cappuccino/AppKit/CPImageView.j

/*
 * CPImageView.j
 * AppKit
 *
 * Created by Francisco Tolmasky.
 * Copyright 2008, 280 North, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

@import <Foundation/CPNotificationCenter.j>

@import "CPControl.j"
@import "CPImage.j"
@import "CPShadowView.j"

@global CPImagesPboardType
@global appkit_tag_dom_elements

@global document

@typedef CPImageAlignment
CPImageAlignCenter      = 0;
CPImageAlignTop         = 1;
CPImageAlignTopLeft     = 2;
CPImageAlignTopRight    = 3;
CPImageAlignLeft        = 4;
CPImageAlignBottom      = 5;
CPImageAlignBottomLeft  = 6;
CPImageAlignBottomRight = 7;
CPImageAlignRight       = 8;

var CPImageViewEmptyPlaceholderImage = nil;

/*!
    @ingroup appkit
    @class CPImageView

    This class is a control that displays an image.
*/
@implementation CPImageView : CPControl
{
    DOMElement          _DOMImageElement;

    BOOL                _hasShadow;
    CPView              _shadowView;

    BOOL                _isEditable;

    CGRect              _imageRect;
    CPImageAlignment    _imageAlignment;
}

+ (void)initialize
{
    if (self !== [CPImageView class])
        return;

    var bundle = [CPBundle bundleForClass:[CPView class]];

    CPImageViewEmptyPlaceholderImage = [[CPImage alloc] initWithContentsOfFile:[bundle pathForResource:@"empty.png"]];
}

+ (Class)_binderClassForBinding:(CPString)aBinding
{
    if (aBinding === CPValueBinding || aBinding === CPValueURLBinding || aBinding === CPValuePathBinding || aBinding === CPDataBinding)
        return [CPImageViewValueBinder class];
    else if ([aBinding hasPrefix:CPEditableBinding])
        return [CPMultipleValueAndBinding class];

    return [super _binderClassForBinding:aBinding];
}

- (id)initWithFrame:(CGRect)aFrame
{
    self = [super initWithFrame:aFrame];

    if (self)
    {
#if PLATFORM(DOM)
        [self _createDOMImageElement];
#endif
    }

    return self;
}

- (void)_createDOMImageElement
{
#if PLATFORM(DOM)
    var image = [self objectValue],
        isCSSBasedImage = [image isCSSBased],
        isIMGImageElement = _DOMImageElement && (_DOMImageElement.nodeName == "IMG");

    // First, check if we need to destroy a current DOM image element. This is the case if :
    // - we have one but not the right one (that is a DIV but needing an IMG, and vice versa)

    if (_DOMImageElement)
    {
        if ((isIMGImageElement && isCSSBasedImage) || (!isIMGImageElement && !isCSSBasedImage))
        {
            // OK, destroy it

            _DOMElement.removeChild(_DOMImageElement);

            _DOMImageElement = nil;

            // CSS styling cleaning
            _cssStylePreviousState = @[];
            _cssStyleNode = nil;
        }
        else
            return;
    }

    _DOMImageElement = document.createElement(isCSSBasedImage ? "div" : "img");
    _DOMImageElement.style.position = "absolute";
    _DOMImageElement.style.left = "0px";
    _DOMImageElement.style.top = "0px";

    if ([CPPlatform supportsDragAndDrop])
    {
        _DOMImageElement.setAttribute("draggable", "true");
        _DOMImageElement.style["-khtml-user-drag"] = "element";
    }

    _DOMImageElement.style.visibility = "hidden";
    AppKitTagDOMElement(self, _DOMImageElement);

    CPDOMDisplayServerAppendChild(_DOMElement, _DOMImageElement);
#endif
}

/*!
    Returns the view's image.
*/
- (CPImage)image
{
    return [self objectValue];
}

- (void)setImage:(CPImage)anImage
{
    [self setObjectValue:anImage];
}

/*! @ignore */
- (void)setObjectValue:(CPImage)anImage
{
    var oldImage = [self objectValue];

    if (oldImage === anImage)
        return;

    [super setObjectValue:anImage];

    var defaultCenter = [CPNotificationCenter defaultCenter];

    if (oldImage)
        [defaultCenter removeObserver:self name:CPImageDidLoadNotification object:oldImage];

    var newImage = [self objectValue];

