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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 "core/CSSPropertyNames.h"
     33 #include "core/css/StylePropertySet.h"
     34 #include "core/css/parser/CSSParser.h"
     35 #include "core/html/HTMLCanvasElement.h"
     36 #include "core/html/canvas/CanvasGradient.h"
     37 #include "core/html/canvas/CanvasPattern.h"
     38 #include "platform/graphics/GraphicsContext.h"
     39 #include "wtf/PassRefPtr.h"
     40 
     41 namespace blink {
     42 
     43 enum ColorParseResult { ParsedRGBA, ParsedCurrentColor, ParsedSystemColor, ParseFailed };
     44 
     45 static ColorParseResult parseColor(RGBA32& parsedColor, const String& colorString)
     46 {
     47     if (equalIgnoringCase(colorString, "currentcolor"))
     48         return ParsedCurrentColor;
     49     const bool useStrictParsing = true;
     50     if (CSSParser::parseColor(parsedColor, colorString, useStrictParsing))
     51         return ParsedRGBA;
     52     if (CSSParser::parseSystemColor(parsedColor, colorString))
     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);
     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(PassRefPtrWillBeRawPtr<CanvasGradient> gradient)
    116     : m_type(Gradient)
    117     , m_gradient(gradient)
    118 {
    119 }
    120 
    121 CanvasStyle::CanvasStyle(PassRefPtrWillBeRawPtr<CanvasPattern> pattern)
    122     : m_type(ImagePattern)
    123     , m_pattern(pattern)
    124 {
    125 }
    126 
    127 PassRefPtrWillBeRawPtr<CanvasStyle> CanvasStyle::createFromString(const String& color)
    128 {
    129     RGBA32 rgba;
    130     ColorParseResult parseResult = parseColor(rgba, color);
    131     switch (parseResult) {
    132     case ParsedRGBA:
    133     case ParsedSystemColor:
    134         return adoptRefWillBeNoop(new CanvasStyle(rgba));
    135     case ParsedCurrentColor:
    136         return adoptRefWillBeNoop(new CanvasStyle(CurrentColor));
    137     case ParseFailed:
    138         return nullptr;
    139     default:
    140         ASSERT_NOT_REACHED();
    141         return nullptr;
    142     }
    143 }
    144 
    145 PassRefPtrWillBeRawPtr<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 adoptRefWillBeNoop(new CanvasStyle(colorWithOverrideAlpha(rgba, alpha)));
    152     case ParsedCurrentColor:
    153         return adoptRefWillBeNoop(new CanvasStyle(CurrentColorWithOverrideAlpha, alpha));
    154     case ParseFailed:
    155         return nullptr;
    156     default:
    157         ASSERT_NOT_REACHED();
    158         return nullptr;
    159     }
    160 }
    161 
    162 PassRefPtrWillBeRawPtr<CanvasStyle> CanvasStyle::createFromGradient(PassRefPtrWillBeRawPtr<CanvasGradient> gradient)
    163 {
    164     if (!gradient)
    165         return nullptr;
    166     return adoptRefWillBeNoop(new CanvasStyle(gradient));
    167 }
    168 
    169 PassRefPtrWillBeRawPtr<CanvasStyle> CanvasStyle::createFromPattern(PassRefPtrWillBeRawPtr<CanvasPattern> pattern)
    170 {
    171     if (!pattern)
    172         return nullptr;
    173     return adoptRefWillBeNoop(new CanvasStyle(pattern));
    174 }
    175 
    176 bool CanvasStyle::isEquivalentColor(const CanvasStyle& other) const
    177 {
    178     if (m_type != other.m_type)
    179         return false;
    180 
    181     switch (m_type) {
    182     case RGBA:
    183         return m_rgba == other.m_rgba;
    184     case CMYKA:
    185         return m_cmyka.c == other.m_cmyka.c
    186             && m_cmyka.m == other.m_cmyka.m
    187             && m_cmyka.y == other.m_cmyka.y
    188             && m_cmyka.k == other.m_cmyka.k
    189             && m_cmyka.a == other.m_cmyka.a;
    190     case Gradient:
    191     case ImagePattern:
    192     case CurrentColor:
    193     case CurrentColorWithOverrideAlpha:
    194         return false;
    195     }
    196 
    197     ASSERT_NOT_REACHED();
    198     return false;
    199 }
    200 
    201 bool CanvasStyle::isEquivalentRGBA(float r, float g, float b, float a) const
    202 {
    203     if (m_type != RGBA)
    204         return false;
    205 
    206     return m_rgba == makeRGBA32FromFloats(r, g, b, a);
    207 }
    208 
    209 bool CanvasStyle::isEquivalentCMYKA(float c, float m, float y, float k, float a) const
    210 {
    211     if (m_type != CMYKA)
    212         return false;
    213 
    214     return c == m_cmyka.c
    215         && m == m_cmyka.m
    216         && y == m_cmyka.y
    217         && k == m_cmyka.k
    218         && a == m_cmyka.a;
    219 }
    220 
    221 void CanvasStyle::applyStrokeColor(GraphicsContext* context)
    222 {
    223     if (!context)
    224         return;
    225     switch (m_type) {
    226     case RGBA:
    227         context->setStrokeColor(m_rgba);
    228         break;
    229     case CMYKA: {
    230         // FIXME: Do this through platform-independent GraphicsContext API.
    231         // We'll need a fancier Color abstraction to support CMYKA correctly
    232         context->setStrokeColor(m_rgba);
    233         break;
    234     }
    235     case Gradient:
    236         context->setStrokeGradient(canvasGradient()->gradient());
    237         break;
    238     case ImagePattern:
    239         context->setStrokePattern(canvasPattern()->pattern());
    240         break;
    241     case CurrentColor:
    242     case CurrentColorWithOverrideAlpha:
    243         ASSERT_NOT_REACHED();
    244         break;
    245     }
    246 }
    247 
    248 void CanvasStyle::applyFillColor(GraphicsContext* context)
    249 {
    250     if (!context)
    251         return;
    252     switch (m_type) {
    253     case RGBA:
    254         context->setFillColor(m_rgba);
    255         break;
    256     case CMYKA: {
    257         // FIXME: Do this through platform-independent GraphicsContext API.
    258         // We'll need a fancier Color abstraction to support CMYKA correctly
    259         context->setFillColor(m_rgba);
    260         break;
    261     }
    262     case Gradient:
    263         context->setFillGradient(canvasGradient()->gradient());
    264         break;
    265     case ImagePattern:
    266         context->setFillPattern(canvasPattern()->pattern());
    267         break;
    268     case CurrentColor:
    269     case CurrentColorWithOverrideAlpha:
    270         ASSERT_NOT_REACHED();
    271         break;
    272     }
    273 }
    274 
    275 void CanvasStyle::trace(Visitor* visitor)
    276 {
    277     visitor->trace(m_gradient);
    278     visitor->trace(m_pattern);
    279 }
    280 
    281 }
    282