(void)applicationWillResignActive:(UIApplication *)application {
NSLog(#"to background");
UIApplication *app = [UIApplication sharedApplication];
// Request permission to run in the background. Provide an
// expiration handler in case the task runs long.
NSAssert(bgTask == UIBackgroundTaskInvalid, nil);
bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
// Synchronize the cleanup call on the main thread in case
// the task actually finishes at around the same time.
dispatch_async(dispatch_get_main_queue(), ^{
if (bgTask != UIBackgroundTaskInvalid)
{
[app endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}
});
}];
// Start the long-running task and return immediately.
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// Do the work associated with the task.
[self performSelector:#selector(hai) withObject:nil afterDelay:30];
NSLog(#"App staus: applicationDidEnterBackground");
dispatch_async(dispatch_get_main_queue(), ^{
if (bgTask != UIBackgroundTaskInvalid)
{
[app endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}
});
});
}
Related
I'm using AWS Transfer Utility to upload media to the S3 bucket and it's working fine in the background but after the media upload, I have to call a REST API (POST) call to my server which is failing when the app is in the background. How can I call rest API when the app is in the background?
Here is my code
- (void)didUploadedAllMedias:(BOOL)yesOrNo {
if (yesOrNo) {
UIApplicationState state = [[UIApplication sharedApplication] applicationState];
if (state == UIApplicationStateBackground){
[self notifyUserForMedia:YES];
}
self.postStatus = BG_SERVICE_STATUS_FINISHING_UP;
if (self.delegate && [self.delegate respondsToSelector:#selector(finishingUP)]) {
[self.delegate finishingUP];
[self executeWebServiceCall];
}
}
else {
self.postStatus = BG_SERVICE_STATUS_ERROR;
UIApplicationState state = [[UIApplication sharedApplication] applicationState];
if (state == UIApplicationStateBackground){
[self notifyUserForMedia:YES];
}
}
}
- (void)executeWebServiceCall {
UIApplicationState state = [[UIApplication sharedApplication] applicationState];
if (state == UIApplicationStateBackground){
__weak typeof(self) weakSelf = self;
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1.0 * NSEC_PER_SEC)), dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
__strong typeof(weakSelf) strongSelf = weakSelf;
if(strongSelf){
[strongSelf submitPost];
}
});
}else {
__weak typeof(self) weakSelf = self;
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
__strong typeof(weakSelf) strongSelf = weakSelf;
if(strongSelf){
[strongSelf submitPost];
}
});
}
}
On the foreground, it works perfectly fine. In the background, it's like waiting for the app to come in the foreground and executed automatically, and sometimes the request timed out.
What i'm trying to do is an app that runs a code when a call is incoming. I know I cannot get any details of the caller and that is fine.
My issue so far is that it's only working when the app is in foreground.
This is my code:
#import <CoreTelephony/CoreTelephonyDefines.h>
#import <CoreTelephony/CTCallCenter.h>
#import <CoreTelephony/CTCall.h>
CTCallCenter *callCenter = [[CTCallCenter alloc] init];
[callCenter setCallEventHandler:^(CTCall *call) {
ONLog(#"Event handler called");
if ([call.callState isEqualToString: CTCallStateConnected]) {
ONLog(#"Connected");
} else if ([call.callState isEqualToString: CTCallStateDialing]) {
ONLog(#"Dialing");
} else if ([call.callState isEqualToString: CTCallStateDisconnected]) {
ONLog(#"Disconnected");
} else if ([call.callState isEqualToString: CTCallStateIncoming]) {
ONLog(#"Incomming");
}
}];
Can someone help me with making this run as a background task?
EDIT:
I used Richas' code like this:
__block UIBackgroundTaskIdentifier yourBackgroundTaskName;
yourBackgroundTaskName = [application beginBackgroundTaskWithExpirationHandler:^{
// CODE FOR EXPIRATION HANDLER BLOCK
[application endBackgroundTask: yourBackgroundTaskName];
yourBackgroundTaskName = UIBackgroundTaskInvalid;
}];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// DO YOUR STUFF HERE. START OF BACKGROUND TASK.
