//
//  DetailViewController.m
//  iOSDemo
//
//  Created by adam on 29/09/2012.
//  Copyright (c) 2012 na. All rights reserved.
//
#import "DetailViewController.h"

@interface ImageLoadingOptions : NSObject
@property(nonatomic) CGSize overrideImageSize;
@property(nonatomic) float overrideImageRenderScale; 
@property(nonatomic,strong) SVGKSourceLocalFile* localFileSource;
- (id)initWithSource:(SVGKSource*) source;
@end

static NSString * const kTimeIntervalForLastReRenderOfSVGFromMemory = @"timeIntervalForLastReRenderOfSVGFromMemory";

@implementation ImageLoadingOptions
- (id)initWithSource:(SVGKSource*) source
{
    self = [super init];
    if (self) {
		if( [source isKindOfClass:[SVGKSourceLocalFile class]])
		self.localFileSource = (SVGKSourceLocalFile*) source;
		else
			; // cannot auto-select loading options for anything except local files / bundle files
		
        self.overrideImageRenderScale = 1.0;
		self.overrideImageSize = CGSizeZero;
    }
    return self;
}
@end

@interface DetailViewController ()

@property (nonatomic, strong) UIPopoverController *popoverController;

@property (nonatomic, strong) NSDate* startParseTime, * endParseTime;

- (void)loadSVGFrom:(SVGKSource *) svgSource;
- (void)shakeHead;

/** Apple's NSTimer class is an old OS X class that doesn't place nicely with ObjC blocks
 (Apple needs to upgrade it). It sets up some nasty retain cycles and you can't set
 the .userInfo after its started (a side-effect of the internal retain'ing Apple does)
 
 By storing this reference here, we can give a block a reference in advance, while also
 giving the block's output to the timer as .userinfo at creation time
 */
@property (nonatomic, strong) NSTimer* tickerLoadingApplesNSTimerSucks;

@end


@implementation DetailViewController
@synthesize scrollViewForSVG;

@synthesize toolbar, popoverController, contentView, detailItem;
@synthesize viewActivityIndicator;
@synthesize exportText = _exportText;

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
    }
    return self;
}

- (void)dealloc {
	self.detailItem = nil;
    self.contentView = nil;
}

-(void)viewDidLoad
{
	[super viewDidLoad];
	self.scrollViewForSVG.delegate = self;
}

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    [self setupNavigationBar];
}

CALayer* lastTappedLayer;
CGFloat lastTappedLayerOriginalBorderWidth;
CGColorRef lastTappedLayerOriginalBorderColor;
CATextLayer *textLayerForLastTappedLayer;
-(void) deselectTappedLayer
{
	if( lastTappedLayer != nil )
	{
#if ALLOW_SVGKFASTIMAGEVIEW_TO_DO_HIT_TESTING
		if( [self.contentView isKindOfClass:[SVGKFastImageView class]])
		{
			[lastTappedLayer removeFromSuperlayer]; // nothing else needed
		}
		else
#endif
		{
			lastTappedLayer.borderWidth = lastTappedLayerOriginalBorderWidth;
			lastTappedLayer.borderColor = lastTappedLayerOriginalBorderColor;
		}
		
		[textLayerForLastTappedLayer removeFromSuperlayer];
		textLayerForLastTappedLayer = nil;
		
		lastTappedLayer = nil;
	}
}

- (void)setupNavigationBar {
    NSString *renderTitle = self.requiresLayeredImageView ? @"LayeredImageView" : @"FastImageView";
    UIBarButtonItem *renderItem = [[UIBarButtonItem alloc] initWithTitle:renderTitle style:UIBarButtonItemStylePlain target:self action:@selector(toggleRender:)];
    UIBarButtonItem *debugItem = [[UIBarButtonItem alloc] initWithTitle:@"Debug" style:UIBarButtonItemStylePlain target:self action:@selector(showHideBorder:)];
    UIBarButtonItem *animateItem = [[UIBarButtonItem alloc] initWithTitle:@"Animate" style:UIBarButtonItemStylePlain target:self action:@selector(animate:)];
    self.navigationItem.rightBarButtonItems = @[renderItem, debugItem, animateItem];
}

