I am trying to create a simple animation with CABasicAnimation that will always hold a constant speed, even if the distance the animation must travel is never the same. Here is my code so far, it is scrolling a label that will always vary in size, but cannot yet hold a constant speed. Help is much appreciated.
CABasicAnimation *theAnimation;
theAnimation = [CABasicAnimation animationWithKeyPath:#"transform.translation.x"];
theAnimation.speed = 1.0f;
NSNumber *fromValue = [NSNumber numberWithFloat:self.mainLabel.frame.origin.x];
NSNumber *toValue = [NSNumber numberWithFloat:-self.mainLabel.frame.size.width - self.view.frame.size.height];
theAnimation.fromValue = fromValue;
theAnimation.toValue = toValue;
//theAnimation.duration = toValue.floatValue - fromValue.floatValue;//Not right.
theAnimation.repeatCount = 999;
theAnimation.autoreverses = NO;
[mainLabel.layer addAnimation:theAnimation forKey:#"animateLayer"];
Did you try add:
theAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
in example after
theAnimation.speed = 1.0f;
?
This function set linear sped of animation.
Related
In this code i am using animation.But at a time i need to change the image alpha value also.
-(void)animation
{
CGPoint point = CGPointMake(imgView.frame.origin.x, imgView.frame.origin.y);
imgView.layer.position = point;
CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:#"position.x"];
anim.fromValue = [NSValue valueWithCGPoint:point];
anim.toValue = [NSValue valueWithCGPoint:CGPointMake(point.x + 50, point.y)];
anim.duration = 10.0f;
anim.repeatCount =1;
anim.removedOnCompletion = YES;
anim.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
[imgView.layer addAnimation:anim forKey:#"position.x"];
imgView.layer.position = point;
}
You can use the opacity key of CABasicAnimation for doing this:
CABasicAnimation *alphaAnimation = [CABasicAnimation animationWithKeyPath:#"opacity"];
alphaAnimation.fromValue = [NSNumber numberWithFloat:1.0];
alphaAnimation.toValue = [NSNumber numberWithFloat:0.0];
[imgView.layer addAnimation:alphaAnimation forKey:#"opacity"];
Edit:
For animating through specified values you can use CAKeyframeAnimation:
CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:#"opacity"];
animation.duration = 10.0f;
animation.repeatCount = 1;
animation.values = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:1.0,
[NSNumber numberWithFloat:0.5],
[NSNumber numberWithFloat:1.0],nil];
animation.keyTimes = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:0.0],
[NSNumber numberWithFloat:5.0],
[NSNumber numberWithFloat:10.0], nil];
[imgView.layer addAnimation:animation forKey:#"opacity"];
In order to decrease the alpha as the same time/rate the x position of your view is moving, just put the position setting code together with the alpha setting code in the same block of animation, like below:
CGPoint finalPoint = CGPointMake(500, imgView.center.y); //change for any final point you want
CGFloat finalAlpha = 0.0; //change the final alpha as you want
UIView animateWithDuration:1.0 animations:^{ //change the duration as you want
imgView.alpha = finalAlpha;
imgView.center = finalPoint;
}];
This "fades to invisible" self.view in 500ms.
Anything you do prior to invoking it will be set "immediately", everything you set within the `animation' block (like setting new frame coordinates) will be interpolated over the specified duration.
[UIView animateWithDuration:0.50
delay:0.0
options:( UIViewAnimationOptionAllowUserInteraction
| UIViewAnimationOptionBeginFromCurrentState
| UIViewAnimationOptionCurveEaseInOut)
animations:^ {
self.view.alpha = 0.0f ;
}
completion: ^(BOOL){
[self.view removeFromSuperview] ;
self.view = nil ;
}
] ;
You may use a CABasicAnimation object (a different one because you will animate a different KeyPath, namely alpha, for this) and use NSNumbers for fromValue and toValue.
Another (and easiest) way is to use the UIView helper methods dedicated to animation ( animateWithDuration:… and all), especially if you have to animate multiple properties at the same time (you may animate both the frame and the alpha with the same animation block if it fits your needs and simplify your code).
You can also mix CABasicAnimation for the frame and [UIView animateWithDuration:…] for the alpha, whatever combination you need depending on if your animations are complex and need to be customized (custom timing function, non-linear animation, …) or not.
//your code of changing x position will be here
now implement my code which is written below.
UIView animateWithDuration:1.0 animations:^{
imgView.alpha = 0.5;//must be in between 0 to 1
}];
now when your imageview move to next position as you are saying, write below code
//your code for imageview for next position..
now implement below code...
UIView animateWithDuration:0.5 animations:^{
imgView.alpha = 1.0;//must be in between 0 to 1
}];
let me know it is working or not!!!! Hope it helps...
Happy Coding!!!
I have this simple animation that moves an image from one point to another:
CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:#"position"];
anim.fromValue = [NSValue valueWithCGPoint:CGPointMake(px2.x, px2.y)];
anim.toValue = [NSValue valueWithCGPoint:CGPointMake(P3x, P3y)];
anim.duration = 1.5f;
anim.repeatCount =1;
anim.removedOnCompletion = YES;
anim.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
[LA addAnimation:anim forKey:#"positionTest"];
The problem is that the image becomes blurry while in motion, the motion is not very fast.
Is there a way to reduce this motion blur?
If you take a screenshot during the animation is it definitely blurred? Also is the blurring a pixellated blur or is it more like a soft gaussian blur?
