DevTools: control touch emulation from the browser side only.

content/browser/devtools/renderer_overrides_handler.cc

Index: content/browser/devtools/renderer_overrides_handler.cc
diff --git a/content/browser/devtools/renderer_overrides_handler.cc b/content/browser/devtools/renderer_overrides_handler.cc
index b068a85f084a5cde0500aae2c2fc74aef4238658..39e726c31af755800545e17dded272efe82ea29b 100644
--- a/content/browser/devtools/renderer_overrides_handler.cc
+++ b/content/browser/devtools/renderer_overrides_handler.cc
@@ -22,6 +22,7 @@
 #include "content/browser/renderer_host/render_view_host_delegate.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/renderer_host/render_widget_host_view_base.h"
+#include "content/browser/web_contents/web_contents_impl.h"
 #include "content/common/view_messages.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
@@ -70,6 +71,7 @@ static int kCaptureRetryLimit = 2;
 RendererOverridesHandler::RendererOverridesHandler()
     : has_last_compositor_frame_metadata_(false),
       capture_retry_count_(0),
+      touch_emulation_enabled_(false),
       weak_factory_(this) {
   RegisterCommandHandler(
       devtools::DOM::setFileInputFiles::kName,
@@ -121,6 +123,11 @@ RendererOverridesHandler::RendererOverridesHandler()
           &RendererOverridesHandler::PageCaptureScreenshot,
           base::Unretained(this)));
   RegisterCommandHandler(
+      devtools::Page::setTouchEmulationEnabled::kName,
+      base::Bind(
+          &RendererOverridesHandler::PageSetTouchEmulationEnabled,
+          base::Unretained(this)));
+  RegisterCommandHandler(
       devtools::Page::canScreencast::kName,
       base::Bind(
           &RendererOverridesHandler::PageCanScreencast,
@@ -150,8 +157,8 @@ RendererOverridesHandler::RendererOverridesHandler()
 RendererOverridesHandler::~RendererOverridesHandler() {}
 
 void RendererOverridesHandler::OnClientDetached() {
-  if (screencast_command_ && host_)
-    host_->SetTouchEventEmulationEnabled(false, false);
+  if (touch_emulation_enabled_)
+    SetTouchEventEmulationEnabled(false);
   screencast_command_ = NULL;
 }
 
@@ -173,18 +180,14 @@ void RendererOverridesHandler::OnVisibilityChanged(bool visible) {
 void RendererOverridesHandler::SetRenderViewHost(
     RenderViewHostImpl* host) {
   host_ = host;
-  if (screencast_command_ && host)
-    host->SetTouchEventEmulationEnabled(true, true);
+  if (touch_emulation_enabled_)
+    SetTouchEventEmulationEnabled(true);
 }
 
 void RendererOverridesHandler::ClearRenderViewHost() {
   host_ = NULL;
 }
 
-bool RendererOverridesHandler::OnSetTouchEventEmulationEnabled() {
-  return screencast_command_.get() != NULL;
-}
-
 void RendererOverridesHandler::InnerSwapCompositorFrame() {
   if ((base::TimeTicks::Now() - last_frame_time_).InMilliseconds() <
           kFrameRateThresholdMs) {
@@ -308,9 +311,7 @@ RendererOverridesHandler::ClearBrowserCookies(
 scoped_refptr<DevToolsProtocol::Response>
 RendererOverridesHandler::PageDisable(
     scoped_refptr<DevToolsProtocol::Command> command) {
-  if (screencast_command_ && host_)
-    host_->SetTouchEventEmulationEnabled(false, false);
-  screencast_command_ = NULL;
+  OnClientDetached();
   return NULL;
 }
 
@@ -488,6 +489,24 @@ void RendererOverridesHandler::ScreenshotCaptured(
 }
 
 scoped_refptr<DevToolsProtocol::Response>
+RendererOverridesHandler::PageSetTouchEmulationEnabled(
+    scoped_refptr<DevToolsProtocol::Command> command) {
+  base::DictionaryValue* params = command->params();
+  bool enabled;
+  if (!params || !params->GetBoolean(
+      devtools::Page::setTouchEmulationEnabled::kParamEnabled,
+      &enabled)) {
+    // Pass to renderer.
+    return NULL;
+  }
+
+  if (touch_emulation_enabled_ != enabled)
+    SetTouchEventEmulationEnabled(enabled);
+  // Pass to renderer.
+  return NULL;
+}
+
+scoped_refptr<DevToolsProtocol::Response>
 RendererOverridesHandler::PageCanScreencast(
     scoped_refptr<DevToolsProtocol::Command> command) {
   base::DictionaryValue* result = new base::DictionaryValue();
@@ -505,7 +524,7 @@ RendererOverridesHandler::PageStartScreencast(
   screencast_command_ = command;
   if (!host_)
     return command->InternalErrorResponse("Could not connect to view");
-  host_->SetTouchEventEmulationEnabled(true, true);
+  SetTouchEventEmulationEnabled(true);
   bool visible = !host_->is_hidden();
   NotifyScreencastVisibility(visible);
   if (visible) {
@@ -522,8 +541,7 @@ RendererOverridesHandler::PageStopScreencast(
     scoped_refptr<DevToolsProtocol::Command> command) {
   last_frame_time_ = base::TimeTicks();
   screencast_command_ = NULL;
-  if (host_)
-    host_->SetTouchEventEmulationEnabled(false, false);
+  SetTouchEventEmulationEnabled(false);
   return command->SuccessResponse(NULL);
 }
 
@@ -978,4 +996,14 @@ RendererOverridesHandler::InputEmulateTouchFromMouseEvent(
   return command->SuccessResponse(NULL);
 }
 
+void RendererOverridesHandler::SetTouchEventEmulationEnabled(bool enabled) {

[dgozman, 2014/08/17 12:39:20]

Calls from start/stopScreencast and setTouchEventEmulation may interfere here. I
see them both useful for android with external keyboard for example. I propose
to rename this method to |UpdateTouchEventEmulationInHost| and check for both
flags: |screencast_command_| and |touch_emulation_enabled_|.

[pfeldman, 2014/08/17 14:47:14]

Could you remind me why we enable touch while screencasting?

[dgozman, 2014/08/17 15:01:41]

We use touch emulator to handle emulateTouchFromMouseEvent command.

+  touch_emulation_enabled_ = enabled;
+  if (!host_)
+    return;
+  host_->SetTouchEventEmulationEnabled(enabled);
+  WebContents* web_contents = WebContents::FromRenderViewHost(host_);
+  if (web_contents)
+    web_contents->SetForceDisableOverscrollContent(enabled);
+}
+
 }  // namespace content