I have a custom CALayer with an animatable property called progress. The basic code is:
#implementation AnimatedPieChartLayer
#dynamic progress;
+ (BOOL)needsDisplayForKey:(NSString *)key {
return [key isEqualToString: #"progress"] || [super needsDisplayForKey: key];
}
- (id <CAAction>)actionForKey:(NSString *)key {
if ([self presentationLayer] != nil) {
if ([key isEqualToString: #"progress"]) {
CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath: key];
[anim setFromValue: [[self presentationLayer] valueForKey: key]];
[anim setDuration: 0.75f];
return anim;
}
}
return [super actionForKey: key];
}
- (void)drawInContext:(CGContextRef)context {
// do stuff
}
#end
In the view controller I do this, to try and get my animation to start from the beginning every time:
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear: animated];
[pieChart setProgress: 0.0];
}
This all works perfectly. I put the layer on a view, the view in a view controller, and it all works as expected.
The complication is that my view controller is inside a UIScrollView. This presents a situation where the user could swipe away from my view controller before the CALayer animation completes. If they swipe back quickly, the CALayer animation does something weird. It reverses. It's like the animation is trying to go back to the beginning. Once it gets there it starts over, and animates the way it is supposed to.
So the question is, how can I prevent this. I want the animation to start from the beginning every time the view is displayed – regardless of what happened last time.
Any suggestions?
UPDATE
Here's a visual example of the problem:
Working:
Failing:
In the setup you have there, you have an implicit animation for the key "progress" so that whenever the progress property of the layer changes, it animates. This works both when the value increases and when it decreases (as seen in your second image).
To restore the layer to the default 0 progress state without an animation, you can wrap the property change in a CATransaction where all actions are disabled. This will disable the implicit animation so that you can start over from 0 progress.
[CATransaction begin];
[CATransaction setDisableActions:YES]; // all animations are disabled ...
[pieChart setProgress: 0.0];
[CATransaction commit]; // ... until this line
Probably too simple a suggestion to merit an 'answer,' but I would suggest canceling the animation. Looks like you could rewrite this code pretty easily so that the progress updates were checking some complete flag and then when the view get hidden, kill it. This thread has some good ideas on it.
Related
I have a UIButton subclass that does some custom drawing and animations. That is all working fine and dandy.
However, most of my buttons dismiss the current view via their superview calling [self dismissViewControllerAnimated] once it is confirmed with the model that whatever the button push was supposed to accomplish was actually done, and I want there to be a delay to allow the animation to complete before dismissing the view.
I am able to easily enough animate the UIButton subclass on touchesEnded and then call [super touchesEnded], which works fine except that it doesn't let my animations finish before dismissing the view. Like this:
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
CABasicAnimation *myAnimation = [CABasicAnimation animationWithKeyPath:#"transform.foo"];
//set up myAnimation's properties
[self.layer addAnimation:shakeAnimation forKey:nil];
[super touchesEnded:touches withEvent:event]; //works! but no delay
}
My first attempt at creating a delay was by using CATransaction, as follows:
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
CABasicAnimation *myAnimation = [CABasicAnimation animationWithKeyPath:#"transform.foo"];
//set up myAnimation's properties
[CATransaction begin];
[CATransaction setCompletionBlock:^{
[super touchesEnded:touches withEvent:event]; //doesn't seem to do anything :-/
}];
[self.layer addAnimation:shakeAnimation forKey:nil];
[CATransaction commit];
}
Which, as far as I can tell, is executing CATransaction's completionBlock, but it just isn't doing anything.
I've also tried assigning the touches and event arguments from touchesEnded to both properties and global variables, and then executing [super touchesEnded] in another method called by an NSTimer. The same thing seems to be occurring where the code is executing, but my call to [super touchesEnded] isn't doing anything.
I've dug around online for hours. Added stubs of the other touches methods from UIResponder which just contain [super touches...]. Tried setting up my global variables for the method called by NSTimer differently (I very well may be missing something in regards to global variables...). This button is being created by the Storyboard, but I've set the class to my custom class, so I don't think UIButton's +(UIButton *)buttonWithType method is affecting this.
