My animatewithduration, completion block is performed only once - ios

I use the following block of code to slide a UIView down and when finished rotate another UIView.
The second part of the animation, the completion block is only performed once which means the 1st animation is not completed else it would reach the completion block.
On the iphone simulator it looks as if the 1st animation did finish...
can anyone help me figure this out?
my NSLog says:
finished 1st
started 2nd
finished 1st
finished 1st
finished 1st
.
.
.
- (IBAction) move
{
[UIView animateWithDuration:0.7 animations:^{
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.7];
[UIView setAnimationRepeatCount:1];
[UIView setAnimationRepeatAutoreverses:NO];
CGPoint pos = movingtTable.center;
float moveDistance = 220.0;
if(!isViewVisible){
//expose the view
pos.y = pos.y+moveDistance;
//disable selection for xy table
xTable.userInteractionEnabled = NO;
yTable.userInteractionEnabled = NO;
//angle = M_PI;
}
else
{
pos.y = pos.y-moveDistance;
xTable.userInteractionEnabled = YES;
yTable.userInteractionEnabled = YES;
//angle = -M_PI;
}
isViewVisible = !isViewVisible;
movingtTable.center = pos;
NSLog(#"finished 1st");
}completion:^(BOOL finished){
NSLog(#"started 2nd");
[UIView animateWithDuration:0.4 animations:^{
//[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.4];
//[UIView setAnimationRepeatCount:1];
//[UIView setAnimationRepeatAutoreverses:NO];
arrows.transform = CGAffineTransformMakeRotation(angle);
}completion:^(BOOL finished){
angle = -angle;
}];
}];

Why are you trying to initialize another UIView animation inside the animateWithDuration block code? Update your code to the following and make sure you're not performing multiple animations of a single view at a time.
- (IBAction) move
{
[UIView animateWithDuration:0.7 animations:^{
CGPoint pos = movingtTable.center;
float moveDistance = 220.0;
if(!isViewVisible){
//expose the view
pos.y = pos.y+moveDistance;
//disable selection for xy table
xTable.userInteractionEnabled = NO;
yTable.userInteractionEnabled = NO;
//angle = M_PI;
}
else
{
pos.y = pos.y-moveDistance;
xTable.userInteractionEnabled = YES;
yTable.userInteractionEnabled = YES;
//angle = -M_PI;
}
isViewVisible = !isViewVisible;
movingtTable.center = pos;
NSLog(#"finished 1st");
}
completion:^(BOOL finished){
NSLog(#"started 2nd");
[UIView animateWithDuration:0.4 animations:^{
arrows.transform = CGAffineTransformMakeRotation(angle);
}completion:^(BOOL finished){
angle = -angle;
}];
}];
BTW: The block code requires some serious refactoring, if you ask me :)

You are mixing and matching paradigms and I believe that is causing the issue you are seeing. You are creating an animation block, but inside of that block you are creating a new animation routine with the 'old' paradigm for running UIView animations. Apple is leading people away from the old paradigm and I would encourage you to ONLY use blocks as well.
This is why the completion block only runs once, the UIView animateWith block code only runs once. However, your internal animation code runs multiple times.
Take out:
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.7];
[UIView setAnimationRepeatCount:1];
[UIView setAnimationRepeatAutoreverses:NO];
If you want your animation block to run several times, then use the full method:
animateWithDuration:delay:options:animations:completion:
Make the delay = 0, and set your options to UIViewAnimationOptionRepeat, or whatever you need to accomplish the number of cycles you want the block to complete.
Here is my suggestion assuming you want it to repeat:
- (IBAction) move
{
[UIView animateWithDuration:0.7
delay:0
options:UIViewAnimationOptionRepeat
animations:^{
CGPoint pos = movingtTable.center;
float moveDistance = 220.0;
if(!isViewVisible) {
//expose the view
pos.y = pos.y+moveDistance;
//disable selection for xy table
xTable.userInteractionEnabled = NO;
yTable.userInteractionEnabled = NO;
//angle = M_PI;
}
else {
pos.y = pos.y-moveDistance;
xTable.userInteractionEnabled = YES;
yTable.userInteractionEnabled = YES;
//angle = -M_PI;
}
isViewVisible = !isViewVisible;
movingtTable.center = pos;
NSLog(#"finished 1st");
}
completion:^(BOOL finished){
NSLog(#"started 2nd");
[UIView animateWithDuration:0.4
animations:^{
arrows.transform = CGAffineTransformMakeRotation(angle);
}
completion:^(BOOL finished){
angle = -angle;
}];
}];
}

