[WIP] Allow scroll events to permanently change the default gesture handler in RootView

ui/views/controls/slider.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/controls/slider.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 299 matching lines @@
   SchedulePaint();
 }
 
 void Slider::OnBlur() {
   View::OnBlur();
   SchedulePaint();
 }
 
 void Slider::OnGestureEvent(ui::GestureEvent* event) {
   switch (event->type()) {
-    // In a multi point gesture only the touch point will generate
+    // In a multi point gesture only the (first?) touch point will generate

[sadrul, 2014/07/24 19:12:13]

yes. Looks like someone accidentally the word.

     // an ET_GESTURE_TAP_DOWN event.
     case ui::ET_GESTURE_TAP_DOWN:
       OnSliderDragStarted();
       PrepareForMove(event->location());
       // Intentional fall through to next case.
     case ui::ET_GESTURE_SCROLL_BEGIN:
     case ui::ET_GESTURE_SCROLL_UPDATE:
       MoveButtonTo(event->location());
       event->SetHandled();
       break;
-    case ui::ET_GESTURE_END:
+    case ui::ET_GESTURE_SCROLL_END:
+    case ui::ET_SCROLL_FLING_START:
+    case ui::ET_GESTURE_TAP:
       MoveButtonTo(event->location());
       event->SetHandled();
       if (event->details().touch_points() <= 1)
         OnSliderDragEnded();
       break;
+    case ui::ET_GESTURE_TWO_FINGER_TAP:
+      MoveButtonTo(event->location());
+      event->SetHandled();
+      OnSliderDragEnded();
+      break;

[sadrul, 2014/07/24 19:12:13]

Is this necessary?

     default:
       break;
   }
 }
 
 void Slider::AnimationProgressed(const gfx::Animation* animation) {
   animating_value_ = animation->CurrentValueBetween(animating_value_, value_);
   SchedulePaint();
 }
 
 void Slider::GetAccessibleState(ui::AXViewState* state) {
   state->role = ui::AX_ROLE_SLIDER;
   state->name = accessible_name_;
   state->value = base::UTF8ToUTF16(
       base::StringPrintf("%d%%", static_cast<int>(value_ * 100 + 0.5)));
 }
 
 void Slider::OnSliderDragStarted() {
   if (listener_)
     listener_->SliderDragStarted(this);
 }
 
 void Slider::OnSliderDragEnded() {
   if (listener_)
     listener_->SliderDragEnded(this);
 }
 
 }  // namespace views