NSLog(#"Background time Remaining: %f",[[UIApplication sharedApplication] backgroundTimeRemaining]);
self.callCenter = [[CTCallCenter alloc] init];
[self.callCenter setCallEventHandler:^(CTCall *call) {
ONLog(#"Event handler called");
if ([call.callState isEqualToString: CTCallStateConnected]) {
ONLog(#"Connected");
} else if ([call.callState isEqualToString: CTCallStateDialing]) {
ONLog(#"Dialing");
} else if ([call.callState isEqualToString: CTCallStateDisconnected]) {
ONLog(#"Disconnected");
} else if ([call.callState isEqualToString: CTCallStateIncoming]) {
ONLog(#"Incomming");
}
}];
//WHEN YOU ARE DONE WITH YOUR TASK, TELL THAT TO SYSTEM
[application endBackgroundTask: yourBackgroundTaskName];
yourBackgroundTaskName = UIBackgroundTaskInvalid;
});
It only buys me 180 seconds of background running...
It's not working :) The call is not detected
You should check for following two methods for your problem:
- (UIBackgroundTaskIdentifier)beginBackgroundTaskWithName:(NSString *)taskName expirationHandler:(void (^)(void))handler`
- (UIBackgroundTaskIdentifier)beginBackgroundTaskWithExpirationHandler:(void (^)(void))handler
You can implement any of them in applicationDidEnterBackground & that can buy you some time (5-10 minutes). Code might be something like following:
- (void)applicationDidEnterBackground:(UIApplication *)application
{
UIBackgroundTaskIdentifier yourBackgroundTaskName;
yourBackgroundTaskName = [application beginBackgroundTaskWithExpirationHandler:^{
// CODE FOR EXPIRATION HANDLER BLOCK
[application endBackgroundTask: yourBackgroundTaskName];
yourBackgroundTaskName = UIBackgroundTaskInvalid;
}];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// DO YOUR STUFF HERE. START OF BACKGROUND TASK.
//WHEN YOU ARE DONE WITH YOUR TASK, TELL THAT TO SYSTEM
[application endBackgroundTask: yourBackgroundTaskName];
yourBackgroundTaskName = UIBackgroundTaskInvalid;
});
}
Hope, this should at least get you started.
I want to execute long running task in background in Iphone but code which I using for background task executes only for 3 mins
My code is
- (void)startService{
[self startBackgroundTask];
}
- (void) startBackgroundTask{
self.backgroundDataSendTimer = [NSTimer scheduledTimerWithTimeInterval:backgroundDataSendfrequency
target:self
selector:#selector(dobackgroundDataSendInBackground)
userInfo:nil
repeats:YES];
self.backgroundTask = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{
dispatch_async(dispatch_get_main_queue(), ^
{
if ( self.backgroundTask != UIBackgroundTaskInvalid)
{
[self endBackgroundTask];
self.backgroundTask = UIBackgroundTaskInvalid;
}
});
}];
- (void) endBackgroundTask{
[[UIApplication sharedApplication] endBackgroundTask:self.backgroundTask];
self.backgroundTask = UIBackgroundTaskInvalid;
[self startBackgroundTask];
}
Do you know any way / method to take a photo in iOS and saving it to camera Roll only with a simple button pressure without showing any preview?
I already know how to show the camera view but it show the preview of the image and the user need to click the take photo button to take the photo.
In few Words: the user click the button, the picture is taken, without previews nor double checks to take / save the photo.
I already found the takePicture method of UIIMagePickerController Class http://developer.apple.com/library/ios/documentation/uikit/reference/UIImagePickerController_Class/UIImagePickerController/UIImagePickerController.html#//apple_ref/occ/instm/UIImagePickerController/takePicture
Set the showsCameraControls-Property to NO.
poc = [[UIImagePickerController alloc] init];
[poc setTitle:#"Take a photo."];
[poc setDelegate:self];
[poc setSourceType:UIImagePickerControllerSourceTypeCamera];
poc.showsCameraControls = NO;
You also have to add your own Controls as a custom view on the top of poc.view. But that is very simple and you can add your own UI-style by that way.