Related

iOS: UIView animation block method animating weirdly on multiple fires

I am doing page swipe animation with 2 UIWebViews to render book page effect.
Swipe is fired on next and previous click.
Animation works fine until the next or previous button is clicked multiple times in succession.
Here's what I am doing:
display webview1 by default
on right swipe, make webview1 frame x origin negative to hide it. And make webview2 frame x origin as 0 to display it.
similarly for left swipe.
Here is my code to swipe:
-(void)pageChange
{
#try{
[UIView commitAnimations];
NSString *finalPath;
finalPath = [NSString stringWithFormat:#"%#/%#",self.strBookPath, [arrHtmlPages objectAtIndex:currentPage]];
NSData *htmlData = [NSData dataWithContentsOfFile:finalPath];
__block CGRect basketTopFrame = webViewPage.frame;
[UIView animateWithDuration:DURATION delay:0.0f options:UIViewAnimationOptionCurveEaseOut animations:^{
if (_webview2.frame.origin.x == self.view.frame.size.width) {
basketTopFrame.origin.x = -(self.view.frame.size.width);
[webViewPage setFrame:basketTopFrame];
basketTopFrame.origin.x = self.view.frame.size.width;
_webview2.frame = basketTopFrame;
[_webview2 loadData:htmlData MIMEType:#"text/html" textEncodingName:#"UTF-8" baseURL:[NSURL fileURLWithPath:self.strBookPath isDirectory:YES]];
[UIView animateWithDuration:DURATION delay:0.0 options:UIViewAnimationOptionCurveEaseIn animations:^{
//basketTopFrame = webViewPage.frame;
basketTopFrame.origin.x = 0;
_webview2.frame = basketTopFrame;
//NSLog(#"web1: %f",webViewPage.frame.origin.x);
//NSLog(#"web2 : %f", _webview2.frame.origin.x);
} completion:^(BOOL finished){
basketTopFrame.origin.x = self.view.frame.size.width;
webViewPage.frame=basketTopFrame;
}];
} else {
basketTopFrame.origin.x = -(self.view.frame.size.width);
[_webview2 setFrame:basketTopFrame];
basketTopFrame.origin.x = self.view.frame.size.width;
webViewPage.frame = basketTopFrame;
[webViewPage loadData:htmlData MIMEType:#"text/html" textEncodingName:#"UTF-8" baseURL:[NSURL fileURLWithPath:self.strBookPath isDirectory:YES]];
[UIView animateWithDuration:DURATION delay:0.0 options:UIViewAnimationOptionCurveEaseIn animations:^{
//basketTopFrame = webViewPage.frame;
basketTopFrame.origin.x = 0;
webViewPage.frame = basketTopFrame;
//NSLog(#"web1 in: %f",webViewPage.frame.origin.x);
//NSLog(#"web2 in: %f", _webview2.frame.origin.x);
} completion:^(BOOL finished){
basketTopFrame.origin.x = self.view.frame.size.width;
_webview2.frame=basketTopFrame;
}];
}
} completion:^(BOOL finished){
NSLog(#"web1 in: %f",webViewPage.frame.origin.x);
NSLog(#"web2 in: %f", _webview2.frame.origin.x);
}];
}#catch(NSException *e){
NSLog(#"exception : %#",e.description);
}
}
This code is just for right swipe. Left swipe also has similar code.
- (IBAction)btnNext_click:(id)sender {
[self swipeRight:nil]; //this calls pageChange()
}
When the above method is fired many times with very very short interval(user clicks on it rigorously), then both the webviews get frame x origin as width of device(in my case 768), and both get hidden.
Where am I getting wrong? How do I solve this?
There is easy solution for this: Disable buttons during animation. Look for userInteractionEnabled property for buttons and set it to NO during animation. When animation finishes, enable it again. It is very convenient with block based animations as you will enable it in completion handler. Hope this helps.