-(NSString*) layerInfo:(CALayer*) l
{
	return [NSString stringWithFormat:@"%@:%@", [l class], NSStringFromCGRect(l.frame)];
}

/**
 Example of how to handle gaps on an SVG
 */
-(void) handleTapGesture:(UITapGestureRecognizer*) recognizer
{
	CGPoint p = [recognizer locationInView:self.scrollViewForSVG];
	
#if ALLOW_SVGKFASTIMAGEVIEW_TO_DO_HIT_TESTING // look how much code this requires! It's insane! Use SVGKLayeredImageView instead if you need hit-testing!
	SVGKImage* svgImage = nil; // ONLY used for the hacky code below that demonstrates how complex hit-testing is on an SVGKFastImageView
	
	/**
	 WARNING:
	 
	 Whenever you're using SVGKFastImageView, it "hides" the raw CALayers from you, and Apple
	 doesn't provide an easy way around this (we do it this way because there are missing methods
	 and bugs in Apple's UIScrollView, which SVGKFastImageView fixes).
	 
	 So, you cannot do a hittest on "SVGKFastImageView.layer" - that will always return the root,
	 empty, full-size layer.
	 
	 Instead, you have to hit-test the layer INSIDE the fast imageview.
	 
	 --------
	 
	 HOWEVER: YOU SHOULD NOT BE DOING THIS!
	 
	 IF YOU NEED TO DO HIT-TESTING, USE SVGKLayeredImageView (as per the docs!)
	 
	 THE EXAMPLE CODE HERE SHOWS YOU HOW YOU COULD, IN THEORY, DO HIT-TESTING WITH EITHER, BUT IT
	 IS HIGHLY RECOMMENDED NEVER TO USE HIT-TESTING WITH SVGKFastImageView!
	 */
#endif
	CALayer* layerForHitTesting;
	
#if ALLOW_SVGKFASTIMAGEVIEW_TO_DO_HIT_TESTING // look how much code this requires! It's insane! Use SVGKLayeredImageView instead if you need hit-testing!
	if( [self.contentView isKindOfClass:[SVGKFastImageView class]])
	{
		layerForHitTesting = ((SVGKFastImageView*)self.contentView).image.CALayerTree;
		svgImage = ((SVGKFastImageView*)self.contentView).image;
		
		/**
		 ALSO, because SVGKFastImageView DOES NOT ALTER the underlying layers when it zooms
		 (the zoom is handled "fast" and done internally at 100% accuracy),
		 any zoom will be ignored for the hit-test - we have to MANUALLY apply the zoom
		 */
		CGSize scaleConvertImageToViewForHitTest = CGSizeMake( self.contentView.bounds.size.width / svgImage.size.width, self.contentView.bounds.size.height / svgImage.size.height ); // this is a copy/paste of the internal "SCALING" logic used in SVGKFastImageView
		
		p = CGPointApplyAffineTransform( p, CGAffineTransformInvert( CGAffineTransformMakeScale( scaleConvertImageToViewForHitTest.width, scaleConvertImageToViewForHitTest.height)) ); // must do the OPPOSITE of the zoom (to convert the 'seeming' point to the 'actual' point
	}
	else
#endif
		layerForHitTesting = self.contentView.layer;
	
	
	CALayer* hitLayer = [layerForHitTesting hitTest:p];
	
	if( hitLayer == lastTappedLayer )
		[self deselectTappedLayer]; // do this both ways, but have to do it AFTER the if-test because it nil's one of the if-phrases!
	else {
		[self deselectTappedLayer]; // do this both ways, but have to do it AFTER the if-test because it nil's one of the if-phrases!
	
