Adds scroll position/scale emulation to DevTools.

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 98e643a44e64dca77d52ce88f4565dad52213cf9..6483f32fccd1ed7ae6c80e5f81e09c8c6a2a386c 100644
--- a/third_party/WebKit/Source/web/InspectorEmulationAgent.cpp
+++ b/third_party/WebKit/Source/web/InspectorEmulationAgent.cpp
@@ -16,7 +16,17 @@
 
 namespace blink {
 
+namespace {
+static const double kMaxScale = 10.0;
+} // namespace
+
 namespace EmulationAgentState {
+static const char scrollAndScaleOverrideEnabled[] = "scrollAndScaleOverrideEnabled";
+static const char framePositionXOverride[] = "framePositionXOverride";
+static const char framePositionYOverride[] = "framePositionYOverride";
+static const char visualViewportPositionXOverride[] = "visualViewportPositionXOverride";
+static const char visualViewportPositionYOverride[] = "visualViewportPositionYOverride";
+static const char pageScaleOverride[] = "pageScaleOverride";
 static const char scriptExecutionDisabled[] = "scriptExecutionDisabled";
 static const char touchEventEmulationEnabled[] = "touchEventEmulationEnabled";
 static const char emulatedMedia[] = "emulatedMedia";
@@ -45,6 +55,17 @@ WebViewImpl* InspectorEmulationAgent::webViewImpl()
 void InspectorEmulationAgent::restore()
 {
     ErrorString error;
+    if (m_state->booleanProperty(EmulationAgentState::scrollAndScaleOverrideEnabled, false)) {

[dgozman, 2016/07/21 20:54:09]

if (!m_state....)

[Eric Seckler, 2016/07/22 14:44:48]

Whoops, thanks for spotting :)

+        clearScrollAndScaleOverride(&error);
+    } else {
+        setScrollAndScaleOverride(
+            &error,
+            m_state->integerProperty(EmulationAgentState::framePositionXOverride, -1),
+            m_state->integerProperty(EmulationAgentState::framePositionYOverride, -1),
+            m_state->doubleProperty(EmulationAgentState::visualViewportPositionXOverride, -1),
+            m_state->doubleProperty(EmulationAgentState::visualViewportPositionYOverride, -1),
+            m_state->doubleProperty(EmulationAgentState::pageScaleOverride, 0));
+    }
     setScriptExecutionDisabled(&error, m_state->booleanProperty(EmulationAgentState::scriptExecutionDisabled, false));
     setTouchEmulationEnabled(&error, m_state->booleanProperty(EmulationAgentState::touchEventEmulationEnabled, false), protocol::Maybe<String>());
     String16 emulatedMedia;
@@ -55,11 +76,59 @@ void InspectorEmulationAgent::restore()
 void InspectorEmulationAgent::disable(ErrorString*)
 {
     ErrorString error;
+    clearScrollAndScaleOverride(&error);
     setScriptExecutionDisabled(&error, false);
     setTouchEmulationEnabled(&error, false, protocol::Maybe<String>());
     setEmulatedMedia(&error, String());
 }
 
+void InspectorEmulationAgent::setScrollAndScaleOverride(ErrorString* errorString, const Maybe<int>& scrollPositionX, const Maybe<int>& scrollPositionY, const Maybe<double>& visualViewportPositionX, const Maybe<double>& visualViewportPositionY, const Maybe<double>& visualViewportScale)
+{
+    if ((scrollPositionX.isJust() && scrollPositionX.fromJust() < 0 && scrollPositionX.fromJust() != -1)
+        || (scrollPositionY.isJust() && scrollPositionY.fromJust() < 0 && scrollPositionY.fromJust() != -1)) {
+        *errorString = "Scroll position coordinates must be non-negative or -1 (disabled)";

[dgozman, 2016/07/21 20:54:09]

Let's not treat -1 as disabled. We have "optional" just for that.

[Eric Seckler, 2016/07/22 14:44:48]

Done. I was conflicted about this, too, since allowing -1 makes wrapper
functions for the command (e.g. in tests) easier. But it's cleaner without.

+        return;
+    }
+
+    if ((visualViewportPositionX.isJust() && visualViewportPositionX.fromJust() < 0 && visualViewportPositionX.fromJust() != -1)
+        || (visualViewportPositionY.isJust() && visualViewportPositionY.fromJust() < 0 && visualViewportPositionY.fromJust() != -1)) {
+        *errorString = "Visual viewport position coordinates must be non-negative or -1 (disabled)";
+        return;
+    }
+
+    if (visualViewportScale.isJust() && (visualViewportScale.fromJust() < 0 || visualViewportScale.fromJust() > kMaxScale)) {
+        *errorString = "Scale must be positive and not greater than " + Decimal::fromDouble(kMaxScale).toString() + " or 0 (disabled)";
+    }
+
+    setScrollAndScaleOverride(
+        scrollPositionX.fromMaybe(-1),
+        scrollPositionY.fromMaybe(-1),
+        visualViewportPositionX.fromMaybe(-1),
+        visualViewportPositionY.fromMaybe(-1),
+        visualViewportScale.fromMaybe(0));
+}
+
+void InspectorEmulationAgent::setScrollAndScaleOverride(int framePositionX, int framePositionY, double visualViewportPositionX, double visualViewportPositionY, double pageScale)
+{
+    m_state->setBoolean(EmulationAgentState::scrollAndScaleOverrideEnabled, true);
+    m_state->setInteger(EmulationAgentState::framePositionXOverride, framePositionX);
+    m_state->setInteger(EmulationAgentState::framePositionYOverride, framePositionY);
+    m_state->setDouble(EmulationAgentState::visualViewportPositionXOverride, visualViewportPositionX);
+    m_state->setDouble(EmulationAgentState::visualViewportPositionYOverride, visualViewportPositionY);
+    m_state->setDouble(EmulationAgentState::pageScaleOverride, pageScale);
+
+    webViewImpl()->setScrollAndScaleOverride(
+        IntPoint(framePositionX, framePositionY),
+        FloatPoint(visualViewportPositionX, visualViewportPositionY),
+        pageScale);
+}
+
+void InspectorEmulationAgent::clearScrollAndScaleOverride(ErrorString*)
+{
+    m_state->setBoolean(EmulationAgentState::scrollAndScaleOverrideEnabled, false);
+    webViewImpl()->clearScrollAndScaleOverride();
+}
+
 void InspectorEmulationAgent::resetPageScaleFactor(ErrorString*)
 {
     webViewImpl()->resetScaleStateImmediately();