I am adding an infinitely repeating CALayer animation to the cells in a UICollectionView. For some reason, whenever I return to the app after sending it to the background, or return to the view controller after pushing another one on top of it, the animations are removed from the cells. Please let me know if you have any idea why this might be.
When switch app or ViewController, the system will let animations on layer stop(complete), so you can set removedOnCompletion to NO(default is YES), it will work.
Related
i want to use the new UIVC Custom Transition API in my iPad App Project. And i despair of it -.-. what i want to do, sounds very simple at first. My "FirstViewController" (simply the names) is a normal FullScreenVC. From that VC i open a "SecondViewController"modally with the default Presentation style Form Sheet. Everything allright. The SecondViewController is a normal UiTableViewController. So from inside the SecondViewController I want to open a "ThirdViewController" modally as well with a custom transition. This ThridViewController have to overlap the SecondVC with the Form Sheet Presentation and the content of the second view controller have to be dimmed as well. But i get many problems inside the animateTransition-method in the the Transition Delegate. My best idea by now is, making a UIView Snapshot of the from View. Create a new UIView with black background and alpha 0.5 and put it as a subview inside UIView Snapshot. Then transfer the frame and the center of the fromView to the toView and add the UIViewSnappshot as a subview to the toView and send it to the back. finally adding the toView to the containerView.
But when i do this, I get two s*** problems. The First is, that the Transition don't recognize that i am using a Retina display, because i put the center of the fromView to the the toView. But the toView dont overlap the fromView, better its nit at the same postion. Its almost at the left down of the screen and not in the middle of the screen. The second problem is, that the toView content seems to be transculent. In Storyboard and in code i write "be opaque and white bgcolor". But at runtime the see the controls of the view but the bgcolor is the bgcolor of the dimmed View behind it. Why?
At the moment i think i'm a dump guy :( What in hell im doing wrong?
Thanks
Avarlon
I have implemented a UIWebView object into a custom UIView (TSAlertView). My UIWebView sits in the middle of the UIView, as a subview.
When I rotate the iOS device screen, the UIWebView object redraws right on top of the old one, without deleting the old one. All the other elements of this custom UIView are destroyed and redrawn when the screen is rotated.
I imagine I must have missed some sort of procedure for deallocating resources or removing the UIWebView from view. I have tried adding 'autorelease' to the declaration of the UIWebView, but to no avail. I wonder if this is a common symptom of a simple oversight I have made in the way the UIWebView is created?
This seems to be a simple case of not telling the UIWebView object it should destroy itself before it is redrawn on each rotate - but I don't know how I can go about this...
Any wisdom gratefully received.
Ideally while rotating you should not create the views again. Instead you can rearrange the frame in delegates appropriately. In your case you might be creating a UIWebView again, which should be avoided. Instead of that, you can keep it as a class level param(Declare in .h file) and adjust the frame in delegate methods for rotation. Also please note that release/autorelease wont remove your view from superview. You need to call removeFromSuperview method to achieve that.
Check this for view resizing and layout handling
Is there a way to use custom segues to individually animate several different subviews.
For example, I want my modal view to appear by the UINavigationBar fading in (as the source destination's UINavigationBar fades out) and then a UITableView to slide down the screen 'over' the source destination's view controller.
When I try to implement this in the - (void)perform method. My properties don't animate using [UIView animateWithDuration: animations: completion:].
Can anyone provide me with a solution?
Thanks in advance!
You can certainly use custom segues to achieve this - however, I don't think you'll get much help without more details about the setup of your view controllers.
Everything you describe is correct: to create a custom segue you animate the views inside your sourceViewController and destinationViewController inside the segue's perform: method. If they're not animating you might want to check that your segue is actually getting called (you can use breakpoints in the debugger to check this), or that the views you're trying to access inside your view controllers actually exist at that point in time (again, something you can check using the debugger).
For a solution specific to your app you're almost certainly going to have to provide more details about the two view controllers you're trying to transition between. Perhaps you could post your perform: method.
I'm working on an app for a blog site, and I'm trying to keep the Default.png launch image up with a spinning indicator while I load the initial headlines into the tableview.
I set up a viewcontroller/view in my storyboard with the launch image and indicator.
I then have the following in the viewDidLoad: method of my navigationController's rootview
[self.navigationController presentModalViewController:[self.storyboard instantiateViewControllerWithIdentifier:#"SplashLoader"] animated:NO];
And once the headlines are loaded I use:
[self.navigationController dismissModalViewControllerAnimated:NO];
Am I way off base here? Or is this the right way to be doing this?
I've seen people doing something like this in app delegate, but that was before storyboards... If I'm supposed to be doing this in the app delegate then how do I instantiate the view controller out of the storyboard?
Thanks,
Any advice or suggestions would be appreciated.
The way I've done it is to make a UIImageView using the Default.png image. In viewWillAppear: I add it to the view controller's view property. In viewDidAppear: I use a UIView animation to fade out the image view by setting its alpha to 0. Upon completion of the animation, viewDidAppear: removes the image view from its superview and releases it (sets it to nil).
You have to keep a record of how many time viewWillAppear: and viewDidAppear: have been called because you only want this animation to happen when the app launches. Also, you have to think about which image to use to create the image view. If this is an iPhone app, you want to use Default.png. If it's an iPad app, you want to use Default-Portrait~ipad.png or Default-Landscape~ipad.png, depending on the orientation of the device when the app launches.
I'm not sure how you would accomplish the same effect in the app delegate. That seems like an unnecessarily complicated approach to me.
In my iPad app, I save the state (visible/not visible) of a popover. So, during the launch of the app I initialize the UIPopoverController and tell it to show itself by using presentPopoverFromBarButtonItem:permittedArrowDirections:animated:. For the first argument (UIBarButtonItem), I use self.navigationItem.rightBarButtonItem. However, the popover keeps showing up on the left side of the screen (and not underneath the targeted button).
After the app is launched, the behavior is as expected. Any suggestions how to solve this?
For your information, I initialize the rightBarButtonItem and assign it to the navigationItem in the viewDidLoad method and before asking the popover to present itself. I have tried to call the popover in viewWillAppear and viewDidLoad, but the effect is the same.
My best alternative is to use presentPopoverFromRect:inView:permittedArrowDirections:animated: instead and "guess" the position depending on the orientation of the device.
Update: when I rotate the iPad, the popover does jump to the correct position. It seems that the barButtonItem's position is only determined at the last minute and after I ask my popover to present itself.
In situations like these where timing appears to be important I found that the trick of postponing an action until the next iteration of the run loop helps. If developing for iOS 4.0+, this can be easily achieved with GDC:
// call from viewDidAppear:
dispatch_async(dispatch_get_main_queue(), ^{
// call presentPopoverFromBarButtonItem:permittedArrowDirections:animated: here
});