I have created two UIViews Programmatically and set its frame in ViewWillLayoutSubview function, Now I want to create a swapping animation so that each view swap each others position with animation on a click. For getting this animation I have to interchange its frame inside an animation but at the same time ViewWillLayoutSubview get called which sets frame to initial position.
How can I get my UIViews to be swapped with animation using ViewWillLayoutSubview?
I am not using any type of constraint or xib or storyboard. Whole screen is designed programatically.
Thanks in advance.
-(void)viewWillLayoutSubviews
{
if(Once)
{
// create 2 views here
once = NO;
}
}
put this code in button click
CGRect view2Frame = self.view2.frame;
[UIView animateWithDuration:duration delay:0 options:UIViewAnimationOptionCurveLinear animations:^{
//code with animation
self.view2.frame = self.view1.frame;
self.view1.frame = view2Frame;
} completion:^(BOOL finished) {
//code for completion
}];
I have a simple animation that im performing in my scroll view delegate method scrollViewDidEndDragging.
It looks like this:
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
NSLog(#"finger was lifted");
[UIView animateWithDuration:1.0
animations:^{
self.homeLabel.frame = self.view.frame;
}];
}
Using this animation after lifting the finger the my homeLabel is coming from top, and i want to add it a bounce animation to the label, so when it comes from top, instead of landing smoothly it will have a nice bounce...how can i DO THAT? thanksss
You can use the usingSpringWithDamping animation function.
[UIView animateWithDuration:1.0 delay:0 usingSpringWithDamping:0.2 initialSpringVelocity:5.0 options:UIViewAnimationOptionCurveLinear animations:^{
self.homeLabel.frame = self.view.frame;
} completion:^(BOOL finished) {
}];
Adjusting the Spring Damping and Initial Spring Velocity can give you the effect you want.
One good solution is to create a custom layer for your view that overrides the addAnimation:forKey: method to include a custom timing function.
This answer goes into the specifics of how to do that.
Another option is to take a look at key frame animation. This question and answer covers that approach very well.
I have a view and on that there is a AVPlayer on that I need a dissolve animation when the player is
moving from the first video to second video.
I don't know your UIView structure, but you can load the new UIView / AVVideo and use UIView animations to transform the current view to the second one.
// load new UIView
// make it invisible
[UIView animateWithDuration:1
delay:1.5
options:UIViewAnimationCurveEaseOut
animations:^{
// fade in, or change x/y to slide in
}
completion:^(BOOL finished){
NSLog(#"Done!");
}];
I have animated a UIView so that it shrinks when the user touches a toggle button and it expands back to its original size when the user touches the button again. So far everything works just fine. The problem is that the animation takes some time - e.g. 3 seconds. During that time I still want the user to be able to interact with the interface. So when the user touches the button again while the animation is still in progress the animation is supposed to stop right where it is and reverse.
In the Apple Q&As I have found a way to pause all animations immediately:
https://developer.apple.com/library/ios/#qa/qa2009/qa1673.html
But I do not see a way to reverse the animation from here (and omit the rest of the initial animation). How do I accomplish this?
- (IBAction)toggleMeter:(id)sender {
if (self.myView.hidden) {
self.myView.hidden = NO;
[UIView animateWithDuration:3 animations:^{
self.myView.transform = expandMatrix;
} completion:nil];
} else {
[UIView animateWithDuration:3 animations:^{
self.myView.transform = shrinkMatrix;
} completion:^(BOOL finished) {
self.myView.hidden = YES;
}];
}
}
In addition to the below (in which we grab the current state from the presentation layer, stop the animation, reset the current state from the saved presentation layer, and initiate the new animation), there is a much easier solution.
If doing block-based animations, if you want to stop an animation and launch a new animation in iOS versions prior to 8.0, you can simply use the UIViewAnimationOptionBeginFromCurrentState option. (Effective in iOS 8, the default behavior is to not only start from the current state, but to do so in a manner that reflects both the current location as well as the current velocity, rendering it largely unnecessary to worry about this issue at all. See WWDC 2014 video Building Interruptible and Responsive Interactions for more information.)
