I am currently making an app that has a complex loading screen. I have created the loader using UI Animation, but want to add a button that will appear once the loading bar has finished. I have come across the idea of hiding the button for a certain period of time, or making it appear after a certain period of time.
How would I show/hide the button after a period of time?
You could invoke your method to show the button after a certain period of time:
[self performSelector:#selector(showButton) withObject:nil afterDelay:0.5];
Or, probably better, if you want to animate the appearance of the button, you can do both the animation and the delay in a single call, e.g. assuming the button originally has alpha of 0.0:
[UIView animateWithDuration:0.25
delay:0.5
options:nil
animations:^{
myButton.alpha = 1.0;
}
completion:^(BOOL finished){
// if you want to do anything when animation is done, do it here
}
];
Using NSTimer should be the easiest way.
Create NSTimer to do that,
Timer = [NSTimer scheduledTimerWithTimeInterval:5 target:self selector:#selector(hideButton:) userInfo:nil repeats:NO];
-(void)hideButton:(UIButton *)hideButton {
if hideButton.isHidden == false {
hideButton.hidden=TRUE;
} else {
hideButton.hidden = FALSE
}
Related
I'm trying to make a button change color while being pressed for 3 seconds. Once timer reaches 3rd second the color change is permanent but if user releases button before time is up the button goes back to its original color. What I have so far is this:
in viewDidLoad
UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc]
initWithTarget:self
action:#selector(fireSomeMethod)];
longPress.minimumPressDuration = 3.0;
[self.view addGestureRecognizer:longPress];
in fireSomeMethod I have
- (void)someMethod {
[UIView transitionWithView:self.button
duration:2.0
options:UIViewAnimationOptionCurveEaseIn
animations:^{
self.button.backgroundColor = [UIColor redColor];
}
completion:^(BOOL finished) {
NSLog(#"animation finished");
}];
}
This requires me to hold the button down for 3 seconds for the animation to fire and animation itself takes 2 seconds to complete. The desired behavior is that animation starts when longPress starts and I release button before 3 seconds everything goes back to the way it was. Thanks for your help in advance
Make use of button event no need to use UILongPressGestureRecognizer
Make 2 action for your button, one is for Touch Down and other is for Touch Up Inside
like this
// For `Touch Up Inside`
- (IBAction)btnReleased:(id)sender {
[timer invalidate];
NSLog(#"time - %d",timeStarted);
}
// For `Touch Down`
- (IBAction)btnTouchedDown:(id)sender {
timer = [NSTimer scheduledTimerWithTimeInterval:1.0f
target:self
selector:#selector(_timerFired:)
userInfo:nil
repeats:YES];
timeStarted = 0;
}
- (void)_timerFired:(NSTimer *)timer {\
timeStarted++;
}
Create 2 variable timer of type NSTimer and timeStarted of type int. Fire the timer on Touch Down and invalidate it on Touch Up Inside, and in Touch Up Inside action method get the total time till your button is hold.As shown in the above code
I'm trying to build an animation around a UIButton. The UIButton has a UIImageView that contains an image that I'd like to shrink when the UIButton is held down and then when the UIButton is let go, I'd like to play a separate animation that does a bounce.
The issue I'm experiencing right now is that the 2nd part of the animation doesn't seem to play if I press down and then up very quickly. If I press and hold (wait for the first animation to finish), then let go, it seems to work fine.
Here's the relevant code:
-(void)pressedDown
{
[UIView animateWithDuration:0.2 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{
self.heartPart.layer.transform = CATransform3DMakeScale(0.8, 0.8, 1);
} completion:nil];
}
-(void)pressedUp
{
[UIView animateWithDuration:0.8
delay:0.0
usingSpringWithDamping:20
initialSpringVelocity:200
options:UIViewAnimationOptionBeginFromCurrentState
animations:^{
self.heartPart.layer.transform = CATransform3DIdentity;
}
completion:nil];
}];
}
In my ViewDidLoad I add the following:
[self.heartButton addTarget:self
action:#selector(pressedUp)
forControlEvents:UIControlEventTouchUpInside];
[self.heartButton addTarget:self
action:#selector(PressedDown)
forControlEvents:UIControlEventTouchDown];
Any idea how I can get the two animations to sequence and not interrupt each other even on a quick press?
Here's a potential plan of action. Keep two global variables, BOOL buttonPressed and NSDate *buttonPressDate. When the button is pressed, you should set buttonPressed to true and set buttonPressDate to the current date. Now in the touch up method, you would set buttonPressed to false and check whether the time interval between buttonPressDate and the current date is greater than the duration of the animation. If it is, then run the touch up animation; if not, return. In the completion block of the touch down method, you would check if the button was still pressed. If it is, then do nothing; if it's not pressed anymore, then run the touch up animation.
The effect you'll get using this approach should be the following: if you tap the button quickly, it will run the full 0.2-second shrink animation and then run the enlarge animation in sequence.
