/**
 * Copyright 2007-2010 Soggy Waffles. All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 * 
 *    1. Redistributions of source code must retain the above copyright notice, this list of
 *       conditions and the following disclaimer.
 * 
 *    2. Redistributions in binary form must reproduce the above copyright notice, this list
 *       of conditions and the following disclaimer in the documentation and/or other materials
 *       provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY SOGGY WAFFLES ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SOGGY WAFFLES OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * The views and conclusions contained in the software and documentation are those of the
 * authors and should not be interpreted as representing official policies, either expressed
 * or implied, of Soggy Waffles.
 */


#import "SWCenteringClipView.h"
#import "SWScalingScrollView.h"

@implementation SWCenteringClipView

@synthesize bgImagePattern;

- (void)drawRect:(NSRect)rect {
	// Draw a dark gray gradient background, using the new NSGradient class that has been added in Leopard.
	if (backgroundGradient == nil) {
        backgroundGradient = [[NSGradient alloc] initWithStartingColor:[NSColor colorWithCalibratedWhite:0.88 alpha:1.0]
															endingColor:[NSColor colorWithCalibratedWhite:0.78 alpha:1.0]];
	}
	[backgroundGradient drawInRect:[self bounds] angle:90.0];

	NSRect docRect = [[self documentView] bounds];
	
	[NSGraphicsContext saveGraphicsState];
	
	// Create the shadow below and to the right of the shape.
	if (shadow == nil) 
	{
		shadow = [[NSShadow alloc] init];
		[shadow setShadowOffset:NSMakeSize(3.0, -3.0)];
		[shadow setShadowBlurRadius:15.0];
		
		[shadow setShadowColor:[NSColor blackColor]];		
	}
	
	[shadow set];
	
	// Draw the background -- either an image pattern or a color
	if (bgImage) {
		[bgImage drawInRect:[[self documentView] bounds]];
	} else {
		[[NSColor whiteColor] setFill];		
		NSRectFill(docRect);
	}
	
	[NSGraphicsContext restoreGraphicsState];
}

- (void)centerDocument
{
	NSRect docRect = [[self documentView] frame];
	NSRect clipRect = [self bounds];

	// We can leave these values as integers (don't need the "2.0")
	if (docRect.size.width < clipRect.size.width) {
		clipRect.origin.x = roundf((docRect.size.width - clipRect.size.width) / 2.0);
	}
	
	if ( docRect.size.height < clipRect.size.height ) {
		clipRect.origin.y = roundf((docRect.size.height - clipRect.size.height) / 2.0);
	}
	
	// Potentially regenerate the background image
	if (bgImagePattern)
	{
		BOOL needsRedraw = NO;
		
		// Did we change image sizes?
		if (bgImage && !NSEqualSizes([bgImage size], docRect.size))
		{
			[bgImage release];
			bgImage = nil;
			needsRedraw = YES;
		}
		
		// Do we not have an image?
		if (!bgImage && !NSEqualSizes(docRect.size, NSZeroSize))
		{
			[SWImageTools initImageRep:&bgImage withSize:docRect.size];
			needsRedraw = YES;
		}
		
		// Did either (or both) of the above flip the needsRedraw flag?
		if (bgImage && needsRedraw) 
		{
			SWLockFocus(bgImage);
			CGContextDrawTiledImage([[NSGraphicsContext currentContext] graphicsPort], 
									CGRectMake(0, 0, [bgImagePattern size].width, [bgImagePattern size].height), 
									[[NSBitmapImageRep imageRepWithData:[bgImagePattern TIFFRepresentation]] CGImage]);
			SWUnlockFocus(bgImage);
		}
	}
	
	// Probably the most efficient way to move the bounds origin.
	[self scrollToPoint:clipRect.origin];
}

- (NSPoint)constrainScrollPoint:(NSPoint)proposedNewOrigin
{
	NSRect docRect = [[self documentView] frame];
	NSRect clipRect = [self bounds];
	NSPoint newScrollPoint = proposedNewOrigin;
	CGFloat maxX = docRect.size.width - clipRect.size.width;
	CGFloat maxY = docRect.size.height - clipRect.size.height;
	
	// If the clip view is wider than the doc, we can't scroll horizontally
	if (docRect.size.width < clipRect.size.width) {
		newScrollPoint.x = round(maxX / 2.0);
	} else {
		newScrollPoint.x = round(MAX(0,MIN(newScrollPoint.x,maxX)));
	}
	
	// If the clip view is taller than the doc, we can't scroll vertically
	if (docRect.size.height < clipRect.size.height) {
		newScrollPoint.y = round( maxY / 2.0 );
	} else {
		newScrollPoint.y = round( MAX(0,MIN(newScrollPoint.y,maxY)) );
	}

	return newScrollPoint;
}

- (void)viewBoundsChanged:(NSNotification *)notification
{
	[super viewBoundsChanged:notification];
	[self centerDocument];
}

- (void)viewFrameChanged:(NSNotification *)notification
{
	[super viewFrameChanged:notification];
	[self centerDocument];
}

// ----------------------------------------
// These superclass methods change the bounds rect directly without sending any notifications,
// so we're not sure what other work they silently do for us. As a result, we let them do their
// work and then swoop in behind to change the bounds origin ourselves. This appears to work
// just fine without us having to reinvent the methods from scratch.

- (void)setBoundsOrigin:(NSPoint)newOrigin
{
	[super setBoundsOrigin:newOrigin];
	[self centerDocument];
}

- (void)setBoundsSize:(NSSize)newSize
{
	[super setBoundsSize:newSize];
	[self centerDocument];
}

- (void)setFrame:(NSRect)frameRect
{
	[super setFrame:frameRect];
	[self centerDocument];
}

- (void)setFrameOrigin:(NSPoint)newOrigin
{
	[super setFrameOrigin:newOrigin];
	[self centerDocument];
}

- (void)setFrameSize:(NSSize)newSize
{
	[super setFrameSize:newSize];
	[self centerDocument];
}

- (void)setFrameRotation:(CGFloat)angle
{
	[super setFrameRotation:angle];
	[self centerDocument];
}

// Keeps the focus on the top-left corner
- (BOOL)isFlipped
{
	return YES;
}

- (void)dealloc
{
	[backgroundGradient release];
	[shadow release];
	[bgImage release];
	[bgImagePattern release];
	[super dealloc];
}


@end