Expose native, desktop and mobile gesture detection defaults

content/browser/renderer_host/input/touch_emulator.cc

Index: content/browser/renderer_host/input/touch_emulator.cc
diff --git a/content/browser/renderer_host/input/touch_emulator.cc b/content/browser/renderer_host/input/touch_emulator.cc
index 61ae63ef1fffa283ce8a9e543cefadf9ebc8002b..2d0112a8482860d64f560ef90b739965c2c7319f 100644
--- a/content/browser/renderer_host/input/touch_emulator.cc
+++ b/content/browser/renderer_host/input/touch_emulator.cc
@@ -29,8 +29,9 @@ namespace {
 
 ui::GestureProvider::Config GetGestureProviderConfig() {
   // TODO(dgozman): Use different configs to emulate mobile/desktop as
-  // requested by renderer.
-  ui::GestureProvider::Config config = ui::DefaultGestureProviderConfig();
+  // requested by renderer, crbug/425586.
+  ui::GestureProvider::Config config = ui::GetGestureProviderConfig(
+      ui::GestureProviderConfigType::GENERIC_MOBILE);

[dgozman, 2014/10/28 11:25:21]

Great!

[tdresser, 2014/10/28 13:41:41]

Can't you also emulate a touch screen laptop?

Also, aren't the lines below redundant now?

[jdduke (slow), 2014/10/30 22:06:54]

I guess I would consider desktop as PC/laptop, and mobile as phone/tablet, but
if you have some better names for that dichotomy I'm all ears :)
Yeah, I left them as a safeguard in case |PLATFORM_DEFAULT| is ever a supplied
type.

[tdresser, 2014/10/31 12:34:11]

Oh nevermind, I was confused.

   config.gesture_begin_end_types_enabled = false;
   config.gesture_detector_config.swipe_enabled = false;
   config.gesture_detector_config.two_finger_tap_enabled = false;
@@ -157,8 +158,14 @@ bool TouchEmulator::HandleMouseEvent(const WebMouseEvent& mouse_event) {
 
   UpdateShiftPressed((mouse_event.modifiers & WebInputEvent::ShiftKey) != 0);
 
-  if (FillTouchEventAndPoint(mouse_event) &&
-      gesture_provider_.OnTouchEvent(MotionEventWeb(touch_event_))) {
+  if (mouse_event.type != WebInputEvent::MouseDown &&
+      mouse_event.type != WebInputEvent::MouseMove &&
+      mouse_event.type != WebInputEvent::MouseUp) {
+    return true;
+  }
+
+  if (gesture_provider_.OnTouchEvent(MotionEventWeb(touch_event_))) {
+    FillTouchEventAndPoint(mouse_event);
     ForwardTouchEventToClient();
   }
 
@@ -394,12 +401,6 @@ void TouchEmulator::ScrollEnd(const WebGestureEvent& event) {
 }
 
 bool TouchEmulator::FillTouchEventAndPoint(const WebMouseEvent& mouse_event) {
-  if (mouse_event.type != WebInputEvent::MouseDown &&
-      mouse_event.type != WebInputEvent::MouseMove &&
-      mouse_event.type != WebInputEvent::MouseUp) {
-    return false;
-  }
-
   WebInputEvent::Type eventType;
   switch (mouse_event.type) {
     case WebInputEvent::MouseDown:
@@ -413,12 +414,14 @@ bool TouchEmulator::FillTouchEventAndPoint(const WebMouseEvent& mouse_event) {
       break;
     default:
       eventType = WebInputEvent::Undefined;
-      NOTREACHED();
+      NOTREACHED() << "Invalid event for touch emulation: " << mouse_event.type;
   }
   touch_event_.touchesLength = 1;
   touch_event_.modifiers = mouse_event.modifiers;
   WebTouchEventTraits::ResetTypeAndTouchStates(
       eventType, mouse_event.timeStampSeconds, &touch_event_);
+  touch_event_.defaultActionMayCauseScrolling =

[dgozman, 2014/10/28 11:25:22]

So, this function should be called exactly after
|gesture_provider_.OnTouchEvent| now? Maybe add a comment mentioning this
restriction?

[jdduke (slow), 2014/10/30 22:06:54]

Yeah, this was pretty unclear. I reworked the logic a bit, and made the scroll
causality an explicit part of the GestureProvider::OnTouchEvent API.

+      gesture_provider_.LastTouchEventDidGenerateScroll();
 
   WebTouchPoint& point = touch_event_.touches[0];
   point.id = 0;