[UIView animateWithDuration:3.0
delay:0.0
options:UIViewAnimationOptionBeginFromCurrentState | UIViewAnimationOptionAllowUserInteraction
animations:^{
// specify the new `frame`, `transform`, etc. here
}
completion:NULL];
You can achieve this by stopping the current animation and starting the new animation from where the current one left off. You can do this with Quartz 2D:
Add QuartzCore.framework to your project if you haven't already. (In contemporary versions of Xcode, it is often unnecessary to explicitly do this as it is automatically linked to the project.)
Import the necessary header if you haven't already (again, not needed in contemporary versions of Xcode):
#import <QuartzCore/QuartzCore.h>
Have your code stop the existing animation:
[self.subview.layer removeAllAnimations];
Get a reference to the current presentation layer (i.e. the state of the view as it is precisely at this moment):
CALayer *currentLayer = self.subview.layer.presentationLayer;
Reset the transform (or frame or whatever) according to the current value in the presentationLayer:
self.subview.layer.transform = currentLayer.transform;
Now animate from that transform (or frame or whatever) to the new value:
[UIView animateWithDuration:1.0
delay:0.0
options:UIViewAnimationOptionAllowUserInteraction
animations:^{
self.subview.layer.transform = newTransform;
}
completion:NULL];
Putting that all together, here is a routine that toggles my transform scale from 2.0x to identify and back:
- (IBAction)didTouchUpInsideAnimateButton:(id)sender
{
CALayer *currentLayer = self.subview.layer.presentationLayer;
[self.subview.layer removeAllAnimations];
self.subview.layer.transform = currentLayer.transform;
CATransform3D newTransform;
self.large = !self.large;
if (self.large)
newTransform = CATransform3DMakeScale(2.0, 2.0, 1.0);
else
newTransform = CATransform3DIdentity;
[UIView animateWithDuration:1.0
delay:0.0
options:UIViewAnimationOptionAllowUserInteraction
animations:^{
self.subview.layer.transform = newTransform;
}
completion:NULL];
}
Or if you wanted to toggle frame sizes from 100x100 to 200x200 and back:
- (IBAction)didTouchUpInsideAnimateButton:(id)sender
{
CALayer *currentLayer = self.subview.layer.presentationLayer;
[self.subview.layer removeAllAnimations];
CGRect newFrame = currentLayer.frame;
self.subview.frame = currentLayer.frame;
self.large = !self.large;
if (self.large)
newFrame.size = CGSizeMake(200.0, 200.0);
else
newFrame.size = CGSizeMake(100.0, 100.0);
[UIView animateWithDuration:1.0
delay:0.0
options:UIViewAnimationOptionAllowUserInteraction
animations:^{
self.subview.frame = newFrame;
}
completion:NULL];
}
By the way, while it generally doesn't really matter for really quick animations, for slow animations like yours, you might want to set the duration of the reversing animation to be the same as how far you've progressed in your current animation (e.g., if you're 0.5 seconds into a 3.0 second animation, when you reverse, you probably don't want to take 3.0 seconds to reverse that small portion of the animation that you have done so far, but rather just 0.5 seconds). Thus, that might look like:
- (IBAction)didTouchUpInsideAnimateButton:(id)sender
{
CFTimeInterval duration = kAnimationDuration; // default the duration to some constant
CFTimeInterval currentMediaTime = CACurrentMediaTime(); // get the current media time
static CFTimeInterval lastAnimationStart = 0.0; // media time of last animation (zero the first time)
// if we previously animated, then calculate how far along in the previous animation we were
// and we'll use that for the duration of the reversing animation; if larger than
// kAnimationDuration that means the prior animation was done, so we'll just use
// kAnimationDuration for the length of this animation
if (lastAnimationStart)
duration = MIN(kAnimationDuration, (currentMediaTime - lastAnimationStart));
// save our media time for future reference (i.e. future invocations of this routine)
lastAnimationStart = currentMediaTime;
// if you want the animations to stay relative the same speed if reversing an ongoing
// reversal, you can backdate the lastAnimationStart to what the lastAnimationStart
// would have been if it was a full animation; if you don't do this, if you repeatedly
// reverse a reversal that is still in progress, they'll incrementally speed up.
