TVOutManager.m

//
//  TVOutManager.m
//  TVOutOS4Test
//
//  Created by Rob Terrell (rob@touchcentric.com) on 8/16/10.
//  Copyright 2010 TouchCentric LLC. All rights reserved.
//
// http://www.touchcentric.com/blog/


#import <QuartzCore/QuartzCore.h>
#import "TVOutManager.h"

#define kFPS 15

//
// Warning: once again, we can't use UIGetScreenImage for shipping apps (as of late July 2010)
// however, it gives a better result (shows the status bar, UIKit transitions, better fps) so 
// you may want to use it for non-app-store builds (i.e. private demo, trade show build, etc.)
// Just uncomment both lines below.
//
//#define USE_UIGETSCREENIMAGE 
//CGImageRef UIGetScreenImage();
//

@implementation TVOutManager

@synthesize tvSafeMode;
@synthesize implementation;

+ (TVOutManager *)sharedInstance
{
	static TVOutManager *sharedInstance;
	
	@synchronized(self)
	{
		if (!sharedInstance)
			sharedInstance = [[TVOutManager alloc] init];
		return sharedInstance;
	}
}


- (id) init
{
    self = [super init];
    if (self) {
		// can't imagine why, but just in case
		[[NSNotificationCenter defaultCenter] removeObserver: self];
		
		// catch screen-related notifications
		[[NSNotificationCenter defaultCenter] addObserver: self selector: @selector(screenDidConnectNotification:) name: UIScreenDidConnectNotification object: nil];
		[[NSNotificationCenter defaultCenter] addObserver: self selector: @selector(screenDidDisconnectNotification:) name: UIScreenDidDisconnectNotification object: nil];
		[[NSNotificationCenter defaultCenter] addObserver: self selector: @selector(screenModeDidChangeNotification:) name: UIScreenModeDidChangeNotification object: nil];
		
		// catch orientation notifications
		[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
		[[NSNotificationCenter defaultCenter] addObserver: self selector: @selector(deviceOrientationDidChange:) name: UIDeviceOrientationDidChangeNotification object: nil];		
    }
    return self;
}

-(void) dealloc
{
	[[NSNotificationCenter defaultCenter] removeObserver: self];
	[super dealloc];
}

-(void) setTvSafeMode:(BOOL) val
{
	if (tvoutWindow) {
		if (tvSafeMode == YES && val == NO) {
			[UIView beginAnimations:@"zoomIn" context: nil];
			tvoutWindow.transform = CGAffineTransformScale(tvoutWindow.transform, 1.25, 1.25);
			[UIView commitAnimations];
			[tvoutWindow setNeedsDisplay];
		}
		else if (tvSafeMode == NO && val == YES) {
			[UIView beginAnimations:@"zoomOut" context: nil];
			tvoutWindow.transform = CGAffineTransformScale(tvoutWindow.transform, .8, .8);
			[UIView commitAnimations];			
			[tvoutWindow setNeedsDisplay];
		}
	}
	tvSafeMode = val;
}

- (void) setImplementation:(TVOutImplementation) theImplementation
{
	if(tvoutWindow && theImplementation != implementation)
	{
		NSLog(@"TVOutManager: TVOutManager Started. Can't change implementations while running.");
	}
	else 
	{
		implementation = theImplementation;
	}
}

- (TVOutImplementation) implementation
{
	return implementation;
}

- (void) startTVOut
{
	// you need to have a main window already open when you call start
	if ([[UIApplication sharedApplication] keyWindow] == nil) return;
	
	NSArray* screens = [UIScreen screens];
	if ([screens count] <= 1) {
		NSLog(@"TVOutManager: startTVOut failed (no external screens detected)");
		return;	
	}
	
	if (tvoutWindow) {
		// tvoutWindow already exists, so this is a re-connected cable, or a mode chane
		[tvoutWindow release], tvoutWindow = nil;
	}
	
	if (!tvoutWindow) {
		deviceWindow = [[UIApplication sharedApplication] keyWindow];
		
