As a test I made one layout that displays cells in a vertical line and another that displays them in a horizontal layout. When I call [collectionView setCollectionViewLayout:layout animated:YES]; it animates between the two positions very cleanly.
Now that I'd like to do is have all the views do a few spins, warps and flips around the screen (probably using CAKeyframeAnimations) before finally arriving at their destination, but I can't find a good place to hook this in.
I tried subclassing UICollectionViewLayoutAttributes to contain an animation property, then setting those animations in an overridden applyLayoutAttributes: method of the UICollectionViewCell I'm using. This works... EXCEPT it appears to happen only after the layout transition is complete. If I wanted to use this, I'd have to have the layout not change the current positions of the objects right away, only after the it reaches this apply attributes part of the code, and that seems like a lot of work...
Or I could subclass UICollectionView and override setCollectionViewLayout:animated:, but that also seems like a lot of state to keep around between layouts. Neither of these optins seems right, because there's such an easy way to animate additions/deletions of cells within a layout. I feel like there should be something similar for hooking into the animations between layouts.
Does anyone know the best way to get what I'm looking to accomplish?
#define degreesToRadians(x) (M_PI * (x) / 180.0)
UICollectionView *collectionView = self.viewController.collectionView;
HorizontalCollectionViewLayout *horizontalLayout = [HorizontalCollectionViewLayout new];
NSTimeInterval duration = 2;
[collectionView.visibleCells enumerateObjectsUsingBlock:^(UICollectionViewCell *cell, NSUInteger index, BOOL *stop)
{
CABasicAnimation *rotationAnimation;
rotationAnimation = [CABasicAnimation animationWithKeyPath:#"transform.rotation"];
rotationAnimation.toValue = #(degreesToRadians(360));
rotationAnimation.duration = duration;
rotationAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
[cell.layer addAnimation:rotationAnimation forKey:#"rotationAnimation"];
}];
[UIView animateWithDuration:duration
animations:^
{
collectionView.collectionViewLayout = horizontalLayout;
}];
Related
What I Want to Do:
In Messages.app on OS 10.10, when you scroll the left-most pane (the list of conversations) upwards, a nice horizontal line fades in over about 0.5 seconds. When you scroll back down, the line fades back out.
What I Have:
I am trying to achieve this effect in my own app and I've gotten very close. I subclassed NSScrollView and have done the following:
- (void) awakeFromNib
{
_topBorderLayer = [[CALayer alloc] init];
CGColorRef bgColor = CGColorCreateGenericGray(0.8, 1.0f);
_topBorderLayer.backgroundColor = bgColor;
CGColorRelease(bgColor);
_topBorderLayer.frame = CGRectMake(0.0f, 0.0f, self.bounds.size.width, 1.0f);
_topBorderLayer.autoresizingMask = kCALayerWidthSizable;
_topBorderLayer.zPosition = 1000000000;
_fadeInAnimation = [[CABasicAnimation animationWithKeyPath:#"opacity"] retain];
_fadeInAnimation.duration = 0.6f;
_fadeInAnimation.fromValue = #0;
_fadeInAnimation.toValue = #1;
_fadeInAnimation.removedOnCompletion = YES;
_fadeInAnimation.fillMode = kCAFillModeBoth;
[self.layer insertSublayer:_topBorderLayer atIndex:0];
}
- (void) layoutSublayersOfLayer:(CALayer *)layer
{
NSPoint origin = [self.contentView documentVisibleRect].origin;
// 10 is a fudge factor for blank space above first row's actual content
if (origin.y > 10)
{
if (!_topBorderIsShowing)
{
_topBorderIsShowing = YES;
[_topBorderLayer addAnimation:_fadeInAnimation forKey:nil];
_topBorderLayer.opacity = 1.0f;
}
}
else
{
if (!_topBorderIsShowing)
{
_topBorderIsShowing = NO;
// Fade out animation here; omitted for brevity
}
}
}
The Problem
The "border" sublayer that I add is not drawing over top of all other content in the ScrollView, so that we end up with this:
The frames around the image, textfield and checkbox in this row of my outlineView are "overdrawing" my border layer.
What Causes This
I THINK this is because the scrollView is contained inside an NSVisualEffectView that has Vibrancy enabled. The reason I think this is that if I change the color of my "border" sublayer to 100% black, this issue disappears. Likewise, if I turn on "Reduce Transparency" in OS X's System Preferences > Accessibility, the issue disappears.
