views slider: Add support for gestures.

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 "base/logging.h"
 #include "base/message_loop.h"
 #include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
@@ skipping 60 matching lines @@
     AnimationProgressed(move_animation_.get());
   } else {
     SchedulePaint();
   }
   if (GetWidget()) {
     GetWidget()->NotifyAccessibilityEvent(
         this, ui::AccessibilityTypes::EVENT_VALUE_CHANGED, true);
   }
 }
 
+void Slider::MoveButtonTo(const gfx::Point& point) {
+  gfx::Insets inset = GetInsets();
+  if (orientation_ == HORIZONTAL) {
+    int amount = base::i18n::IsRTL() ? width() - inset.left() - point.x() :
+                                       point.x() - inset.left();
+    SetValueInternal(static_cast<float>(amount) / (width() - inset.width()),
+                     VALUE_CHANGED_BY_USER);
+  } else {
+    SetValueInternal(1.0f - static_cast<float>(point.y()) / height(),
+                     VALUE_CHANGED_BY_USER);
+  }
+}
+
 void Slider::SetAccessibleName(const string16& name) {
   accessible_name_ = name;
 }
 
 gfx::Size Slider::GetPreferredSize() {
   const int kSizeMajor = 200;
   const int kSizeMinor = 40;
 
   if (orientation_ == HORIZONTAL)
     return gfx::Size(std::max(width(), kSizeMajor), kSizeMinor);
@@ skipping 47 matching lines @@
   paint.setStyle(SkPaint::kFill_Style);
   paint.setAntiAlias(true);
   paint.setColor(kButtonColor);
   canvas->sk_canvas()->drawCircle(button_cx, button_cy, kButtonRadius, paint);
   View::OnPaint(canvas);
 }
 
 bool Slider::OnMousePressed(const views::MouseEvent& event) {
   if (listener_)
     listener_->SliderDragStarted(this);
-  return OnMouseDragged(event);
+  MoveButtonTo(event.location());
+  return true;
 }
 
 bool Slider::OnMouseDragged(const views::MouseEvent& event) {
-  gfx::Insets inset = GetInsets();
-  if (orientation_ == HORIZONTAL) {
-    int amount = base::i18n::IsRTL() ? width() - inset.left() - event.x() :
-                                       event.x() - inset.left();
-    SetValueInternal(static_cast<float>(amount) / (width() - inset.width()),
-                     VALUE_CHANGED_BY_USER);
-  } else {
-    SetValueInternal(1.0f - static_cast<float>(event.y()) / height(),
-                     VALUE_CHANGED_BY_USER);
-  }
+  MoveButtonTo(event.location());
   return true;
 }
 
 void Slider::OnMouseReleased(const views::MouseEvent& event) {
   if (listener_)
     listener_->SliderDragEnded(this);
 }
 
 bool Slider::OnKeyPressed(const views::KeyEvent& event) {
   if (orientation_ == HORIZONTAL) {
     if (event.key_code() == ui::VKEY_LEFT) {
       SetValueInternal(value_ - keyboard_increment_, VALUE_CHANGED_BY_USER);
       return true;
     } else if (event.key_code() == ui::VKEY_RIGHT) {
       SetValueInternal(value_ + keyboard_increment_, VALUE_CHANGED_BY_USER);
       return true;
     }
   } else {
     if (event.key_code() == ui::VKEY_DOWN) {
       SetValueInternal(value_ - keyboard_increment_, VALUE_CHANGED_BY_USER);
       return true;
     } else if (event.key_code() == ui::VKEY_UP) {
       SetValueInternal(value_ + keyboard_increment_, VALUE_CHANGED_BY_USER);
       return true;
     }
   }
   return false;
 }
 
+ui::GestureStatus Slider::OnGestureEvent(const views::GestureEvent& event) {
+  if (event.type() == ui::ET_GESTURE_SCROLL_UPDATE ||
+      event.type() == ui::ET_GESTURE_TAP_DOWN) {
+    MoveButtonTo(event.location());
+    return ui::GESTURE_STATUS_CONSUMED;
+  }
+  return ui::GESTURE_STATUS_UNKNOWN;
+}
+
 void Slider::AnimationProgressed(const ui::Animation* animation) {
   animating_value_ = animation->CurrentValueBetween(animating_value_, value_);
   SchedulePaint();
 }
 
 void Slider::GetAccessibleState(ui::AccessibleViewState* state) {
   state->role = ui::AccessibilityTypes::ROLE_SLIDER;
   state->name = accessible_name_;
   state->value = UTF8ToUTF16(
       base::StringPrintf("%d%%", (int)(value_ * 100 + 0.5)));
 }
 
 }  // namespace views