src/univ/scrthumb.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        univ/scrthumb.cpp
   3 // Purpose:     wxScrollThumb and related classes
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     13.02.01
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2001 Vadim Zeitlin
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 #ifdef __GNUG__
  21     #pragma implementation "univscrthumb.h"
  22 #endif
  23
  24 #include "wx/wxprec.h"
  25
  26 #ifdef __BORLANDC__
  27     #pragma hdrstop
  28 #endif
  29
  30 #ifndef WX_PRECOMP
  31     #include "wx/window.h"
  32 #endif // WX_PRECOMP
  33
  34 #include "wx/univ/scrtimer.h"
  35 #include "wx/univ/scrthumb.h"
  36
  37 // ----------------------------------------------------------------------------
  38 // wxScrollThumbCaptureData: the struct used while dragging the scroll thumb
  39 // ----------------------------------------------------------------------------
  40
  41 struct WXDLLEXPORT wxScrollThumbCaptureData
  42 {
  43     // start mouse capture after the user clicked the mouse button btn on this
  44     // part of the control
  45     wxScrollThumbCaptureData(wxScrollThumb::Shaft part,
  46                              int btn,
  47                              wxControlWithThumb *control)
  48     {
  49         m_shaftPart = part;
  50         m_btnCapture = btn;
  51         m_timerScroll = NULL;
  52
  53         m_window = control->GetWindow();
  54         m_window->CaptureMouse();
  55     }
  56
  57     // release mouse
  58     ~wxScrollThumbCaptureData()
  59     {
  60         if ( m_window )
  61         {
  62             m_window->ReleaseMouse();
  63         }
  64
  65         delete m_timerScroll;
  66     }
  67
  68     // the thumb part being held pressed
  69     wxScrollThumb::Shaft m_shaftPart;
  70
  71     // the mouse button which started the capture (-1 if none)
  72     int m_btnCapture;
  73
  74     // the window which has captured the mouse
  75     wxWindow *m_window;
  76
  77     // the offset between the mouse position and the start of the thumb which
  78     // is kept constant while dragging the thumb
  79     wxCoord m_ofsMouse;
  80
  81     // the timer for generating the scroll events when scrolling by page
  82     wxScrollTimer *m_timerScroll;
  83 };
  84
  85 // ----------------------------------------------------------------------------
  86 // wxScrollTimer: the timer used when the arrow is kept pressed
  87 // ----------------------------------------------------------------------------
  88
  89 class wxScrollThumbTimer : public wxScrollTimer
  90 {
  91 public:
  92     wxScrollThumbTimer(wxControlWithThumb *control,
  93                        wxScrollThumb::Shaft shaftPart)
  94     {
  95         m_control = control;
  96         switch ( shaftPart )
  97         {
  98             case wxScrollThumb::Shaft_Above:
  99                 m_inc = -1;
 100                 break;
 101
 102             default:
 103                 wxFAIL_MSG(_T("unexpected shaft part in wxScrollThumbTimer"));
 104                 // fall through
 105
 106             case wxScrollThumb::Shaft_Below:
 107                 m_inc = 1;
 108                 break;
 109         }
 110
 111         m_control->OnPageScrollStart();
 112
 113         StartAutoScroll();
 114     }
 115
 116 protected:
 117     virtual bool DoNotify()
 118     {
 119         return m_control->OnPageScroll(m_inc);
 120     }
 121
 122     wxControlWithThumb *m_control;
 123     int m_inc;
 124 };
 125
 126 // ============================================================================
 127 // implementation
 128 // ============================================================================
 129
 130 // ----------------------------------------------------------------------------
 131 // wxScrollThumb constructor and dtor
 132 // ----------------------------------------------------------------------------
 133
 134 wxScrollThumb::wxScrollThumb(wxControlWithThumb *control)
 135 {
 136     m_shaftPart = Shaft_None;
 137     m_control = control;
 138     m_captureData = NULL;
 139 }
 140
 141 wxScrollThumb::~wxScrollThumb()
 142 {
 143     // it should have been destroyed
 144     wxASSERT_MSG( !m_captureData, _T("memory leak in wxScrollThumb") );
 145 }
 146
 147 // ----------------------------------------------------------------------------
 148 // wxScrollThumb mouse handling
 149 // ----------------------------------------------------------------------------
 150
 151 bool wxScrollThumb::HandleMouse(const wxMouseEvent& event) const
 152 {
 153     // is this a click event?
 154     int btn = event.GetButton();
 155     if ( btn == -1 )
 156     {
 157         // no...