You receive the image-data as usually within the imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:
To take the photo, you call
[poc takePicture];
from your custom button.
Hope, that works for you.
Assuming you want a point-and-shoot method, you can create an AVSession and just call the UIImageWriteToSavedPhotosAlbum method.
Here is a link that goes into that exact process: http://www.musicalgeometry.com/?p=1297
It's also worth noting that your users need to have given the app access to their camera roll or you may experience issues saving the images.
You need to design your own custom preview according to your size, on capture button pressed and call buttonPressed method and do stuff what you want
(void)buttonPressed:(UIButton *)sender {
NSLog(#" Capture Clicked");
[self.imagePicker takePicture];
//[NSTimer scheduledTimerWithTimeInterval:3.0f target:self
selector:#selector(timerFired:) userInfo:nil repeats:NO];
}
following is code that will take photo without showing preview screen. when i tried the accepted answer, which uses UIImagePickerController, the preview screen showed, then auto disappeared. with the code below, user taps 'takePhoto' button, and the devices takes photo with zero change to UI (in my app, i add a green check mark next to take photo button). the code below is from apple https://developer.apple.com/LIBRARY/IOS/samplecode/AVCam/Introduction/Intro.html with the 'extra functions' (that do not relate to taking still photo) commented out. thank you incmiko for suggesting this code in your answer iOS take photo from camera without modalViewController.
updating code, 26 mar 2015:
to trigger snap photo:
[self snapStillImage:sender];
in .h file:
#import <AVFoundation/AVFoundation.h>
#import <AssetsLibrary/AssetsLibrary.h>
// include code below in header file, after #import and before #interface
// avfoundation copy paste code
static void * CapturingStillImageContext = &CapturingStillImageContext;
static void * RecordingContext = &RecordingContext;
static void * SessionRunningAndDeviceAuthorizedContext = &SessionRunningAndDeviceAuthorizedContext;
// avfoundation, include code below after #interface
// avf - Session management.
#property (nonatomic) dispatch_queue_t sessionQueue; // Communicate with the session and other session objects on this queue.
#property (nonatomic) AVCaptureSession *session;
#property (nonatomic) AVCaptureDeviceInput *videoDeviceInput;
#property (nonatomic) AVCaptureMovieFileOutput *movieFileOutput;
#property (nonatomic) AVCaptureStillImageOutput *stillImageOutput;
// avf - Utilities.
#property (nonatomic) UIBackgroundTaskIdentifier backgroundRecordingID;
#property (nonatomic, getter = isDeviceAuthorized) BOOL deviceAuthorized;
#property (nonatomic, readonly, getter = isSessionRunningAndDeviceAuthorized) BOOL sessionRunningAndDeviceAuthorized;
#property (nonatomic) BOOL lockInterfaceRotation;
#property (nonatomic) id runtimeErrorHandlingObserver;
in .m file:
#pragma mark - AV Foundation
- (BOOL)isSessionRunningAndDeviceAuthorized
{
return [[self session] isRunning] && [self isDeviceAuthorized];
}
+ (NSSet *)keyPathsForValuesAffectingSessionRunningAndDeviceAuthorized
{
return [NSSet setWithObjects:#"session.running", #"deviceAuthorized", nil];
}
// call following method from viewDidLoad
- (void)CreateAVCaptureSession
{
// Create the AVCaptureSession
AVCaptureSession *session = [[AVCaptureSession alloc] init];
[self setSession:session];
// Check for device authorization
[self checkDeviceAuthorizationStatus];
// In general it is not safe to mutate an AVCaptureSession or any of its inputs, outputs, or connections from multiple threads at the same time.
// Why not do all of this on the main queue?
