Access to CAMZoomSlider instance to clear it's delegate - ios

I am presently using UIImagePicker and my app crashes on iOS 8 with the following workflow:
Start the camera, zoom it which shows the zoom slider below and then take a picture. Select Use Photo and app crashes.
After looking more into the crash "didHideZoomSlider" message is sent to the deallocated instance of image picker view.
Here is my code:
imagePicker = [[UIImagePickerController alloc] init];
imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
imagePicker.mediaTypes = [[NSArray alloc] initWithObjects:(NSString *)kUTTypeImage, nil];
imagePicker.allowsEditing = YES;
imagePicker.delegate = self;
[myController presentViewController:imagePicker animated:animated completion:nil];
I tried a couple of things. My controller holds a strong reference to the image picker, I tried making it a weak reference and the app still crashes. Also I need a strong reference so I actually cannot make it weak.
Although this looks like an Apple bug and someone has already logged it (http://openradar.appspot.com/18762927) I wanted to try the workaround they are using. However I am not able to get to "CAMZoomSlider" through UIImagePicker's instance.
Does anyone know how to get to CAMZoomSlider?

I was able to clear the CAZoomSlider delegate by doing the following in a subclassed UIImagePickerController class. And sure enough, it seems to have resolved the crash.
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
[self clearZoomSliderDelegate:self.view.subviews];
}
- (void)clearZoomSliderDelegate:(NSArray*)subviews
{
for (UIView *subview in subviews)
{
if ([subview isKindOfClass:NSClassFromString(#"CAMZoomSlider")])
{
if ([subview respondsToSelector:#selector(setDelegate:)]) {
[subview performSelector:#selector(setDelegate:) withObject:nil];
}
return;
}
else if (subview.subviews != nil) {
[self clearZoomSliderDelegate:subview.subviews];
}
}
}

Related

UIImagePickerController didFinishPickingMediaWithInfo sometime is not called

Hi Im making altered reality app. My main controller is derived from UIImagePickerController. Here is how I create it:
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
if (!self.overlayController) {
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
self.sourceType = UIImagePickerControllerSourceTypeCamera;
self.cameraCaptureMode = UIImagePickerControllerCameraCaptureModePhoto;
self.cameraDevice = UIImagePickerControllerCameraDeviceRear;
self.showsCameraControls = false;
self.allowsEditing = false;
self.overlayController = [[[ControlsViewController alloc] initWithNibName:#"ControlsViewController" bundle:[NSBundle mainBundle] picker:self] autorelease];
[self.view addSubview:self.overlayController.view]; // need to add as subview otherwise mouse events captured by UIImagePickerController
self.overlayController.view.frame = CGRectMake(0,0, self.view.frame.size.width, self.view.frame.size.height);
}
}
[cameraControls setCamera:self];
}
Basically controller exists through whole lifecycle of the app. Now when I take photo with code below most of the time it works fine but sometime didFinishPickingMediaWithInfo isn't called. Usual behavior is I see camera focus starts adjust blur-in/out and then it stabilizes but didFinishPickingMediaWithInfo will never be called. Looks like if camera goes into some kind of calibration mode it may not fire this event. Anyone have solution? I hope there is maybe some kind of extra callback (like error processing Im missing).
I can even hear camera shutters simulated sound interrupted when camera goes into that weird calibration mode.
//self.cameraPicker points to the instance of my main controller that I created earlier
-(void) setCamera:(UIImagePickerController *)picker {
self.cameraPicker = picker;
picker.delegate = self;
}
-(void) takePicture {
[self.cameraPicker takePicture];
}
-(void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
NSLog(#"Picture ready");
}