How to autorepeat a set of chained UIView animations using UIViewAnimationOptionRepeat

I am trying to chain a set of UIView animateWithDuration: using the flag UIViewAnimationOptionRepeat
The animation steps I am trying to repeat are:
Animate a UIView 100 pixels to the left
Fade the UIView out (opacity '0')
While faded out (invisible), move it back to the original position (100 px to the right)
Fade the UIView back in (set opacity to '1')
Repeat the animation using flag UIViewAnimationOptionRepeat
I am not able to repeat the whole chain of animations - and only able to repeat the top most animation.
The code I have tried is this:
[UIView animateWithDuration:1 delay:0 options:UIViewAnimationOptionRepeat animations:^{
self.handImageView.frame = CGRectMoveByXPixels(self.handImageView.frame, -100);
[UIView animateWithDuration:0.5 delay:1 options:0 animations:^{
self.handImageView.alpha = 0;
} completion:^(BOOL finished) {
self.handImageView.frame = CGRectMoveByXPixels(self.handImageView.frame, 100);
[UIView animateWithDuration:0.5 delay:0 options:0 animations:^{
self.handImageView.alpha = 1;
} completion:^(BOOL finished) {
}];
}];
} completion:^(BOOL finished) {
}];
The problem is that an animation that uses UIViewAnimationOptionRepeat never finishes and therefore never calls the completion block. However, you can repeat the animations using the performSelector method, as shown in the code below.
- (void)repeatingAnimationForView:(UIView *)view
{
[UIView animateWithDuration:1 delay:0 options:0
animations:^{ view.frame = CGRectMoveByXPixels(view.frame, -100); }
completion:^(BOOL finished) { if ( finished ) {
[UIView animateWithDuration:0.5 delay:0 options:0
animations:^{ view.alpha = 0; }
completion:^(BOOL finished) { if ( finished ) {
view.frame = CGRectMoveByXPixels(view.frame, 100);
[UIView animateWithDuration:0.5 delay:0 options:0
animations:^{ view.alpha = 1; }
completion:^(BOOL finished) { if ( finished ) {
if ( self.enableRepeatingAnimation )
[self performSelector:#selector(repeatingAnimationForView:) withObject:view afterDelay:0];
}}]; }}]; }}];
}
- (void)stopRepeatingAnimationForView:(UIView *)view
{
self.enableRepeatingAnimation = NO;
[view.layer removeAllAnimations];
view.frame = CGRectMake( 100, 137, 80, 50 );
view.alpha = 1;
}
- (void)startRepeatingAnimationForView:(UIView *)view
{
self.enableRepeatingAnimation = YES;
[self repeatingAnimationForView:view];
}
To stop the animations immediately, call the stopRepeatingAnimationForView method as shown above. To stop the animations at the end of a cycle, simply set self.enableRepeatingAnimation to NO.