// -[AVCaptureSession startRunning] is a blocking call which can take a long time. We dispatch session setup to the sessionQueue so that the main queue isn't blocked (which keeps the UI responsive).
dispatch_queue_t sessionQueue = dispatch_queue_create("session queue", DISPATCH_QUEUE_SERIAL);
[self setSessionQueue:sessionQueue];
dispatch_async(sessionQueue, ^{
[self setBackgroundRecordingID:UIBackgroundTaskInvalid];
NSError *error = nil;
AVCaptureDevice *videoDevice = [ViewController deviceWithMediaType:AVMediaTypeVideo preferringPosition:AVCaptureDevicePositionFront];
AVCaptureDeviceInput *videoDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:&error];
if (error)
{
NSLog(#"%#", error);
}
if ([session canAddInput:videoDeviceInput])
{
[session addInput:videoDeviceInput];
[self setVideoDeviceInput:videoDeviceInput];
dispatch_async(dispatch_get_main_queue(), ^{
// Why are we dispatching this to the main queue?
// Because AVCaptureVideoPreviewLayer is the backing layer for AVCamPreviewView and UIView can only be manipulated on main thread.
// Note: As an exception to the above rule, it is not necessary to serialize video orientation changes on the AVCaptureVideoPreviewLayer’s connection with other session manipulation.
});
}
/* AVCaptureDevice *audioDevice = [[AVCaptureDevice devicesWithMediaType:AVMediaTypeAudio] firstObject];
AVCaptureDeviceInput *audioDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:audioDevice error:&error];
if (error)
{
NSLog(#"%#", error);
}
if ([session canAddInput:audioDeviceInput])
{
[session addInput:audioDeviceInput];
}
*/
AVCaptureMovieFileOutput *movieFileOutput = [[AVCaptureMovieFileOutput alloc] init];
if ([session canAddOutput:movieFileOutput])
{
[session addOutput:movieFileOutput];
AVCaptureConnection *connection = [movieFileOutput connectionWithMediaType:AVMediaTypeVideo];
if ([connection isVideoStabilizationSupported])
[connection setEnablesVideoStabilizationWhenAvailable:YES];
[self setMovieFileOutput:movieFileOutput];
}
AVCaptureStillImageOutput *stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
if ([session canAddOutput:stillImageOutput])
{
[stillImageOutput setOutputSettings:#{AVVideoCodecKey : AVVideoCodecJPEG}];
[session addOutput:stillImageOutput];
[self setStillImageOutput:stillImageOutput];
}
});
}
// call method below from viewWilAppear
- (void)AVFoundationStartSession
{
dispatch_async([self sessionQueue], ^{
[self addObserver:self forKeyPath:#"sessionRunningAndDeviceAuthorized" options:(NSKeyValueObservingOptionOld | NSKeyValueObservingOptionNew) context:SessionRunningAndDeviceAuthorizedContext];
[self addObserver:self forKeyPath:#"stillImageOutput.capturingStillImage" options:(NSKeyValueObservingOptionOld | NSKeyValueObservingOptionNew) context:CapturingStillImageContext];
[self addObserver:self forKeyPath:#"movieFileOutput.recording" options:(NSKeyValueObservingOptionOld | NSKeyValueObservingOptionNew) context:RecordingContext];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(subjectAreaDidChange:) name:AVCaptureDeviceSubjectAreaDidChangeNotification object:[[self videoDeviceInput] device]];
__weak ViewController *weakSelf = self;
[self setRuntimeErrorHandlingObserver:[[NSNotificationCenter defaultCenter] addObserverForName:AVCaptureSessionRuntimeErrorNotification object:[self session] queue:nil usingBlock:^(NSNotification *note) {
ViewController *strongSelf = weakSelf;
dispatch_async([strongSelf sessionQueue], ^{
// Manually restarting the session since it must have been stopped due to an error.
