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 SciTech Software, Inc. (www.scitechsoft.com)
   9 // Licence:     wxWidgets licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  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     #include "wx/renderer.h"
  33 #endif // WX_PRECOMP
  34
  35 #include "wx/univ/scrtimer.h"
  36 #include "wx/univ/scrthumb.h"
  37
  38 // ----------------------------------------------------------------------------
  39 // wxScrollThumbCaptureData: the struct used while dragging the scroll thumb
  40 // ----------------------------------------------------------------------------
  41
  42 struct WXDLLEXPORT wxScrollThumbCaptureData
  43 {
  44     // start mouse capture after the user clicked the mouse button btn on this
  45     // part of the control
  46     wxScrollThumbCaptureData(wxScrollThumb::Shaft part,
  47                              int btn,
  48                              wxControlWithThumb *control)
  49     {
  50         m_shaftPart = part;
  51         m_btnCapture = btn;
  52         m_timerScroll = NULL;
  53
  54         m_window = control->GetWindow();
  55         m_window->CaptureMouse();
  56     }
  57
  58     // release mouse
  59     ~wxScrollThumbCaptureData()
  60     {
  61         if ( m_window )
  62         {
  63             m_window->ReleaseMouse();
  64         }
  65
  66         delete m_timerScroll;
  67     }
  68
  69     // the thumb part being held pressed
  70     wxScrollThumb::Shaft m_shaftPart;
  71
  72     // the mouse button which started the capture (-1 if none)
  73     int m_btnCapture;
  74
  75     // the window which has captured the mouse
  76     wxWindow *m_window;
  77
  78     // the offset between the mouse position and the start of the thumb which
  79     // is kept constant while dragging the thumb
  80     wxCoord m_ofsMouse;
  81
  82     // the timer for generating the scroll events when scrolling by page
  83     wxScrollTimer *m_timerScroll;
  84 };
  85
  86 // ----------------------------------------------------------------------------
  87 // wxScrollTimer: the timer used when the arrow is kept pressed
  88 // ----------------------------------------------------------------------------
  89
  90 class wxScrollThumbTimer : public wxScrollTimer
  91 {
  92 public:
  93     wxScrollThumbTimer(wxControlWithThumb *control,
  94                        wxScrollThumb::Shaft shaftPart)
  95     {
  96         m_control = control;
  97         switch ( shaftPart )
  98         {
  99             case wxScrollThumb::Shaft_Above:
 100                 m_inc = -1;
 101                 break;
 102
 103             default:
 104                 wxFAIL_MSG(_T("unexpected shaft part in wxScrollThumbTimer"));
 105                 // fall through
 106
 107             case wxScrollThumb::Shaft_Below:
 108                 m_inc = 1;
 109                 break;
 110         }
 111
 112         m_control->OnPageScrollStart();
 113
 114         StartAutoScroll();
 115     }
 116
 117 protected:
 118     virtual bool DoNotify()
 119     {
 120         return m_control->OnPageScroll(m_inc);
 121     }
 122
 123     wxControlWithThumb *m_control;
 124     int m_inc;
 125 };
 126
 127 // ============================================================================
 128 // implementation
 129 // ============================================================================
 130
 131 // ----------------------------------------------------------------------------
 132 // wxScrollThumb constructor and dtor
 133 // ----------------------------------------------------------------------------
 134
 135 wxScrollThumb::wxScrollThumb(wxControlWithThumb *control)
 136 {
 137     m_shaftPart = Shaft_None;
 138     m_control = control;
 139     m_captureData = NULL;
 140 }
 141
 142 wxScrollThumb::~wxScrollThumb()
 143 {
 144     // it should have been destroyed
 145     wxASSERT_MSG( !m_captureData, _T("memory leak in wxScrollThumb") );
 146 }
 147
 148 // ----------------------------------------------------------------------------
 149 // wxScrollThumb mouse handling
 150 // ----------------------------------------------------------------------------
 151
 152 bool wxScrollThumb::HandleMouse(const wxMouseEvent& event) const
 153 {
 154     // is this a click event?
 155     int btn = event.GetButton();
 156     if ( btn == -1 )
 157     {
 158         // no...