I think the Vibrancy compositing is taking my grey border sublayer and the layers that represent each of those components in the outlineView row and mucking up the colors.
So... how do I stop that for a single layer? I've tried all sorts of things to overcome this. I feel like I'm 99% of the way to a solid implementation, but can't fix this last issue. Can anyone help?
NB:
I am aware that it's dangerous to muck directly with layers in a layer-backed environment. Apple's docs make it clear that we can't change certain properties of a view's layer if we're using layer-backing. However: adding and removing sublayers (as I am) is not a prohibited action.
Update:
This answer, while it works, causes problems if you're using AutoLayout. You'll start to get warnings that the scrollView still needs update after calling Layout because something dirtied the layout in the middle of updating. I have not been able to find a workaround for that, yet.
Original solution:
Easiest way to fix the problem is just to inset the contentView by the height of the border sublayer with this:
- (void) tile
{
id contentView = [self contentView];
[super tile];
[contentView setFrame:NSInsetRect([contentView frame], 0.0, 1.0)];
}
Should have thought of it hours ago. Works great. I'll leave the question for anyone who might be looking to implement these nice fading-borders.
I put UIImageView in my Scene from Object library, and give it an image and defined OUTLET in .h file. Now I want to check its coordinates, or center point, or frame X,Y,Width,Height.
I am using
This
CGRect newFrameSize = CGRectMake(recycleBin.frame.origin.x, recycleBin.frame.origin.y,
recycleBin.frame.size.width, recycleBin.frame.size.height);
or
CGRect newFrameSize = recycleBin.frame;
by using this
NSLog(#"%#", NSStringFromCGRect(newFrameSize));
gives same result that is
2013-01-16 21:42:25.101 xyzapp[6474:c07] {{0, 0}, {0, 0}}
I want its actual position and size when viewcontroller loaded, so when user click on image view it will fadeout by zoom-in towards users and will disappear, and when user tap on reset button, it fadein and zoom-in back to original form (reverse to the previous animation).
Also give me hint, how to perform this animation on UIImageView or any button or label. Thx
Unfortunately, you can't check an item's actual frame as set in IB in -viewDidLoad. The earliest you can check it (that I've found) is by overriding -viewDidAppear:. But, since -viewDidAppear: could be called multiple times throughout the life of the view, you need to make sure you're not saving the frame it's in the modified state.
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
if(savedFrame == CGRectZero) {
savedFrame = self.recycleBin.frame;
NSLog(#"Frame: %#", NSStringFromCGRect(savedFrame));
}
}
Where savedFrame is a member variable (or you could make it a property).
From the description of the animation you're wanting, it sounds like adjusting the frame isn't the way to go about it. It sounds like you're wanting to get the effect of the view stretching and fading out (and the reverse when being reset)? If so, some code like this might be more so what you're looking for...
Fade out:
float animationDuration = 2.0f; // Duration of animation in seconds
float zoomScale = 3.0f; // How much to zoom in duration the animation
[UIView animateWithDuration:animationDuration animations:^{
CGAffineTransform transform = CGAffineTransformMakeScale(zoomScale, zoomScale);
self.recycleBin.transform = transform;
self.recycleBin.alpha = 0; // Make fully transparent
}];
And then, to reset the view:
float animationDuration = 2.0f; // Duration of animation in seconds
[UIView animateWithDuration:animationDuration animations:^{
CGAffineTransform transform = CGAffineTransformMakeScale(1.0f, 1.0f);
self.recycleBin.transform = transform;
self.recycleBin.alpha = 1.0; // Make fully opaque
}];
You can play around with the numbers to see if you get the effects you desire. Most animations in iOS are actually extremely simple to do. This code would work for any UIView subclass.
It sounds as if your IBOutlet is not attached to your class.
Open up your view controller header file (if that is where you property declaration is) and look beside the declaration:
Notice how on the first IBOutlet, the circle (to the left of the line number) is filled in. This means that it is connected to your scene. However, the second one is not (the circle is not filled in).
