/*

     File: AVScreenShackDocument.m

 Abstract: Document, owns session, screen capture input, and movie file output

  Version: 2.1

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 */

#import "AVScreenShackDocument.h"

#import <AVFoundation/AVFoundation.h>

@interface AVScreenShackDocument ()

@property (weak) IBOutlet NSView *captureView;

- (IBAction)startRecording:(id)sender;

- (IBAction)stopRecording:(id)sender;

- (IBAction)setDisplayAndCropRect:(id)sender;

@end

@implementation AVScreenShackDocument

{

    CGDirectDisplayID           display;

    AVCaptureMovieFileOutput    *captureMovieFileOutput;

    NSMutableArray              *shadeWindows;

}

#pragma mark Capture

- (BOOL)createCaptureSession:(NSError **)outError

{

    /* Create a capture session. */

    self.captureSession = [[AVCaptureSession alloc] init];

    if ([self.captureSession canSetSessionPreset:AVCaptureSessionPresetHigh])

    {

        /* Specifies capture settings suitable for high quality video and audio output. */

        [self.captureSession setSessionPreset:AVCaptureSessionPresetHigh];

    }

    /* Add the main display as a capture input. */

    display = CGMainDisplayID();

    self.captureScreenInput = [[AVCaptureScreenInput alloc] initWithDisplayID:display];

    if ([self.captureSession canAddInput:self.captureScreenInput]) 

    {

        [self.captureSession addInput:self.captureScreenInput];

    } 

    else 

    {

        return NO;

    }

    /* Add a movie file output + delegate. */

    captureMovieFileOutput = [[AVCaptureMovieFileOutput alloc] init];

    [captureMovieFileOutput setDelegate:self];

    if ([self.captureSession canAddOutput:captureMovieFileOutput]) 

    {

        [self.captureSession addOutput:captureMovieFileOutput];

    } 

    else 

    {

        return NO;

    }

    /* Register for notifications of errors during the capture session so we can display an alert. */

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(captureSessionRuntimeErrorDidOccur:) name:AVCaptureSessionRuntimeErrorNotification object:self.captureSession];

    return YES;

}

/*

 AVCaptureVideoPreviewLayer is a subclass of CALayer that you use to display 

 video as it is being captured by an input device.

 You use this preview layer in conjunction with an AV capture session.

 */

-(void)addCaptureVideoPreview

{

    /* Create a video preview layer. */

    AVCaptureVideoPreviewLayer *videoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.captureSession];

    /* Configure it.*/

    [videoPreviewLayer setFrame:[[self.captureView layer] bounds]];

    [videoPreviewLayer setAutoresizingMask:kCALayerWidthSizable|kCALayerHeightSizable];

    /* Add the preview layer as a sublayer to the view. */

    [[self.captureView layer] addSublayer:videoPreviewLayer];

    /* Specify the background color of the layer. */

    [[self.captureView layer] setBackgroundColor:CGColorGetConstantColor(kCGColorBlack)];

}

/*

 An AVCaptureScreenInput's minFrameDuration is the reciprocal of its maximum frame rate.  This property

 may be used to request a maximum frame rate at which the input produces video frames.  The requested

 rate may not be achievable due to overall bandwidth, so actual frame rates may be lower.

 */

- (float)maximumScreenInputFramerate

{

    Float64 minimumVideoFrameInterval = CMTimeGetSeconds([self.captureScreenInput minFrameDuration]);

    return minimumVideoFrameInterval > 0.0f ? 1.0f/minimumVideoFrameInterval : 0.0;

}

/* Set the screen input maximum frame rate. */

- (void)setMaximumScreenInputFramerate:(float)maximumFramerate

{

    CMTime minimumFrameDuration = CMTimeMake(1, (int32_t)maximumFramerate);

    /* Set the screen input's minimum frame duration. */

    [self.captureScreenInput setMinFrameDuration:minimumFrameDuration];

}

/* Add a display as an input to the capture session. */

-(void)addDisplayInputToCaptureSession:(CGDirectDisplayID)newDisplay cropRect:(CGRect)cropRect

{

    /* Indicates the start of a set of configuration changes to be made atomically. */

    [self.captureSession beginConfiguration];

