I am using CABasicanimation for rotate an UIView. I am using this code:
CABasicAnimation *rotationAnimation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.z"];
NSNumber *currentAngle = [CircleView.layer.presentationLayer valueForKeyPath:#"transform.rotation"];
rotationAnimation.fromValue = currentAngle;
rotationAnimation.toValue = #(50*M_PI);
rotationAnimation.duration = 50.0f; // this might be too fast
rotationAnimation.repeatCount = HUGE_VALF; // HUGE_VALF is defined in math.h so import it
[CircleView.layer addAnimation:rotationAnimation forKey:#"rotationAnimationleft"];
in this I want perfect X,Y position while "UIView" is rotating. How can I achieve this?
I Got A Answer Of This Question Please Go To This Link For Answer
Go to This Link For Answer
So, if I understand you correctly, you just want to get the X and Y coordinates of your view during rotation?
You can do this by logging the frame of the presentationLayer, like this:
- (IBAction)buttonAction:(UIButton *)sender {
CGRect position = [[CircleView.layer presentationLayer] frame];
NSLog(#"%#", NSStringFromCGRect(position));
}
Related
I want current position of animating UIView during animation and I am using this code.
CABasicAnimation * m_pAnimationObj = [CABasicAnimation animationWithKeyPath:#"transform.translation"];
[m_pAnimationObj setFromValue:[NSValue valueWithCGPoint:CGPointMake(0,-50)]];
[m_pAnimationObj setToValue:[NSValue valueWithCGPoint:CGPointMake(0,[UIScreen mainScreen].bounds.size.height+100)]];
m_pAnimationObj.duration = 2.0;
m_pAnimationObj.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
[DropImage.layer addAnimation:m_pAnimationObj forKey:#"animations"];
Please answer if anyone knows about this.
Thank you in advance!
Use this code:
CGRect currentCenter = [drawingView.layer.presentationLayer center];
or
CGRect currentFrame = [DropImage.layer.presentationLayer frame];
I have two images. first one is something like a transparent hole and should be static while the second one is scooter like image which needs to continuously scrolling horizontally that should give a effect of video.
Can anybody suggest me what to do to achieve the same.
Please check the code Infinity Scroll
You can animate X position of your image view like this:
CGPoint point0 = imView.layer.position;
CGPoint point1 = { NSIntegerMax, point0.y };
CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:#"position.x"];
anim.fromValue = #(point0.x);
anim.toValue = #(point1.x);
anim.duration = 1.5f;
anim.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
// First we update the model layer's property.
imView.layer.position = point1;
// Now we attach the animation.
[imView.layer addAnimation:anim forKey:#"position.x"];
For infinite scrolling, set your scrollview' contentSize correctly:
scrollView.contentSize = CGSizeMake(NSIntegerMax, kScreenHeight); // Deduce kScreenHeight based on device height
I need to rotate a UIView around a fixed point.
bubbleTail = [[BubbleTail alloc] initWithFrame:bubbleTailFrame];
[self addSubview:bubbleTail];
bubbleTail.layer.anchorPoint = triangle_top_left;
CGAffineTransform transform = CGAffineTransformMakeRotation(M_PI * 180 / 180.0);
bubbleTail.transform = transform;
This works only if I comment the .anchorPoint line.
How do I rotate the view about a point inside the view?
The below should help. The tricky part is that setting the anchorpoint after adding a view with a frame then moves the view. I've gotten around this by initiating the UIView without a frame, then setting the position, bounds and anchorpoint of its layer. I then use the rotation to rotate around the anchor point.