[[strongSelf session] startRunning];
});
}]];
[[self session] startRunning];
});
}
// call method below from viewDidDisappear
- (void)AVFoundationStopSession
{
dispatch_async([self sessionQueue], ^{
[[self session] stopRunning];
[[NSNotificationCenter defaultCenter] removeObserver:self name:AVCaptureDeviceSubjectAreaDidChangeNotification object:[[self videoDeviceInput] device]];
[[NSNotificationCenter defaultCenter] removeObserver:[self runtimeErrorHandlingObserver]];
[self removeObserver:self forKeyPath:#"sessionRunningAndDeviceAuthorized" context:SessionRunningAndDeviceAuthorizedContext];
[self removeObserver:self forKeyPath:#"stillImageOutput.capturingStillImage" context:CapturingStillImageContext];
[self removeObserver:self forKeyPath:#"movieFileOutput.recording" context:RecordingContext];
});
}
- (BOOL)prefersStatusBarHidden
{
return YES;
}
- (BOOL)shouldAutorotate
{
// Disable autorotation of the interface when recording is in progress.
return ![self lockInterfaceRotation];
}
- (NSUInteger)supportedInterfaceOrientations
{
return UIInterfaceOrientationMaskAll;
}
- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration
{
// [[(AVCaptureVideoPreviewLayer *)[[self previewView] layer] connection] setVideoOrientation:(AVCaptureVideoOrientation)toInterfaceOrientation];
}
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
if (context == CapturingStillImageContext)
{
BOOL isCapturingStillImage = [change[NSKeyValueChangeNewKey] boolValue];
if (isCapturingStillImage)
{
[self runStillImageCaptureAnimation];
}
}
else if (context == RecordingContext)
{
BOOL isRecording = [change[NSKeyValueChangeNewKey] boolValue];
dispatch_async(dispatch_get_main_queue(), ^{
if (isRecording)
{
// [[self cameraButton] setEnabled:NO];
// [[self recordButton] setTitle:NSLocalizedString(#"Stop", #"Recording button stop title") forState:UIControlStateNormal];
// [[self recordButton] setEnabled:YES];
}
else
{
// [[self cameraButton] setEnabled:YES];
// [[self recordButton] setTitle:NSLocalizedString(#"Record", #"Recording button record title") forState:UIControlStateNormal];
// [[self recordButton] setEnabled:YES];
}
});
}
else if (context == SessionRunningAndDeviceAuthorizedContext)
{
BOOL isRunning = [change[NSKeyValueChangeNewKey] boolValue];
dispatch_async(dispatch_get_main_queue(), ^{
if (isRunning)
{
// [[self cameraButton] setEnabled:YES];
// [[self recordButton] setEnabled:YES];
// [[self stillButton] setEnabled:YES];
}
else
{
// [[self cameraButton] setEnabled:NO];
// [[self recordButton] setEnabled:NO];
// [[self stillButton] setEnabled:NO];
}
});
}
else
{
[super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
}
}
#pragma mark Actions
- (IBAction)toggleMovieRecording:(id)sender
{
// [[self recordButton] setEnabled:NO];
dispatch_async([self sessionQueue], ^{
if (![[self movieFileOutput] isRecording])
{
[self setLockInterfaceRotation:YES];
if ([[UIDevice currentDevice] isMultitaskingSupported])
{
// Setup background task. This is needed because the captureOutput:didFinishRecordingToOutputFileAtURL: callback is not received until AVCam returns to the foreground unless you request background execution time. This also ensures that there will be time to write the file to the assets library when AVCam is backgrounded. To conclude this background execution, -endBackgroundTask is called in -recorder:recordingDidFinishToOutputFileURL:error: after the recorded file has been saved.
[self setBackgroundRecordingID:[[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:nil]];
}
// Update the orientation on the movie file output video connection before starting recording.
// [[[self movieFileOutput] connectionWithMediaType:AVMediaTypeVideo] setVideoOrientation:[[(AVCaptureVideoPreviewLayer *)[[self previewView] layer] connection] videoOrientation]];
// Turning OFF flash for video recording
[ViewController setFlashMode:AVCaptureFlashModeOff forDevice:[[self videoDeviceInput] device]];
// Start recording to a temporary file.