UIView animation on completion not working properly

I have a problem using a slider to trigger a series of animations, here's the code:
-(void)slideAlpha:(id)sender{
self.bigPhotoViewA.alpha = self.alphaSlider.value;
if (self.alphaSlider.value == 1){
[UIView animateWithDuration:1
animations:^{
self.alphaSlider.alpha = 0;
} completion:nil
];
[self performSelector:#selector(nextPhotoAnimation) withObject:self afterDelay:5.0 ];
}
}
-(void) nextPhotoAnimation{
self.alphaSlider.value = 0;
[UIView animateWithDuration:2
animations:^{
self.bigPhotoViewA.alpha = 0.0;
self.bigPhotoView.alpha = 0.0;
self.smallPhotoView.center = CGPointMake(startX, startY);
}
completion:^(BOOL finished) {
NSLog(#"Animation ended");
self.smallPhotoView.image = ((UIImage *)[smallImagesArray objectAtIndex:imageCount]);
}
];
}
So, when the slider reaches a value of 1, nextPhotoAnimation is launched after a delay. So far so good. The problem comes inside nextPhotoAnimation. The animations block runs ok, but the completion block runs several times every time nextPhotoAnimation is called. I get the NSLog from 6 to 9 times displayed when nextPhotoAnimation starts, and then I get it again at the right time, after 2 seconds.
I've tried to replicate the problem with simpler code and the animation/completion flow works just fine.
Try this in nextPhotoAnimation,
-(void) nextPhotoAnimation{
self.alphaSlider.value = 0;
[UIView animateWithDuration:2
animations:^{
self.bigPhotoViewA.alpha = 0.0;
self.bigPhotoView.alpha = 0.0;
self.smallPhotoView.center = CGPointMake(startX, startY);
}
completion:^(BOOL finished) {
if (finished) {
NSLog(#"Animation ended");
self.smallPhotoView.image = ((UIImage *)[smallImagesArray objectAtIndex:imageCount]);
}
}
];
}
neither you are using
[UIView beginAnimations:nil context:nil];
nor
[UIView commitAnimations];
Best way is to create a UIView and then use the protocols.call your methods using [self YOURMETHOD]; in the View.
:-)

When creating an animation to cause a UIImageView to go up and down (almost float) infinitely, how do I stop a pause at the end of the animation?

Here's the code I'm using to take a UIImageView and make it float up and down.
[UIView animateKeyframesWithDuration:2.0 delay:0.0 options:UIViewKeyframeAnimationOptionRepeat animations:^{
[UIView addKeyframeWithRelativeStartTime:0.0 relativeDuration:0.25 animations:^{
self.slider.transform = CGAffineTransformMakeTranslation(0, -5.0);
}];
[UIView addKeyframeWithRelativeStartTime:0.25 relativeDuration:0.5 animations:^{
self.slider.transform = CGAffineTransformMakeTranslation(0, 5.0);
}];
[UIView addKeyframeWithRelativeStartTime:0.75 relativeDuration:0.25 animations:^{
self.slider.transform = CGAffineTransformMakeTranslation(0, 0.0);
}];
} completion:^(BOOL finished) {
}];
However, it comes out looking like this with this delay after the animation ends and before it restarts.
How do I make it fluid?
I'm not sure what effect you're going for exactly, but I think this gives you something like your code does without the delay. I usually do this by animating a constraint, rather than using transforms. In this example, I've made an IBOutlet (topCon) to the constraint to the top of the view:
-(IBAction)floatView:(id)sender {
static int i= 1;
static float duration = .25;
[UIView animateWithDuration:duration delay:0 options:UIViewAnimationOptionCurveLinear animations:^{
self.topCon.constant = self.topCon.constant - (5 * i);
[self.view layoutIfNeeded];
} completion:^(BOOL finished) {
i = (i == 1 || i == 2)? -2 : 2;
duration = 0.5;
[self floatView:self];
}];
}

