The system's camera app has a UI effect. After taking a photo, it will show the animation, which is the photo shrink and move to the left bottom corner.
How can I implement the effect in my app?
Thanks.
In the view that you're trying to shrink call something like this code:
[UIView animateWithDuration:1.0 animations:^{
// self is the view in this case
// if you call this from the controller, use self.view
self.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y, smallWidth, smallHeight);
self.bounds = CGRectOffset(self.bounds, amountToMoveX, amountToMoveY);
}];
This might not be exactly the animation you're looking for but it should give you a good start.
Related
I am trying to make a simple application where there are 3 buttons. When user clicks any of the button, they are animated(moved) to their new positions! All this works from this code:
[UIView animateWithDuration:1.2
delay:0.1
options: UIViewAnimationCurveEaseOut
animations:^
{
//Moving the Sum (UIButton which will move through this animation)
CGRect frame = Sum.frame;
frame.origin.y = -20;
frame.origin.x = (-120);
Sum.frame = frame;
.....
....
}
completion:^(BOOL finished)
{
NSLog(#"Completed");
//adding subview after the animation is complete! newView is an example!
[self.view addSubview:newView];}];
The Problem is that once i add a subview to the main view, All buttons come back to their old position! meaning they weren't moved permanently.. how can i solve this? Plz help guys!
What happens when you add a view? A layout is performed. You could have done two mistakes
You are using autolayout.
If you are using autolayout, changing frames directly is not advised and a relayout will update the views to their original position using current constraints.
You are setting the frame position in layoutSubviews, viewWillLayout or viewDidLayout.
Check where you are setting the original position. Can the method be called multiple times?
You have save the X,Y Position of the new frame & then set this frame by coding.
I started studying objective-c using the iPhone and iPad apps for Absolute Beginners by Rory Lewis book but i got stuck on the 5th chapter.
I want to make a button that shrinks an image.
My problem is, that after I wrote all the code, the image shrinks to the point (0, 0) of the UIImageView (the top left), while in the video the image shrinks to its center. I've done some research and found out that CGAffineTransform uses the center of the object to make translations, rotations etc.
So why does it not work in my case?
I have the latest Xcode version and haven't done anything strange.
I hope I've been clear. Sorry for my English.
EDIT
Sorry for the code, but i wrote the question from my phone.
Anyway the incriminated part goes something like this
- (IBAction)shrink:(id)sender {
if(hasShrink == NO){
[shrinkButton setTitle:#"Grow" forState:UIControlStateNormal];
}
else if(hasShrink == YES){
[shrinkButton setTitle:#"Shrink" forState:UIControlStateNormal];
}
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:1.0];
myIcon.transform = CGAffineTransformMakeScale(.25, .25);
hasShrink = YES;
[UIView commitAnimations];
}
All the animations are correctly written and the app does work, it just shrinks to the top left. Why is the point not set to the center of the UIImageView by default like it should be?
EDIT:
I figured out it was a problem caused by AutoLayout.
Once disabled everything went smooth ;)
If you are transforming a view mangled managed by auto-layout, you may experience some strange side-effects. See this answer for more details.
The solution I ended up employing was to encapsulate the view I wanted to transform inside another view of exactly the same size. The outer view had the appropriate layout constraints applied to it while the inner view was simply centered in its container. Applying a CGAffineTransform scale transform to the inner view now centers properly.
Old question... but just in case others come looking:
The CGAffineTransform acts (rotates, scales) around an anchorPoint.
If you are sizing to 0, 0 then your anchor point is set to 0, 0. If you want it to size to a different point, such as the center of the image, you need to change the anchor point.
The anchor is part of a layer
So if you have a UIImageView called imageview, you would make a call like this to set the anchor to the center of imageview:
[imageview.layer setAnchorPoint:CGPointMake(0.5, 0.5)];
Try something like this:
CGAffineTransform t = CGAffineTransformMakeScale(0.5, 0.5);
CGPoint center = imageView.center; // or any point you want
[UIView animateWithDuration:0.5
animations:^{
imageView.transform = t;
imageView.center = center;
}
completion:^(BOOL finished) {
/* do something next */
}];
Next time show your code. It will be easier to help you.
