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      1 /*
      2  * Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
      3  * Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies)
      4  * Copyright (C) 2007 Alp Toker <alp (at) atoker.com>
      5  * Copyright (C) 2008 Eric Seidel <eric (at) webkit.org>
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
     17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     20  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     21  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     22  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     23  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     24  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include "config.h"
     30 #include "core/html/canvas/CanvasStyle.h"
     31 
     32 #include "CSSPropertyNames.h"
     33 #include "core/css/CSSParser.h"
     34 #include "core/css/StylePropertySet.h"
     35 #include "core/html/HTMLCanvasElement.h"
     36 #include "core/html/canvas/CanvasGradient.h"
     37 #include "core/html/canvas/CanvasPattern.h"
     38 #include "core/platform/graphics/GraphicsContext.h"
     39 #include "wtf/Assertions.h"
     40 #include "wtf/PassRefPtr.h"
     41 
     42 namespace WebCore {
     43 
     44 enum ColorParseResult { ParsedRGBA, ParsedCurrentColor, ParsedSystemColor, ParseFailed };
     45 
     46 static ColorParseResult parseColor(RGBA32& parsedColor, const String& colorString, Document* document = 0)
     47 {
     48     if (equalIgnoringCase(colorString, "currentcolor"))
     49         return ParsedCurrentColor;
     50     if (CSSParser::parseColor(parsedColor, colorString))
     51         return ParsedRGBA;
     52     if (CSSParser::parseSystemColor(parsedColor, colorString, document))
     53         return ParsedSystemColor;
     54     return ParseFailed;
     55 }
     56 
     57 RGBA32 currentColor(HTMLCanvasElement* canvas)
     58 {
     59     if (!canvas || !canvas->inDocument() || !canvas->inlineStyle())
     60         return Color::black;
     61     RGBA32 rgba = Color::black;
     62     CSSParser::parseColor(rgba, canvas->inlineStyle()->getPropertyValue(CSSPropertyColor));
     63     return rgba;
     64 }
     65 
     66 bool parseColorOrCurrentColor(RGBA32& parsedColor, const String& colorString, HTMLCanvasElement* canvas)
     67 {
     68     ColorParseResult parseResult = parseColor(parsedColor, colorString, canvas ? canvas->document() : 0);
     69     switch (parseResult) {
     70     case ParsedRGBA:
     71     case ParsedSystemColor:
     72         return true;
     73     case ParsedCurrentColor:
     74         parsedColor = currentColor(canvas);
     75         return true;
     76     case ParseFailed:
     77         return false;
     78     default:
     79         ASSERT_NOT_REACHED();
     80         return false;
     81     }
     82 }
     83 
     84 CanvasStyle::CanvasStyle(Type type, float overrideAlpha)
     85     : m_type(type)
     86     , m_overrideAlpha(overrideAlpha)
     87 {
     88 }
     89 
     90 CanvasStyle::CanvasStyle(RGBA32 rgba)
     91     : m_type(RGBA)
     92     , m_rgba(rgba)
     93 {
     94 }
     95 
     96 CanvasStyle::CanvasStyle(float grayLevel, float alpha)
     97     : m_type(RGBA)
     98     , m_rgba(makeRGBA32FromFloats(grayLevel, grayLevel, grayLevel, alpha))
     99 {
    100 }
    101 
    102 CanvasStyle::CanvasStyle(float r, float g, float b, float a)
    103     : m_type(RGBA)
    104     , m_rgba(makeRGBA32FromFloats(r, g, b, a))
    105 {
    106 }
    107 
    108 CanvasStyle::CanvasStyle(float c, float m, float y, float k, float a)
    109     : m_type(CMYKA)
    110     , m_rgba(makeRGBAFromCMYKA(c, m, y, k, a))
    111     , m_cmyka(c, m, y, k, a)
    112 {
    113 }
    114 
    115 CanvasStyle::CanvasStyle(PassRefPtr<CanvasGradient> gradient)
    116     : m_type(Gradient)
    117     , m_gradient(gradient)
    118 {
    119 }
    120 
    121 CanvasStyle::CanvasStyle(PassRefPtr<CanvasPattern> pattern)
    122     : m_type(ImagePattern)
    123     , m_pattern(pattern)
    124 {
    125 }
    126 
    127 PassRefPtr<CanvasStyle> CanvasStyle::createFromString(const String& color, Document* document)
    128 {
    129     RGBA32 rgba;
    130     ColorParseResult parseResult = parseColor(rgba, color, document);
    131     switch (parseResult) {
    132     case ParsedRGBA:
    133     case ParsedSystemColor:
    134         return adoptRef(new CanvasStyle(rgba));
    135     case ParsedCurrentColor:
    136         return adoptRef(new CanvasStyle(CurrentColor));
