[devtools] Add a command to emulate the default background color.

third_party/WebKit/Source/web/InspectorEmulationAgent.cpp

Index: third_party/WebKit/Source/web/InspectorEmulationAgent.cpp
diff --git a/third_party/WebKit/Source/web/InspectorEmulationAgent.cpp b/third_party/WebKit/Source/web/InspectorEmulationAgent.cpp
index f661594577ef716c1108aaf48cbcc8102f487974..b501644ae11f78e069fa867b13d241b28e7dc02b 100644
--- a/third_party/WebKit/Source/web/InspectorEmulationAgent.cpp
+++ b/third_party/WebKit/Source/web/InspectorEmulationAgent.cpp
@@ -4,11 +4,15 @@
 
 #include "web/InspectorEmulationAgent.h"
 
+#include "core/dom/Document.h"
+#include "core/dom/DocumentLifecycle.h"
 #include "core/frame/FrameHost.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/Settings.h"
+#include "core/inspector/protocol/DOM.h"
 #include "core/page/Page.h"
 #include "platform/geometry/DoubleRect.h"
+#include "platform/graphics/Color.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebFloatPoint.h"
 #include "public/platform/WebThread.h"
@@ -27,6 +31,10 @@ static const char forcedViewportEnabled[] = "forcedViewportEnabled";
 static const char forcedViewportX[] = "forcedViewportX";
 static const char forcedViewportY[] = "forcedViewportY";
 static const char forcedViewportScale[] = "forcedViewportScale";
+static const char defaultBackgroundColorOverrideRGBA[] =
+    "defaultBackgroundColorOverrideRGBA";
+static const char defaultBackgroundColorOriginalRGBA[] =
+    "defaultBackgroundColorOriginalRGBA";
 }
 
 InspectorEmulationAgent* InspectorEmulationAgent::create(
@@ -64,6 +72,16 @@ void InspectorEmulationAgent::restore() {
         m_state->doubleProperty(EmulationAgentState::forcedViewportY, 0),
         m_state->doubleProperty(EmulationAgentState::forcedViewportScale, 1));
   }
+  auto rgbaValue =
+      m_state->get(EmulationAgentState::defaultBackgroundColorOverrideRGBA);
+  if (rgbaValue) {
+    blink::protocol::ErrorSupport errors;
+    auto rgba = protocol::DOM::RGBA::fromValue(rgbaValue, &errors);
+    if (!errors.hasErrors()) {
+      setDefaultBackgroundColorOverride(
+          Maybe<protocol::DOM::RGBA>(std::move(rgba)));
+    }
+  }
 }
 
 Response InspectorEmulationAgent::disable() {
@@ -72,6 +90,7 @@ Response InspectorEmulationAgent::disable() {
   setEmulatedMedia(String());
   setCPUThrottlingRate(1);
   resetViewport();
+  setDefaultBackgroundColorOverride(Maybe<protocol::DOM::RGBA>());
   return Response::OK();
 }
 
@@ -169,6 +188,60 @@ void InspectorEmulationAgent::virtualTimeBudgetExpired() {
   frontend()->virtualTimeBudgetExpired();
 }
 
+Response InspectorEmulationAgent::setDefaultBackgroundColorOverride(
+    Maybe<protocol::DOM::RGBA> color) {
+  if (!color.isJust()) {
+    // Reset to the original color if one is set.
+    auto rgbaValue =
+        m_state->get(EmulationAgentState::defaultBackgroundColorOriginalRGBA);

[dgozman, 2017/01/24 20:12:49]

You don't have to store original in the state. Instead, you should have an
override in WebViewImpl (similar to another one we have) and just clear it from
here. That way, WebViewImpl would know about the default one and the override
one and prefer one to another.

[Eric Seckler, 2017/01/25 10:33:37]

Thanks! Done.

+    if (rgbaValue) {
+      blink::protocol::ErrorSupport errors;
+      auto rgba = protocol::DOM::RGBA::fromValue(rgbaValue, &errors);
+      if (!errors.hasErrors())
+        setBaseBackgroundColor(rgba.get());
+    }
+
+    // Clear the state.
+    m_state->remove(EmulationAgentState::defaultBackgroundColorOverrideRGBA);
+    m_state->remove(EmulationAgentState::defaultBackgroundColorOriginalRGBA);
+
+    return Response::OK();
+  }
+
+  // Save override and original color to state.
+  blink::protocol::DOM::RGBA* override = color.fromJust();
+  m_state->setValue(EmulationAgentState::defaultBackgroundColorOverrideRGBA,
+                    override->toValue());
+  if (!m_state->get(EmulationAgentState::defaultBackgroundColorOriginalRGBA)) {
+    auto original = getBaseBackgroundColor();
+    m_state->setValue(EmulationAgentState::defaultBackgroundColorOriginalRGBA,
+                      original->toValue());
+  }
+
+  setBaseBackgroundColor(override);
+  return Response::OK();
+}
+
+std::unique_ptr<protocol::DOM::RGBA>
+InspectorEmulationAgent::getBaseBackgroundColor() {
+  auto color = webViewImpl()->baseBackgroundColor();
+  double alpha = color.alpha() / 255.0f;
+  return blink::protocol::DOM::RGBA::create()
+      .setR(color.red())
+      .setG(color.green())
+      .setB(color.blue())
+      .setA(alpha)
+      .build();
+}
+
+void InspectorEmulationAgent::setBaseBackgroundColor(
+    protocol::DOM::RGBA* rgba) {
+  // Clamping of values is done by Color() constructor.
+  int alpha = lroundf(255.0f * rgba->getA(1.0f));
+  webViewImpl()->setBaseBackgroundColor(
+      Color(rgba->getR(), rgba->getG(), rgba->getB(), alpha).rgb());
+}
+
 DEFINE_TRACE(InspectorEmulationAgent) {
   visitor->trace(m_webLocalFrameImpl);
   InspectorBaseAgent::trace(visitor);