		CGSize max;
		max.width = 0;
		max.height = 0;
		UIScreenMode *maxScreenMode = nil;
		UIScreen *external = [[UIScreen screens] objectAtIndex: 1];
		for(int i = 0; i < [[external availableModes] count]; i++)
		{
			UIScreenMode *current = [[[[UIScreen screens] objectAtIndex:1] availableModes] objectAtIndex: i];
			if (current.size.width > max.width)
			{
				max = current.size;
				maxScreenMode = current;
			}
		}
		external.currentMode = maxScreenMode;
		
		tvoutWindow = [[UIWindow alloc] initWithFrame: CGRectMake(0,0, max.width, max.height)];
		tvoutWindow.userInteractionEnabled = NO;
		tvoutWindow.screen = external;
				
		// size the mirrorView to expand to fit the external screen
		CGRect mirrorRect = [[UIScreen mainScreen] bounds];
		CGFloat horiz = max.width / CGRectGetWidth(mirrorRect);
		CGFloat vert = max.height / CGRectGetHeight(mirrorRect);
		CGFloat bigScale = horiz < vert ? horiz : vert;
		mirrorRect = CGRectMake(mirrorRect.origin.x, mirrorRect.origin.y, mirrorRect.size.width * bigScale, mirrorRect.size.height * bigScale);
		
		mirrorView = [[UIImageView alloc] initWithFrame: mirrorRect];
		mirrorView.center = tvoutWindow.center;
		
		// TV safe area -- scale the window by 20% -- for composite / component, not needed for VGA output
		if (tvSafeMode) tvoutWindow.transform = CGAffineTransformScale(tvoutWindow.transform, .8, .8);
		[tvoutWindow addSubview: mirrorView];
		[mirrorView release];
		[tvoutWindow makeKeyAndVisible];
		tvoutWindow.hidden = NO;		
		tvoutWindow.backgroundColor = [UIColor darkGrayColor];
		
		// orient the view properly
		if ([UIDevice currentDevice].orientation == UIDeviceOrientationLandscapeLeft) {
			mirrorView.transform = CGAffineTransformRotate(CGAffineTransformIdentity, M_PI * 1.5);			
		} else if ([UIDevice currentDevice].orientation == UIDeviceOrientationLandscapeRight) {
			mirrorView.transform = CGAffineTransformRotate(CGAffineTransformIdentity, M_PI * -1.5);
		}
		startingTransform = mirrorView.transform;

		[deviceWindow makeKeyAndVisible];

		[self updateTVOut];

		
		if (self.implementation == kTVOutImplementationBackgroundThread)
		{
			[NSThread detachNewThreadSelector:@selector(updateLoop) toTarget:self withObject:nil];
		}
		else if(self.implementation == kTVOutImplementationMainThread)
		{
			updateTimer = [NSTimer scheduledTimerWithTimeInterval: (1.0/kFPS) target: self selector: @selector(updateTVOut) userInfo: nil repeats: YES];
			[updateTimer retain];
		}
		else if(self.implementation == kTVOutImplementationCADisplayLink)
		{
			[self performSelectorInBackground:@selector(caDisplayLinkWorker) withObject:nil];
		}
		else {
			NSLog(@"TVOutManager: Unknown implementation. Defaulting to kTVOutImplementationMainThread");
			[NSThread detachNewThreadSelector:@selector(updateLoop) toTarget:self withObject:nil];
		}

	}
}

- (void) caDisplayLinkWorker{
	done = NO;
	NSAutoreleasePool *pool = [[NSAutoreleasePool alloc]init];
	CADisplayLink *displayLink =	[CADisplayLink displayLinkWithTarget:self selector:@selector(updateTVOutForCADisplayLink)];
	[displayLink setFrameInterval:(60 / kFPS)];
	[displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];
	[displayLink retain];
	while (!done) {
		[[NSRunLoop currentRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:0.5f]];
	}
	[displayLink invalidate];
	[displayLink release];
	displayLink = nil;
	[pool release];
}

- (void) stopTVOut;
{
	done = YES;
	if (updateTimer) {
		[updateTimer invalidate];
		[updateTimer release], updateTimer = nil;
	}
	if (tvoutWindow) {
		[tvoutWindow release], tvoutWindow = nil;
		mirrorView = nil;
	}
}