CABasicAnimation *rotation;
rotation = [CABasicAnimation animationWithKeyPath:#"transform.rotation"];
rotation.fromValue = [NSNumber numberWithFloat:0];
rotation.toValue = [NSNumber numberWithFloat:((360*M_PI)/180)];
rotation.duration = 60.0;
rotation.repeatCount = HUGE_VALF;
UIView *myview = [[UIView alloc] init];
[self.view addSubview:myview];
[myview setBackgroundColor:[UIColor orangeColor]];
[myview.layer setPosition:CGPointMake(10, 10)];
[myview.layer setBounds:CGRectMake(0, 0, 100, 100)];
[myview.layer setAnchorPoint:CGPointMake(0, 0)];
[myview.layer addAnimation:rotation forKey:#"myAnimation"];
Someone please correct me if this is not the best method or if there are mistakes - I only know what I currently know - e.g. when I should use a . or f after a float.
So it seems CGAffineTransformMakeRotation rotates it around the center of the view?
Say you have point P (px,py) in view, you want view to be rotated around that.
Let's A(ax,ay) = P - center = (px - centerx, py - centery).
And you have angle alpha.
Then you could make a translate matrix with - A, then multipy it with rotation matrix with alpha, then multipy it with translate matrix with + A.
The functions you'll need are: CGAffineTransformMakeTranslation, CGAffineTransformMakeRotation, CGAffineTransformConcat.
P.S. Not sure if this will work (also not sure how view rect is represented, maybe it first assumption about rotation around center is wrong, then you shoud assume A = P), but that's how it's done with affine transforms.
In my iphone app I have a UIButton that I rotate 180 degrees into view when another UIButton is pressed, then when clicked again the button rotates a further 180 degrees back to where it started.
This all works fine the very first time the complete 360 degree process occurs, but if I try to start from the start again it snaps 180 degrees then tries to rotate it from that point. Can anyone point me in the right direction? Here's my code so far...
showAnimation= [CAKeyframeAnimation animationWithKeyPath:#"transform.rotation"];
showAnimation.duration = self.showAnimationDuration;
showAnimation.repeatCount = 1;
showAnimation.fillMode = kCAFillModeForwards;
showAnimation.removedOnCompletion = NO;
showAnimation.cumulative = YES;
showAnimation.delegate = self;
float currentAngle =[[[rotateMe.layer presentationLayer] valueForKeyPath:#"transform.rotation.z"] floatValue];
//Rotate 180 degrees from current rotation
showAnimation.values = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:currentAngle],
[NSNumber numberWithFloat:currentAngle + (0.5 * M_PI)],
[NSNumber numberWithFloat:currentAngle + M_PI], nil];
[rotateMe.layer addAnimation:showAnimation forKey:#"show"];
On completion of the animation I then update the rotateMe.transform rotation to the layer's rotation so that it becomes usable.
- (void)animationDidStop:(CAKeyframeAnimation *)anim finished:(BOOL)flag
{
float currentAngle =[[[self.layer presentationLayer] valueForKeyPath:#"transform.rotation.z"] floatValue];
NSLog(#"End: %f", currentAngle);
rotateMe.transform = CGAffineTransformMakeRotation(0);
}
I have achieved the fully working effect with
[UIView animateWithDuration:1.0f]
animations:^{
CGAffineTransform transform = CGAffineTransformRotate(rotateMe.transform, DEGREES_TO_RADIANS(179.999f));
rotateMe.transform = transform;
}
];
But I'd like to make the animation more complex, hence the CAKeyframeAnimation.
You could configure the animation to be additive and animate from 0 to 180 degrees if you need all the key frames. If you don't need the different key frames the you can simply do it with a basic animation and the byValue property. The next time the animation is added it rotate 180 more degrees than whatever rotation is on the view.
If you are setting the actual value in the delegate callback then there is no need for fill mode and not removing the animation on completion.
CABasicAnimation *showAnimation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.z"];
showAnimation.byValue = M_PI;
showAnimation.duration = self.showAnimationDuration;
showAnimation.delegate = self;
[rotateMe.layer addAnimation:showAnimation forKey:#"show"];
or using a key frame animation (as explained above: make it additive and animate from 0 to 180 degrees).
