src/univ/scrthumb.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/univ/scrthumb.cpp
   3 // Purpose:     wxScrollThumb and related classes
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     13.02.01
   7 // Copyright:   (c) 2001 SciTech Software, Inc. (www.scitechsoft.com)
   8 // Licence:     wxWindows licence
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 // ============================================================================
  12 // declarations
  13 // ============================================================================
  14
  15 // ----------------------------------------------------------------------------
  16 // headers
  17 // ----------------------------------------------------------------------------
  18
  19 #include "wx/wxprec.h"
  20
  21 #ifdef __BORLANDC__
  22     #pragma hdrstop
  23 #endif
  24
  25 #ifndef WX_PRECOMP
  26     #include "wx/window.h"
  27 #endif // WX_PRECOMP
  28
  29 #include "wx/renderer.h"
  30 #include "wx/univ/scrtimer.h"
  31 #include "wx/univ/scrthumb.h"
  32
  33 // ----------------------------------------------------------------------------
  34 // wxScrollThumbCaptureData: the struct used while dragging the scroll thumb
  35 // ----------------------------------------------------------------------------
  36
  37 struct WXDLLEXPORT wxScrollThumbCaptureData
  38 {
  39     // start mouse capture after the user clicked the mouse button btn on this
  40     // part of the control
  41     wxScrollThumbCaptureData(wxScrollThumb::Shaft part,
  42                              int btn,
  43                              wxControlWithThumb *control)
  44     {
  45         m_shaftPart = part;
  46         m_btnCapture = btn;
  47         m_timerScroll = NULL;
  48
  49         m_window = control->GetWindow();
  50         m_window->CaptureMouse();
  51     }
  52
  53     // release mouse
  54     ~wxScrollThumbCaptureData()
  55     {
  56         if ( m_window )
  57         {
  58             m_window->ReleaseMouse();
  59         }
  60
  61 #if wxUSE_TIMER
  62         delete m_timerScroll;
  63 #endif // wxUSE_TIMER
  64     }
  65
  66     // the thumb part being held pressed
  67     wxScrollThumb::Shaft m_shaftPart;
  68
  69     // the mouse button which started the capture (-1 if none)
  70     int m_btnCapture;
  71
  72     // the window which has captured the mouse
  73     wxWindow *m_window;
  74
  75     // the offset between the mouse position and the start of the thumb which
  76     // is kept constant while dragging the thumb
  77     wxCoord m_ofsMouse;
  78
  79     // the timer for generating the scroll events when scrolling by page
  80     wxScrollTimer *m_timerScroll;
  81 };
  82
  83 // ----------------------------------------------------------------------------
  84 // wxScrollTimer: the timer used when the arrow is kept pressed
  85 // ----------------------------------------------------------------------------
  86
  87 #if wxUSE_TIMER
  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(wxT("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 #endif // wxUSE_TIMER
 127
 128 // ============================================================================
 129 // implementation
 130 // ============================================================================
 131
 132 // ----------------------------------------------------------------------------
 133 // wxScrollThumb constructor and dtor
 134 // ----------------------------------------------------------------------------
 135
 136 wxScrollThumb::wxScrollThumb(wxControlWithThumb *control)
 137 {
 138     m_shaftPart = Shaft_None;
 139     m_control = control;
 140     m_captureData = NULL;
 141 }
 142
 143 wxScrollThumb::~wxScrollThumb()
 144 {
 145     // it should have been destroyed
 146     wxASSERT_MSG( !m_captureData, wxT("memory leak in wxScrollThumb") );
 147 }
 148
 149 // ----------------------------------------------------------------------------
 150 // wxScrollThumb mouse handling
 151 // ----------------------------------------------------------------------------
 152
 153 bool wxScrollThumb::HandleMouse(const wxMouseEvent& event) const
 154 {
 155     // is this a click event?
 156     int btn = event.GetButton();
 157     if ( btn == -1 )
 158     {
 159         // no...