- (void) updateTVOutForCADisplayLink
{
	NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
	[self updateTVOut];
	[pool release];
}


- (void) updateTVOut;
{
#ifdef USE_UIGETSCREENIMAGE
	// UIGetScreenImage() is no longer allowed in shipping apps, see https://devforums.apple.com/thread/61338
	// however, it's better for demos, since it includes the status bar and captures animated transitions
	
	CGImageRef cgScreen = UIGetScreenImage();
	if (cgScreen) image = [UIImage imageWithCGImage:cgScreen];
	mirrorView.image = image;
	CGImageRelease(cgScreen);
	
#else
	
	// from http://developer.apple.com/iphone/library/qa/qa2010/qa1703.html	
	// bonus, this works in the simulator; sadly, it doesn't capture the status bar
	//
	// if you are making an OpenGL app, use UIGetScreenImage() above or switch the
	// following code to match Apple's sample at http://developer.apple.com/iphone/library/qa/qa2010/qa1704.html
	// note that you'll need to pass in a reference to your eaglview to get that to work.
	
	if(UIGraphicsBeginImageContextWithOptions != NULL)
	{
		UIGraphicsBeginImageContextWithOptions(deviceWindow.bounds.size, NO, 0);
	}
	else 
	{
		UIGraphicsBeginImageContext(deviceWindow.bounds.size);
	}

	CGContextRef context = UIGraphicsGetCurrentContext();
	
	// get every window's contents (i.e. so you can see alerts, ads, etc.)
	for (UIWindow *window in [[UIApplication sharedApplication] windows])
    {
		if (![window respondsToSelector:@selector(screen)] || [window screen] == [UIScreen mainScreen])
        {
            CGContextSaveGState(context);
            CGContextTranslateCTM(context, [window center].x, [window center].y);
            CGContextConcatCTM(context, [window transform]);
            CGContextTranslateCTM(context, -[window bounds].size.width * window.layer.anchorPoint.x, -[window bounds].size.height * window.layer.anchorPoint.y);
            [[window layer] renderInContext:context];
            CGContextRestoreGState(context);
        }
    }	
	image = UIGraphicsGetImageFromCurrentImageContext();
	UIGraphicsEndImageContext();
	mirrorView.image = image;

#endif
}


- (void)updateLoop;
{
	NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
	done = NO;
	
	while ( ! done )
	{
		[self performSelectorOnMainThread:@selector(updateTVOut) withObject:nil waitUntilDone:NO];
		[NSThread sleepForTimeInterval: (1.0/kFPS) ];
	}
	[pool release];
}

-(void) screenDidConnectNotification: (NSNotification*) notification
{
	NSLog(@"Screen connected: %@", [notification object]);
	[self startTVOut];
}

-(void) screenDidDisconnectNotification: (NSNotification*) notification
{
	NSLog(@"Screen disconnected: %@", [notification object]);
	[self stopTVOut];
}

-(void) screenModeDidChangeNotification: (NSNotification*) notification
{
	NSLog(@"Screen mode changed: %@", [notification object]);
	[self startTVOut];
}

-(void) deviceOrientationDidChange: (NSNotification*) notification
{
	if (mirrorView == nil || done == YES) return;
	if ([UIDevice currentDevice].orientation == UIDeviceOrientationLandscapeLeft) {
		[UIView beginAnimations:@"turnLeft" context:nil];
		mirrorView.transform = CGAffineTransformRotate(CGAffineTransformIdentity, M_PI * 1.5);			
		[UIView commitAnimations];
	} else if ([UIDevice currentDevice].orientation == UIDeviceOrientationLandscapeRight) {
		[UIView beginAnimations:@"turnRight" context:nil];
		mirrorView.transform = CGAffineTransformRotate(CGAffineTransformIdentity, M_PI * -1.5);
		[UIView commitAnimations];
	} else {
		[UIView beginAnimations:@"turnUp" context:nil];
		mirrorView.transform = CGAffineTransformIdentity;
		[UIView commitAnimations];
	}	
}

@end