Fork: Add setting to blend background with existing content
Cherry-pick of uncommitted https://codereview.chromium.org/23483051/ PS8
BUG: 10750978
If both base background color (WebView::setBaseBackgroundColor) and
background color (set by document) has alpha, then the background color
should be blended into existing content.
This behavior is important in Android WebView, which is a view inside
the Android view tree and needs to blend with views below it.
Change-Id: Ica4cdeaa35b971b75ef1e664cd54f3fc7f95507a
diff --git a/Source/core/page/Settings.in b/Source/core/page/Settings.in
index e4c6f77..c00b5e5 100644
--- a/Source/core/page/Settings.in
+++ b/Source/core/page/Settings.in
@@ -38,6 +38,7 @@
supportsMultipleWindows initial=true
javaScriptCanAccessClipboard initial=false
shouldPrintBackgrounds initial=false
+shouldClearDocumentBackground initial=true
textAreasAreResizable initial=false, setNeedsStyleRecalcInAllFrames=1
authorAndUserStylesEnabled initial=true, setNeedsStyleRecalcInAllFrames=1
diff --git a/Source/core/rendering/RenderBoxModelObject.cpp b/Source/core/rendering/RenderBoxModelObject.cpp
index d2be443..289bfed 100644
--- a/Source/core/rendering/RenderBoxModelObject.cpp
+++ b/Source/core/rendering/RenderBoxModelObject.cpp
@@ -706,29 +706,28 @@
if (!boxShadowShouldBeAppliedToBackground)
backgroundRect.intersect(paintInfo.rect);
- // If we have an alpha and we are painting the root element, go ahead and blend with the base background color.
- Color baseColor;
- bool shouldClearBackground = false;
- if (isOpaqueRoot) {
- baseColor = view()->frameView()->baseBackgroundColor();
- if (!baseColor.alpha())
- shouldClearBackground = true;
- }
-
GraphicsContextStateSaver shadowStateSaver(*context, boxShadowShouldBeAppliedToBackground);
if (boxShadowShouldBeAppliedToBackground)
applyBoxShadowForBackground(context, this);
- if (baseColor.alpha()) {
- if (bgColor.alpha())
- baseColor = baseColor.blend(bgColor);
+ if (isOpaqueRoot) {
+ // If we have an alpha and we are painting the root element, go ahead and blend with the base background color.
+ Color baseColor = view()->frameView()->baseBackgroundColor();
+ bool shouldClearDocumentBackground = document()->settings() && document()->settings()->shouldClearDocumentBackground();
+ CompositeOperator operation = shouldClearDocumentBackground ? CompositeCopy : context->compositeOperation();
- context->fillRect(backgroundRect, baseColor, CompositeCopy);
+ if (baseColor.alpha()) {
+ if (bgColor.alpha())
+ baseColor = baseColor.blend(bgColor);
+ context->fillRect(backgroundRect, baseColor, operation);
+ } else if (bgColor.alpha()) {
+ context->fillRect(backgroundRect, bgColor, operation);
+ } else if (shouldClearDocumentBackground) {
+ context->clearRect(backgroundRect);
+ }
} else if (bgColor.alpha()) {
- CompositeOperator operation = shouldClearBackground ? CompositeCopy : context->compositeOperation();
- context->fillRect(backgroundRect, bgColor, operation);
- } else if (shouldClearBackground)
- context->clearRect(backgroundRect);
+ context->fillRect(backgroundRect, bgColor, context->compositeOperation());
+ }
}
}
diff --git a/Source/web/WebSettingsImpl.cpp b/Source/web/WebSettingsImpl.cpp
index b69c54d..cdaafc4 100644
--- a/Source/web/WebSettingsImpl.cpp
+++ b/Source/web/WebSettingsImpl.cpp
@@ -597,6 +597,11 @@
m_settings->setShouldPrintBackgrounds(enabled);
}
+void WebSettingsImpl::setShouldClearDocumentBackground(bool enabled)
+{
+ m_settings->setShouldClearDocumentBackground(enabled);
+}
+
void WebSettingsImpl::setEnableScrollAnimator(bool enabled)
{
m_settings->setScrollAnimatorEnabled(enabled);
diff --git a/Source/web/WebSettingsImpl.h b/Source/web/WebSettingsImpl.h
index 9908d74..e25d45a 100644
--- a/Source/web/WebSettingsImpl.h
+++ b/Source/web/WebSettingsImpl.h
@@ -140,6 +140,7 @@
virtual void setShouldDisplaySubtitles(bool);
virtual void setShouldDisplayTextDescriptions(bool);
virtual void setShouldPrintBackgrounds(bool);
+ virtual void setShouldClearDocumentBackground(bool);
virtual void setShouldRespectImageOrientation(bool);
virtual void setShowFPSCounter(bool);
virtual void setShowPaintRects(bool);
diff --git a/public/web/WebSettings.h b/public/web/WebSettings.h
index 56668da..69a68f9 100644
--- a/public/web/WebSettings.h
+++ b/public/web/WebSettings.h
@@ -144,6 +144,7 @@
virtual void setSelectionIncludesAltImageText(bool) = 0;
virtual void setSerifFontFamily(const WebString&, UScriptCode = USCRIPT_COMMON) = 0;
virtual void setShouldPrintBackgrounds(bool) = 0;
+ virtual void setShouldClearDocumentBackground(bool) = 0;
virtual void setShouldRespectImageOrientation(bool) = 0;
virtual void setShowFPSCounter(bool) = 0;
virtual void setShowPaintRects(bool) = 0;