Check this project: https://github.com/djromero/StackOverflow/archive/Q-13706255.zip
You must study how autolayout and autoresize affect your views. In the project above both are disabled to let you see how it works.
In the Comcast Xfinity iPad app, there is a small button called "Filter by" at the bottom of the screen.
When a user touch the button, a overlay menu will slide up (like the menu UI in Android).
Can anyone give me some hints about how to create this kind of overlay menu?
Thanks.
For this you can create a UIView in your nib and make it look like the menu you need, then in viewdidload you can set its origin to be just off the screen and when you want it to appear just use an animation to slide it up into view and then slide it back off the screen when you're done.
In viewDidLoad:
CGRect frame = [your_menu_view].frame;
frame.origin.y += frame.size.height;
[your_menu_view].frame = frame;
When you are ready to show it:
NSTimeInterval animationDuration = 0.3;//play around with the animation length here
CGRect frame = [your_menu_view].frame;
[UIView beginAnimations:#"MenuSlideIn" context:nil];
[UIView setAnimationDuration:animationDuration];
frame.origin -= frame.size.height;
[your_menu_view].frame = frame;
[UIView commitAnimations];
Then use the same to get rid of it except subtract add its height.
haven't tested it but it should work.
I'm trying to recreate the flipping album animation in iPod.app on the iPad (Music.app in iOS 5). Getting the flipping to work is easy, but I'm having trouble with positioning and enlarging the album. Right now I'm using this code:
[UIView transitionWithView:self.containerView duration:5.0 options:UIViewAnimationOptionTransitionFlipFromLeft | UIViewAnimationOptionShowHideTransitionViews animations:^(void) {
self.firstView.hidden = YES;
self.secondView.hidden = NO;
self.containerView.frame = CGRectMake(600.0, 0.0, 168.0, 1004.0);
} completion:nil];
The flipping works, but there is something strange going on in the animation. The container view does indeed move and resize, but the subviews (firstView and secondView) do not.
Because the superview clips to its bounds (even though I set that to NO; another strange thing!), it appears like the subviews are getting "cut" when the container view moves.
I hope you guys understand the problem. Any Core Animation hero who can help me with this? Thanks.
Have you set the autoresize mask on the child views? Those are used to automatically resize or reposition a view when its superview’s bounds change.
I am looking for a way to do a UIViewAnimationTransitionCurlUp or UIViewAnimationTransitionCurlDown transition on the iPhone but instead of top to bottom, do it from the left to right (or top/bottom in landscape mode). I've seen this asked aroud the internet a few times but none sems to get an answer. However I feel this is doable.
I have tried changing the View's transform and the view.layer's transform but that didn't affect the transition. Since the transition changes when the device changes orientation I presume there is a way to fool the device to use the landscape transition in portrait mode and vice versa?
It's possible to do curls in any of the four directions by using a container view. Set the container view's transformation to the angle you want and then do the curl by adding your view to the container view, not your app's main view which does not have a transformed frame:
NSView* parent = viewController.view; // the main view
NSView* containerView = [[[UIView alloc] initWithFrame:parent.bounds] autorelease];
containerView.transform = CGAffineTransformMakeRotation(<your angle here, should probably be M_PI_2 * some integer>);
[parent addSubview:containerView];
[UIView beginAnimations:nil context:nil];
[UIView setAnimationTransition:UIViewAnimationTransitionCurlUp forView:containerView cache:YES];
[containerView addSubview:view];
[UIView commitAnimations];
I actually managed to achieve this effect by changing the orientation of my UIViewController. The strange thing is, I had my controller nesten in another one when it wasn't working, but when I set him as the immediate view controller, it worked.
Code that does it:
In a UIViewController that is the main view controller in my app delegate and only allows landscape orientation (as you see in the 2nd method below) I have the following:
-(void)goToPage:(int)page flipUp:(BOOL)flipUp {
//do stuff...
