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