Now, if you don't want the touch down animation to run in the case of a quick touch, you should probably delay the first animation and check if the button is still pressed when you start it. If it was a quick touch, you would run a modified animation that covered both the touch down and touch up phases.
You could try out the following :-
//Set only one target with TouchUpInside.
[self.heartButton addTarget:self
action:#selector(pressedUp)
forControlEvents:UIControlEventTouchUpInside];
-(void)pressedDown
{
[UIView animateWithDuration:0.2 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{
self.heartPart.layer.transform = CATransform3DMakeScale(0.8, 0.8, 1);
}
completion:
[self pressedUp];
//Or
[self performSelector:#selector(pressedUp) withObject:self afterDelay:0.5];
];
}
-(void)pressedUp
{
[UIView animateWithDuration:0.8
delay:0.0
usingSpringWithDamping:20
initialSpringVelocity:200
options:UIViewAnimationOptionBeginFromCurrentState
animations:^{
self.heartPart.layer.transform = CATransform3DIdentity;
}
completion:nil];
}];
}
This way as first animation is completed then next animation will start But my concern is that it won't look appropriate and it would be a bit long animation to show to a user. Rest it's upto your app design and what all it is going to achieve with it.
I assume you are familiar with the concept of operations. If not then NSOperations allow you to keep your code modular and enable you to set the order of execution.
You could create a custom subclass of NSOperation and run animation within its execution block, then add operations with animations on queue each time user interacts with the button.
Apart from documentation from Apple, there is a great example of how to subclass NSOperation available on Github:
https://github.com/robertmryan/AFHTTPSessionOperation/blob/master/Source/AsynchronousOperation.m
Based on that "blueprint" for your custom operations, it's very trivial to achieve what you want, i.e.:
#interface PressDownAnimationOperation : AsynchronousOperation
- (instancetype)initWithView:(UIView *)view;
#end
#implementation PressDownAnimationOperation {
UIView *_view;
}
- (instancetype)initWithView:(UIView *)view {
self = [super init];
if(self) {
_view = view;
}
return self;
}
- (void)main {
// dispatch UIKit related stuff on main thread
dispatch_async(dispatch_get_main_queue(), ^{
// animate
[UIView animateWithDuration:0.2 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{
_view.layer.transform = CATransform3DMakeScale(0.8, 0.8, 1);
} completion:^(BOOL finished){
// mark operation as finished
[self completeOperation];
}];
});
}
#end
Now in order to run animations you need to create NSOperationQueue. You can keep it within your view controller, i.e.:
#implementation ViewController {
NSOperationQueue *_animationQueue;
}
- (void)viewDidLoad {
[super viewDidLoad];
_animationQueue = [[NSOperationQueue alloc] init];
// limit queue to run single operation at a time
_animationQueue.maxOperationCount = 1;
}
#end
Now when you want to chain animations, you simply create new operation, add it to queue and that's it, i.e.:
- (void)pressedDown {
NSOperation *animationOperation = [[PressDownAnimationOperation alloc] init];
[_animationQueue addOperation:animationOperation];
}
If user taps too fast and you notice that your operation queue is clogged with animations, you can simply cancel all animations before adding new one, i.e.:
[_animationQueue cancelAllOperations];
In theory this progress bar should last 7 seconds, however it seems to run a little long. My math has to be incorrect or I'm overlooking something.
Timer should be firing 100 times in 1 second and the progress bar should take about 7 times longer than that to reach 1.0
Any help would be greatly appreciated.
- (void)startTimer;
{
[pBar showProgress:self.progress];
[self.timer invalidate];
self.timer = nil;
if (self.progress < 1.0) {
CGFloat step = 0.01;
self.timer = [NSTimer scheduledTimerWithTimeInterval:step target:self
selector:#selector(startTimer)
userInfo:nil repeats:NO];
self.progress = self.progress + 0.00143;
} else {
[self performSelector:#selector(stopProgress)
withObject:nil afterDelay:0.5];
}
}
You should not update as often as you do. 100 times per second is way too often. 60 would be sufficient to achieve a good frame-rate in theory. However a UIProgressBar can update its value with an animation. Hence you only need to update say 70 times in total or 10 times per second and make the changes with an animation.
I would go for 10 animated updates or less. Or you could try to update with one animation:
[UIView animateWithDuration:7.0 animations:^{
[progressView setProgress:1.0 animated:YES]; //maybe try animated: NO here
} completion:^(BOOL finished) {
//ended
}];
While I did not test this approach, it seems far cleaner than manually performing what essentially is a timed animation of the progress.
Hi everyone,
small question.
I have an UIView class that I created, AnimatedUIView.