NSString *outputFilePath = [NSTemporaryDirectory() stringByAppendingPathComponent:[#"movie" stringByAppendingPathExtension:#"mov"]];
[[self movieFileOutput] startRecordingToOutputFileURL:[NSURL fileURLWithPath:outputFilePath] recordingDelegate:self];
}
else
{
[[self movieFileOutput] stopRecording];
}
});
}
- (IBAction)changeCamera:(id)sender
{
// [[self cameraButton] setEnabled:NO];
// [[self recordButton] setEnabled:NO];
// [[self stillButton] setEnabled:NO];
dispatch_async([self sessionQueue], ^{
AVCaptureDevice *currentVideoDevice = [[self videoDeviceInput] device];
AVCaptureDevicePosition preferredPosition = AVCaptureDevicePositionUnspecified;
AVCaptureDevicePosition currentPosition = [currentVideoDevice position];
switch (currentPosition)
{
case AVCaptureDevicePositionUnspecified:
preferredPosition = AVCaptureDevicePositionBack;
break;
case AVCaptureDevicePositionBack:
preferredPosition = AVCaptureDevicePositionFront;
break;
case AVCaptureDevicePositionFront:
preferredPosition = AVCaptureDevicePositionBack;
break;
}
AVCaptureDevice *videoDevice = [ViewController deviceWithMediaType:AVMediaTypeVideo preferringPosition:preferredPosition];
AVCaptureDeviceInput *videoDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:nil];
[[self session] beginConfiguration];
[[self session] removeInput:[self videoDeviceInput]];
if ([[self session] canAddInput:videoDeviceInput])
{
[[NSNotificationCenter defaultCenter] removeObserver:self name:AVCaptureDeviceSubjectAreaDidChangeNotification object:currentVideoDevice];
[ViewController setFlashMode:AVCaptureFlashModeAuto forDevice:videoDevice];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(subjectAreaDidChange:) name:AVCaptureDeviceSubjectAreaDidChangeNotification object:videoDevice];
[[self session] addInput:videoDeviceInput];
[self setVideoDeviceInput:videoDeviceInput];
}
else
{
[[self session] addInput:[self videoDeviceInput]];
}
[[self session] commitConfiguration];
dispatch_async(dispatch_get_main_queue(), ^{
// [[self cameraButton] setEnabled:YES];
// [[self recordButton] setEnabled:YES];
// [[self stillButton] setEnabled:YES];
});
});
}
- (IBAction)snapStillImage:(id)sender
{
dispatch_async([self sessionQueue], ^{
// Update the orientation on the still image output video connection before capturing.
// [[[self stillImageOutput] connectionWithMediaType:AVMediaTypeVideo] setVideoOrientation:[[(AVCaptureVideoPreviewLayer *)[[self previewView] layer] connection] videoOrientation]];
// Flash set to Auto for Still Capture
[ViewController setFlashMode:AVCaptureFlashModeAuto forDevice:[[self videoDeviceInput] device]];
// Capture a still image.
[[self stillImageOutput] captureStillImageAsynchronouslyFromConnection:[[self stillImageOutput] connectionWithMediaType:AVMediaTypeVideo] completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
if (imageDataSampleBuffer)
{
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
UIImage *image = [[UIImage alloc] initWithData:imageData];
// do someting good with saved image
[self saveImageToParse:image];
}
}];
});
}
- (IBAction)focusAndExposeTap:(UIGestureRecognizer *)gestureRecognizer
{
// CGPoint devicePoint = [(AVCaptureVideoPreviewLayer *)[[self previewView] layer] captureDevicePointOfInterestForPoint:[gestureRecognizer locationInView:[gestureRecognizer view]]];
// [self focusWithMode:AVCaptureFocusModeAutoFocus exposeWithMode:AVCaptureExposureModeAutoExpose atDevicePoint:devicePoint monitorSubjectAreaChange:YES];
}
- (void)subjectAreaDidChange:(NSNotification *)notification
{
CGPoint devicePoint = CGPointMake(.5, .5);
[self focusWithMode:AVCaptureFocusModeContinuousAutoFocus exposeWithMode:AVCaptureExposureModeContinuousAutoExposure atDevicePoint:devicePoint monitorSubjectAreaChange:NO];
}
#pragma mark File Output Delegate
- (void)captureOutput:(AVCaptureFileOutput *)captureOutput didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL fromConnections:(NSArray *)connections error:(NSError *)error
{
if (error)
NSLog(#"%#", error);
[self setLockInterfaceRotation:NO];
// Note the backgroundRecordingID for use in the ALAssetsLibrary completion handler to end the background task associated with this recording. This allows a new recording to be started, associated with a new UIBackgroundTaskIdentifier, once the movie file output's -isRecording is back to NO — which happens sometime after this method returns.
