Home | History | Annotate | Download | only in controls 
      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef UI_VIEWS_CONTROLS_GLOW_HOVER_CONTROLLER_H_
      6 #define UI_VIEWS_CONTROLS_GLOW_HOVER_CONTROLLER_H_
      7 
      8 #include "ui/gfx/animation/animation_delegate.h"
      9 #include "ui/gfx/animation/slide_animation.h"
     10 #include "ui/views/views_export.h"
     11 
     12 namespace gfx {
     13 class Canvas;
     14 class ImageSkia;
     15 class Point;
     16 }
     17 
     18 namespace views {
     19 
     20 class View;
     21 
     22 // GlowHoverController is responsible for drawing a hover effect as is used by
     23 // the tabstrip. Typical usage:
     24 //   OnMouseEntered() -> invoke Show().
     25 //   OnMouseMoved()   -> invoke SetLocation().
     26 //   OnMouseExited()  -> invoke Hide().
     27 //   OnPaint()        -> if ShouldDraw() returns true invoke Draw().
     28 // Internally GlowHoverController uses an animation to animate the glow and
     29 // invokes SchedulePaint() back on the View as necessary.
     30 class VIEWS_EXPORT GlowHoverController : public gfx::AnimationDelegate {
     31  public:
     32   enum Style {
     33     SUBTLE,
     34     PRONOUNCED
     35   };
     36 
     37   explicit GlowHoverController(views::View* view);
     38   virtual ~GlowHoverController();
     39 
     40   // Sets the AnimationContainer used by the animation.
     41   void SetAnimationContainer(gfx::AnimationContainer* container);
     42 
     43   // Sets the location of the hover, relative to the View passed to the
     44   // constructor.
     45   void SetLocation(const gfx::Point& location);
     46 
     47   // Initiates showing the hover.
     48   void Show(Style style);
     49 
     50   // Hides the hover.
     51   void Hide();
     52 
     53   // Hides the hover immediately.
     54   void HideImmediately();
     55 
     56   // Returns the value of the animation.
     57   double GetAnimationValue() const;
     58 
     59   // Returns true if there is something to be drawn. Use this instead of
     60   // invoking Draw() if creating |mask_image| is expensive.
     61   bool ShouldDraw() const;
     62 
     63   // If the hover is currently visible it is drawn to the supplied canvas.
     64   // |mask_image| is used to determine what parts of the canvas to draw on.
     65   void Draw(gfx::Canvas* canvas, const gfx::ImageSkia& mask_image) const;
     66 
     67   // gfx::AnimationDelegate overrides:
     68   virtual void AnimationEnded(const gfx::Animation* animation) OVERRIDE;
     69   virtual void AnimationProgressed(const gfx::Animation* animation) OVERRIDE;
     70 
     71  private:
     72   // View we're drawing to.
     73   views::View* view_;
     74 
     75   // Opacity of the glow ramps up over time.
     76   gfx::SlideAnimation animation_;
     77 
     78   // Location of the glow, relative to view.
     79   gfx::Point location_;
     80   double opacity_scale_;
     81 
     82   DISALLOW_COPY_AND_ASSIGN(GlowHoverController);
     83 };
     84 
     85 }  // namespace views
     86 
     87 #endif  // UI_VIEWS_CONTROLS_GLOW_HOVER_CONTROLLER_H_
     88