#if ALLOW_SVGKFASTIMAGEVIEW_TO_DO_HIT_TESTING // look how much code this requires! It's insane! Use SVGKLayeredImageView instead if you need hit-testing!
		if( [self.contentView isKindOfClass:[SVGKFastImageView class]])
		{
			/** NEVER DO THIS - this is a proof-of-concept, but instead you should ALWAYS
			 use SVGKLayeredImageView if you want to do hit-testing!
			 */
            NSLog(@"WARNING: don't use SVGKFastImageView for hit-testing");
			
			/**
			 Because SVGKFastImageView "hides" the layers, any visual changes we make
			 will NOT be reflected on-screen.
			 
			 Instead, we have to put a NEW layer over the top
			 */
			CALayer* absolutePositionedCloneLayer = [svgImage newCopyPositionedAbsoluteOfLayer:hitLayer];
			
			lastTappedLayer = [[CALayer alloc] init];
			lastTappedLayer.frame = absolutePositionedCloneLayer.frame;
			
			/**
			 ALSO, because SVGKFastImageView DOES NOT ALTER the underlying layers when it zooms
			 (the zoom is handled "fast" and done internally at 100% accuracy),
			 any zoom will be ignored for the new layer - we have to MANUALLY apply the zoom
			 */
			CGSize scaleConvertImageToView = CGSizeMake( self.contentView.bounds.size.width / svgImage.size.width, self.contentView.bounds.size.height / svgImage.size.height ); // this is a copy/paste of the internal "SCALING" logic used in SVGKFastImageView
			lastTappedLayer.frame = CGRectApplyAffineTransform( lastTappedLayer.frame, CGAffineTransformMakeScale(scaleConvertImageToView.width, scaleConvertImageToView.height));
			
			[self.contentView.layer addSublayer:lastTappedLayer];
		}
		else
#endif
			lastTappedLayer = hitLayer;
		
		if( lastTappedLayer != nil )
		{
			lastTappedLayerOriginalBorderColor = lastTappedLayer.borderColor;
			lastTappedLayerOriginalBorderWidth = lastTappedLayer.borderWidth;
			
			lastTappedLayer.borderColor = [UIColor greenColor].CGColor;
			lastTappedLayer.borderWidth = 3.0;
			
#if SHOW_DEBUG_INFO_ON_EACH_TAPPED_LAYER
			/** mtrubnikov's code for adding a text overlay showing exactly what you tapped
			 */
			NSString* textToDraw = [NSString stringWithFormat:@"%@ (%@): {%.1f, %.1f} {%.1f, %.1f}", hitLayer.name, [hitLayer class], lastTappedLayer.frame.origin.x, lastTappedLayer.frame.origin.y, lastTappedLayer.frame.size.width, lastTappedLayer.frame.size.height];
			
			UIFont* fontToDraw = [UIFont fontWithName:@"Helvetica"
												 size:14.0f];
            CGSize sizeOfTextRect = [textToDraw sizeWithAttributes:@{NSFontAttributeName: fontToDraw}];
			
			textLayerForLastTappedLayer = [[CATextLayer alloc] init];
			[textLayerForLastTappedLayer setFont:@"Helvetica"];
			[textLayerForLastTappedLayer setFontSize:14.0f];
			[textLayerForLastTappedLayer setFrame:CGRectMake(0, 0, sizeOfTextRect.width, sizeOfTextRect.height)];
			[textLayerForLastTappedLayer setString:textToDraw];
			[textLayerForLastTappedLayer setAlignmentMode:kCAAlignmentLeft];
			[textLayerForLastTappedLayer setForegroundColor:[UIColor redColor].CGColor];
			[textLayerForLastTappedLayer setContentsScale:[[UIScreen mainScreen] scale]];
			[textLayerForLastTappedLayer setShouldRasterize:NO];
			[self.contentView.layer addSublayer:textLayerForLastTappedLayer];
			/*
			 * mtrubnikov's code for adding a text overlay showing exactly what you tapped*/
#endif
		}
	}
}

#pragma mark - CRITICAL: this method makes Apple render SVGs in sharp focus

-(void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)finalScale
{
	/** NB: very important! The "finalScale" parameter to this method is SLIGHTLY DIFFERENT from the scale that Apple reports in the other delegate methods
	 
	 This is very confusing, clearly it's bit of a hack - the other methods get called
	 at slightly the wrong time, and so their data is slightly wrong (out-by-one animation step).
	 