UIBackgroundTaskIdentifier backgroundRecordingID = [self backgroundRecordingID];
[self setBackgroundRecordingID:UIBackgroundTaskInvalid];
[[[ALAssetsLibrary alloc] init] writeVideoAtPathToSavedPhotosAlbum:outputFileURL completionBlock:^(NSURL *assetURL, NSError *error) {
if (error)
NSLog(#"%#", error);
[[NSFileManager defaultManager] removeItemAtURL:outputFileURL error:nil];
if (backgroundRecordingID != UIBackgroundTaskInvalid)
[[UIApplication sharedApplication] endBackgroundTask:backgroundRecordingID];
}];
}
#pragma mark Device Configuration
- (void)focusWithMode:(AVCaptureFocusMode)focusMode exposeWithMode:(AVCaptureExposureMode)exposureMode atDevicePoint:(CGPoint)point monitorSubjectAreaChange:(BOOL)monitorSubjectAreaChange
{
dispatch_async([self sessionQueue], ^{
AVCaptureDevice *device = [[self videoDeviceInput] device];
NSError *error = nil;
if ([device lockForConfiguration:&error])
{
if ([device isFocusPointOfInterestSupported] && [device isFocusModeSupported:focusMode])
{
[device setFocusMode:focusMode];
[device setFocusPointOfInterest:point];
}
if ([device isExposurePointOfInterestSupported] && [device isExposureModeSupported:exposureMode])
{
[device setExposureMode:exposureMode];
[device setExposurePointOfInterest:point];
}
[device setSubjectAreaChangeMonitoringEnabled:monitorSubjectAreaChange];
[device unlockForConfiguration];
}
else
{
NSLog(#"%#", error);
}
});
}
+ (void)setFlashMode:(AVCaptureFlashMode)flashMode forDevice:(AVCaptureDevice *)device
{
if ([device hasFlash] && [device isFlashModeSupported:flashMode])
{
NSError *error = nil;
if ([device lockForConfiguration:&error])
{
[device setFlashMode:flashMode];
[device unlockForConfiguration];
}
else
{
NSLog(#"%#", error);
}
}
}
+ (AVCaptureDevice *)deviceWithMediaType:(NSString *)mediaType preferringPosition:(AVCaptureDevicePosition)position
{
NSArray *devices = [AVCaptureDevice devicesWithMediaType:mediaType];
AVCaptureDevice *captureDevice = [devices firstObject];
for (AVCaptureDevice *device in devices)
{
if ([device position] == position)
{
captureDevice = device;
break;
}
}
return captureDevice;
}
#pragma mark UI
- (void)runStillImageCaptureAnimation
{
/*
dispatch_async(dispatch_get_main_queue(), ^{
[[[self previewView] layer] setOpacity:0.0];
[UIView animateWithDuration:.25 animations:^{
[[[self previewView] layer] setOpacity:1.0];
}];
});
*/
}
- (void)checkDeviceAuthorizationStatus
{
NSString *mediaType = AVMediaTypeVideo;
[AVCaptureDevice requestAccessForMediaType:mediaType completionHandler:^(BOOL granted) {
if (granted)
{
//Granted access to mediaType
[self setDeviceAuthorized:YES];
}
else
{
//Not granted access to mediaType
dispatch_async(dispatch_get_main_queue(), ^{
[[[UIAlertView alloc] initWithTitle:#"AVCam!"