I have an odd problem in one of my chain animations. I have block object for each of the blocks on my screen (26 of them), and when the user presses them I perform a flip. It works great, but I'm adding a scale animation before I do these to make them about 50% bigger on the screen. So, my sequence is:
enlarge
delay (let user see the large image)
spin-out 90% (removes block from view) - using transform.rotation.y
change image & spin-in
shrink.
I have setup the window view controller to be a delegate of these blocks, such that it can pass a counter to the blocks so I can position the right sublayer on the top (using setZposition).
It all works great, except when I have 2 blocks on positioned above/below each other on the screen, such that the enlarge will cause them to overlap, and then when the spin-out animation starts, it immediately has the right side of the block pop behind the block below it. I've tried changing the animation to transform.rotation.x and get the same behavior when the blocks are side-to-side.
I'm not sure if it's an iOS bug of if I'm just not doing something correct. Any suggestions are greatly appreciated. Here is the spin-out method:
- (void)spinOut:(id)sender
{
NSTimeInterval animationTime=0.85;
[UIView animateWithDuration:animationTime
delay:0
options: UIViewAnimationOptionCurveLinear
animations:^{
// setup the animation to spin the current view out
[CATransaction begin];
[CATransaction setDisableActions:YES];
CABasicAnimation *spinOut = [CABasicAnimation animationWithKeyPath:#"transform.rotation.y"];
[spinOut setDelegate:self];
[spinOut setDuration:animationTime];
CAMediaTimingFunction *tf = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
[spinOut setTimingFunction:tf];
[spinOut setFromValue:[NSNumber numberWithFloat:M_PI * 0.0]];
[spinOut setToValue:[NSNumber numberWithFloat:M_PI * 0.5]];
[spinOut setRemovedOnCompletion:NO];
[spinOut setFillMode:kCAFillModeForwards];
// setup variables used to roll in the next view on animation completion.
[pageView.layer addAnimation:spinOut forKey:kMyVeryOwnABCsSpinOutKey];
[CATransaction commit];
}
completion:^(BOOL finished){
[self setFlipOutAnimationTimer:[NSTimer scheduledTimerWithTimeInterval:animationTime target:self selector:#selector(spinIn:) userInfo:nil repeats:NO]];
}];
}
OK - this is an old question, but I kindof figured out this problem. Since I was flipping these images around the Y axis, I was able to change the animated image's Zposition. In my startAnimation method, I added:
float pageLevelLayerPosition;
// logic to set the zposition variable 100 more than anything nearby
_originalImageViewZPosition = bigImageView.layer.zPosition;
[bigImageView.layer setZPosition:pageLevelLayerPosition];
and then when in the animationDidStop, I added the relevant line of code to reset it back to 0 where I was removing the animation. I had some code to manage the variable so that I was assured that the number was greater than anything nearby.
I guess if I ever get into 3-D animation, then I'll need to control this much more closely, but that is what was causing my problem.
My app uses CALayer to draw views. More precisely, it uses the drawLayer:inContext: method on a sublayer of a UIView's top layer. This is a nice way to get the 'implicit' animation of consecutive drawLayer:inContext: drawings to fade into each other over time. The fading animations happen fairly fast, maybe in 0.25 seconds, but to change its duration, simply implement another delegate method called actionForLayer:forKey:. In this perfectly working example implementation here the default duration is stretched to 2.0 seconds:
- (id<CAAction>)actionForLayer:(CALayer *)layer forKey:(NSString *)event
{
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:event];
animation.duration = 2.0;
return animation;
// or return nil for the default duration.
}
On to the issue at hand.
If you call [sublayer setNeedsDisplay] faster than the fades have time to complete, with each new fade you'll see a sudden jump. From the looks of it, the fade that's in progress is cancelled and it's final state is used as the starting point of the new fade. This might not be very surprising, but the visual result is rather unwanted.
Consider the scenario of a ten second fade from black to white, with another fade, to black, triggered five seconds after the start. The animation will start fading from black to white, but when it's at a 'half way gray' it jumps to full white before fading to black again.
Is there a way to prevent this from happening? Can I get the layer to fade from the gray back down to black? Is there a CALayer drawing equivalent of saying UIViewAnimationOptionBeginFromCurrentState (used in UIView animations)?
Cheers.
A layer's animation is only a visual representation of what the layer should look like as it animates. In CA when you animate from one state to another, the entire state of the layer changes immediately. A presentation layer is created and displays the animation, and when the animation completes the actual layer is left in place at the end.
