/*

     File: ImageBrowserBackgroundLayer.m

 Abstract: 

 Abstract:  IKImageBrowserView is a view that can display and browse a

 large amount of images and movies. This sample code demonstrates

 how to use the view in a Cocoa Application.

  Version: 1.1

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 Inc. ("Apple") in consideration of your agreement to the following

 terms, and your use, installation, modification or redistribution of

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 redistribute this Apple software.

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 license, under Apple's copyrights in this original Apple software (the

 "Apple Software"), to use, reproduce, modify and redistribute the Apple

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 Neither the name, trademarks, service marks or logos of Apple Inc. may

 be used to endorse or promote products derived from the Apple Software

 without specific prior written permission from Apple.  Except as

 expressly stated in this notice, no other rights or licenses, express or

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 MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION

 THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS

 FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND

 OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.

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 Copyright (C) 2013 Apple Inc. All Rights Reserved.

 */

#import "ImageBrowserBackgroundLayer.h"

@implementation ImageBrowserBackgroundLayer

@synthesize owner;

// -------------------------------------------------------------------------

//  init

// -------------------------------------------------------------------------

- (id) init

{

    if((self = [super init])){

        //needs to redraw when bounds change

        [self setNeedsDisplayOnBoundsChange:YES];

    }

    return self;

}

// -------------------------------------------------------------------------

//  actionForKey:

//

// always return nil, to never animate

// -------------------------------------------------------------------------

- (id<CAAction>)actionForKey:(NSString *)event

{

    return nil;

}

// -------------------------------------------------------------------------

//  drawInContext:

//

// draw a metal background that scrolls when the image browser scroll

// -------------------------------------------------------------------------

- (void)drawInContext:(CGContextRef)context

{

    //retreive bounds and visible rect

    NSRect visibleRect = [owner visibleRect];

    NSRect bounds = [owner bounds];

    //retreive background image

    CGImageRef image = NULL;

    NSString *path = [[NSBundle mainBundle] pathForResource:[@"metal_background.tif" stringByDeletingPathExtension] ofType:[@"metal_background.tif" pathExtension]];

    if (!path) {

        return;

    }

    CGImageSourceRef imageSource = CGImageSourceCreateWithURL((CFURLRef)[NSURL fileURLWithPath:path], NULL);

    if (!imageSource) {

        return;

    }

    image = CGImageSourceCreateImageAtIndex(imageSource, 0, NULL);

    if (!image) {

        CFRelease(imageSource);

        return;

    }

    float width = (float) CGImageGetWidth(image);

    float height = (float) CGImageGetHeight(image);

    //compute coordinates to fill the view

    float left, top, right, bottom;

    top = bounds.size.height - NSMaxY(visibleRect);

    top = fmod(top, height);

    top = height - top;

    right = NSMaxX(visibleRect);

    bottom = -height;

    // tile the image and take in account the offset to 'emulate' a scrolling background

    for (top = visibleRect.size.height-top; top>bottom; top -= height){

        for(left=0; left<right; left+=width){

            CGContextDrawImage(context, CGRectMake(left, top, width, height), image);

        }

    }

    CFRelease(imageSource);

    CFRelease(image);

}

@end