What am I missing? Is there some small thing I'm forgetting about or is there just no way to delay the call to [super touchesEnded] from a UIButton subclass?
I was not able to solve this, only find a way around it.
My last stab at solving this was to figure out whether the [super touchesEnded...] inside the completion block was being executed in a thread that was different from the thread it was executed in when it was outside the completion block... and no, they both appear to be the main thread (Apple's documentation on CATransaction does state that its completionBlock is always run in the main thread).
So in case someone else is banging their head against this, here's my less-than-elegant solution:
1.) In my subclass of UIButton I created a weak property called containingVC.
2.) In every single (ugh) VC that uses the custom button class I have to do this:
#implemenation VCThatUsesCustomButtonsOneOfWayTooMany
-(void)viewDidLayoutSubviews
{
[super viewDidLayoutSubviews];
self.firstCustomButton.containingVC = self;
self.secondCustomButton.containingVC = self;
self.thirdCustomButton.containingVC = self;
....
self.lastCustomButton.containingVC = self;
//you're probably better off using an IBOutletColletion and NSArray's makeObjectPerformSelector:withObject...
}
#end
3.) Then in my custom UIButton class I have something like this:
-(void)animateForPushDismissCurrView
{
CAAnimation *buttonAnimation = ...make animation
[CATransaction begin];
[CATransaction setCompletionBlock:^{
[self.containingVC performSegueWithIdentifier:#"segueID" sender:self.containingVC];
}];
[self.layer addAnimation:buttonAnimation forKey:nil];
[CATransaction commit];
}
4.) Then in whatever VC that the user is currently interacting with, after making sure the button has done whatever it was supposed to do (in my case it checks with the model to confirm that the relevant change was made), each button has to call [someCustomButton animateForPushDismissCurrView] which then animates the button press and then fires the UIStoryboardSegue that actually dismisses the view.
Obviously this would work for going deeper, not just unwinding, but you'd need additional logic in the custom button's -(void)animateForPush method or a separate method entirely.
Again, if I'm missing something here, I'd love to know what it is. This seems like an absurd number of hoops to jump through to accomplish what seems like a simple task.
Lastly, and most importantly, if it just won't work with the [super touchesEnded...] method in CATransaction's completionBlock, I'd like to know WHY. I suspect that it has something to do with threads or the weirdness that is Objective-C's super keyword.
I am using setNeedsDisplay on my GUI, but there update is sometimes not done. I am using UIPageControllView, each page has UIScrollView with UIView inside.
I have the following pipeline:
1) application comes from background - called applicationWillEnterForeground
2) start data download from server
2.1) after data download is finished, trigger selector
3) use dispatch_async with dispatch_get_main_queue() to fill labels, images etc. with new data
3.1) call setNeedsDisplay on view (also tried on scroll view and page controller)
Problem is, that step 3.1 is called, but changes apper only from time to time. If I swap pages, the refresh is done and I can see new data (so download works correctly). But without manual page turn, there is no update.
Any help ?
Edit: code from step 3 and 3.1 (removed _needRefresh variables pointed in comments)
-(void)FillData {
dispatch_async(dispatch_get_main_queue(), ^{
NSString *stateID = [DataManager ConvertStateToStringFromID:_activeCity.actual_weather.state];
if ([_activeCity.actual_weather.is_night boolValue] == YES)
{
self.contentBgImage.image = [UIImage imageNamed:[NSString stringWithFormat:#"bg_%#_noc", [_bgs objectForKey:stateID]]];
if (_isNight == NO)
{
_bgTransparencyInited = NO;
}
_isNight = YES;
}
else
{
self.contentBgImage.image = [UIImage imageNamed:[NSString stringWithFormat:#"bg_%#", [_bgs objectForKey:stateID]]];
if (_isNight == YES)
{
_bgTransparencyInited = NO;
}
_isNight = NO;
}
[self.contentBgImage setNeedsDisplay]; //refresh background image
[self CreateBackgroundTransparency]; //create transparent background if colors changed - only from time to time
self.contentView.parentController = self;
[self.contentView FillData]; //Fill UIView with data - set labels texts to new ones
//_needRefresh is set to YES after application comes from background
[self.contentView setNeedsDisplay]; //This do nothing ?
