UIImagePicker view not removing itself after first use - iphone

Question

I have an app that is adding a view that is used to call UIImagePickerController. When the use hits the add image button, the following code executes:
'- (IBAction)addPhoto:(id)sender {
// Call background tap in case any keyboards are still up
[self backgroundTap:sender];
if (jpegData) {
// If we already chose an image, don't allow to choose another.
// Have to cancel out and come back!
return;
}
// Shows the photo picker so the user can take or select an image
photoPickerViewController = [[PhotoPickerViewController alloc] initWithNibName:#"PhotoPicker" bundle:nil];
photoPickerViewController.delegate = self;
// Add it to the subview - it will auto animate in/out
[self.view addSubview:photoPickerViewController.view];
}
This presents the user with a view that I created that has 3 buttons: Take photo, choose existing photo, and cancel. Cancel just cancels back to the main view. If take photo or choose existing is called, this code is executed:
'- (IBAction)choosePhoto:(id)sender {
// Show an image picker to allow the user to choose a new photo.
UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
imagePicker.delegate = self;
if((UIButton*)sender == chooseExistingButton) {
imagePicker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
} else {
imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
imagePicker.showsCameraControls = YES;
}
[self presentModalViewController:imagePicker animated:YES];
[imagePicker release];
}
When if the user cancels out from the image picker, we go back to the main view. No problem. If however they complete image selection (either through taking a photo or choosing an existing one) then we call:
'- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
// Ok, dismiss the modal picker, bring up the activity indicator and dispatch a thread
// that will do all the photo processing ...
BOOL isFromCamera = picker.sourceType == UIImagePickerControllerSourceTypeCamera;
// Dismiss the picker view controller
[picker dismissModalViewControllerAnimated:NO];
// And remove our view from the list of views
[self.view removeFromSuperview];
if (isFromCamera)
{
// Declare the completion block to use
ALAssetsLibraryWriteImageCompletionBlock compBlock = ^(NSURL *assetURL, NSError *error) {
if (error != nil || assetURL == nil) {
NSLog(#"Failed to save photo: %#", error);
[delegate photoSetURLForImage:nil];
}
else {
NSLog(#"URL is : %#", [assetURL absoluteString]);
[delegate photoSetURLForImage:assetURL];
}
};
ALAssetsLibrary* library = [[[ALAssetsLibrary alloc] init] autorelease];
[library writeImageToSavedPhotosAlbum:cgimage
metadata:meta
completionBlock:compBlock];
return;
}
else {
// Use the URL to get the metadata for the image that was picked ...
NSURL* url = [(NSDictionary*)info objectForKey:#"UIImagePickerControllerReferenceURL"];
if (url) {
// Define a result and failure block for fetching from the ALAsset
ALAssetsLibraryAssetForURLResultBlock resultblock = ^(ALAsset* myasset)
{
ALAssetRepresentation *rep = [myasset defaultRepresentation];
NSLog(#"URL is : %#", [[rep url] absoluteString]);
[delegate photoSetURLForImage:[rep url]];
};
// And also define a failure block
ALAssetsLibraryAccessFailureBlock failureblock = ^(NSError *myerror)
{
[delegate photoSetURLForImage:nil];
};
ALAssetsLibrary* assetslibrary = [[[ALAssetsLibrary alloc] init] autorelease];
[assetslibrary assetForURL:url
resultBlock:resultblock
failureBlock:failureblock];
return;
}
}
// If we get here, something went very wrong
UIAlertView *alert = [[[UIAlertView alloc] initWithTitle:#"Error" message:#"An error occured while retrieving the image" delegate:self cancelButtonTitle:#"Ok" otherButtonTitles:nil] autorelease];
[alert show];
}
Now, the first time I run through this code, all works great. As soon as I hit "use" on the image I took with the camera, or I select an image from the camera roll, the UIImagePicker view and the view that launches it go away and I'm back at the main view while I wait for the ALAsset calls to do their thing.
The problem starts when I try to repeat this process a second time. After selecting an image or taking one, the processing begins, but the views do not go away, until all of the processing by the ALAsset calls has completed. I can't figure out why this is. Why it works the first time, but not anytime after. Is there some caching mechanism I have to clear? Anyways, if anybody can offer up some advice, I'd be very grateful.
Thanks,
J

Answer 1

Yet again it appears I'll be answering my own question. This is starting to become a habit lol.
So it appears that the ALAsset calls aren't spinning off a new thread which is what I thought they were supposed to do. My bad. So to resolve, it was just a matter of spawning a new thread to do all the ALAsset stuff, and in the main thread dismissing my picker and what not.
Problem solved, yay!