 159         return FALSE;
 160     }
 161
 162     // when the mouse is pressed on any scrollbar element, we capture it
 163     // and hold capture until the same mouse button is released
 164     if ( event.ButtonDown() || event.ButtonDClick() )
 165     {
 166         if ( HasCapture() )
 167         {
 168             // mouse already captured, nothing to do
 169             return FALSE;
 170         }
 171
 172         // determine which part of the window the user clicked in
 173         Shaft shaftPart = m_control->HitTest(event.GetPosition());
 174
 175         if ( shaftPart == Shaft_None )
 176         {
 177             // mouse pressed over something else
 178             return FALSE;
 179         }
 180
 181         // capture the mouse
 182         wxConstCast(this, wxScrollThumb)->m_captureData =
 183             new wxScrollThumbCaptureData(shaftPart, btn, m_control);
 184
 185         // modify the visual appearance before sending the event which will
 186         // cause a redraw
 187         m_control->SetShaftPartState(shaftPart, wxCONTROL_PRESSED);
 188
 189         if ( shaftPart == Shaft_Thumb )
 190         {
 191             // save the mouse offset from the thumb position - we will keep it
 192             // constant while dragging the thumb
 193             m_captureData->m_ofsMouse =
 194                 GetMouseCoord(event) - m_control->ThumbPosToPixel();
 195
 196             // generate an additional event if we start dragging the thumb
 197             m_control->OnThumbDragStart(GetThumbPos(event));
 198         }
 199         else // not the thumb
 200         {
 201             // start timer for auto scrolling when the user presses the mouse
 202             // in the shaft above or below the thumb
 203             m_captureData->m_timerScroll =
 204                 new wxScrollThumbTimer(m_control, shaftPart);
 205         }
 206     }
 207     // release mouse if the *same* button went up
 208     else if ( HasCapture() && (btn == m_captureData->m_btnCapture) )
 209     {
 210         Shaft shaftPart = m_captureData->m_shaftPart;
 211
 212         // if we were dragging the thumb, send the one last event
 213         if ( shaftPart == Shaft_Thumb )
 214         {
 215             m_control->OnThumbDragEnd(GetThumbPos(event));
 216         }
 217
 218         // release the mouse and free capture data
 219         delete m_captureData;
 220         wxConstCast(this, wxScrollThumb)->m_captureData = NULL;
 221
 222         m_control->SetShaftPartState(shaftPart, wxCONTROL_PRESSED, FALSE);
 223     }
 224     else // another mouse button released
 225     {
 226         // we don't process this
 227         return FALSE;
 228     }
 229
 230     return TRUE;
 231 }
 232
 233 bool wxScrollThumb::HandleMouseMove(const wxMouseEvent& event) const
 234 {
 235     if ( HasCapture() )
 236     {
 237         if ( (m_captureData->m_shaftPart == Shaft_Thumb) && event.Moving() )
 238         {
 239             // make the thumb follow the mouse by keeping the same offset
 240             // between the mouse position and the top/left of the thumb
 241             m_control->OnThumbDrag(GetThumbPos(event));
 242         }
 243
 244         // we process all mouse events while the mouse is captured by us
 245         return TRUE;
 246     }
 247     else // no capture
 248     {
 249         Shaft shaftPart;
 250         if ( event.Leaving() )
 251         {
 252             // no part of the shaft has mouse if it left the window completely
 253             shaftPart = Shaft_None;
 254         }
 255         else // Moving() or Entering(), treat them the same here
 256         {
 257             shaftPart = m_control->HitTest(event.GetPosition());
 258         }
 259
 260         if ( shaftPart != m_shaftPart )
 261         {
 262             // update the highlighted state
 263             m_control->SetShaftPartState(m_shaftPart, wxCONTROL_CURRENT, FALSE);
 264             wxConstCast(this, wxScrollThumb)->m_shaftPart = shaftPart;
 265             m_control->SetShaftPartState(m_shaftPart, wxCONTROL_CURRENT, TRUE);
 266         }
 267
 268         // if the event happened on the shaft, it was for us and we processed
 269         // it
 270         return shaftPart != Shaft_None;
 271     }
 272 }
 273
 274 wxCoord wxScrollThumb::GetMouseCoord(const wxMouseEvent& event) const
 275 {
 276     wxPoint pt = event.GetPosition();
 277     return m_control->IsVertical() ? pt.y : pt.x;
 278 }
 279
 280 int wxScrollThumb::GetThumbPos(const wxMouseEvent& event) const
 281 {
 282     wxCHECK_MSG( m_captureData && m_captureData->m_shaftPart == Shaft_Thumb, 0,
 283                  _T("can't be called when thumb is not dragged") );
 284
 285     int x = GetMouseCoord(event) - m_captureData->m_ofsMouse;
 286     return m_control->PixelToThumbPos(x);
 287 }