Allow sliders to be adjusted with arrow keys

R=sky@chromium.org
BUG=118012


Review URL: http://codereview.chromium.org/9845005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@128730 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 32 insertions, 0 deletions

diff --git a/ui/views/controls/slider.cc b/ui/views/controls/slider.cc
index c42902b..c806536 100644
--- a/ui/views/controls/slider.cc
+++ b/ui/views/controls/slider.cc
@@ -28,9 +28,11 @@ Slider::Slider(SliderListener* listener, Orientation orientation)
     : listener_(listener),
       orientation_(orientation),
       value_(0.f),
+      keyboard_increment_(0.1f),
       animating_value_(0.f),
       value_is_valid_(false) {
   EnableCanvasFlippingForRTLUI(true);
+  set_focusable(true);
 }
 
 Slider::~Slider() {
@@ -40,6 +42,10 @@ void Slider::SetValue(float value) {
   SetValueInternal(value, VALUE_CHANGED_BY_API);
 }
 
+void Slider::SetKeyboardIncrement(float increment) {
+  keyboard_increment_ = increment;
+}
+
 void Slider::SetValueInternal(float value, SliderChangeReason reason) {
   bool old_value_valid = value_is_valid_;
 
@@ -154,6 +160,27 @@ bool Slider::OnMouseDragged(const views::MouseEvent& event) {
   return true;
 }
 
+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;
+}
+
 void Slider::AnimationProgressed(const ui::Animation* animation) {
   animating_value_ = animation->CurrentValueBetween(animating_value_, value_);
   SchedulePaint();
diff --git a/ui/views/controls/slider.h b/ui/views/controls/slider.h
index 2e7a21f..d98c5fd 100644
--- a/ui/views/controls/slider.h
+++ b/ui/views/controls/slider.h
@@ -48,6 +48,9 @@ class VIEWS_EXPORT Slider : public View,
   float value() const { return value_; }
   void SetValue(float value);
 
+  // Set the delta used for changing the value via keyboard.
+  void SetKeyboardIncrement(float increment);
+
   void SetAccessibleName(const string16& name);
 
  private:
@@ -58,6 +61,7 @@ class VIEWS_EXPORT Slider : public View,
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
   virtual bool OnMousePressed(const views::MouseEvent& event) OVERRIDE;
   virtual bool OnMouseDragged(const views::MouseEvent& event) OVERRIDE;
+  virtual bool OnKeyPressed(const views::KeyEvent& event) OVERRIDE;
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
 
   // ui::AnimationDelegate overrides:
@@ -69,6 +73,7 @@ class VIEWS_EXPORT Slider : public View,
   scoped_ptr<ui::SlideAnimation> move_animation_;
 
   float value_;
+  float keyboard_increment_;
   float animating_value_;
   bool value_is_valid_;
   string16 accessible_name_;