	 ONLY the values passed as params to this method are correct!
	 */

	/**
	 * If we use the SVGKLayeredImageView then there is no need to redraw the image - only update scale on text elements
	 */
	if ([self.contentView isKindOfClass:[SVGKLayeredImageView class]]) {
		finalScale *= [UIScreen mainScreen].scale;

		NSMutableDictionary
				* newActions = [@{kCAOnOrderIn : [NSNull null], kCAOnOrderOut : [NSNull null], @"sublayers" : [NSNull null], @"contents" : [NSNull null], @"bounds" : [NSNull null]} mutableCopy];

		[CATransaction begin];
		[CATransaction setDisableActions:YES];

		// Override actions to prevent implicit CALayer animations that happen when setting scale
		[self setActions:newActions andUpdateScale:finalScale onTextSublayersOf:((SVGKLayeredImageView*)view).image.CALayerTree];

		[CATransaction commit];
	}
	else
	{
		/**

         Apple's implementation of zooming is EXTREMELY poorly designed; it's a hack onto a class
         that was only designed to do panning (hence the name: uiSCROLLview)

         So ... "zooming" via a UIScrollView is NOT integrated with UIView
         rendering - in a UIView subclass, you CANNOT KNOW whether you have been "zoomed"
         (i.e.: had your view contents ruined horribly by Apple's class)

         The three lines that follow are - allegedly - Apple's preferred way of handling
         the situation. Note that we DO NOT SET view.frame! According to official docs,
         view.frame is UNDEFINED (this is very worrying, breaks a huge amount of UIKit-related code,
         but that's how Apple has documented / implemented it!)
         */
		view.transform = CGAffineTransformIdentity; // this alters view.frame! But *not* view.bounds
		view.bounds = CGRectApplyAffineTransform(view.bounds, CGAffineTransformMakeScale(finalScale, finalScale));
		[view setNeedsDisplay];

		/**
         Workaround for another bug in Apple's hacks for UIScrollView:

          - when you reset the transform, as advised by Apple, you "break" Apple's memory of the scroll factor.
             ... because they "forgot" to store it anywhere (they read your view.transform as if it were a private
                 variable inside UIScrollView! This causes MANY bugs in applications :( )
         */
		self.scrollViewForSVG.minimumZoomScale /= finalScale;
		self.scrollViewForSVG.maximumZoomScale /= finalScale;
	}
}

- (void) setActions:(NSMutableDictionary*)actions andUpdateScale:(float)scale onTextSublayersOf:(CALayer*)layer {
	if ([layer isKindOfClass:[CATextLayer class]]){
		layer.actions = actions;
		layer.contentsScale = scale;
	}

	for (CALayer* sublayer in layer.sublayers) {
		[self setActions:actions andUpdateScale:scale onTextSublayersOf:sublayer];
	}
}

#pragma mark - rest of class

- (void)setDetailItem:(id)newDetailItem {
	if (detailItem != newDetailItem) {
        detailItem = newDetailItem;
        [self reload];
	}
	
	if (self.popoverController) {
		[self.popoverController dismissPopoverAnimated:YES];
	}
}

- (void)setContentView:(SVGKImageView *)newContentView {
    if (contentView == newContentView) {
        return;
    }
    if (contentView) {
        [contentView removeObserver:self forKeyPath:kTimeIntervalForLastReRenderOfSVGFromMemory];
    }
    if (newContentView) {
        /** Fast image view renders asynchronously, so we have to wait for a callback that its finished a render... */
        [newContentView addObserver:self forKeyPath:kTimeIntervalForLastReRenderOfSVGFromMemory options:0 context:nil];
    }
    contentView = newContentView;
}

