src/apps/mediaplayer/interface/PeakView.h

   1 /*
   2  * Copyright (C) 1998-1999 Be Incorporated. All rights reseved.
   3  * Distributed under the terms of the Be Sample Code license.
   4  *
   5  * Copyright (C) 2001-2008 Stephan Aßmus. All rights reserved.
   6  * Distributed under the terms of the MIT license.
   7  */
   8
   9 /*----------------------------------------------------------
  10 PURPOSE:
  11 gui class for displaying stereo audio peak level info
  12
  13 FEATURES:
  14 - uses a bitmap, but not a view accepting one, to redraw
  15 without flickering.
  16 - can be configured to use it's own message runner instead
  17 of the windows current pulse (in case you have text views in
  18 the window as well, which use a slow pulse for cursor blinking)
  19 - if used with own message runner, refresh delay is configurable
  20 - can be used in a dynamic liblayout gui
  21
  22 USAGE:
  23 To display the peak level of your streaming audio, just
  24 calculate the local maximum of both channels within your
  25 audio buffer and call SetMax() once for every buffer. The
  26 PeakView will take care of the rest.
  27 min = 0.0
  28 max = 1.0
  29 ----------------------------------------------------------*/
  30 #ifndef PEAK_VIEW_H
  31 #define PEAK_VIEW_H
  32
  33
  34 #include <View.h>
  35
  36 class BBitmap;
  37 class BMessageRunner;
  38
  39 class PeakView : public BView {
  40 public:
  41                                                                 PeakView(const char* name,
  42                                                                         bool useGlobalPulse = true,
  43                                                                         bool displayLabels = true);
  44         virtual                                         ~PeakView();
  45
  46         // BView interface
  47         virtual void                            MessageReceived(BMessage* message);
  48         virtual void                            AttachedToWindow();
  49         virtual void                            DetachedFromWindow();
  50         virtual void                            MouseDown(BPoint where);
  51         virtual void                            Draw(BRect area);
  52         virtual void                            FrameResized(float width, float height);
  53         virtual void                            Pulse();
  54         virtual BSize                           MinSize();
  55
  56         // PeakView
  57                         bool                            IsValid() const;
  58                         void                            SetPeakRefreshDelay(bigtime_t delay);
  59                         void                            SetPeakNotificationWhat(uint32 what);
  60
  61                         void                            SetChannelCount(uint32 count);
  62                         void                            SetMax(float max, uint32 channel);
  63
  64 private:
  65                         BRect                           _BackBitmapFrame() const;
  66                         void                            _ResizeBackBitmap(int32 width, int32 channels);
  67                         void                            _UpdateBackBitmap();
  68                         void                            _RenderSpan(uint8* span, uint32 width,
  69                                                                         float current, float peak, bool overshot);
  70                         void                            _DrawBitmap();
  71
  72 private:
  73                         bool                            fUseGlobalPulse;
  74                         bool                            fDisplayLabels;
  75                         bool                            fPeakLocked;
  76
  77                         bigtime_t                       fRefreshDelay;
  78                         BMessageRunner*         fPulse;
  79
  80                         struct ChannelInfo {
  81                                 float                   current_max;
  82                                 float                   last_max;
  83                                 bigtime_t               last_overshot_time;
  84                         };
  85
  86                         ChannelInfo*            fChannelInfos;
  87                         uint32                          fChannelCount;
  88                         bool                            fGotData;
  89
  90                         BBitmap*                        fBackBitmap;
  91                         font_height                     fFontHeight;
  92
  93                         uint32                          fPeakNotificationWhat;
  94 };
  95
  96 #endif // PEAK_VIEW_H