src/apps/cortex/support/MouseTrackingHelpers.h

   1 /*
   2  * Copyright (c) 1999-2000, Eric Moon.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions, and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions, and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * 3. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
  20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  21  * OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  23  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
  27  * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31
  32 // MouseTrackingHelpers.h
  33 // e.moon 8mar99
  34 //
  35 // Some helper classes for mouse tracking, designed to make
  36 // it easier to delegate drag operations to a parent class
  37 // (especially useful for pane-separator bars & other operations
  38 //  in which a view is moved or resized as the user drags
  39 //  within it.)
  40 //
  41 // HISTORY
  42 //   e.moon 11may99: fixed m_bTracking bug (not init'd in ctor)
  43 //                   fixed mouseTrackingBegin() documentation
  44 //                   (point is in view, not screen, coords)
  45
  46 #ifndef __MouseTrackingHelpers_H__
  47 #define __MouseTrackingHelpers_H__
  48
  49 #include <View.h>
  50
  51 #include "cortex_defs.h"
  52 __BEGIN_CORTEX_NAMESPACE
  53
  54 class MouseTrackingSourceView;
  55
  56 // interface for a mouse-tracking destination
  57 class IMouseTrackingDestination {
  58 public:                                                 // operations
  59         IMouseTrackingDestination() { }
  60         virtual ~IMouseTrackingDestination() { }
  61         // a MouseTrackingSourceView has started tracking the mouse
  62         // (point is in pSource view coordinates)
  63         virtual void mouseTrackingBegin(
  64                 MouseTrackingSourceView* pSource,
  65                 uint32 buttons,
  66                 BPoint point)=0;
  67
  68         // mouse-tracking update from child view
  69         // (point is in screen coordinates)
  70         virtual void mouseTrackingUpdate(
  71                 uint32 buttons,
  72                 float xDelta,
  73                 float yDelta,
  74                 BPoint point)=0;
  75
  76         // mouse-tracking done
  77         virtual void mouseTrackingEnd()=0;
  78 };
  79
  80 // mouse-tracking 'source' view
  81 // hands off to a destination view (by default its immediate
  82 // parent)
  83
  84 class MouseTrackingSourceView : public BView {
  85         typedef BView _inherited;
  86
  87 public:                                                 // types & constants
  88         // these bits determine which mouse axes will be tracked
  89         // (ie. if TRACK_HORIZONTAL isn't set, mouseTrackUpdate()
  90         //  will always be called with xDelta == 0.0)
  91         enum mouse_tracking_flag_t {
  92                 TRACK_HORIZONTAL = 1,
  93                 TRACK_VERTICAL = 2
  94         };
  95
  96 public:                                                         // ctor/dtor
  97         MouseTrackingSourceView(
  98                 BRect frame,
  99                 const char* pName,
 100                 uint32 resizeMode=B_FOLLOW_LEFT|B_FOLLOW_TOP,
 101                 uint32 flags=B_WILL_DRAW|B_FRAME_EVENTS,
 102                 uint32 trackingFlags=TRACK_HORIZONTAL|TRACK_VERTICAL);
 103
 104         ~MouseTrackingSourceView();
 105
 106         bool isTracking() const { return m_bTracking; }
 107
 108         // get mouse-down point in screen coordinates; returns
 109         // B_OK on success, or B_ERROR if no longer tracking
 110         // the mouse.
 111         status_t getTrackingOrigin(BPoint* poPoint) const;
 112
 113         // fetch/set the destination handler
 114         // (if not yet attached to a window, or if no parent
 115         // implements IMouseTrackDestination, trackingDestination()
 116         // returns 0)
 117         //
 118         // setting the destination handler isn't allowed if a tracking
 119         // operation is currently in progress
 120
 121         IMouseTrackingDestination* trackingDestination() const {
 122                 return m_pDest;
 123         }
 124         status_t setTrackingDestination(IMouseTrackingDestination* pDest);
 125
 126 public:                                                         // BView impl.
 127
 128         // handle mouse events
 129         virtual void MouseDown(BPoint point);
 130         virtual void MouseMoved(BPoint point, uint32 transit,
 131                 const BMessage* pMsg);
 132         virtual void MouseUp(BPoint point);
 133
 134         // look for a default destination
 135         virtual void AttachedToWindow();
 136
 137 /*
 138         // track current frame rectangle
 139         virtual void FrameResized(float width, float height);
 140 */
 141 protected:                                                      // members
 142
 143         IMouseTrackingDestination*              m_pDest;
 144         uint32                          m_trackingFlags;
 145
 146         // mouse-tracking state
 147         bool                                            m_bTracking;
 148         BPoint                          m_prevPoint; // in screen coords
 149         BPoint                          m_initPoint; // in screen coords
 150
 151 //      BRect                                   m_prevFrame;
 152 };
 153
 154 __END_CORTEX_NAMESPACE
 155 #endif /* __MouseTrackingHelpers_H__ */