 160         return false;
 161     }
 162
 163     // when the mouse is pressed on any scrollbar element, we capture it
 164     // and hold capture until the same mouse button is released
 165     if ( event.ButtonDown() || event.ButtonDClick() )
 166     {
 167         if ( HasCapture() )
 168         {
 169             // mouse already captured, nothing to do
 170             return false;
 171         }
 172
 173         // determine which part of the window the user clicked in
 174         Shaft shaftPart = m_control->HitTest(event.GetPosition());
 175
 176         if ( shaftPart == Shaft_None )
 177         {
 178             // mouse pressed over something else
 179             return false;
 180         }
 181
 182         // capture the mouse
 183         wxConstCast(this, wxScrollThumb)->m_captureData =
 184             new wxScrollThumbCaptureData(shaftPart, btn, m_control);
 185
 186         // modify the visual appearance before sending the event which will
 187         // cause a redraw
 188         m_control->SetShaftPartState(shaftPart, wxCONTROL_PRESSED);
 189
 190         if ( shaftPart == Shaft_Thumb )
 191         {
 192             // save the mouse offset from the thumb position - we will keep it
 193             // constant while dragging the thumb
 194             m_captureData->m_ofsMouse =
 195                 GetMouseCoord(event) - m_control->ThumbPosToPixel();
 196
 197             // generate an additional event if we start dragging the thumb
 198             m_control->OnThumbDragStart(GetThumbPos(event));
 199         }
 200 #if wxUSE_TIMER
 201         else // not the thumb
 202         {
 203             // start timer for auto scrolling when the user presses the mouse
 204             // in the shaft above or below the thumb
 205             m_captureData->m_timerScroll =
 206                 new wxScrollThumbTimer(m_control, shaftPart);
 207         }
 208 #endif // wxUSE_TIMER
 209     }
 210     // release mouse if the *same* button went up
 211     else if ( HasCapture() && (btn == m_captureData->m_btnCapture) )
 212     {
 213         Shaft shaftPart = m_captureData->m_shaftPart;
 214
 215         // if we were dragging the thumb, send the one last event
 216         if ( shaftPart == Shaft_Thumb )
 217         {
 218             m_control->OnThumbDragEnd(GetThumbPos(event));
 219         }
 220
 221         // release the mouse and free capture data
 222         delete m_captureData;
 223         wxConstCast(this, wxScrollThumb)->m_captureData = NULL;
 224
 225         m_control->SetShaftPartState(shaftPart, wxCONTROL_PRESSED, false);
 226     }
 227     else // another mouse button released
 228     {
 229         // we don't process this
 230         return false;
 231     }
 232
 233     return true;
 234 }
 235
 236 bool wxScrollThumb::HandleMouseMove(const wxMouseEvent& event) const
 237 {
 238     if ( HasCapture() )
 239     {
 240         if ( (m_captureData->m_shaftPart == Shaft_Thumb) && event.Moving() )
 241         {
 242             // make the thumb follow the mouse by keeping the same offset
 243             // between the mouse position and the top/left of the thumb
 244             m_control->OnThumbDrag(GetThumbPos(event));
 245         }
 246
 247         // we process all mouse events while the mouse is captured by us
 248         return true;
 249     }
 250     else // no capture
 251     {
 252         Shaft shaftPart;
 253         if ( event.Leaving() )
 254         {
 255             // no part of the shaft has mouse if it left the window completely
 256             shaftPart = Shaft_None;
 257         }
 258         else // Moving() or Entering(), treat them the same here
 259         {
 260             shaftPart = m_control->HitTest(event.GetPosition());
 261         }
 262
 263         if ( shaftPart != m_shaftPart )
 264         {
 265             // update the highlighted state
 266             m_control->SetShaftPartState(m_shaftPart, wxCONTROL_CURRENT, false);
 267             wxConstCast(this, wxScrollThumb)->m_shaftPart = shaftPart;
 268             m_control->SetShaftPartState(m_shaftPart, wxCONTROL_CURRENT, true);
 269         }
 270
 271         // if the event happened on the shaft, it was for us and we processed
 272         // it
 273         return shaftPart != Shaft_None;
 274     }
 275 }
 276
 277 wxCoord wxScrollThumb::GetMouseCoord(const wxMouseEvent& event) const
 278 {
 279     wxPoint pt = event.GetPosition();
 280     return m_control->IsVertical() ? pt.y : pt.x;
 281 }
 282
 283 int wxScrollThumb::GetThumbPos(const wxMouseEvent& event) const
 284 {
 285     wxCHECK_MSG( m_captureData && m_captureData->m_shaftPart == Shaft_Thumb, 0,
 286                  wxT("can't be called when thumb is not dragged") );
 287
 288     int x = GetMouseCoord(event) - m_captureData->m_ofsMouse;
 289     return m_control->PixelToThumbPos(x);
 290 }