ui/views/controls/glow_hover_controller.h

   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   ~GlowHoverController() override;
  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   void AnimationEnded(const gfx::Animation* animation) override;
  69   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_