iOS 7 UIImagePicker preview black screen

When i try to load camera from my code, camera preview is black. If I wait for 10-20 seconds it will show real camera preview. I found several questions and some of them suggest that running some other code in background should be the reason for this. However I don't have any code running in background.
How should I fix this?
This is my code where I run camera
UIImagePickerController *photoPicker = [[UIImagePickerController alloc] init];
photoPicker.delegate = self;
photoPicker.sourceType = UIImagePickerControllerSourceTypeCamera;
[self presentViewController:photoPicker animated:YES completion:NULL];
About 5 months ago my team discovered a memory leak with UIImageViewController in iOS7. Each instantiation slowed down the app exponentially (i.e. first alloc-init had a 1 second delay, second had a 2 second delay, third had a 5 second delay). Eventually, we were having 30-60 delays (similar to what you're experiencing).
We resolved the issue by subclassing UIImagePickerController and making it a Singleton. That way it was only ever initialized once. Now our delay is minimal and we avoid the leak. If subclassing isn't an option, try a class property in your viewController and just lazy load it like so.
-(UIImagePickerController *)imagePicker{
if(!_imagePicker){
_imagePicker = [[UIImagePickerController alloc]init];
_imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
}
return _imagePicker;
}
Then you can just call it later like:
[self presentViewController:self.imagePicker animated:YES completion:nil];
Had this myself - it happens if something is running on the main dispatch thread - are you resizing images by any chance?
It puts the preview onto the main thread and if something is using it, you get a black screen. It's a bug and the workaround is to either take over the main thread or to disable the photo picker until the queue is free
This Should work for you:
- (void)cameraViewPickerController:(UIImagePickerController *)picker
{
[self startCameraControllerFromViewController: picker
usingDelegate: self];
}
- (BOOL) startCameraControllerFromViewController: (UIViewController*) controller
usingDelegate: (id <UIImagePickerControllerDelegate,
UINavigationControllerDelegate>) delegate {
if (([UIImagePickerController isSourceTypeAvailable:
UIImagePickerControllerSourceTypeCamera] == NO)
|| (delegate == nil)
|| (controller == nil))
return NO;
UIImagePickerController *cameraUI = [[UIImagePickerController alloc] init];
cameraUI.sourceType = UIImagePickerControllerSourceTypeCamera;
// Displays a control that allows the user to choose movie capture
cameraUI.mediaTypes = [[NSArray alloc] initWithObjects: (NSString *) kUTTypeImage, (NSString *) kUTTypeMovie,nil];
// Hides the controls for moving & scaling pictures, or for
// trimming movies. To instead show the controls, use YES.
cameraUI.allowsEditing = NO;
cameraUI.delegate = delegate;
[controller presentViewController:cameraUI animated:YES completion:nil];
return YES;
}

UIImagePickerController not full screen

Since the iOS7 upgrade, I have a weird behaviour of the UIImagePickerController. In this application I am using the UIImagePickerController with a cameraOverlayView.
In iOS6 I called the UIImagePickerController using the following code:
_picker = [[UIImagePickerController alloc] init];
if ([UIImagePickerController isCameraDeviceAvailable:UIImagePickerControllerCameraDeviceRear]) {
_picker.sourceType = UIImagePickerControllerSourceTypeCamera;
_picker.cameraCaptureMode = UIImagePickerControllerCameraCaptureModePhoto;
_picker.cameraDevice = UIImagePickerControllerCameraDeviceRear;
_picker.showsCameraControls = NO;
_picker.navigationBarHidden = NO;
_picker.toolbarHidden = YES;
_picker.wantsFullScreenLayout = YES;
_overlayViewController = [[OverlayViewController alloc] init];
_overlayViewController.picker = _picker;
_overlayViewController.frameSize = self.frameSize;
_overlayViewController.delegate = self;
_picker.cameraOverlayView = _overlayViewController.view;
}
else {
_picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
}
_picker.delegate = self;
Where the OverlayViewController is an UIViewController, with a transparent background which draws some custom controls on screen.
But now in iOS 7 the camera is drawn through the statusbar and a black bar appears beneath the live camera view.
I can solve this by applying a CGAffineTransformMakeTranslation to the cameraViewTransform property of the UIImagePickerController, but why is this like this?
In iOS 7, by default UIViewController views take up the entire screen area including the status bar.
wantsFullScreenLayout
is deprecated and ignored. In some cases, this fix works (in the view controller class):
if ([self respondsToSelector:#selector(setEdgesForExtendedLayout:)]) {
[self setEdgesForExtendedLayout:UIRectEdgeNone];
}
In other cases, it's a bit more complicated. It's late here, so see how you go with it. Helpful things to note - in a UIViewController, the following code will give the correct statusbar height on both iOS 6 and iOS 7, should it come to having to align things using CGRect math:
if (UIDeviceOrientationIsLandscape(self.interfaceOrientation)) {
statusBarHeight = [[UIApplication sharedApplication] statusBarFrame].size.width;
} else {
statusBarHeight = [[UIApplication sharedApplication] statusBarFrame].size.height;
}
And then don't forget that in Interface Builder, there are the new "iOS 6 delta" adjustments that allow you to design for iOS 7 and then use offsets to correct for iOS 6.
Anyhow, let me know how you go.
My understanding of the issue, based on a few other SO threads and such, is that UIImagePickerController does not do what we'd expect in terms of managing the status bar via [UIViewController -prefersStatusBarHidden].
This means you either have to disable view controller status bar management entirely, via plist, or figure out a way to get UIImagePickerController to do what we want. On the assumption that you're not looking for the former, I can say I've had success in the latter by putting the picker in a wrapper controller that does what I want (but fall back to your previous code if you still need to detect/support iOS6):
#interface PickerContainer : UIViewController
#property ( nonatomic, weak ) UIImagePickerController* picker;
#end
#implementation PickerContainer
- (void) setPicker: (UIImagePickerController*) picker
{
[self addChildViewController: picker];
[picker didMoveToParentViewController: self];
self->_picker = picker;
}
- (void) viewDidLoad
{
[super viewDidLoad];
self.picker.view.frame = self.view.bounds;
[self.view addSubview: self.picker.view];
}
// Will have no effect in ios6 -- see [-init] for that option
- (BOOL) prefersStatusBarHidden { return YES; }
- (id) init
{
if ( ! ( self = [super init] ) ) return nil;
if ( detectThatThisIsIos6() ) self.wantsFullScreenLayout = YES;
return self;
}
#end
This will work for you, scaled camera, you will have a black bar at the bottom but it will get overlayed by tool bar
https://stackoverflow.com/a/15803947