#if PLATFORM(DOM)
    [self _createDOMImageElement];

    if ([newImage isCSSBased])
        _cssStyleNode = [newImage applyCSSImageForView:self
                                          onDOMElement:_DOMImageElement
                                             styleNode:_cssStyleNode
                                         previousState:@ref(_cssStylePreviousState)];
    else
        _DOMImageElement.src = newImage ? [newImage filename] : [CPImageViewEmptyPlaceholderImage filename];
#endif

    var size = [newImage size];

    if (size && size.width === -1 && size.height === -1)
    {
        [defaultCenter addObserver:self selector:@selector(imageDidLoad:) name:CPImageDidLoadNotification object:newImage];

#if PLATFORM(DOM)
        _DOMImageElement.width = 0;
        _DOMImageElement.height = 0;
#endif

        [_shadowView setHidden:YES];
    }
    else
    {
        [self hideOrDisplayContents];
        [self setNeedsLayout];
        [self setNeedsDisplay:YES];
    }
}

- (void)imageDidLoad:(CPNotification)aNotification
{
    [[CPNotificationCenter defaultCenter] removeObserver:self name:CPImageDidLoadNotification object:[self objectValue]];
    [self hideOrDisplayContents];

    [self setNeedsLayout];
    [self setNeedsDisplay:YES];
}

/*!
    Returns \c YES if the image view draws with
    a drop shadow. The default is \c NO.
*/
- (BOOL)hasShadow
{
    return _hasShadow;
}

/*!
    Sets whether the image view should draw with a drop shadow.
    @param shouldHaveShadow whether the image view should have a shadow
*/
- (void)setHasShadow:(BOOL)shouldHaveShadow
{
    if (_hasShadow == shouldHaveShadow)
        return;

    _hasShadow = shouldHaveShadow;

    if (_hasShadow)
    {
        _shadowView = [[CPShadowView alloc] initWithFrame:[self bounds]];

        [self addSubview:_shadowView];

        [self setNeedsLayout];
        [self setNeedsDisplay:YES];
    }
    else
    {
        [_shadowView removeFromSuperview];

        _shadowView = nil;
    }

    [self hideOrDisplayContents];
}

/*!
    Sets the type of image alignment that should be used to
    render the image.
    @param anImageAlignment the type of scaling to use
*/
- (void)setImageAlignment:(CPImageAlignment)anImageAlignment
{
    if (_imageAlignment == anImageAlignment)
        return;

    _imageAlignment = anImageAlignment;

    if (![self image])
        return;

    [self setNeedsLayout];
    [self setNeedsDisplay:YES];
}

- (unsigned)imageAlignment
{
    return _imageAlignment;
}

/*!
    Sets the type of image scaling that should be used to
    render the image.
    @param anImageScaling the type of scaling to use
*/
- (void)setImageScaling:(CPImageScaling)anImageScaling
{
    [super setImageScaling:anImageScaling];

#if PLATFORM(DOM)
    if ([self currentValueForThemeAttribute:@"image-scaling"] === CPImageScaleAxesIndependently)
    {
        CPDOMDisplayServerSetStyleLeftTop(_DOMImageElement, NULL, 0.0, 0.0);
    }
#endif

    [self setNeedsLayout];
    [self setNeedsDisplay:YES];
}

- (CPUInteger)imageScaling
{
    return [self currentValueForThemeAttribute:@"image-scaling"];
}

/*!
    Toggles the display of the image view.
*/
- (void)hideOrDisplayContents
{
    if (![self image])
    {
#if PLATFORM(DOM)
        _DOMImageElement.style.visibility = "hidden";
#endif
        [_shadowView setHidden:YES];
    }
    else
    {
#if PLATFORM(DOM)
        _DOMImageElement.style.visibility = "visible";
#endif
        [_shadowView setHidden:NO];
    }
}

/*!
    Returns the view's image rectangle
*/
- (CGRect)imageRect
{
    return _imageRect;
}