    /* Is this display the current capture input? */

    if ( newDisplay != display ) 

    {

        /* Display is not the current input, so remove it. */

        [self.captureSession removeInput:self.captureScreenInput];

        AVCaptureScreenInput *newScreenInput = [[AVCaptureScreenInput alloc] initWithDisplayID:newDisplay];

        self.captureScreenInput = newScreenInput;

        if ( [self.captureSession canAddInput:self.captureScreenInput] )

        {

            /* Add the new display capture input. */

            [self.captureSession addInput:self.captureScreenInput];

        }

        [self setMaximumScreenInputFramerate:[self maximumScreenInputFramerate]];

    }

    /* Set the bounding rectangle of the screen area to be captured, in pixels. */

    [self.captureScreenInput setCropRect:cropRect];

    /* Commits the configuration changes. */

    [self.captureSession commitConfiguration];

}

/* Informs the delegate when all pending data has been written to the output file. */

- (void)captureOutput:(AVCaptureFileOutput *)captureOutput didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL fromConnections:(NSArray *)connections error:(NSError *)error

{

    if (error) 

    {

        [self presentError:error];

        return;

    }

    [[NSWorkspace sharedWorkspace] openURL:outputFileURL];

}

- (BOOL)captureOutputShouldProvideSampleAccurateRecordingStart:(AVCaptureOutput *)captureOutput

{

    // We don't require frame accurate start when we start a recording. If we answer YES, the capture output

    // applies outputSettings immediately when the session starts previewing, resulting in higher CPU usage

    // and shorter battery life.

    return NO;

}

#pragma mark NSDocument

/* Initializes a AVScreenShackDocument document. */

- (id)initWithType:(NSString *)typeName error:(NSError **)outError

{

    self = [super initWithType:typeName error:outError];

    if (self) 

    {        

        BOOL success = [self createCaptureSession:outError];

        if (!success) 

        {

            return nil;

        }

    }

    return self;

}

- (void)dealloc

{

    [[NSNotificationCenter defaultCenter] removeObserver:self name:AVCaptureSessionRuntimeErrorNotification object:self.captureSession];

}

- (NSString *)windowNibName

{

    /* 

       Override returning the nib file name of the document.

       If you need to use a subclass of NSWindowController or if your document supports multiple NSWindowControllers, 

       you should remove this method and override -makeWindowControllers instead.

     */

    return @"AVScreenShackDocument";

}

- (void)windowControllerDidLoadNib:(NSWindowController *)aController

{

    [super windowControllerDidLoadNib:aController];

    [self addCaptureVideoPreview];

    /* Start the capture session running. */

    [self.captureSession startRunning];

    [[aController window] setContentBorderThickness:75.f forEdge:NSMinYEdge];

    [[aController window] setMovableByWindowBackground:YES];

}

/* Called when the document is closed. */

- (void)close

{

    /* Stop the capture session running. */

    [self.captureSession stopRunning];

    [super close];

}

/* AVScreenShackDocument does not support saving. */

-(BOOL)isDocumentEdited

{

    return NO;

}

#pragma mark Crop Rect

#define kShadyWindowLevel   (NSDockWindowLevel + 1000)

/* Draws a crop rect on the display. */

- (void)drawMouseBoxView:(DrawMouseBoxView*)view didSelectRect:(NSRect)rect

{

    /* Map point into global coordinates. */

    NSRect globalRect = rect;

    NSRect windowRect = [[view window] frame];

    globalRect = NSOffsetRect(globalRect, windowRect.origin.x, windowRect.origin.y);

    globalRect.origin.y = CGDisplayPixelsHigh(CGMainDisplayID()) - globalRect.origin.y;

    CGDirectDisplayID displayID = display;

    uint32_t matchingDisplayCount = 0;

    /* Get a list of online displays with bounds that include the specified point. */

    CGError e = CGGetDisplaysWithPoint(NSPointToCGPoint(globalRect.origin), 1, &displayID, &matchingDisplayCount);

    if ((e == kCGErrorSuccess) && (1 == matchingDisplayCount)) 

    {

        /* Add the display as a capture input. */

        [self addDisplayInputToCaptureSession:displayID cropRect:NSRectToCGRect(rect)];

    }

    for (NSWindow* w in [NSApp windows])

    {

        if ([w level] == kShadyWindowLevel)

        {

            [w close];

        }

    }

    [[NSCursor currentCursor] pop];

    [shadeWindows removeAllObjects];

}

/* 

 Called when the user sets a Crop Rect for the display.