    137     case ParseFailed:
    138         return 0;
    139     default:
    140         ASSERT_NOT_REACHED();
    141         return 0;
    142     }
    143 }
    144 
    145 PassRefPtr<CanvasStyle> CanvasStyle::createFromStringWithOverrideAlpha(const String& color, float alpha)
    146 {
    147     RGBA32 rgba;
    148     ColorParseResult parseResult = parseColor(rgba, color);
    149     switch (parseResult) {
    150     case ParsedRGBA:
    151         return adoptRef(new CanvasStyle(colorWithOverrideAlpha(rgba, alpha)));
    152     case ParsedCurrentColor:
    153         return adoptRef(new CanvasStyle(CurrentColorWithOverrideAlpha, alpha));
    154     case ParseFailed:
    155         return 0;
    156     default:
    157         ASSERT_NOT_REACHED();
    158         return 0;
    159     }
    160 }
    161 
    162 PassRefPtr<CanvasStyle> CanvasStyle::createFromGradient(PassRefPtr<CanvasGradient> gradient)
    163 {
    164     if (!gradient)
    165         return 0;
    166     return adoptRef(new CanvasStyle(gradient));
    167 }
    168 PassRefPtr<CanvasStyle> CanvasStyle::createFromPattern(PassRefPtr<CanvasPattern> pattern)
    169 {
    170     if (!pattern)
    171         return 0;
    172     return adoptRef(new CanvasStyle(pattern));
    173 }
    174 
    175 bool CanvasStyle::isEquivalentColor(const CanvasStyle& other) const
    176 {
    177     if (m_type != other.m_type)
    178         return false;
    179 
    180     switch (m_type) {
    181     case RGBA:
    182         return m_rgba == other.m_rgba;
    183     case CMYKA:
    184         return m_cmyka.c == other.m_cmyka.c
    185             && m_cmyka.m == other.m_cmyka.m
    186             && m_cmyka.y == other.m_cmyka.y
    187             && m_cmyka.k == other.m_cmyka.k
    188             && m_cmyka.a == other.m_cmyka.a;
    189     case Gradient:
    190     case ImagePattern:
    191     case CurrentColor:
    192     case CurrentColorWithOverrideAlpha:
    193         return false;
    194     }
    195 
    196     ASSERT_NOT_REACHED();
    197     return false;
    198 }
    199 
    200 bool CanvasStyle::isEquivalentRGBA(float r, float g, float b, float a) const
    201 {
    202     if (m_type != RGBA)
    203         return false;
    204 
    205     return m_rgba == makeRGBA32FromFloats(r, g, b, a);
    206 }
    207 
    208 bool CanvasStyle::isEquivalentCMYKA(float c, float m, float y, float k, float a) const
    209 {
    210     if (m_type != CMYKA)
    211         return false;
    212 
    213     return c == m_cmyka.c
    214         && m == m_cmyka.m
    215         && y == m_cmyka.y
    216         && k == m_cmyka.k
    217         && a == m_cmyka.a;
    218 }
    219 
    220 void CanvasStyle::applyStrokeColor(GraphicsContext* context)
    221 {
    222     if (!context)
    223         return;
    224     switch (m_type) {
    225     case RGBA:
    226         context->setStrokeColor(m_rgba);
    227         break;
    228     case CMYKA: {
    229         // FIXME: Do this through platform-independent GraphicsContext API.
    230         // We'll need a fancier Color abstraction to support CMYKA correctly
    231         context->setStrokeColor(m_rgba);
    232         break;
    233     }
    234     case Gradient:
    235         context->setStrokeGradient(canvasGradient()->gradient());
    236         break;
    237     case ImagePattern:
    238         context->setStrokePattern(canvasPattern()->pattern());
    239         break;
    240     case CurrentColor:
    241     case CurrentColorWithOverrideAlpha:
    242         ASSERT_NOT_REACHED();
    243         break;
    244     }
    245 }
    246 
    247 void CanvasStyle::applyFillColor(GraphicsContext* context)
    248 {
    249     if (!context)
    250         return;
    251     switch (m_type) {
    252     case RGBA:
    253         context->setFillColor(m_rgba);
    254         break;
    255     case CMYKA: {
    256         // FIXME: Do this through platform-independent GraphicsContext API.
    257         // We'll need a fancier Color abstraction to support CMYKA correctly
    258         context->setFillColor(m_rgba);
    259         break;
    260     }
    261     case Gradient:
    262         context->setFillGradient(canvasGradient()->gradient());
    263         break;
    264     case ImagePattern:
    265         context->setFillPattern(canvasPattern()->pattern());
    266         break;
    267     case CurrentColor:
    268     case CurrentColorWithOverrideAlpha:
    269         ASSERT_NOT_REACHED();
    270         break;
    271     }
    272 }
    273 
    274 }
    275