/*!
    Add a description
*/
- (void)layoutSubviews
{
    if (![self image])
        return;

    var bounds = [self bounds],
        image = [self image],
        imageScaling = [self currentValueForThemeAttribute:@"image-scaling"],
        x = 0.0,
        y = 0.0,
        insetWidth = (_hasShadow ? [_shadowView horizontalInset] : 0.0),
        insetHeight = (_hasShadow ? [_shadowView verticalInset] : 0.0),
        boundsWidth = CGRectGetWidth(bounds),
        boundsHeight = CGRectGetHeight(bounds),
        width = boundsWidth - insetWidth,
        height = boundsHeight - insetHeight;

    if (imageScaling === CPImageScaleAxesIndependently)
    {
        #if PLATFORM(DOM)
            _DOMImageElement.width = ROUND(width);
            _DOMImageElement.height = ROUND(height);
        #endif
    }
    else
    {
        var size = [image size];

        if (size.width == -1 && size.height == -1)
            return;

        switch (imageScaling)
        {
            case CPImageScaleProportionallyDown:
                if (width >= size.width && height >= size.height)
                {
                    width = size.width;
                    height = size.height;
                    break;
                }

                // intentionally fall through to the next case

            case CPImageScaleProportionallyUpOrDown:
                var imageRatio = size.width / size.height,
                    viewRatio = width / height;

                if (viewRatio > imageRatio)
                    width = height * imageRatio;
                else
                    height = width / imageRatio;
                break;

            case CPImageScaleAxesIndependently:
            case CPImageScaleNone:
                width = size.width;
                height = size.height;
                break;
        }

        #if PLATFORM(DOM)
            _DOMImageElement.width = ROUND(width);
            _DOMImageElement.height = ROUND(height);
        #endif

        var x,
            y;

        switch (_imageAlignment)
        {
            case CPImageAlignLeft:
            case CPImageAlignTopLeft:
            case CPImageAlignBottomLeft:
                x = 0.0;
                break;

            case CPImageAlignRight:
            case CPImageAlignTopRight:
            case CPImageAlignBottomRight:
                x = boundsWidth - width;
                break;

            default:
                x = (boundsWidth - width) / 2.0;
                break;
        }

        switch (_imageAlignment)
        {
            case CPImageAlignTop:
            case CPImageAlignTopLeft:
            case CPImageAlignTopRight:
                y = 0.0;
                break;

            case CPImageAlignBottom:
            case CPImageAlignBottomLeft:
            case CPImageAlignBottomRight:
                y = boundsHeight - height;
                break;

            default:
                y = (boundsHeight - height) / 2.0;
                break;
        }

#if PLATFORM(DOM)
        CPDOMDisplayServerSetStyleLeftTop(_DOMImageElement, NULL, x, y);
#endif
    }

#if PLATFORM(DOM)
    if ([image isCSSBased] && [image _shouldBeResized])
    {
        [image _setDisplaySize:CGSizeMake(ROUND(width), ROUND(height))];

        _cssStyleNode = [image applyCSSImageForView:self
                                       onDOMElement:_DOMImageElement
                                          styleNode:_cssStyleNode
                                      previousState:@ref(_cssStylePreviousState)];
    }
#endif

    _imageRect = CGRectMake(x, y, width, height);

    if (_hasShadow)
        [_shadowView setFrame:CGRectMake(x - [_shadowView leftInset], y - [_shadowView topInset], width + insetWidth, height + insetHeight)];
}

- (void)mouseDown:(CPEvent)anEvent
{
    // Should we do something with this event?
    [[self nextResponder] mouseDown:anEvent];
}

- (void)setEditable:(BOOL)shouldBeEditable
{
    if (_isEditable === shouldBeEditable)
        return;

    _isEditable = shouldBeEditable;

    if (_isEditable)
        [self registerForDraggedTypes:[CPImagesPboardType]];

    else
    {
        var draggedTypes = [self registeredDraggedTypes];

        [self unregisterDraggedTypes];

        [draggedTypes removeObjectIdenticalTo:CPImagesPboardType];