Try setting view.layer.shouldRasterize = yes and layer.rasterizationScale = UIScreen.mainScreen.scale;
I'm using following code to animate a view. It basically rotates the view by 225 degrees angle.
[viewToOpen.layer removeAllAnimations];
viewToOpen.hidden = NO;
viewToOpen.userInteractionEnabled = NO;
if (viewToOpen.layer.anchorPoint.x != 0.0f) {
viewToOpen.layer.anchorPoint = CGPointMake(0.0f, 0.5f);
viewToOpen.center = CGPointMake(viewToOpen.center.x - viewToOpen.bounds.size.width/2.0f, viewToOpen.center.y);
}
CABasicAnimation *transformAnimation = [CABasicAnimation animationWithKeyPath:#"transform"];
transformAnimation.removedOnCompletion = NO;
transformAnimation.duration = duration;
transformAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
CATransform3D endTransform = CATransform3DMakeAffineTransform(CGAffineTransformMakeRotation(225));
transformAnimation.toValue = [NSValue valueWithCATransform3D:endTransform];
CAAnimationGroup *theGroup = [CAAnimationGroup animation];
theGroup.delegate = self;
theGroup.duration = duration;
[theGroup setValue:[NSNumber numberWithInt:viewToOpen.tag] forKey:#"viewToOpenTag"];
theGroup.animations = [NSArray arrayWithObjects:transformAnimation, nil];
theGroup.removedOnCompletion = NO;
[viewToOpen.layer addAnimation:theGroup forKey:#"flipViewOpen"];
But the problem is that, at the end of animation, the view is coming back to original position. I would like to keep the view in same position even after animation completes. How can I do it?
I believe you're experiencing the same issue as can be seen in this question and this one. You either need to set fillMode to kCAFillModeForwards or set the transform of the layer when the animation has been completed.
I am rotating a view with this:
CGAffineTransform rotatedTransform = CGAffineTransformRotate(CGAffineTransformIdentity, rotationValue);
I have an object which I want to spin around for about 320 degrees. Now Core Animation is clever and just rotates it as much as needed, doing that by rotating it with -40 degrees. So the object rotates the other way around with a shorter amount of movement.
I want to constrain it to rotate clockwise. Would I have to do that by changing animations in little steps, or is there an more elegant way?
The following snippet rotates a view called someView by using key-framed animation. The animation consists of 3 frames spread over 1 second, with the view rotated to 0º, 180º and 360º in the first, second and last frames respectively. Code follows:
CALayer* layer = someView.layer;
CAKeyframeAnimation* animation;
animation = [CAKeyframeAnimation animationWithKeyPath:#"transform.rotation.z"];
animation.duration = 1.0;
animation.cumulative = YES;
animation.repeatCount = 1;
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;
animation.values = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:0.0 * M_PI],
[NSNumber numberWithFloat:0.5 * M_PI],
[NSNumber numberWithFloat:1.0 * M_PI], nil];
animation.keyTimes = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:0.0],
[NSNumber numberWithFloat:0.5],
[NSNumber numberWithFloat:1.0], nil];
animation.timingFunctions = [NSArray arrayWithObjects:
[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear],
[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear], nil];
[layer addAnimation:animation forKey:#"transform.rotation.z"];
If you're after counterclockwise animation, you should use negative values. For a slightly more basic animation, you can use CABasicAnimation:
CALayer* layer = someView.layer;
CABasicAnimation* animation;
animation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.z"];
animation.fromValue = [NSNumber numberWithFloat:0.0 * M_PI];
animation.toValue = [NSNumber numberWithFloat:1.0 * M_PI];
animation.duration = 1.0;
animation.cumulative = YES;
animation.repeatCount = 1;
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;
[layer addAnimation:rotationAnimation forKey:#"transform.rotation.z"];
I believe you have to give it another "key frame" if you will to give Core Animation the hint that it needs to go that direction.
Make sure and turn off easing, (at least for the end/beginning of the middle step) otherwise the animation will not look smooth.
How can we Move an Image 360 Degree from the starting point to the ending point?
Moving Image 360 Degree?
You can rotate a view, by some number of radians, regardless of whether it is less than a full rotation or many multiples of a full rotation, without having to split the rotation into pieces. As an example, the following code will spin a view, once per second, for a specified number of seconds. You can easily modify it to spin a view by a certain number of rotations, or by some number of radians.
- (void) runSpinAnimationWithDuration:(CGFloat) duration;
{
CABasicAnimation* rotationAnimation;
rotationAnimation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.z"];
rotationAnimation.toValue = [NSNumber numberWithFloat: M_PI * 2.0 /* full rotation*/ * rotations * duration ];
rotationAnimation.duration = duration;
rotationAnimation.cumulative = YES;
rotationAnimation.repeatCount = 1.0;
rotationAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
[myView.layer addAnimation:rotationAnimation forKey:#"rotationAnimation"];
}
A 360 degree rotation in any axis leaves the view unchanged. So don't touch the image, and you're good to go!
You could use an animation function (CAValueFunction) for this too:
CABasicAnimation *rotationAnimation = [CABasicAnimation animationWithKeyPath:#"transform"];
rotationAnimation.duration = duration;
rotationAnimation.fromValue = [NSNumber numberWithFloat:0.0];
rotationAnimation.toValue = [NSNumber numberWithFloat:M_PI * 2.0];
rotationAnimation.valueFunction = [CAValueFunction functionWithName:kCAValueFunctionRotateZ];
rotationAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
[myView.layer addAnimation:rotationAnimation forKey:nil];