Android double/triple click

content/browser/renderer_host/render_widget_host_view_android.cc

Index: content/browser/renderer_host/render_widget_host_view_android.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_android.cc b/content/browser/renderer_host/render_widget_host_view_android.cc
index e1437b451ef82a6ccbdaa7bcdb0cfded5a8c3592..b4011631617a9eed2566a28a08047350c1cfba0b 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -102,6 +102,9 @@ namespace content {
 namespace {
 
 static const char kAsyncReadBackString[] = "Compositing.CopyFromSurfaceTime";
+static const base::TimeDelta kClickCountInterval =
+    base::TimeDelta::FromSecondsD(0.5);
+static const float kClickCountRadiusDIP = 5;
 
 class PendingReadbackLock;
 
@@ -1801,11 +1804,33 @@ void RenderWidgetHostViewAndroid::SendMouseEvent(
   blink::WebInputEvent::Type webMouseEventType =
       ui::ToWebMouseEventType(motion_event.GetAction());
 
+  const base::TimeTicks current_time = base::TimeTicks::Now();
+  if (webMouseEventType == blink::WebInputEvent::kMouseDown) {
+    if (action_button == ui::MotionEventAndroid::BUTTON_PRIMARY) {
+      gfx::Point mousedown_point(motion_event.GetX(0), motion_event.GetY(0));
+      const base::TimeDelta time_delay =
+          current_time - prev_mousedown_timestamp_;
+      const float distance = (mousedown_point - prev_mousedown_point_).Length();

[aelias_OOO_until_Jul13, 2017/06/21 01:13:12]

Although this doesn't happen on mousemove I still don't really like having a
unnecessary sqrt call in an input critical path because I've seen that bubble up
in profiles before -- I would prefer "LengthSquared() <
kClickCountRadiusDIPSquared)".  I might go back and refactor vector2d.h later to
have a call LengthLessThan() instead of LengthSquared() to make the code nicer,
but for this patch let's go with that.

[amaralp, 2017/06/21 19:34:21]

Done.

+      if (click_count_ > 2 || time_delay > kClickCountInterval ||
+          distance > kClickCountRadiusDIP) {
+        click_count_ = 0;
+      }
+      prev_mousedown_timestamp_ = current_time;
+      prev_mousedown_point_ = mousedown_point;
+    } else {
+      // Reset state if left button isn't pressed.

[aelias_OOO_until_Jul13, 2017/06/21 01:13:12]

"if middle or right button was pressed"

[amaralp, 2017/06/21 19:34:21]

Done.

+      click_count_ = 0;
+      prev_mousedown_timestamp_ = base::TimeTicks();
+      prev_mousedown_point_ = gfx::Point();

[aelias_OOO_until_Jul13, 2017/06/21 01:13:12]

gfx::Point(0, 0) can be a legal offset or close to it, so it's not a principled
invalid value.  I'd suggest deleting this line as it doesn't do anything, to
avoid giving the impression that there might be a bug with double-clicks near
the top-left of the screen.

[amaralp, 2017/06/21 19:34:22]

Done.

+    }
+    click_count_++;
+  }
+
   blink::WebMouseEvent mouse_event = WebMouseEventBuilder::Build(
       webMouseEventType,
       ui::EventTimeStampToSeconds(motion_event.GetEventTime()),
       motion_event.GetX(0), motion_event.GetY(0), motion_event.GetFlags(),
-      motion_event.GetButtonState() ? 1 : 0 /* click count */,
+      motion_event.GetButtonState() ? click_count_ : 0 /* click count */,
       motion_event.GetPointerId(0), motion_event.GetPressure(0),
       motion_event.GetOrientation(0), motion_event.GetTiltX(0),
       motion_event.GetTiltY(0), action_button, motion_event.GetToolType(0));