        [self registerForDraggedTypes:draggedTypes];
    }
}

- (BOOL)isEditable
{
    return _isEditable;
}

- (BOOL)performDragOperation:(CPDraggingInfo)aSender
{
    var images = [CPKeyedUnarchiver unarchiveObjectWithData:[[aSender draggingPasteboard] dataForType:CPImagesPboardType]];

    if ([images count])
    {
        [self setImage:images[0]];
        [self sendAction:[self action] to:[self target]];
    }

    return YES;
}

@end

@implementation CPImageViewValueBinder : CPBinder
{
}

- (void)_updatePlaceholdersWithOptions:(CPDictionary)options
{
    [self _setPlaceholder:nil forMarker:CPMultipleValuesMarker isDefault:YES];
    [self _setPlaceholder:nil forMarker:CPNoSelectionMarker isDefault:YES];
    [self _setPlaceholder:nil forMarker:CPNotApplicableMarker isDefault:YES];
    [self _setPlaceholder:nil forMarker:CPNullMarker isDefault:YES];
}

- (void)setPlaceholderValue:(id)aValue withMarker:(CPString)aMarker forBinding:(CPString)aBinding
{
    [_source setImage:nil];
}

- (void)setValue:(id)aValue forBinding:(CPString)aBinding
{
    var image;

    if (aValue == nil)
        image = nil;
    else if (aBinding === CPDataBinding)
        image = [[CPImage alloc] initWithData:aValue];
    else if (aBinding === CPValueURLBinding || aBinding === CPValuePathBinding)
        image = [CPImage cachedImageWithContentsOfFile:aValue];
    else if (aBinding === CPValueBinding)
        image = aValue;

    [_source setImage:image];
}

- (id)valueForBinding:(CPString)aBinding
{
    var image = [_source image];

    if (aBinding === CPDataBinding)
        return [image data];
    else if (aBinding === CPValueURLBinding || aBinding === CPValuePathBinding)
        return [image filename];
    else if (aBinding === CPValueBinding)
        return image;
}

@end

var CPImageViewImageKey          = @"CPImageViewImageKey",
    CPImageViewImageScalingKey   = @"CPImageViewImageScalingKey",
    CPImageViewImageAlignmentKey = @"CPImageViewImageAlignmentKey",
    CPImageViewHasShadowKey      = @"CPImageViewHasShadowKey",
    CPImageViewIsEditableKey     = @"CPImageViewIsEditableKey";

@implementation CPImageView (CPCoding)

/*!
    Initializes the image view with the provided coder.
    @param aCoder the coder from which data will be read.
    @return the initialized image view
*/
- (id)initWithCoder:(CPCoder)aCoder
{
    self = [super initWithCoder:aCoder];

    if (self)
    {
#if PLATFORM(DOM)
        [self _createDOMImageElement];
#endif

        [self setHasShadow:[aCoder decodeBoolForKey:CPImageViewHasShadowKey]];
        [self setImageAlignment:[aCoder decodeIntForKey:CPImageViewImageAlignmentKey]];

        if ([aCoder decodeBoolForKey:CPImageViewIsEditableKey])
            [self setEditable:YES];

        [self setNeedsLayout];
        [self setNeedsDisplay:YES];
    }

    return self;
}

/*!
    Writes the image view out to the coder.
    @param aCoder the coder to which the image
    view will be written
*/
- (void)encodeWithCoder:(CPCoder)aCoder
{
    // We do this in order to avoid encoding the _shadowView, which
    // should just automatically be created programmatically as needed.
    if (_shadowView)
        [_shadowView removeFromSuperview];

    [super encodeWithCoder:aCoder];

    if (_shadowView)
        [self addSubview:_shadowView];

    [aCoder encodeBool:_hasShadow forKey:CPImageViewHasShadowKey];
    [aCoder encodeInt:_imageAlignment forKey:CPImageViewImageAlignmentKey];

    if (_isEditable)
        [aCoder encodeBool:_isEditable forKey:CPImageViewIsEditableKey];
}

@end

@implementation CPImage (CachedImage)

+ (CPImage)cachedImageWithContentsOfFile:(CPString)aFile
{
    var cached_name = [CPString stringWithFormat:@"%@_%d", [self class], [aFile hash]],
        image = [CPImage imageNamed:cached_name];

    if (!image)
    {
        image = [[CPImage alloc] initWithContentsOfFile:aFile];
        [image setName:cached_name];
    }

    return image;
}

@end