/*

    Copyright (C) 2015 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    This is the "Slide" NSCollectionViewItem subclass implementation.

*/

#import "AAPLSlide.h"

#import "AAPLImageFile.h"

#import "AAPLSlideCarrierView.h"

#import "AAPLSlideLayout.h"

#import "AAPLSlideTableBackgroundView.h"

#import <QuartzCore/QuartzCore.h>

@implementation AAPLSlide

#pragma mark Selection and Highlighting Support

- (void)setHighlightState:(NSCollectionViewItemHighlightState)newHighlightState {

    [super setHighlightState:newHighlightState];

    // Relay the newHighlightState to our AAPLSlideCarrierView.

    [(AAPLSlideCarrierView *)[self view] setHighlightState:newHighlightState];

}

- (void)setSelected:(BOOL)selected {

    [super setSelected:selected];

    // Relay the new "selected" state to our AAPLSlideCarrierView.

    [(AAPLSlideCarrierView *)[self view] setSelected:selected];

}

#pragma mark Represented Object

- (AAPLImageFile *)imageFile {

    return (AAPLImageFile *)(self.representedObject);

}

// We set a Slide's representedObject to point to the AAPLImageFile it stands for.  If you aren't using Bindings to provide the desired content for your item's views, an override of -setRepresentedObject: is a handy place to manually set such content when the model object (AAPLImageFile) is first associated with the item (AAPLSlide).  (Another good place to do that is in the -collectionView:willDisplayItem:forRepresentedObjectAtIndexPath: delegate method, depending how your like to factor your code.)  Our project uses Bindings to populate a Slide's imageView and NSTextFields, but we do use -setRepresentedObject: as an opportunity to request asynchronous loading of the ImageFile's previewImage.  When the previewImage has finished loading on a background thread, the AAPLImageFile will get a -setPreviewImage: message, scheduled for delivery on the main thread.  The Slide's imageView, whose content is bound to our representedObject's previewImage property, will then automatically show the loaded preview image.

- (void)setRepresentedObject:(id)newRepresentedObject {

    [super setRepresentedObject:newRepresentedObject];

    // Request loading of the ImageFile's previewImage.

    [self.imageFile requestPreviewImage];

}

#pragma mark Event Handling

// When a slide is double-clicked, open the image file.

- (void)mouseDown:(NSEvent *)theEvent {

    if ([theEvent clickCount] == 2) {

        [self openImageFile:self];

    } else {

        [super mouseDown:theEvent];

    }

}

#pragma mark Actions

// Open the image file, using the default app for files of its type.

- (IBAction)openImageFile:(id)sender {

    NSURL *url = self.imageFile.url;

    if (url) {

        [[NSWorkspace sharedWorkspace] openURL:url];

    }

}

- (AAPLSlideTableBackgroundView *)slideTableBackgroundView {

    // Find our AAPLSlideTableBackgroundView via NSCollectionViewItem's "collectionView" property.

    NSView *backgroundView = self.collectionView.backgroundView;

    return [backgroundView isKindOfClass:[AAPLSlideTableBackgroundView class]] ? (AAPLSlideTableBackgroundView *)backgroundView : nil;

}

// Set the image as the CollectionView's background (using the "backgroundView" property).

- (IBAction)setCollectionViewBackground:(id)sender {

    self.slideTableBackgroundView.image = [[NSImage alloc] initByReferencingURL:self.imageFile.url];

}

// Clear the CollectionView's background back to its default appearance.

- (IBAction)clearCollectionViewBackground:(id)sender {

    self.slideTableBackgroundView.image = nil;

}

#pragma mark Drag and Drop Support

// Override NSCollectionViewItem's -draggingImageComponents getter to return a snapshot of the entire slide as its dragging image.

- (NSArray *)draggingImageComponents {

    // Image itemRootView.

    NSView *itemRootView = self.view;

    NSRect itemBounds = itemRootView.bounds;

    NSBitmapImageRep *bitmap = [itemRootView bitmapImageRepForCachingDisplayInRect:itemBounds];

    unsigned char *bitmapData = bitmap.bitmapData;

    if (bitmapData) {

        bzero(bitmapData, bitmap.bytesPerRow * bitmap.pixelsHigh);

    }

    /*

        -cacheDisplayInRect:toBitmapImageRep: won't capture the "SlideCarrier"

        image, since it's rendered via the layer contents property.  Work around

        that by drawing the image into the bitmap ourselves, using a bitmap

        graphics context.

    */

    // Work around SlideCarrierView layer contents not being rendered to bitmap.

    NSImage *slideCarrierImage = [NSImage imageNamed:@"SlideCarrier"];

    [NSGraphicsContext saveGraphicsState];

    NSGraphicsContext *oldContext = [NSGraphicsContext currentContext];

    [NSGraphicsContext setCurrentContext:[NSGraphicsContext graphicsContextWithBitmapImageRep:bitmap]];

    [slideCarrierImage drawInRect:itemBounds fromRect:NSZeroRect operation:NSCompositeSourceOver fraction:1.0];

    [NSGraphicsContext setCurrentContext:oldContext];

    [NSGraphicsContext restoreGraphicsState];

    /*

        Invoke -cacheDisplayInRect:toBitmapImageRep: to render the rest of the

        itemRootView subtree into the bitmap.

    */

    [itemRootView cacheDisplayInRect:itemBounds toBitmapImageRep:bitmap];

    NSImage *image = [[NSImage alloc] initWithSize:[bitmap size]];

    [image addRepresentation:bitmap];

    NSDraggingImageComponent *component = [[NSDraggingImageComponent alloc] initWithKey:NSDraggingImageComponentIconKey];

    component.frame = itemBounds;

    component.contents = image;

    return [NSArray arrayWithObject:component];

}

@end