-(void)reload {
    [self deselectTappedLayer]; // do this first because it DEPENDS UPON the type of self.contentView BEFORE the change in value
    // FIXME: re-write this class so that this method does NOT require self.view to exist
    [self view]; // Apple's design to trigger the creation of view. Original design of THIS class is that it breaks if view isn't already existing
    if (self.detailItem) {
        [self loadSVGFrom:self.detailItem];
    }
}

-(void) willLoadNewResource
{
	// update the view
	self.subViewLoadingPopup.hidden = FALSE;
	self.progressLoading.progress = 0;
	[self.viewActivityIndicator startAnimating];
	/** Move the gesture recognizer off the old view */
	if( self.contentView != nil
	   && self.tapGestureRecognizer != nil )
		[self.contentView removeGestureRecognizer:self.tapGestureRecognizer];
	
	[self.labelParseTime removeFromSuperview]; // we'll re-add to the new one
	[self.contentView removeFromSuperview];
}

/**
 If you want to emulate Apple's @2x naming system for UIImage, you can...
 */
-(void) preProcessImageFor2X:(ImageLoadingOptions*) options
{
#if ALLOW_2X_STYLE_SCALING_OF_SVGS_AS_AN_EXAMPLE
	if( [options.localFileSource.filePath hasSuffix:@"@2x"])
	{
		SVGKSourceLocalFile* modifiedSource = [options.localFileSource copy];
		modifiedSource.filePath = [modifiedSource.filePath substringToIndex:modifiedSource.filePath.length - @"@2x".length];
		options.overrideImageRenderScale = 2.0;
		options.localFileSource = modifiedSource;
	}
#endif
}

/**
 If you want to emulate Apple's @WxH naming system for UIImage, you can...
 */
-(void) preProcessImageForAt160x240:(ImageLoadingOptions*) options
{
	if( [options.localFileSource.filePath hasSuffix:@"@160x240"]) // could be any 999x999 you want, up to you to implement!
	{
		SVGKSourceLocalFile* modifiedSource = [options.localFileSource copy];
		
		modifiedSource.filePath = [modifiedSource.filePath substringToIndex:modifiedSource.filePath.length - @"@160x240".length];
		options.overrideImageSize = CGSizeMake( 160, 240 );
		
		options.localFileSource = modifiedSource;
	}
}

- (void)loadSVGFrom:(SVGKSource *) svgSource
{
	[self willLoadNewResource];
	[[NSRunLoop mainRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:0.01]]; // makes the animation appear
	
	self.startParseTime = self.endParseTime = [NSDate date]; // reset them
	
	SVGKImage *document = nil;
		ImageLoadingOptions* loadingOptions = [[ImageLoadingOptions alloc] initWithSource:svgSource];
	
	/** Detect URL vs file */
	self.startParseTime = [NSDate date];
	if( [svgSource isKindOfClass:[SVGKSourceURL class]])
	{
		@try
		{
			/**
			 This would work, but won't let us read any errors:
			 
		document = [SVGKImage imageWithContentsOfURL:[NSURL URLWithString:name]];
			 
			 so, instead, we create an SVGKSource explicitly (as this demo app is taking
			 user-input, and we have no idea how valid it is!)
			 
			 
			 */
			document = [SVGKImage imageWithSource:svgSource];
			
			[self internalLoadedResource:svgSource withOptions:loadingOptions parserOutput:(document==nil)?nil:document.parseErrorsAndWarnings  createImageViewFromDocument:document];
		}
		@catch( NSException* e )
		{
			[[[UIAlertView alloc] initWithTitle:@"SVG load failed" message:[NSString stringWithFormat:@"Error = %@", e] delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil] show];
			
			[self internalLoadedResource:svgSource withOptions:loadingOptions parserOutput:nil createImageViewFromDocument:nil];
		}
		
	}
	else if( [svgSource isKindOfClass:[SVGKSourceLocalFile class]])
	{
		
	/** This demo shows different images being used in different ways.
	 Here we setup special conditions based on the filename etc:
	 */