Slide UILabel Onto View Controller

I'm trying to move a UILabel from a starting position of off the top of my UIViewController in a smooth slide type animation so that it slides down from the top when the view loads and then stops at a y position for about 10 seconds. After 10 seconds I want to slide back off the view again.
-(void) animateInstructionLabel
{
float newX = 50.0f;
float newY = 100.0f;
[UIView transitionWithView:self.lblInstruction
duration:10.0f
options:UIViewAnimationCurveEaseInOut
animations:^(void) {
lblInstruction.center = CGPointMake(newX, newY);
}
completion:^(BOOL finished) {
// Do nothing
}];
}
But I don't know how to do the 10 second delay and then move back within the method above. The end result is that I want this to be a label that appears like a notification and then moves off screen again.
Could someone hep me put these pieces described above together?
EDIT
I am adding this based on answer below:
-(void) animateInstructionLabel
{
float newX = lblInstruction.frame.origin.x;
float newY = 20.0f;
lblInstruction.center = CGPointMake(lblInstruction.frame.origin.x, -20.0f);
lblInstruction.bounds = CGRectMake(lblInstruction.frame.origin.x, -20.0f, 650.0f, 40.0f);
[UIView animateWithDuration:3.0f
delay:0
options:UIViewAnimationCurveEaseInOut
animations:^(void) {
lblInstruction.center = CGPointMake(newX, newY);
}
completion:^(BOOL finished) {
[UIView animateWithDuration:5.0f
delay:5.0
options:UIViewAnimationCurveEaseInOut
animations:^(void) {
lblInstruction.center = CGPointMake(newX, -20);
}
completion:^(BOOL finished) {
// Do nothing
}
];
}
];
}
But even though I am setting the label.center off the screen before the animation starts I am seeing that it moves from top left corner of the viewcontroller to the center of the viewcontroller. It is not keeping the x position that it should be set to before the animation begins.
Try adding this after your animation block (oldX,oldY are the old coordinates, before animating the label in):
double delayInSeconds = 10.0;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
[UIView transitionWithView:self.lblInstruction
duration:10.0f
options:UIViewAnimationCurveEaseInOut
animations:^(void) {
lblInstruction.center = CGPointMake(oldX, oldY);
}
completion:^(BOOL finished) {
// Do nothing
}];
});
Something like this should work:
-(void) animateInstructionLabel {
float newX = 50.0f;
float newY = 100.0f;
labelInstruction.center = CGPointMake(newX, -20); // start off screen
[UIView animateWithDuration:10.0f
delay:0
options:UIViewAnimationCurveEaseInOut
animations:^(void) {
lblInstruction.center = CGPointMake(newX, newY);
}
completion:^(BOOL finished) {
[UIView animateWithDuration:10.0f
delay:10.0
options:UIViewAnimationCurveEaseInOut
animations:^(void) {
lblInstruction.center = CGPointMake(newX, -20);
}
completion:^(BOOL finished) {
// Do nothing
}
];
}
];
}
Here is what worked in case it helps somebody else. I had to use .frame instead of .center to set the initial position and then the subsequent animation back to that position.
-(void) animateInstructionLabel
{
lblInstruction.frame = CGRectMake(lblInstruction.frame.origin.x, -40.0f, 650.0f, 40.0f);
[self.view addSubview:lblInstruction];
lblInstruction.hidden = NO;
float newX = lblInstruction.frame.origin.x;
float newY = 20.0f;
[UIView animateWithDuration:3.0f
delay:0
options:UIViewAnimationCurveEaseInOut
animations:^(void) {
lblInstruction.center = CGPointMake(newX, newY);
}
completion:^(BOOL finished) {
[UIView animateWithDuration:3.0f
delay:5.0
options:UIViewAnimationCurveEaseInOut
animations:^(void) {
lblInstruction.frame = CGRectMake(lblInstruction.frame.origin.x, -40.0f, 650.0f, 40.0f);
}
completion:^(BOOL finished) {
lblInstruction.hidden = YES;
}
];
}
];
}
This smoothly makes the label slide down from off the view, stop for 5 seconds and then smoothly moves it back vertically off the view.
Thanks for the previous answers which lead me to the above final solution.

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