So, my guess is that when you want to transition from one state to another, and the current animation hasn't completed yet, you have to capture the current state of the animation and then use this as the starting point for your next animation.
The problem lies in not being able to modify a layer's current animation.
In the following post I capture the current state of an animation, set that as the current state for the layer and use that as the beginning value from which to animate. The post applies this technique to the speed / duration of an animation, but can also be applied to your scenario.
https://stackoverflow.com/a/9544674/1218605
I'm a little stumped on this one too.
Did you forget to specify the fillMode kCAFillModeForwards. There's more info about that in the reference docs.
For example, I got this to work without any snapping, although I'm not changing the duration.
#implementation FadingLayer
- (void)fadeOut {
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"backgroundColor"];
animation.fillMode = kCAFillModeForwards;
animation.fromValue = (id)[UIColor redColor].CGColor;
animation.toValue = (id)[UIColor colorWithRed:1.0 green:0.0 blue:0.0 alpha:0.0].CGColor;
animation.removedOnCompletion = FALSE;
animation.delegate = self;
[self addAnimation:animation
forKey:#"test"];
}
- (void)fadeIn {
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"backgroundColor"];
animation.fillMode = kCAFillModeForwards;
animation.fromValue = (id)[UIColor colorWithRed:1.0 green:0.0 blue:0.0 alpha:0.0].CGColor;
animation.toValue = (id)[UIColor redColor].CGColor;
animation.removedOnCompletion = FALSE;
animation.delegate = self;
[self addAnimation:animation
forKey:#"test"];
}
#end
You'll probably want to animate a custom property however.
Hope this helps :/
I wanted to accomplish the same thing with a zoom animation of a layer tree. I have a zoom in/out key-equivalent where the user can zoom the layer tree accordingly. However, if the user presses the zoom key-equivalent in rapid succession, there would be a temporary snap-back to the values prior to the onset of the animation, since the previous animation hadn't yet completed.
At the end of the animation code, performing a sole [CATransaction commit] forced any pending transactions to be committed to the layer model before the start of the next animation, and solved the problem.
The documentation says:
+ commit
Commit all changes made during the current transaction.
Declaration
+ (void)commit
Special Considerations
Raises an exception if no current transaction exists.
However, testing this with many [CATransaction commit] messages in succession doesn't actually raise an exception. I've used this same technique to squelch warnings of the form:
CoreAnimation: warning, deleted thread with uncommitted
CATransaction;
in an NSOperation whose thread of execution finishes before layer animations do. It could be that Apple changed this behaviour in recent OS releases to a no-op (which would be much saner) if no current transaction exists, without updating the documentation.
I'm working on a custom UITableViewCell subclass, where everything is drawn in code rather than using UILabels etc. (This is part learning exercise and partly because drawing in code is much faster. I know that for a couple of labels it wouldn't make a huge difference, but eventually I'll want to generalise this to more complex cells.)
Currently I'm struggling with the delete button animation: how to animate the cell shrinking as the delete button slides in.
Firstly, I am drawing in a custom subview of the cell's contentView. Everything is drawn in that one subview.
I am setting the subview's size by catching layoutSubviews on the cell itself, and doing:
- (void)layoutSubviews
{
[super layoutSubviews];
CGRect b = [self.contentView bounds];
[subcontentView setFrame:b];
}
I'm doing this rather than just setting an autoresizing mask because it seemed more reliable in testing, but I can use the autoresizing mask approach in testing if needed.
Now, the default thing that happens when someone hits the minus is the view gets squished.
I can avoid that by, when setting up my cell, calling
subcontentView.contentMode = UIViewContentModeRedraw;
That gives me the correct end result (my custom view redraws with the new size, and is laid out properly, like the first image I posted), but the animation of the transition is unpleasant: it looks like the cell stretches and shrinks back to size.
I know why the animation is working like that: Core Animation doesn't ask your view to redraw for each frame, it gets it to redraw for the end position of the animation and then interpolates to find the middle bits.
Another solution is to do
subcontentView.contentMode = UIViewContentModeLeft;
That just draws the delete button over my cell, so it covers part of it.
If I also implement
- (void) didTransitionToState:(UITableViewCellStateMask)state
{
[self setNeedsDisplay];
}
then once the delete button has slid in the cell 'jumps' to the correct size. That way there's no nice slidey animation, but at least I get the correct result at the end.