	[self preProcessImageFor2X:loadingOptions];
	[self preProcessImageForAt160x240:loadingOptions];
	
	/** Detect the magic name(s) for the nil-demos */
	if( svgSource == nil )
	{
		/** This demonstrates / tests what happens if you create an SVGKLayeredImageView with a nil SVGKImage
		 */
        [self didLoadNewResourceCreatingImageView:[[SVGKLayeredImageView alloc] init]];
	}
	else
	{
		/**
		 the actual loading of the SVG file
		 */

		
#if LOAD_SYNCHRONOUSLY
			document = [SVGKImage imageNamed:[name stringByAppendingPathExtension:@"svg"]];
			[self internalLoadedResource:name withOptions:loadingOptions createImageViewFromDocument:document];
#else
			SVGKParser* parser = [SVGKImage imageWithSource:svgSource
											   onCompletion:^(SVGKImage *loadedImage, SVGKParseResult* parseResult)
			{
				[self.tickerLoadingApplesNSTimerSucks invalidate];
				dispatch_async(dispatch_get_main_queue(), ^{
					// must be on main queue since this affects the UIKit GUI!
					[self internalLoadedResource:svgSource withOptions:loadingOptions parserOutput:parseResult createImageViewFromDocument:loadedImage];
				});
			}];
			self.tickerLoadingApplesNSTimerSucks = [NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(tickLoadingSVG:) userInfo:parser repeats:TRUE];
#endif
		}
	}
	else
	{
		[[[UIAlertView alloc] initWithTitle:@"SVG load failed" message:[NSString stringWithFormat:@"Unknown kind of source. Should be a recognized SVGKSource subclass. Was actually : %@", [svgSource class]] delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil] show];
		
		[self internalLoadedResource:nil withOptions:loadingOptions parserOutput:nil createImageViewFromDocument:nil];
	}
}

/** Updates the on-screen loading bar */
-(void) tickLoadingSVG:(NSTimer*) timer
{
	SVGKParser* parser = (SVGKParser*) timer.userInfo;
	
	dispatch_async(dispatch_get_main_queue(),
	^{
		// must be on main queue since this affects the UIKit GUI!
		self.progressLoading.progress = parser.currentParseRun.parseProgressFractionApproximate;
	});
}

/**
 Creates an appropriate SVGKImageView to display the loaded SVGKImage, and triggers the post-processing
 of on-screen displays
 */
-(void) internalLoadedResource:(SVGKSource*) source withOptions:(ImageLoadingOptions*) loadingOptions parserOutput:(SVGKParseResult*) parseResult createImageViewFromDocument:(SVGKImage*) document
{
	self.endParseTime = [NSDate date];
	
	SVGKImageView* newContentView = nil;
	if( loadingOptions.overrideImageRenderScale != 1.0 )
		document.scale = loadingOptions.overrideImageRenderScale;
	
	if( document == nil )
	{
		if( parseResult == nil )
		{
		[[[UIAlertView alloc] initWithTitle:@"SVG parse failed" message:@"Total failure. See console log" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil] show];
		}
		else
		{
		[[[UIAlertView alloc] initWithTitle:@"SVG parse failed" message:[NSString stringWithFormat:@"Summary: %@",parseResult] delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil] show];			
		}
		newContentView = nil; // signals to the rest of this method: the load failed
	}
	else
	{
		if( document.parseErrorsAndWarnings.rootOfSVGTree != nil )
		{
			//NSLog(@"[%@] Freshly loaded document (name = %@) has size = %@", [self class], name, NSStringFromCGSize(document.size) );
			
			/** NB: the SVG Spec says that the "correct" way to upscale or downscale an SVG is by changing the
			 SVG Viewport. SVGKit automagically does this for you if you ever set a value to image.scale */
			if( ! CGSizeEqualToSize( CGSizeZero, loadingOptions.overrideImageSize ) )
				document.size = loadingOptions.overrideImageSize; // preferred way to scale an SVG! (standards compliant!)
			
