src/gtk/scrolwin.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        gtk/scrolwin.cpp
   3 // Purpose:     wxScrolledWindow implementation
   4 // Author:      Robert Roebling
   5 // Modified by: Ron Lee
   6 //              Vadim Zeitlin: removed 90% of duplicated common code
   7 // Created:     01/02/97
   8 // RCS-ID:      $Id$
   9 // Copyright:   (c) Robert Roebling
  10 // Licence:     wxWindows licence
  11 /////////////////////////////////////////////////////////////////////////////
  12
  13 // ============================================================================
  14 // declarations
  15 // ============================================================================
  16
  17 // ----------------------------------------------------------------------------
  18 // headers
  19 // ----------------------------------------------------------------------------
  20
  21 // For compilers that support precompilation, includes "wx.h".
  22 #include "wx/wxprec.h"
  23
  24 #ifdef __BORLANDC__
  25     #pragma hdrstop
  26 #endif
  27
  28 #include "wx/scrolwin.h"
  29 #include "wx/gtk/private.h"
  30
  31 // ============================================================================
  32 // implementation
  33 // ============================================================================
  34
  35 // ----------------------------------------------------------------------------
  36 // wxScrollHelper implementation
  37 // ----------------------------------------------------------------------------
  38
  39 void wxScrollHelperNative::SetScrollbars(int pixelsPerUnitX, int pixelsPerUnitY,
  40                                          int noUnitsX, int noUnitsY,
  41                                          int xPos, int yPos,
  42                                          bool noRefresh)
  43 {
  44     int xs, ys;
  45     GetViewStart(& xs, & ys);
  46
  47     int old_x = m_xScrollPixelsPerLine * xs;
  48     int old_y = m_yScrollPixelsPerLine * ys;
  49
  50     m_xScrollPixelsPerLine = pixelsPerUnitX;
  51     m_yScrollPixelsPerLine = pixelsPerUnitY;
  52
  53     m_win->m_scrollBar[wxWindow::ScrollDir_Horz]->adjustment->value =
  54     m_xScrollPosition = xPos;
  55     m_win->m_scrollBar[wxWindow::ScrollDir_Vert]->adjustment->value =
  56     m_yScrollPosition = yPos;
  57
  58     // Setting hints here should arguably be deprecated, but without it
  59     // a sizer might override this manual scrollbar setting in old code.
  60     // m_targetWindow->SetVirtualSizeHints( noUnitsX * pixelsPerUnitX, noUnitsY * pixelsPerUnitY );
  61
  62     int w = noUnitsX * pixelsPerUnitX;
  63     int h = noUnitsY * pixelsPerUnitY;
  64     m_targetWindow->SetVirtualSize( w ? w : wxDefaultCoord,
  65                                     h ? h : wxDefaultCoord);
  66
  67     // If the target is not the same as the window with the scrollbars,
  68     // then we need to update the scrollbars here, since they won't have
  69     // been updated by SetVirtualSize().
  70     if (m_targetWindow != m_win)
  71     {
  72         AdjustScrollbars();
  73     }
  74
  75     if (!noRefresh)
  76     {
  77         int new_x = m_xScrollPixelsPerLine * m_xScrollPosition;
  78         int new_y = m_yScrollPixelsPerLine * m_yScrollPosition;
  79
  80         m_targetWindow->ScrollWindow( old_x - new_x, old_y - new_y );
  81     }
  82 }
  83
  84 void wxScrollHelperNative::DoAdjustScrollbar(GtkRange* range,
  85                                              int pixelsPerLine,
  86                                              int winSize,
  87                                              int virtSize,
  88                                              int *pos,
  89                                              int *lines,
  90                                              int *linesPerPage)
  91 {
  92     int upper;
  93     int page_size;
  94     if (pixelsPerLine > 0 && winSize > 0 && winSize < virtSize)
  95     {
  96         upper = (virtSize + pixelsPerLine - 1) / pixelsPerLine;
  97         page_size = winSize / pixelsPerLine;
  98         *lines = upper;
  99         *linesPerPage = page_size;
 100     }
 101     else
 102     {
 103         // GtkRange won't allow upper == lower, so for disabled state use [0,1]
 104         //   with a page size of 1. This will also clamp position to 0.
 105         upper = 1;
 106         page_size = 1;
 107         *lines = 0;
 108         *linesPerPage = 0;
 109     }
 110
 111     GtkAdjustment* adj = range->adjustment;
 112     adj->step_increment = 1;
 113     adj->page_increment =
 114     adj->page_size = page_size;
 115     gtk_range_set_range(range, 0, upper);
 116
 117     // ensure that the scroll position is always in valid range
 118     if (*pos > *lines)
 119         *pos = *lines;
 120 }
 121
 122 void wxScrollHelperNative::AdjustScrollbars()
 123 {
 124     // this flag indicates which window has the scrollbars
 125     m_win->m_hasScrolling = m_xScrollPixelsPerLine != 0 ||
 126                                 m_yScrollPixelsPerLine != 0;
 127
 128     int vw, vh;
 129     m_targetWindow->GetVirtualSize( &vw, &vh );
 130
 131     int w;
 132     m_targetWindow->GetClientSize(&w, NULL);
 133     DoAdjustHScrollbar(w, vw);
 134
 135     int h;
 136     m_targetWindow->GetClientSize(NULL, &h);
 137     DoAdjustVScrollbar(h, vh);
 138
 139     const int w_old = w;
 140     m_targetWindow->GetClientSize(&w, NULL);
 141     if ( w != w_old )
 142     {
 143         // It is necessary to repeat the calculations in this case to avoid an
 144         // observed infinite series of size events, involving alternating
 145         // changes in visibility of the scrollbars.
 146         // At this point, GTK+ has already queued a resize, which will cause
 147         // AdjustScrollbars() to be called again. If the scrollbar visibility
 148         // is not correct before then, yet another resize will occur, possibly
 149         // leading to an unending series if the sizes are just right.
 150         DoAdjustHScrollbar(w, vw);
 151
 152         m_targetWindow->GetClientSize(NULL, &h);
 153         DoAdjustVScrollbar(h, vh);
 154     }
 155 }
 156
 157 void wxScrollHelperNative::DoScroll(int orient,
 158                                     int pos,
 159                                     int pixelsPerLine,
 160                                     int *posOld)
 161 {
 162     if ( pos != -1 && pos != *posOld && pixelsPerLine )
 163     {
 164         m_win->SetScrollPos(orient, pos);
 165         pos = m_win->GetScrollPos(orient);
 166
 167         int diff = (*posOld - pos)*pixelsPerLine;
 168         m_targetWindow->ScrollWindow(orient == wxHORIZONTAL ? diff : 0,
 169                                      orient == wxHORIZONTAL ? 0 : diff);
 170
 171         *posOld = pos;
 172     }
 173 }
 174
 175 void wxScrollHelperNative::Scroll( int x_pos, int y_pos )
 176 {
 177     wxCHECK_RET( m_targetWindow != 0, _T("No target window") );
 178
 179     DoScroll(wxHORIZONTAL, x_pos, m_xScrollPixelsPerLine, &m_xScrollPosition);
 180     DoScroll(wxVERTICAL, y_pos, m_yScrollPixelsPerLine, &m_yScrollPosition);
 181 }