Support for Adaptive Handle Orientation

ui/touch_selection/touch_handle.h

Index: ui/touch_selection/touch_handle.h
diff --git a/ui/touch_selection/touch_handle.h b/ui/touch_selection/touch_handle.h
index 1a1995ea6f0747a1e27321ffb1675411090165dc..96696f240f52f7a81eb7c6eebaa174fd75d8220a 100644
--- a/ui/touch_selection/touch_handle.h
+++ b/ui/touch_selection/touch_handle.h
@@ -25,10 +25,13 @@ class UI_TOUCH_SELECTION_EXPORT TouchHandleDrawable {
  public:
   virtual ~TouchHandleDrawable() {}
   virtual void SetEnabled(bool enabled) = 0;
-  virtual void SetOrientation(TouchHandleOrientation orientation) = 0;
+  virtual void SetOrientation(ui::TouchHandleOrientation orientation,
+                              bool mirror_vertical,
+                              bool mirror_horizontal) = 0;
+  virtual void SetOrigin(const gfx::PointF& origin) = 0;

[mfomitchev, 2015/08/06 14:33:02]

Could you please add some comments to SetOrigin, GetVisibleBounds, and
GetDrawableHorizontalPaddin to establish what padding is and how these methods
account for it (i.e. that visible bounds do not include padding, while SetOrigin
sets the origin of the rect that does include padding)?

[AviD, 2015/08/09 13:55:41]

Done.

   virtual void SetAlpha(float alpha) = 0;
-  virtual void SetFocus(const gfx::PointF& position) = 0;
   virtual gfx::RectF GetVisibleBounds() const = 0;
+  virtual const float GetDrawableHorizontalPadding() const = 0;
 };
 
 // Interface through which |TouchHandle| communicates handle manipulation and
@@ -41,6 +44,7 @@ class UI_TOUCH_SELECTION_EXPORT TouchHandleClient
   virtual void SetNeedsAnimate() = 0;
   virtual scoped_ptr<TouchHandleDrawable> CreateDrawable() = 0;
   virtual base::TimeDelta GetTapTimeout() const = 0;
+  virtual bool IsEnabledAdaptiveHandleOrientation() const = 0;
 };
 
 // Responsible for displaying a selection or insertion handle for text
@@ -48,7 +52,9 @@ class UI_TOUCH_SELECTION_EXPORT TouchHandleClient
 class UI_TOUCH_SELECTION_EXPORT TouchHandle : public TouchSelectionDraggable {
  public:
   // The drawable will be enabled but invisible until otherwise specified.
-  TouchHandle(TouchHandleClient* client, TouchHandleOrientation orientation);
+  TouchHandle(TouchHandleClient* client,
+              TouchHandleOrientation orientation,
+              const gfx::RectF viewport_rect);
   ~TouchHandle() override;
 
   // TouchSelectionDraggable implementation.
@@ -67,10 +73,14 @@ class UI_TOUCH_SELECTION_EXPORT TouchHandle : public TouchSelectionDraggable {
   // If an animation is in-progress, it will be overriden appropriately.
   void SetVisible(bool visible, AnimationStyle animation_style);
 
-  // Update the handle placement to |position|.
+  // Update the focus points for the handles. The Handle will be positioned
+  // either |top| or |bottom| based on the mirror parameters.
   // Note: If a fade out animation is active or the handle is invisible, the
   // handle position will not be updated until the handle regains visibility.
-  void SetPosition(const gfx::PointF& position);
+  void SetFocus(const gfx::PointF& top, const gfx::PointF& bottom);
+
+  // Update the Viewport rect, based on which the handle decide its inversion
+  void SetViewportRect(const gfx::RectF viewport_rect);
 
   // Update the handle visuals to |orientation|.
   // Note: If the handle is being dragged, the orientation change will be
@@ -86,21 +96,30 @@ class UI_TOUCH_SELECTION_EXPORT TouchHandle : public TouchSelectionDraggable {
   // the bounds will be empty.
   gfx::RectF GetVisibleBounds() const;
 
-  const gfx::PointF& position() const { return position_; }
+  // Updates the Handle layout if the is_handle_layout_update_required_ flag is
+  // set. Will be called once per frame update, avoids multiple updates for
+  // for the same frame update due to more than one parameter updates.
+  void UpdateHandleLayout();
+
+  const gfx::PointF& focus_bottom() const { return focus_bottom_; }
   TouchHandleOrientation orientation() const { return orientation_; }
 
  private:
+  gfx::PointF GetHandleOrigin() const;
   void BeginDrag();
   void EndDrag();
   void BeginFade();
   void EndFade();
   void SetAlpha(float alpha);
+  void SetUpdateLayoutRequired() { is_handle_layout_update_required_ = true; }
 
   scoped_ptr<TouchHandleDrawable> drawable_;
 
   TouchHandleClient* const client_;
 
-  gfx::PointF position_;
+  gfx::PointF focus_bottom_;
+  gfx::PointF focus_top_;
+  gfx::RectF viewport_rect_;
   TouchHandleOrientation orientation_;
   TouchHandleOrientation deferred_orientation_;
 
@@ -120,6 +139,12 @@ class UI_TOUCH_SELECTION_EXPORT TouchHandle : public TouchSelectionDraggable {
   bool is_visible_;
   bool is_dragging_;
   bool is_drag_within_tap_region_;
+  bool is_handle_layout_update_required_;
+
+  // Mirror variables determine if the handles should be inverted or not.
+  bool mirror_vertical_;
+  bool mirror_horizontal_;
+  float handle_horizontal_padding_;
 
   DISALLOW_COPY_AND_ASSIGN(TouchHandle);
 };