How do I load an image from the photo roll and add other images from the roll on top of it, possibly sort it, and save the final product?

I'm trying to make some composite images from currently existing ones in the photo rolls.
I have code that seems to work that loads an image from the photo roll onto a UIImageView and displays it to the user; (here's the Action that does that:)
- (IBAction)grabImage:(id)sender
{
if ([_myPopoverController isPopoverVisible])
[_myPopoverController dismissPopoverAnimated:YES];
else
{
if ([UIImagePickerController isSourceTypeAvailable: UIImagePickerControllerSourceTypeSavedPhotosAlbum])
{
UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
imagePicker.delegate = self;
imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
imagePicker.mediaTypes = [NSArray arrayWithObjects: (NSString *) kUTTypeImage, nil];
imagePicker.allowsEditing = NO;
_myPopoverController = [[UIPopoverController alloc] initWithContentViewController:imagePicker];
_myPopoverController.delegate = self;
[_myPopoverController presentPopoverFromRect: [sender frame] inView:self.view permittedArrowDirections:UIPopoverArrowDirectionUp animated:YES ];
_newMedia = NO;
}
}
}
next I want to be able to select more photos, but instead of replacing the current one I want them to be layered one on top of another. Finally, when the user is done layering images, I want them to be able to save the final product to the photo roll.
How do I implement this? Not sure where to start...
thanks in advance,
marina
It turns out that all that was needed to do this is just add CALayers to an UIImageView with various degrees of alpha; instead of wiping out the previous image and replacing it with a new one, I simply add differently alpha's layers of images. Works like a charm!

iOS, ARC: Background thread freezes UI

I have a UIViewController with a UITableView as subview. When a certain cell was clicked an UIImagePickerController should be presented. Because of the long initialization time it takes, I perfom this process in the background when the UIViewController did appear.
Now I added ARC to my project and then it didn't still work. The UI was freezed by the initial process.
Here's my code.
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
[self performSelectorInBackground:#selector(initImagePickerControllerInBackground) withObject:nil];
}
...
- (void)initImagePickerController
{
if (imagePickerController != nil)
return;
imagePickerController = [[UIImagePickerController alloc] init];
imagePickerController.allowsEditing = YES;
imagePickerController.delegate = self;
imagePickerController.mediaTypes = [NSArray arrayWithObject:(NSString *)kUTTypeImage];
}
- (void)initImagePickerControllerInBackground
{
#autoreleasepool
{
[self initImagePickerController];
}
}
What should I change to get it working for me?
UIKit is not a thread safe class and should not be called from outside the main thread. You should not perform this UIImagePickerController allocation/interaction in the background.

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