I guess I could run my own animation in parallel with the delete button appearing, temporarily creating another view with a copy of the image of my view in the old size, setting mine to the new size, and fading between them — that way there would be a nice cross fade instead of a sharp jump. Anyone use such a technique?
Now, you might ask why I can't use the contentStretch property and give it a region to resize. The problem with that is I'm making something to be reasonably generic, so it's not always going to be possible. In this particular example it'd work, but a more complex cell may not.
So, my question (after all of this background) is: what do you do in this situation? Does anyone have the animating delete button working for custom drawn cells? If not, what's the best compromise?
This worked for me finally. in subclass of UITableViewCell
subDrawContentView.contentMode = UIViewContentModeLeft;
overide layout subviews method
- (void)layoutSubviews {
CGRect b = [subDrawContentView bounds];
b.size.width = (!self.showingDeleteConfirmation) ? 320 : 300;
[subDrawContentView setFrame:b];
[subDrawContentView setNeedsDisplay];
[super layoutSubviews];
}
So I will paste the code first and then I will explain:
-(void)startCancelAnimation{
[cancelButton setAlpha:0.0f];
[cancelButton setFrame:CGRectMake(320., cancelButton.frame.origin.y, cancelButton.frame.size.width, cancelButton.frame.size.height)];
cancelButton.hidden=NO;
[UIView animateWithDuration:0.4
animations:^(void){
[progressView setFrame:CGRectMake(progressView.frame.origin.x, progressView.frame.origin.y, 159.0, progressView.frame.size.height)];
[text setFrame:CGRectMake(text.frame.origin.x, text.frame.origin.y, 159.0, text.frame.size.height)];
[cancelButton setFrame:CGRectMake(244., cancelButton.frame.origin.y, cancelButton.frame.size.width, cancelButton.frame.size.height)];
[cancelButton setAlpha:1.0f];
} ];
}
-(void)stopCancelAnimation{
[UIView animateWithDuration:0.4
animations:^(void){
[cancelButton setFrame:CGRectMake(320., cancelButton.frame.origin.y, cancelButton.frame.size.width, cancelButton.frame.size.height)];
[cancelButton setAlpha:0.0f];
}completion:^(BOOL completion){
cancelButton.hidden=YES;
[cancelButton setAlpha:1.0f];
[progressView setFrame:CGRectMake(progressView.frame.origin.x, progressView.frame.origin.y, DEFAULT_WIDTH_PROGRESS, progressView.frame.size.height)];
[text setFrame:CGRectMake(text.frame.origin.x, text.frame.origin.y, DEFAULT_WIDTH_TEXT, text.frame.size.height)];
}
];
}
-(void)decideAnimation{
if([cancelButton isHidden]){
[self startCancelAnimation];
}
else{
[self stopCancelAnimation];
}
}
So what I have there is a button that looks like this:
I have an IBOutlet to it. And what I am doing is resizing a UIProgressView and a UITextField (you can resize whatever you want). As for the code is pretty simple, but if you need any help to understand what's going on, please ask. Also, don't forget to add the Swip Gesture to the UITableView... Like this:
UISwipeGestureRecognizer *gesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(didSwipe:)];
gesture.numberOfTouchesRequired=1;
gesture.direction = UISwipeGestureRecognizerDirectionRight;
[table addGestureRecognizer:gesture];
[gesture release];
Finally the method that does it all:
-(void)didSwipe:(UIGestureRecognizer *)gestureRecognizer {
if (gestureRecognizer.state == UIGestureRecognizerStateEnded) {
//Get the cell of the swipe...
CGPoint swipeLocation = [gestureRecognizer locationInView:self.table];
NSIndexPath *swipedIndexPath = [self.table indexPathForRowAtPoint:swipeLocation];
UITableViewCell* swipedCell = [self.table cellForRowAtIndexPath:swipedIndexPath];
//Make sure its a cell with content and not an empty one.
if([swipedCell isKindOfClass:[AMUploadsTableViewCell class]]){
// It will start the animation here
[(AMUploadsTableViewCell*)swipedCell decideAnimation];
// Do what you want :)
}
}
}
So as you can see the whole animation is created manually, so you can control exactly what you want. :)