In the init, I create a subview that I animate like this:
- (void)animateView{
[UIView animateWithDuration:4.0
delay:1.0
options: nil
animations:^{
// Animation PART 1
}
completion:^(BOOL completed){
[UIView animateWithDuration:4.0
animations:^{
// Animation PART 2
}
completion:^(BOOL completed){
[self animateView];
}
];
}
];
}
I have to call [self animateView] myself in the second completion block rather than using option repeat because I want to delay 1 second only the first animation.
Everything works fine, I alloc and init my view and add it as a subview, and it is animated as should.
But, when I close my superview, I guess ARC does its work and deallocs the animatedView, but my CPU goes 100 % !
I have investigated and if I comment the call to [self animateView], my CPU doesn't skyrocket when I close the superview.
So I've managed to solve the problem (by putting a condition before the call and changing a boolean value before closing the superview, keepAnimating = NO) , I just wanted to understand WHY it does this?
Why does it try to keep animating, and why does it use so much CPU?
If I put an NSLog in the completion block, I first see it every 8 seconds, but when I close the superview, the NSLog just keeps appearing every ms...
BTW: it relates to this question : UIView animation using 90%CPU , which was not really answered. Thanks a lot!
CPU going to 100% almost always means infinite recursion.
We can only guess because only Apple knows what's inside the animation source code.
In this case I guess this could be caused by triggering the animation when the animation cannot run anymore (e.g. there is no layer since we are in dealloc state). That would mean the completion handler is called immediately and that leads to infinite recursion.
There are safer ways to create infinite animations (e.g. using CAAnimation on the layer).
You should not use self in side the block. It will create a retain cycle. If it is necessary to call self create a weak self pointer. Code like this
__weak typeof(self) weakself = self;
[UIView animateWithDuration:4.0
delay:1.0
options: nil
animations:^{
// Animation PART 1
}
completion:^(BOOL completed){
[UIView animateWithDuration:4.0
animations:^{
// Animation PART 2
}
completion:^(BOOL completed){
[weakself animateView];
}
];
}
];
But main issue with your code is you calling animateView recursively without any base case. So i consuming CPU cycles... do not use animateView without base case.
Try using timer
Write following line in your viewDidLoad or any where else from where you want animation to start.
[NSTimer scheduledTimerWithTimeInterval:9 target:self selector:#selector(animateView) userInfo:nil repeats:YES];
// 9 is total animation duration.....
update your animateView method as follows:
- (void)animateView{
[UIView animateWithDuration:4.0
delay:1.0
options: nil
animations:^{
// Animation PART 1
}
completion:^(BOOL completed){
[UIView animateWithDuration:4.0
animations:^{
// Animation PART 2
}
completion:^(BOOL completed){
}
];
}
];
}
I'm trying to make multiple buttons fall down the screen all at once, at different speeds. But when I have my if statement check if it passed through the value, all the other buttons disappear with it. I'm also incrementing the score to go -1 each time a button passes through the Y value. Any help is appreciated, thanks.
- (void)b1Fall
{
b1.center = CGPointMake(b1.center.x, b1.center.y+6);
if (b1.center.y >= 506) {
[self updateScore];
b1.center = CGPointMake(44, 11);
}
}
- (void)b2Fall
{
b2.center = CGPointMake(b2.center.x, b2.center.y+7);
if (b2.center.y >= 506) {
[self updateScore];
b2.center = CGPointMake(160, 11);
}
}
- (void)b3Fall
{
b3.center = CGPointMake(b3.center.x, b3.center.y+8);
if (b3.center.y >= 506) {
[self updateScore];
b3.center = CGPointMake(276, 11);
}
}
- (void)updateScore
{
healthLabel.text = [NSString stringWithFormat:#"%d", [healthLabel.text intValue]-1];
}
- (void)viewDidLoad
{
[super viewDidLoad];
// REMOVE AFTER TESTING
b1Timer = [NSTimer scheduledTimerWithTimeInterval:0.02 target:self selector:#selector(b1Fall) userInfo:nil repeats:true];
b2Timer = [NSTimer scheduledTimerWithTimeInterval:0.02 target:self selector:#selector(b2Fall) userInfo:nil repeats:true];
b2Timer = [NSTimer scheduledTimerWithTimeInterval:0.02 target:self selector:#selector(b3Fall) userInfo:nil repeats:true];
}
A few things:
1.) Put these animations in viewDidAppear instead of viewDidLoad - you want the animation to begin when the user is actually looking at the buttons, not when the view is loaded into memory, where the user may not be able to see it (viewDidLoad).
2.) Don't use NSTimer for animations, use this:
[UIView animateWithDuration:0.5
delay:1.0
options: UIViewAnimationCurveEaseOut
animations:^{
}
completion:^(BOOL finished){
// loop your animation here.
}];
3.) If you want to make a game, I don't recommend using this approach. All animations using UIKit are going to perform on the main thread and block the user flow. What you want is a framework like Cocos2D where the animations are doing in the GPU and ASYNC game logic is readily supported. UIKit isn't a good choice for game development in general.