[_grad display]; //refresh gradient
});
}
And here is selector called after data download (in MainViewController)
-(void)FinishDownload:(NSNotification *)notification
{
dispatch_async(dispatch_get_main_queue(), ^{
[_activeViewController FillData]; //call method shown before
//try call some more refresh - also useless
[self.pageControl setNeedsDisplay];
//[self reloadInputViews];
[self.view setNeedsDisplay];
});
}
In AppDelegate I have this for application comes from background:
-(void)applicationWillEnterForeground:(UIApplication *)application
{
MainViewController *main = (MainViewController *)[(SWRevealViewController *)self.window.rootViewController frontViewController];
[main UpdateData];
}
In MainViewController
-(void)UpdateData
{
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(FinishForecastDownload:) name:#"FinishDownload" object:nil]; //create selector
[[DataManager SharedManager] DownloadForecastDataWithAfterSelector:#"FinishDownload"]; //trigger download
}
try this:
[self.view performSelectorOnMainThread:#selector(setNeedsLayout) withObject:nil waitUntilDone:NO];
or check this link:
http://blackpixel.com/blog/2013/11/performselectoronmainthread-vs-dispatch-async.html
setNeedsDisplay triggers drawRect: and is used to "redraw the pixels" of the view , not to configure the view or its subviews.
You could override drawRect: and modify your labels, etc. there but that's not what it is made for and neither setNeedsLayout/layoutSubviews is.
You should create your own updateUI method where you use your fresh data to update the UI and not rely on specialized system calls meant for redrawing pixels (setNeedsDisplay) or adjusting subviews' frames (drawRect:).
You should set all your label.text's, imageView.image's, etc in the updateUI method. Also it is a good idea to try to only set those values through this method and not directly from any method.
None of proposed solutions worked. So at the end, I have simply remove currently showed screen from UIPageControllView and add this screen again. Something like changing the page there and back again programatically.
Its a bit slower, but works fine.
I'm using an interactive custom push transition with a UIPercentDrivenInteractiveTransition. The gesture recognizer successfully calls the interaction controller's updateInteractiveTransition. Likewise, the animation successfully completes when I call the interaction controller's finishInteractiveTransition.
But, sometimes I get a extra bit of distracting animation at the end (where it seems to repeat the latter part of the animation). With reasonably simple animations, I rarely see this symptom on the iPhone 5 (though I routinely see it on the simulator when working on slow laptop). If I make the animation more computationally expensive (e.g. lots of shadows, multiple views animating different directions, etc.), the frequency of this problem on the device increases.
Has anyone else seen this problem and figured out a solution other than streamlining the animations (which I admittedly should do anyway) and/or writing my own interaction controllers? The UIPercentDrivenInteractiveTransition approach has a certain elegance to it, but I'm uneasy with the fact that it misbehaves non-deterministically. Have others seen this behavior? Does anyone know of other solutions?
To illustrate the effect, see the image below. Notice how the second scene, the red view, when the animation finishes, seems to repeat the latter part of its animation a second time.
This animation is generated by:
repeatedly calling updateInteractiveTransition, progressing update from 0% to 40%;
momentarily pausing (so you can differentiate between the interactive transition and the completion animation resulting from finishInteractiveTransition);
then calling finishInteractiveTransition to complete the animation; and
the animation controller's animation's completion block calls completeTransition for the transitionContext, in order to clean everything up.
Doing some diagnostics, it appears that it is this last step that triggers that extraneous bit of animation. The animation controller's completion block is called when the animation is finished, but as soon as I call completeTransition, it sometimes repeats the last bit of the animation (notably when using complex animations).