 158         return FALSE;
 159     }
 160
 161     // when the mouse is pressed on any scrollbar element, we capture it
 162     // and hold capture until the same mouse button is released
 163     if ( event.ButtonDown() || event.ButtonDClick() )
 164     {
 165         if ( HasCapture() )
 166         {
 167             // mouse already captured, nothing to do
 168             return FALSE;
 169         }
 170
 171         // determine which part of the window the user clicked in
 172         Shaft shaftPart = m_control->HitTest(event.GetPosition());
 173
 174         if ( shaftPart == Shaft_None )
 175         {
 176             // mouse pressed over something else
 177             return FALSE;
 178         }
 179
 180         // capture the mouse
 181         wxConstCast(this, wxScrollThumb)->m_captureData =
 182             new wxScrollThumbCaptureData(shaftPart, btn, m_control);
 183
 184         // modify the visual appearance before sending the event which will
 185         // cause a redraw
 186         m_control->SetShaftPartState(shaftPart, wxCONTROL_PRESSED);
 187
 188         if ( shaftPart == Shaft_Thumb )
 189         {
 190             // save the mouse offset from the thumb position - we will keep it
 191             // constant while dragging the thumb
 192             m_captureData->m_ofsMouse =
 193                 GetMouseCoord(event) - m_control->ThumbPosToPixel();
 194
 195             // generate an additional event if we start dragging the thumb
 196             m_control->OnThumbDragStart(GetThumbPos(event));
 197         }
 198         else // not the thumb
 199         {
 200             // start timer for auto scrolling when the user presses the mouse
 201             // in the shaft above or below the thumb
 202             m_captureData->m_timerScroll =
 203                 new wxScrollThumbTimer(m_control, shaftPart);
 204         }
 205     }
 206     // release mouse if the *same* button went up
 207     else if ( HasCapture() && (btn == m_captureData->m_btnCapture) )
 208     {
 209         Shaft shaftPart = m_captureData->m_shaftPart;
 210
 211         // if we were dragging the thumb, send the one last event
 212         if ( shaftPart == Shaft_Thumb )
 213         {
 214             m_control->OnThumbDragEnd(GetThumbPos(event));
 215         }
 216
 217         // release the mouse and free capture data
 218         delete m_captureData;
 219         wxConstCast(this, wxScrollThumb)->m_captureData = NULL;
 220
 221         m_control->SetShaftPartState(shaftPart, wxCONTROL_PRESSED, FALSE);
 222     }
 223     else // another mouse button released
 224     {
 225         // we don't process this
 226         return FALSE;
 227     }
 228
 229     return TRUE;
 230 }
 231
 232 bool wxScrollThumb::HandleMouseMove(const wxMouseEvent& event) const
 233 {
 234     if ( HasCapture() )
 235     {
 236         if ( (m_captureData->m_shaftPart == Shaft_Thumb) && event.Moving() )
 237         {
 238             // make the thumb follow the mouse by keeping the same offset
 239             // between the mouse position and the top/left of the thumb
 240             m_control->OnThumbDrag(GetThumbPos(event));
 241         }
 242
 243         // we process all mouse events while the mouse is captured by us
 244         return TRUE;
 245     }
 246     else // no capture
 247     {
 248         Shaft shaftPart;
 249         if ( event.Leaving() )
 250         {
 251             // no part of the shaft has mouse if it left the window completely
 252             shaftPart = Shaft_None;
 253         }
 254         else // Moving() or Entering(), treat them the same here
 255         {
 256             shaftPart = m_control->HitTest(event.GetPosition());
 257         }
 258
 259         if ( shaftPart != m_shaftPart )
 260         {
 261             // update the highlighted state
 262             m_control->SetShaftPartState(m_shaftPart, wxCONTROL_CURRENT, FALSE);
 263             wxConstCast(this, wxScrollThumb)->m_shaftPart = shaftPart;
 264             m_control->SetShaftPartState(m_shaftPart, wxCONTROL_CURRENT, TRUE);
 265         }
 266
 267         // if the event happened on the shaft, it was for us and we processed
 268         // it
 269         return shaftPart != Shaft_None;
 270     }
 271 }
 272
 273 wxCoord wxScrollThumb::GetMouseCoord(const wxMouseEvent& event) const
 274 {
 275     wxPoint pt = event.GetPosition();
 276     return m_control->IsVertical() ? pt.y : pt.x;
 277 }
 278
 279 int wxScrollThumb::GetThumbPos(const wxMouseEvent& event) const
 280 {
 281     wxCHECK_MSG( m_captureData && m_captureData->m_shaftPart == Shaft_Thumb, 0,
 282                  _T("can't be called when thumb is not dragged") );
 283
 284     int x = GetMouseCoord(event) - m_captureData->m_ofsMouse;
 285     return m_control->PixelToThumbPos(x);
 286 }