 First dims the display, then allows the user specify a rectangular

 area of the display to capture.

*/

- (IBAction)setDisplayAndCropRect:(id)sender

{

    if(!shadeWindows) {

        shadeWindows = [NSMutableArray array];

    }

    for (NSScreen* screen in [NSScreen screens])

    {

        NSRect frame = [screen frame];

        NSWindow * window = [[NSWindow alloc] initWithContentRect:frame styleMask:NSBorderlessWindowMask backing:NSBackingStoreBuffered defer:NO];

        [window setBackgroundColor:[NSColor blackColor]];

        [window setAlphaValue:.5];

        [window setLevel:kShadyWindowLevel];

        [window setReleasedWhenClosed:NO];

        DrawMouseBoxView* drawMouseBoxView = [[DrawMouseBoxView alloc] initWithFrame:frame];

        drawMouseBoxView.delegate = self;

        [window setContentView:drawMouseBoxView];

        [window makeKeyAndOrderFront:self];

        [shadeWindows addObject:window];

    }

    [[NSCursor crosshairCursor] push];

}

- (void)alertDidEnd:(NSAlert *)alert returnCode:(NSInteger)returnCode contextInfo:(void *)contextInfo

{

    // Do nothing

}

- (void)captureSessionRuntimeErrorDidOccur:(NSNotification *)notification

{

    NSError *error = [notification userInfo][AVCaptureSessionErrorKey];

    NSAlert *alert = [[NSAlert alloc] init];

    [alert setAlertStyle:NSCriticalAlertStyle];

    [alert setMessageText:[error localizedDescription]];

    NSString *informativeText = [error localizedRecoverySuggestion];

    informativeText = informativeText ? informativeText : [error localizedFailureReason]; // No recovery suggestion, then at least tell the user why it failed.

    [alert setInformativeText:informativeText];

    [alert beginSheetModalForWindow:[self windowForSheet]

                      modalDelegate:self

                     didEndSelector:@selector(alertDidEnd:returnCode:contextInfo:)

                        contextInfo:NULL];

}

#pragma mark Start/Stop Button Actions

/* Called when the user presses the 'Start' button to start a recording. */

- (IBAction)startRecording:(id)sender

{

    NSLog(@"Minimum Frame Duration: %f, Crop Rect: %@, Scale Factor: %f, Capture Mouse Clicks: %@, Capture Mouse Cursor: %@, Remove Duplicate Frames: %@",

          CMTimeGetSeconds([self.captureScreenInput minFrameDuration]),

          NSStringFromRect(NSRectFromCGRect([self.captureScreenInput cropRect])),

          [self.captureScreenInput scaleFactor],

          [self.captureScreenInput capturesMouseClicks] ? @"Yes" : @"No",

          [self.captureScreenInput capturesCursor] ? @"Yes" : @"No",

          [self.captureScreenInput removesDuplicateFrames] ? @"Yes" : @"No");

    /* Create a recording file */

    char *screenRecordingFileName = strdup([[@"~/Desktop/AVScreenShackRecording_XXXXXX" stringByStandardizingPath] fileSystemRepresentation]);

    if (screenRecordingFileName)

    {

        int fileDescriptor = mkstemp(screenRecordingFileName);

        if (fileDescriptor != -1)

        {

            NSString *filenameStr = [[NSFileManager defaultManager] stringWithFileSystemRepresentation:screenRecordingFileName length:strlen(screenRecordingFileName)];

            /* Starts recording to a given URL. */

            [captureMovieFileOutput startRecordingToOutputFileURL:[NSURL fileURLWithPath:[filenameStr stringByAppendingPathExtension:@"mov"]] recordingDelegate:self];

        }

        remove(screenRecordingFileName);

        free(screenRecordingFileName);

    }

}

/* Called when the user presses the 'Stop' button to stop a recording. */

- (IBAction)stopRecording:(id)sender

{

    [captureMovieFileOutput stopRecording];

}

@end