			if( self.requiresLayeredImageView )
			{
				newContentView = [[SVGKLayeredImageView alloc] initWithSVGKImage:document];
			}
			else
			{
				newContentView = [[SVGKFastImageView alloc] initWithSVGKImage:document];
				
				NSLog(@"[%@] WARNING: workaround for Apple bugs: UIScrollView spams tiny changes to the transform to the content view; currently, we have NO WAY of efficiently measuring whether or not to re-draw the SVGKImageView. As a temporary solution, we are DISABLING the SVGKImageView's auto-redraw-at-higher-resolution code - in general, you do NOT want to do this", [self class]);
				
				((SVGKFastImageView*)newContentView).disableAutoRedrawAtHighestResolution = TRUE;
			}
		}
		
		if( parseResult.errorsFatal.count > 0 )
		{
			[[[UIAlertView alloc] initWithTitle:@"SVG parse failed" message:[NSString stringWithFormat:@"%@",parseResult] delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil] show];
//			[[[[UIAlertView alloc] initWithTitle:@"SVG parse failed" message:[NSString stringWithFormat:@"%i fatal errors, %i warnings. First fatal = %@",[document.parseErrorsAndWarnings.errorsFatal count],[document.parseErrorsAndWarnings.errorsRecoverable count]+[document.parseErrorsAndWarnings.warnings count], ((NSError*)[document.parseErrorsAndWarnings.errorsFatal objectAtIndex:0]).localizedDescription] delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil] autorelease] show];
			newContentView = nil; // signals to the rest of this method: the load failed
			
		}
	}
	
	self.sourceOfCurrentDocument = source;
	
	[self didLoadNewResourceCreatingImageView:newContentView];
}

/**
 Reconfigures the view to display the newly-loaded image, and display meta info
 about how long it took to parse, etc
 */
-(void) didLoadNewResourceCreatingImageView:(SVGKImageView*) newContentView
{
	if( newContentView != nil )
	{
		/**
		 * NB: at this point we're guaranteed to have a "new" replacemtent ready for self.contentView
		 */
		
		/******* swap the new contentview in ************/
		self.contentView = newContentView;
		
		if( self.labelParseTime == nil )
		{
			self.labelParseTime = [[UILabel alloc] init];
			self.labelParseTime.autoresizingMask = UIViewAutoresizingFlexibleWidth;
			self.labelParseTime.backgroundColor = [UIColor colorWithWhite:1 alpha:0.5];
			self.labelParseTime.textColor = [UIColor blackColor];
			self.labelParseTime.text = @"(parsing)";
		}
        self.labelParseTime.frame = CGRectMake(0, 0, self.view.bounds.size.width, 20);
		
		[self.contentView addSubview:self.labelParseTime];
	
		/** set the border for new item */
		self.contentView.showBorder = FALSE;
	
		/** Move the gesture recognizer onto the new one */	
		if( self.tapGestureRecognizer == nil )
		{
			self.tapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTapGesture:)];
		}
		[self.contentView addGestureRecognizer:self.tapGestureRecognizer];
		
		[self.scrollViewForSVG addSubview:self.contentView];
		[self.scrollViewForSVG setContentSize: self.contentView.frame.size];
		
		float screenToDocumentSizeRatio = self.scrollViewForSVG.frame.size.width / self.contentView.frame.size.width;
		
		self.scrollViewForSVG.minimumZoomScale = MIN( 1, screenToDocumentSizeRatio );
		self.scrollViewForSVG.maximumZoomScale = MAX( 1, screenToDocumentSizeRatio );
		
		self.labelParseTime.text = [NSString stringWithFormat:@"(parsed: %.2f secs, rendered: %.2f secs)", [self.endParseTime timeIntervalSinceDate:self.startParseTime], self.contentView.timeIntervalForLastReRenderOfSVGFromMemory ];
		
		/**
		 EXAMPLE:
		 
		 How to find particular nodes in the tree, after parsing.
		 
