ui/views/controls/throbber.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_THROBBER_H_
   6 #define UI_VIEWS_CONTROLS_THROBBER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/compiler_specific.h"
  10 #include "base/time/time.h"
  11 #include "base/timer/timer.h"
  12 #include "ui/views/view.h"
  13
  14 namespace gfx {
  15 class ImageSkia;
  16 }
  17
  18 namespace views {
  19
  20 // Throbbers display an animation, usually used as a status indicator.
  21
  22 class VIEWS_EXPORT Throbber : public View {
  23  public:
  24   // |frame_time_ms| is the amount of time that should elapse between frames
  25   //                 (in milliseconds)
  26   // If |paint_while_stopped| is false, this view will be invisible when not
  27   // running.
  28   Throbber(int frame_time_ms, bool paint_while_stopped);
  29   Throbber(int frame_time_ms, bool paint_while_stopped, gfx::ImageSkia* frames);
  30   virtual ~Throbber();
  31
  32   // Start and stop the throbber animation
  33   virtual void Start();
  34   virtual void Stop();
  35
  36   // Set custom throbber frames. Otherwise IDR_THROBBER is loaded.
  37   void SetFrames(const gfx::ImageSkia* frames);
  38
  39   // Overridden from View:
  40   virtual gfx::Size GetPreferredSize() const OVERRIDE;
  41   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
  42
  43  protected:
  44   // Specifies whether the throbber is currently animating or not
  45   bool running_;
  46
  47  private:
  48   void Run();
  49
  50   bool paint_while_stopped_;
  51   int frame_count_;  // How many frames we have.
  52   base::Time start_time_;  // Time when Start was called.
  53   const gfx::ImageSkia* frames_;  // Frames images.
  54   base::TimeDelta frame_time_;  // How long one frame is displayed.
  55   base::RepeatingTimer<Throbber> timer_;  // Used to schedule Run calls.
  56
  57   DISALLOW_COPY_AND_ASSIGN(Throbber);
  58 };
  59
  60 // A SmoothedThrobber is a throbber that is representing potentially short
  61 // and nonoverlapping bursts of work.  SmoothedThrobber ignores small
  62 // pauses in the work stops and starts, and only starts its throbber after
  63 // a small amount of work time has passed.
  64 class VIEWS_EXPORT SmoothedThrobber : public Throbber {
  65  public:
  66   explicit SmoothedThrobber(int frame_delay_ms);
  67   SmoothedThrobber(int frame_delay_ms, gfx::ImageSkia* frames);
  68   virtual ~SmoothedThrobber();
  69
  70   virtual void Start() OVERRIDE;
  71   virtual void Stop() OVERRIDE;
  72
  73   void set_start_delay_ms(int value) { start_delay_ms_ = value; }
  74   void set_stop_delay_ms(int value) { stop_delay_ms_ = value; }
  75
  76  private:
  77   // Called when the startup-delay timer fires
  78   // This function starts the actual throbbing.
  79   void StartDelayOver();
  80
  81   // Called when the shutdown-delay timer fires.
  82   // This function stops the actual throbbing.
  83   void StopDelayOver();
  84
  85   // Delay after work starts before starting throbber, in milliseconds.
  86   int start_delay_ms_;
  87
  88   // Delay after work stops before stopping, in milliseconds.
  89   int stop_delay_ms_;
  90
  91   base::OneShotTimer<SmoothedThrobber> start_timer_;
  92   base::OneShotTimer<SmoothedThrobber> stop_timer_;
  93
  94   DISALLOW_COPY_AND_ASSIGN(SmoothedThrobber);
  95 };
  96
  97 // A CheckmarkThrobber is a special variant of throbber that has three states:
  98 //   1. not yet completed (which paints nothing)
  99 //   2. working (which paints the throbber animation)
 100 //   3. completed (which paints a checkmark)
 101 //
 102 class VIEWS_EXPORT CheckmarkThrobber : public Throbber {
 103  public:
 104   CheckmarkThrobber();
 105
 106   // If checked is true, the throbber stops spinning and displays a checkmark.
 107   // If checked is false, the throbber stops spinning and displays nothing.
 108   void SetChecked(bool checked);
 109
 110   // Overridden from Throbber:
 111   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
 112
 113  private:
 114   static const int kFrameTimeMs = 30;
 115
 116   // Whether or not we should display a checkmark.
 117   bool checked_;
 118
 119   // The checkmark image.
 120   const gfx::ImageSkia* checkmark_;
 121
 122   DISALLOW_COPY_AND_ASSIGN(CheckmarkThrobber);
 123 };
 124
 125 }  // namespace views
 126
 127 #endif  // UI_VIEWS_CONTROLS_THROBBER_H_