Transparency

third_party/WebKit/WebCore/rendering/RenderThemeChromiumWin.cpp

 /*
  * This file is part of the WebKit project.
  *
  * Copyright (C) 2006 Apple Computer, Inc.
  * Copyright (C) 2008, 2009 Google, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 20 matching lines @@
 #include "ChromiumBridge.h"
 #include "CSSStyleSheet.h"
 #include "CSSValueKeywords.h"
 #include "Document.h"
 #include "FontSelector.h"
 #include "FontUtilsChromiumWin.h"
 #include "GraphicsContext.h"
 #include "RenderBox.h"
 #include "ScrollbarTheme.h"
 #include "SkiaUtils.h"
-#include "ThemeHelperChromiumWin.h"
+#include "TransparencyWin.h"
 #include "UserAgentStyleSheets.h"
 #include "WindowsVersion.h"
 
 // FIXME: This dependency should eventually be removed.
 #include <skia/ext/skia_utils_win.h>
 
 #define SIZEOF_STRUCT_WITH_SPECIFIED_LAST_MEMBER(structName, member) \
     offsetof(structName, member) + \
     (sizeof static_cast<structName*>(0)->member)
 #define NONCLIENTMETRICS_SIZE_PRE_VISTA \
     SIZEOF_STRUCT_WITH_SPECIFIED_LAST_MEMBER(NONCLIENTMETRICS, lfMessageFont)
 
 namespace WebCore {
 
+namespace {
+
+bool canvasHasMultipleLayers(const SkCanvas* canvas)
+{
+    SkCanvas::LayerIter iter(const_cast<SkCanvas*>(canvas), false);
+    iter.next();  // There is always at least one layer.
+    return !iter.done();  // There is > 1 layer if the the iterator can stil advance.
+}
+
+class ThemePainter : public TransparencyWin {
+public:
+    ThemePainter(GraphicsContext* context, const IntRect& r) {
+        // Compute the transform mode.
+        TransformMode transformMode;
+        const TransformationMatrix& matrix = context->getCTM();
+        if (matrix.b() != 0 || matrix.c() != 0)  // Skew.
+            transformMode = Untransform;
+        else if (matrix.a() != 1.0 || matrix.d() != 1.0)  // Scale.
+            transformMode = ScaleTransform;
+        else  // Nothing interesting.
+            transformMode = KeepTransform;
+
+        // Compute the layer mode.
+        LayerMode layerMode;
+        if (context->platformContext()->isDrawingToImageBuffer())  // Might have transparent background.
+            layerMode = WhiteLayer;
+        else if (canvasHasMultipleLayers(context->platformContext()->canvas()))  // Needs antialiasing help.
+            layerMode = OpaqueCompositeLayer;
+        else  // Nothing interesting.
+            layerMode = transformMode == KeepTransform ? NoLayer : OpaqueCompositeLayer;
+
+        init(context, layerMode, transformMode, r);
+    }
+};
+
+}  // namespace
+
 static void getNonClientMetrics(NONCLIENTMETRICS* metrics) {
     static UINT size = WebCore::isVistaOrNewer() ?
         sizeof(NONCLIENTMETRICS) : NONCLIENTMETRICS_SIZE_PRE_VISTA;
     metrics->cbSize = size;
     bool success = !!SystemParametersInfo(SPI_GETNONCLIENTMETRICS, size, metrics, 0);
     ASSERT(success);
 }
 
 enum PaddingType {
     TopPadding,
@@ skipping 300 matching lines @@
 void RenderThemeChromiumWin::setRadioSize(RenderStyle* style) const
 {
     // Use same sizing for radio box as checkbox.
     setCheckboxSize(style);
 }
 
 bool RenderThemeChromiumWin::paintButton(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r)
 {
     const ThemeData& themeData = getThemeData(o);
 
-    WebCore::ThemeHelperWin helper(i.context, r);
-    ChromiumBridge::paintButton(helper.context(),
+    WebCore::ThemePainter painter(i.context, r);
+    ChromiumBridge::paintButton(painter.context(),
                                 themeData.m_part,
                                 themeData.m_state,
                                 themeData.m_classicState,
-                                helper.rect());
+                                painter.drawRect());
     return false;
 }
 
 bool RenderThemeChromiumWin::paintTextField(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r)
 {
     return paintTextFieldInternal(o, i, r, true);
 }
 
 bool RenderThemeChromiumWin::paintSearchField(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r)
 {
@@ skipping 42 matching lines @@
     else
         buttonX = o->style()->direction() == LTR ? r.right() - spacingRight - buttonWidth : r.x() + spacingLeft;
 
     // Compute the rectangle of the button in the destination image.
     IntRect rect(buttonX,
                  r.y() + spacingTop,
                  std::min(buttonWidth, r.right() - r.x()),
                  r.height() - (spacingTop + spacingBottom));
 
     // Get the correct theme data for a textfield and paint the menu.
-    WebCore::ThemeHelperWin helper(i.context, rect);
-    ChromiumBridge::paintMenuList(helper.context(),
+    WebCore::ThemePainter painter(i.context, rect);
+    ChromiumBridge::paintMenuList(painter.context(),
                                   CP_DROPDOWNBUTTON,
                                   determineState(o),
                                   determineClassicState(o),
-                                  helper.rect());
+                                  painter.drawRect());
     return false;
 }
 
 void RenderThemeChromiumWin::adjustMenuListButtonStyle(CSSStyleSelector* selector, RenderStyle* style, Element* e) const
 {
     adjustMenuListStyle(selector, style, e);
 }
 
 // Used to paint styled menulists (i.e. with a non-default border)
 bool RenderThemeChromiumWin::paintMenuListButton(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r)
@@ skipping 96 matching lines @@
         break;
     }
 
     result.m_state = determineState(o);
     result.m_classicState |= determineClassicState(o);
 
     return result;
 }
 
 bool RenderThemeChromiumWin::paintTextFieldInternal(RenderObject* o,
-                                            const RenderObject::PaintInfo& i,
-                                            const IntRect& r,
-                                            bool drawEdges)
+                                                    const RenderObject::PaintInfo& i,
+                                                    const IntRect& r,
+                                                    bool drawEdges)
 {
     // Nasty hack to make us not paint the border on text fields with a
     // border-radius. Webkit paints elements with border-radius for us.
     // FIXME: Get rid of this if-check once we can properly clip rounded
     // borders: http://b/1112604 and http://b/1108635
     // FIXME: make sure we do the right thing if css background-clip is set.
     if (o->style()->hasBorderRadius())
         return false;
 
     const ThemeData& themeData = getThemeData(o);
 
-    WebCore::ThemeHelperWin helper(i.context, r);
-    ChromiumBridge::paintTextField(helper.context(),
+    WebCore::ThemePainter painter(i.context, r);
+    ChromiumBridge::paintTextField(painter.context(),
                                    themeData.m_part,
                                    themeData.m_state,
                                    themeData.m_classicState,
-                                   helper.rect(),
+                                   painter.drawRect(),
                                    o->style()->backgroundColor(),
                                    true,
                                    drawEdges);
     return false;
 }
 
 int RenderThemeChromiumWin::menuListInternalPadding(RenderStyle* style, int paddingType) const
 {
     // This internal padding is in addition to the user-supplied padding.
     // Matches the FF behavior.
@@ skipping 14 matching lines @@
 // static
 void RenderThemeChromiumWin::setFindInPageMode(bool enable) {
   if (m_findInPageMode == enable)
       return;
 
   m_findInPageMode = enable;
   theme()->platformColorsDidChange();
 }
 
 } // namespace WebCore