I don't think it's relevant, but this is my code for configuring the navigation controller to perform interactive transitions:
- (void)viewDidLoad
{
[super viewDidLoad];
self.navigationController.delegate = self;
self.interationController = [[UIPercentDrivenInteractiveTransition alloc] init];
}
- (id<UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController
animationControllerForOperation:(UINavigationControllerOperation)operation
fromViewController:(UIViewController*)fromVC
toViewController:(UIViewController*)toVC
{
if (operation == UINavigationControllerOperationPush)
return [[PushAnimator alloc] init];
return nil;
}
- (id <UIViewControllerInteractiveTransitioning>)navigationController:(UINavigationController*)navigationController
interactionControllerForAnimationController:(id <UIViewControllerAnimatedTransitioning>)animationController
{
return self.interationController;
}
My PushAnimator is:
#implementation PushAnimator
- (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext
{
return 5.0;
}
- (void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext
{
UIViewController* toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
UIViewController* fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
[[transitionContext containerView] addSubview:toViewController.view];
toViewController.view.frame = CGRectOffset(fromViewController.view.frame, fromViewController.view.frame.size.width, 0);;
[UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{
toViewController.view.frame = fromViewController.view.frame;
} completion:^(BOOL finished) {
[transitionContext completeTransition:![transitionContext transitionWasCancelled]];
}];
}
#end
Note, when I put logging statement where I call completeTransition, I can see that this extraneous bit of animation happens after I call completeTransition (even though the animation was really done at that point). This would suggest that that extra animation may have been a result of the call to completeTransition.
FYI, I've done this experiment with a gesture recognizer:
- (void)handlePan:(UIScreenEdgePanGestureRecognizer *)gesture
{
CGFloat width = gesture.view.frame.size.width;
if (gesture.state == UIGestureRecognizerStateBegan) {
[self performSegueWithIdentifier:#"pushToSecond" sender:self];
} else if (gesture.state == UIGestureRecognizerStateChanged) {
CGPoint translation = [gesture translationInView:gesture.view];
[self.interactionController updateInteractiveTransition:ABS(translation.x / width)];
} else if (gesture.state == UIGestureRecognizerStateEnded ||
gesture.state == UIGestureRecognizerStateCancelled)
{
CGPoint translation = [gesture translationInView:gesture.view];
CGPoint velocity = [gesture velocityInView:gesture.view];
CGFloat percent = ABS(translation.x + velocity.x * 0.25 / width);
if (percent < 0.5 || gesture.state == UIGestureRecognizerStateCancelled) {
[self.interactionController cancelInteractiveTransition];
} else {
[self.interactionController finishInteractiveTransition];
}
}
}
I also did it by calling the updateInteractiveTransition and finishInteractiveTransition manually (eliminating the gesture recognizer from the equation), and it still exhibits this strange behavior:
[self performSegueWithIdentifier:#"pushToSecond" sender:self];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
[self.interactionController updateInteractiveTransition:0.40];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
[self.interactionController finishInteractiveTransition];
});
});
Bottom line, I've concluded that this is a problem isolated to UIPercentDrivenInteractiveTransition with complex animations. I can minimize the problem by simplifying them (e.g. snapshotting and animated snapshotted views). I also suspect I could solve this by not using UIPercentDrivenInteractiveTransition and writing my own interaction controller, which would do the animation itself, without trying to interpolate the animationWithDuration block.
But I was wondering if anyone has figured out any other tricks to using UIPercentDrivenInteractiveTransition with complex animations.
This problem arises only in simulator.
SOLUTION: self.interactiveAnimator.completionSpeed = 0.999;
bug reported here: http://openradar.appspot.com/14675246
I've seen something similar. I have two possible workarounds. One is to use delayed performance in the animation completion handler:
} completion:^(BOOL finished) {
double delayInSeconds = 0.1;
dispatch_time_t popTime =
dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
BOOL cancelled = [transitionContext transitionWasCancelled];
[transitionContext completeTransition:!cancelled];
});
self.interacting = NO;
}];
The other possibility is: don't use percent-drive animation! I've never had a problem like this when driving the interactive custom animation myself manually.