message:#"AVCam doesn't have permission to use Camera, please change privacy settings"
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles:nil] show];
[self setDeviceAuthorized:NO];
});
}
}];
}
I want to display a progress HUD right before starting a long task, and dismiss it once the task is done. Right now the UI freezes for some time, then the HUD shows for a second before disappearing. After another 4-5 seconds the task is finished and it displays its results, but the progress HUD is already gone.
- (void) addProcess:(NSString *)searchTerm
{
dispatch_sync(dispatch_get_main_queue(), ^{
UIApplication *app = [UIApplication sharedApplication];
app.networkActivityIndicatorVisible = YES;
[SVProgressHUD showWithMaskType:SVProgressHUDMaskTypeGradient];
});
//DO SOME VERY LONG STUFF HERE
dispatch_sync(dispatch_get_main_queue(), ^{
UIApplication *app = [UIApplication sharedApplication];
app.networkActivityIndicatorVisible = NO;
[SVProgressHUD dismiss];
});
}
I use SVProgressHUD for the progress HUD. I am calling the method addProcess using dispatch_async()
If I use the old +[NSThread detach...], it's working flawlessly, but I don't want to use it anymore.
A couple of things:
The key observation is to always use dispatch_async unless you need dispatch_sync. You don't need synchronous operation here, so just use dispatch_async for your UI updates.
If you're running addProcess from the main queue, it doesn't need to dispatch the first UI update back to the main queue. Obviously, if you're running this from a background queue, you do.
The original question had the dispatch to the background queue within addProcess, which makes more sense to me (keeps all the GCD stuff nicely encapsulated). You've updated your answer to say that you're invoking this via dispatch_async([self addProcess]) (by which I presume you meant to a global queue, not the main queue), which I'm less crazy about. I address both scenarios in my code samples below.
So, in short, if you're invoking this via [self addProcess] (without dispatching that, itself, to the background queue) I'd suggest:
- (void) addProcess:(NSString *)searchTerm
{
UIApplication *app = [UIApplication sharedApplication];
app.networkActivityIndicatorVisible = YES;
[SVProgressHUD showWithMaskType:SVProgressHUDMaskTypeGradient];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
//DO SOME VERY LONG STUFF HERE
dispatch_async(dispatch_get_main_queue(), ^{
UIApplication *app = [UIApplication sharedApplication];
app.networkActivityIndicatorVisible = NO;
[SVProgressHUD dismiss];
});
});
}
Or, alternatively,
- (void) addProcess:(NSString *)searchTerm
{
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
dispatch_async(dispatch_get_main_queue(), ^{
UIApplication *app = [UIApplication sharedApplication];
app.networkActivityIndicatorVisible = YES;
[SVProgressHUD showWithMaskType:SVProgressHUDMaskTypeGradient];
});
//DO SOME VERY LONG STUFF HERE
dispatch_async(dispatch_get_main_queue(), ^{
UIApplication *app = [UIApplication sharedApplication];
app.networkActivityIndicatorVisible = NO;
[SVProgressHUD dismiss];
});
});
}
And if you're doing ...
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
[self addProcess];
});
then it's just:
- (void) addProcess:(NSString *)searchTerm
{
dispatch_async(dispatch_get_main_queue(), ^{
UIApplication *app = [UIApplication sharedApplication];
app.networkActivityIndicatorVisible = YES;
[SVProgressHUD showWithMaskType:SVProgressHUDMaskTypeGradient];
});
//DO SOME VERY LONG STUFF HERE
dispatch_async(dispatch_get_main_queue(), ^{
UIApplication *app = [UIApplication sharedApplication];
app.networkActivityIndicatorVisible = NO;
[SVProgressHUD dismiss];
});
}