		 In this case, we search for all SVG <g> tags, which usually mean grouped-objects in Inkscape etc:
		 NodeList* elementsUsingTagG = [document.DOMDocument getElementsByTagName:@"g"];
		 NSLog( @"[%@] checking for SVG standard set of elements with XML tag/node of <g>: %@", [self class], elementsUsingTagG.internalArray );
		 */
	}
	
	[self.viewActivityIndicator stopAnimating];
	self.subViewLoadingPopup.hidden = TRUE;
}

-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
	
	if( [keyPath isEqualToString:kTimeIntervalForLastReRenderOfSVGFromMemory ] )
	{
		self.labelParseTime.text = [NSString stringWithFormat:@"(parsed: %.2f secs, rendered: %.2f secs)", [self.endParseTime timeIntervalSinceDate:self.startParseTime], self.contentView.timeIntervalForLastReRenderOfSVGFromMemory ];
	}
}

- (IBAction)toggleRender:(id)sender {
    if (self.requiresLayeredImageView) {
        self.requiresLayeredImageView = NO;
    } else {
        self.requiresLayeredImageView = YES;
    }
    [self setupNavigationBar];
    [self reload];
}

- (IBAction)animate:(id)sender {
	if ([self.sourceOfCurrentDocument.keyForAppleDictionaries rangeOfString:@"/Monkey.svg"].location != NSNotFound) {
		[self shakeHead];
    } else if ([self.sourceOfCurrentDocument.keyForAppleDictionaries rangeOfString:@"/parent-clip.svg"].location != NSNotFound) {
        [self moveGreenSquare];
    }
}


- (void)shakeHead {
	CALayer *layer = [self.contentView.image layerWithIdentifier:@"head"];
	
	CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
	animation.duration = 0.25f;
	animation.autoreverses = YES;
	animation.repeatCount = 100000;
	animation.fromValue = [NSNumber numberWithFloat:0.1f];
	animation.toValue = [NSNumber numberWithFloat:-0.1f];
	
	[layer addAnimation:animation forKey:@"shakingHead"];
}

- (void)moveGreenSquare {
    CALayer *layer = [self.contentView.image layerWithIdentifier:@"greensquare"];
    
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"position"];
    animation.duration = 1;
    animation.autoreverses = YES;
    animation.repeatCount = 100000;
    animation.fromValue = [NSValue valueWithCGPoint:CGPointMake(50, 50)];
    animation.toValue = [NSValue valueWithCGPoint:CGPointMake(-50, -50)];
    
    [layer addAnimation:animation forKey:@"moveGreenSquare"];
}

- (IBAction) showHideBorder:(id)sender
{
	self.contentView.showBorder = ! self.contentView.showBorder;
	
	/**
	 NB: normally, the following would NOT be needed - the SVGKImageView would automatically
	 detect it needs to be re-drawn.
	 
	 But ... because we're doing zooming in this class, and Apple's zooming causes huge performance problems,
	 we disabled the auto-redraw in the loadResource: method above.
	 
	 So, now, we have to manually tell the SVGKImageView to redraw
	 */
	[self.contentView setNeedsDisplay];
}

#pragma mark - Split view

- (void)splitViewController:(UISplitViewController *)splitController willHideViewController:(UIViewController *)viewController withBarButtonItem:(UIBarButtonItem *)barButtonItem forPopoverController:(UIPopoverController *)argumentPopoverController
{
    barButtonItem.title = NSLocalizedString(@"Master", @"Master");
    [self.navigationItem setLeftBarButtonItem:barButtonItem animated:YES];
    self.popoverController = argumentPopoverController;
}

- (void)splitViewController:(UISplitViewController *)splitController willShowViewController:(UIViewController *)viewController invalidatingBarButtonItem:(UIBarButtonItem *)barButtonItem
{
    // Called when the view is shown again in the split view, invalidating the button and popover controller.
    [self.navigationItem setLeftBarButtonItem:nil animated:YES];
    self.popoverController = nil;
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
	return YES;
}

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    return self.contentView;
}


@end