if (duration < kAnimationDuration)
lastAnimationStart -= (kAnimationDuration - duration);
// grab the state of the layer as it is right now
CALayer *currentLayer = self.subview.layer.presentationLayer;
// cancel any animations in progress
[self.subview.layer removeAllAnimations];
// set the transform to be as it is now, possibly in the middle of an animation
self.subview.layer.transform = currentLayer.transform;
// toggle our flag as to whether we're looking at large view or not
self.large = !self.large;
// set the transform based upon the state of the `large` boolean
CATransform3D newTransform;
if (self.large)
newTransform = CATransform3DMakeScale(2.0, 2.0, 1.0);
else
newTransform = CATransform3DIdentity;
// now animate to our new setting
[UIView animateWithDuration:duration
delay:0.0
options:UIViewAnimationOptionAllowUserInteraction
animations:^{
self.subview.layer.transform = newTransform;
}
completion:NULL];
}
There is a common trick you can use to do this, but it is necessary to write a separate method to shrink (and another similar one to expand):
- (void) shrink {
[UIView animateWithDuration:0.3
animations:^{
self.myView.transform = shrinkALittleBitMatrix;
}
completion:^(BOOL finished){
if (continueShrinking && size>0) {
size=size-1;
[self shrink];
}
}];
}
So now, the trick is to break the 3 seconds animation of shrinking into 10 animations (or more than 10, of course) of 0.3 sec each in which you shrink 1/10th of the whole animation: shrinkALittleBitMatrix. After each animation is finished you call the same method only when the bool ivar continueShrinking is true and when the int ivar size is positive (the view in full size would be size=10 and the view with minimum size would be size=0). When you press the button you change the ivar continueShrinking to FALSE, and then call expand. This will stop the animation in less than 0.3 seconds.
Well, you have to fill the details but I hope it helps.
First: how to remove or cancel a animation with view?
[view.layer removeAllAnimations]
if the view have many animations, such as, one animation is move from top to bottom, other is move from left to right;
you can cancel or remove a special animation like this:
[view.layer removeAnimationForKey:#"someKey"];
// the key is you assign when you create a animation
CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:#"someKey"];
when you do that, animation will stop, it will invoke it's delegate:
- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag
if flag == 1, indicate animation is completed.
if flag == 0, indicate animation is not completed, it maybe cancelled、removed.
Second: so , you can do what you want to do in this delegate method.
if you want get the view's frame when the remove code excute, you can do this:
currentFrame = view.layer.presentationlayer.frame;
Note:
when you get the current frame and remove animation , the view will also animate a period time, so currentFrame is not the last frame in the device screen.
I cann't resolve this question at now. if some day I can, I will update this question.
I've got a UIView Animation going on that I need to cancel in my iOS app. I've tried this:
[self.view.layer removeAllAnimations];
But it didn't work. The animation continued. Here is my animation code:
[UIView animateWithDuration:1.4 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{
recognizer.view.transform = CGAffineTransformTranslate(recognizer.view.transform, translation.x, translation.y);
} completion:^(BOOL finished) {
NSLog(#"completed animation, now do whatever");
}];
Does anybody have any ideas as to why it's not working?
You are adding that animation to recognizer's view, hence you will have to remove it from that same view's layer.
So instead of
[self.view.layer removeAllAnimations];
you may want to
[recognizer.view.layer removeAllAnimations];
And to keep the current status of the transformation, fetch that one from the presentation layer. The presentation layer is the one that actually reflects the changes during the animation.
recognizer.view.layer.transform = recognizer.view.layer.presentationLayer.transform;
Ok - just figured it out. Changed the component beng animated from the gesture recogniser on top of the image view to the image view itself. Now, just before the code to stop the animation, I have:
truckView.frame = [[trackView.layer presentationLayer] frame];
[truckView.layer removeAllAnimations];
So this is the way to do it. Thanks for the help that led me to this answer,
Sam