGroup.duration = ti_duration;
theGroup.repeatCount = 0;
theGroup.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
theGroup.animations = [NSArray arrayWithObjects:/*positionAnimation,*/ crossFade, nil]; // you can add more
[self.layer addAnimation:theGroup forKey:#"move"];
[UIView beginAnimations:#"changeSize" context:nil];
[UIView setAnimationDuration:duration];
self.bounds = CGRectMake(self.bounds.origin.x, self.bounds.origin.y, self.transferSize.width, self.transferSize.height);
[UIView commitAnimations];
The animation method containing this sourcecode is in a subclass of UIView. This subclass contains several UIImages and one UIImageView where the image to be displayed is contained in.
Have i forgotten some essential thing or why is my first image not fading away?
Can it be because it is animated from some other animation at the same time?
I hope someone can help me with this.
Greets
Maverick
Think of CAAnimations as operations applied to the CALayer. The animations current state do not change the layers original contents.
When the original state seems to snap back at the end of the animation it is actually just the animations operation being removed, and the real layers state is being revealed again.
What you need to do is to register a delegate for your animation, and change the actual self.layer.contents when the animation ends.
First:
crossFade.delegate = self;
Then implement:
- (void)animationDidStop:(CABasicAnimation *)animation finished:(BOOL)flag {
self.layer.contents = animation.toValue;
}
Try this code...It worked for me.
-(void)crossFadeImage{
CABasicAnimation *crossFade = [CABasicAnimation animationWithKeyPath:#"contents"];
crossFade.duration = 2.0;
crossFade.fromValue = img1.CGImage;
crossFade.toValue = img2.CGImage;
[self.background.layer addAnimation:crossFade forKey:#"animateContents"];
self.background.image = img2;
}
I need to make my little guy (in a UIIamgeView) jump forward and it has to look natural. I want to know is there a way to do it with CoreAnimation (beginAnimation/commitAnimation)?
I could do it by setting a point in between in the air but the movement looks not natural :P
Reading Brad Larson's post, I ended up with a nice function to make my image follow a circle.
You need to import QuartzCore framework: #import
Here is the code:
// Set up path movement
CAKeyframeAnimation *pathAnimation = [CAKeyframeAnimation animationWithKeyPath:#"position"];
pathAnimation.calculationMode = kCAAnimationPaced;
pathAnimation.fillMode = kCAFillModeForwards;
pathAnimation.removedOnCompletion = NO;
pathAnimation.repeatCount = INFINITY;
//pathAnimation.rotationMode = #"auto";
pathAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
pathAnimation.duration = 5.0;
// Create a circle path
CGMutablePathRef curvedPath = CGPathCreateMutable();
CGRect circleContainer = CGRectMake(0, 0, 400, 400); // create a circle from this square, it could be the frame of an UIView
CGPathAddEllipseInRect(curvedPath, NULL, circleContainer);
pathAnimation.path = curvedPath;
CGPathRelease(curvedPath);
[self.imageView.layer addAnimation:pathAnimation forKey:#"myCircleAnimation"];
Create a CAKeyframeAnimation and assign a CGPath to its path property.
To follow up on Ole's answer, my answer to this question provides code to perform such a curved animation using a CAKeyframeAnimation.
I'm using a CAKeyframeAnimation to animate a view along a CGPath. When the animation is done, I'd like to be able to call some other method to perform another action. Is there a good way to do this?
I've looked at using UIView's setAnimationDidStopSelector:, however from the docs this looks like it only applies when used within a UIView animation block (beginAnimations and commitAnimations). I also gave it a try just in case, but it doesn't seem to work.
Here's some sample code (this is within a custom UIView sub-class method):
// These have no effect since they're not in a UIView Animation Block
[UIView setAnimationDelegate:self];
[UIView setAnimationDidStopSelector:#selector(animationDidStop:finished:context:)];
// Set up path movement
CAKeyframeAnimation *pathAnimation = [CAKeyframeAnimation animationWithKeyPath:#"path"];
pathAnimation.calculationMode = kCAAnimationPaced;
pathAnimation.fillMode = kCAFillModeForwards;
pathAnimation.removedOnCompletion = NO;
pathAnimation.duration = 1.0f;
CGMutablePathRef path = CGPathCreateMutable();
CGPathMoveToPoint(path, NULL, self.center.x, self.center.y);
// add all points to the path
for (NSValue* value in myPoints) {
CGPoint nextPoint = [value CGPointValue];
CGPathAddLineToPoint(path, NULL, nextPoint.x, nextPoint.y);
}
pathAnimation.path = path;
CGPathRelease(path);
[self.layer addAnimation:pathAnimation forKey:#"pathAnimation"];
A workaround I was considering that should work, but doesn't seem like the best way, is to use NSObject's performSelector:withObject:afterDelay:. As long as I set the delay equal to the duration of the animation, then it should be fine.
Is there a better way? Thanks!
Or you can enclose your animation with:
[CATransaction begin];
[CATransaction setCompletionBlock:^{
/* what to do next */
}];
/* your animation code */
[CATransaction commit];
And set the completion block to handle what you need to do.
CAKeyframeAnimation is a subclass of CAAnimation. There is a delegate property in CAAnimation. The delegate can implement the -animationDidStop:finished: method. The rest should be easy.
Swift 3 syntax for this answer.
CATransaction.begin()
CATransaction.setCompletionBlock {
//Actions to be done after animation
}
//Animation Code
CATransaction.commit()