CAKeyframeAnimation *showAnimation = [CAKeyframeAnimation animationWithKeyPath:#"transform.rotation.z"];
showAnimation.additive = YES; // Make the values relative to the current value
showAnimation.values = #[0, /*all your intermediate values here... ,*/ M_PI];
showAnimation.duration = self.showAnimationDuration;
showAnimation.delegate = self;
[rotateMe.layer addAnimation:showAnimation forKey:#"show"];
I'm trying to rotate some UIView around its center, so the simple code goes something like
(in pseudocode):
[UIView beginAnimations:#"crazyRotate" context:nil];
[UIView setAnimationDuration:1.0];
someview.transform = CGAffineTransformMakeRotation(angle);
[UIView commitAnimations]
now if I set angle to say M_PI/2 the thing rotates nicely.
if I set it to 2*M_PI, well it does "nothing". I can understand that the matrix translates to something that does nothing (rotating 360 means "stay" in a sense),
yet, I want to rotate it 5 times (think of a newspaper rotate scale coming at you effect -- I'm not great at describing, hope someone understands).
So, I tried adding setting angle to 180 deg (M_PI) and add a nested animatationBlock.
but I guess that since I'm setting the same property (someview.transition) again it ignores it somehow).
I tried setting repeat count of the animation to 2 with angle M_PI but it seems to simply rotate 180, going back to straight position and then initiating the rotate again.
So, I'm a little out of ideas,
any help appreciated!
--t
You can use the following animation on your UIView's layer property. I've tested it.
Objective-C
UIView *viewToSpin = ...;
CABasicAnimation* spinAnimation = [CABasicAnimation
animationWithKeyPath:#"transform.rotation"];
spinAnimation.toValue = [NSNumber numberWithFloat:5*2*M_PI];
[viewToSpin.layer addAnimation:spinAnimation forKey:#"spinAnimation"];
Swift 5.0
let viewToSpin = UIView() // However you have initialized your view
let spinAnimation = CABasicAnimation.init(keyPath: "transform.rotation")
spinAnimation.toValue = NSNumber(value: 5.0 * 2.0 * Float.pi)
viewToSpin.layer.add(spinAnimation, forKey: "spinAnimation")
As Brad Larson indicated, you can do this with a CAKeyframeAnimation. For instance,
CAKeyframeAnimation *rotationAnimation;
rotationAnimation =
[CAKeyframeAnimation animationWithKeyPath:#"transform.rotation.z"];
rotationAnimation.values = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:0.0 * M_PI],
[NSNumber numberWithFloat:0.75 * M_PI],
[NSNumber numberWithFloat:1.5 * M_PI],
[NSNumber numberWithFloat:2.0 * M_PI], nil];
rotationAnimation.calculationMode = kCAAnimationPaced;
rotationAnimation.removedOnCompletion = NO;
rotationAnimation.fillMode = kCAFillModeForwards;
rotationAnimation.timingFunction =
[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
rotationAnimation.duration = 10.0;
CALayer *layer = [viewToSpin layer];
[layer addAnimation:rotationAnimation forKey:#"rotationAnimation"];
You can control the duration of the total animation with the rotationAnimation.duration property, and the acceleration and deceleration (and calculation of steps in between) with the rotationAnimation.timingFunction property.
Getting a continuous spinning effect is a little tricky, but I describe a means to do it here. Yes, Core Animation seems to optimize transforms to the closest ending position within the unit circle. The method I describe there chains a few half-rotation animations together to make full rotations, although you do notice a slight stutter in the handoff from one animation to the next.
Perhaps a CAKeyframeAnimation constructed with these half-rotation values would be the right way to go. Then you could also control acceleration and deceleration.
CABasicAnimation* animation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.z"];
animation.fromValue = [NSNumber numberWithFloat:0.0f];
animation.toValue = [NSNumber numberWithFloat: 2*M_PI];
animation.duration = 8.0f;
animation.repeatCount = INFINITY;
[self.myView.layer addAnimation:animation forKey:#"SpinAnimation"];