The reason for this error in my case was setting the frame of the view being animated multiple times. I'm only setting the view frame ONCE and it fixed my issues.
So in this case, the frame of "toViewController.view" was set TWICE, thus making the animation have an unwanted behavior
I have the following routine to simply animate an image across the screen.
-(void)animateGrasland {
[UIView animateWithDuration:5 delay:0.0 options:UIViewAnimationOptionCurveLinear
animations:^{
CGRect newFrame = CGRectMake(100,100,1024,768);
self.grasland.frame = newFrame;
}
completion:^(BOOL finished) {
}
];
}
I want to start the animation immediately after I load the View. And to last for 5 seconds. So I have been experimenting with several options to calls of the function.
Option I - This option immediately shows the image at the new position, no animation!
- (void)viewDidLoad {
[super viewDidLoad];
[self animateGrasland];
}
Option II - This option animates the image to the new position. Bingo.
- (void)viewDidLoad {
[super viewDidLoad];
[NSTimer scheduledTimerWithTimeInterval:0.001 target:self selector:#selector(animateGrasland) userInfo:nil repeats:NO];
}
I have bene playing with the delay in the Time a little and for 0.001 sec the animation will start. If the duration is 0.0001 sec the image is displayed immediately at the new position, so without animation. I expect that the duration of the parsing of the viewDidLoad (and other background routines causes this).
So because the initial position (0,0), which is set in the storyboard, is updated during the viewDidLoad, the Animation is not triggered. And the animation moves immediately to its finished state.
Try calling animateGrasland in viewDidAppear: instead of viewDidLoad, like this:
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated]
[self animateGrasland];
}
// Remove your implementation of the viewDidLoad method or at least the call to animateGrasland
viewDidLoad is called after the view is loaded into the memory, while viewDidAppear: is called after the view is added to the view hierarchy. In your case, this means right after the view is visible. Since you want your animation to start as soon as the view is visible, you should start it in viewDidAppear:
I have a problem with an animation.
The problem is that if I try to animate a view that is already created all goes well, if I try to create and animate a view at the same time the animation doesn't work.
Can anyone help me?
My Methods
+ (LoginView *)sharedInstance {
#synchronized(self) {
if (nil == _sharedInstance) {
_sharedInstance = (LoginView *)[[[NSBundle mainBundle] loadNibNamed:#"LoginView" owner:nil options:nil] objectAtIndex:0];
}
}
return _sharedInstance;
}
- (void)hide:(BOOL)value animated:(BOOL)animated {
CATransition * animation = [CATransition animation];
animation.type = kCATransitionFade;
[animation setDuration:1.0];
if(_autoManageModalView)
[animation setDelegate:self];
[[self layer] removeAllAnimations];
[[self layer] addAnimation:animation forKey:kCATransition];
self.hidden = value;
}
How I call them
[[LoginView sharedInstance] hide:NO animated:YES];
The first time (with the same call) animation doesn't work, from the secondo time all goes well. Thank in advance!
You are animating your view too early in its lifecycle. In theory, you create a view, then display it somewhere (e.g., addSubview:), then you animate it.
It is highly possible, though I have not checked it, that the first time that your hide:animated: method is called the self.layer property is null; in any case, the animation would happen before the view is displayed, so you would not see it.
All in all, first display the view, then call the hide:animated: method on it.
After your comment: try and call the hide:animated: method through a method like:
performSelector:withObject:afterDelay:
If you specify a 0.0 delay, this will simply queue the call to hide:animate: on the main loop, so that all the processing related to loadNibNamed: can happen and so give your view the time to be set up for display correctly.
In order to use performSelector:withObject:afterDelay: you will need to modify your method signature so that it takes one argument and this must be an NSObject-derived type, not a primitive type.