// start the animated transition
[UIView beginAnimations:#"page transition" context:nil];
[UIView setAnimationDuration:1.0];
[UIView setAnimationTransition:flipUp ? UIViewAnimationTransitionCurlUp : UIViewAnimationTransitionCurlDown forView:self.view cache:YES];
//insert your new subview
//[self.view insertSubview:currentPage.view atIndex:self.view.subviews.count];
// commit the transition animation
[UIView commitAnimations];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
return (interfaceOrientation == UIInterfaceOrientationLandscapeRight);
}
I also struggled with this. To get the curl to come from the right or left you can create an intermediate view and transform it. So, let's say the view you're transitioning (myView) is a child of the main window (parentView):
-parentView
-->myView
You will insert an intermediate view in between (easily done in Interface Builder):
-parentView
-->containerView
--->myView
Then, use the following code to flip the container 90 deg left and the transitioned view 90 deg right:
containerView.transform = CGAffineTransformMakeRotation(-M_PI_2);
myView.transform = CGAffineTransformMakeRotation(M_PI_2);
myView will still appear upright to the user but the transition will think it's applied at 90 degrees from the left.
Note that depending on how auto-scaling your views are, you might have to fix the frame sizes after applying the transform, eg
containerView.frame = CGRectMake(0.0, 0.0, 768.0, 1024.0);
myWebView.frame = CGRectMake(0.0, 0.0, 768.0, 1024.0);
Hope this helps. The is the closest you can get to UIViewAnimationTransitionCurlLeft and UIViewAnimationTransitionCurlRight.
I tried the solution of fluXa on iOS5 (So I had to use [UIView trans......]) but it didn't work: the curl still went up or downwards. Apparently the transition now don't take the transform of the view into account. So in case someone else wants to do the same trick on iOS5, the solution is to add another container in between and animate the transition from there.
Here is my code, which is a bit specific since I want to curl 'up' to the left, but with the lower corner curling. As if I am tearing a page out of a note book.
UIView* parent = self.view; // the main view
CGRect r = flipRectSize(parent.bounds);
UIView* containerView = [[UIView alloc] initWithFrame:r];
CGAffineTransform t = CGAffineTransformMakeRotation(-M_PI_2);
t = CGAffineTransformTranslate(t, -80, -80);
containerView.transform = CGAffineTransformScale(t, -1, 1);
[parent addSubview:containerView];
UIView* container2 = [[UIView alloc] initWithFrame:r];
[containerView addSubview:container2];
UIImageView* v = [[UIImageView alloc] initWithFrame:r];
v.image = [UIImage imageWithCGImage:contents.CGImage scale:contents.scale orientation:UIImageOrientationLeftMirrored];
[container2 addSubview:v];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 0.001 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{
[UIView transitionWithView:container2
duration:DURATION_CURL_ANIMATION
options:UIViewAnimationOptionTransitionCurlUp
animations:^{
[v removeFromSuperview];
} completion:^(BOOL finished) {
if (completion) {
completion(finished);
}
[containerView removeFromSuperview];}];});
Notes:
I must admit that the affine transform translate (80,80) doesn't make sense in my mind, but it is necessary for iphone, probably won't work on iPad.
flipSizeRect flips the width and height of a rectangle (you already got that, right?)
the dispatch_after is necessary because I added the container and then want to remove a view from the hierarchy. If I leave out the dispatch nothing animates. My best guess is that we first need to let the system do a layout pass before we can animate a removal.
I don't think there is a way beyond writing a custom animation.
More importantly you probably shouldn't try to it. The curl up and curl down are part of the user interface grammar that tells the user that a view is being lifted up or put down over the existing view. It's supposed to be like a sticky note being put down and then removed. A left<->right curl will most likely be interpreted as the something like ripping a page out of a book. It will confuse users.
Whenever you find yourself trying to do something in the interface that the standard API doesn't do easily, you should ask yourself whether such a novel method will communicate something important to user and whether it is similar to the existing interface grammar. If not, then you shouldn't bother.
Unusual interfaces have an initial wow factor but they lead to frustration and errors in day-to-day use. They can also cause Apple to refuse your app.