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 wxScrollHelper::SetScrollbars(int pixelsPerUnitX, int pixelsPerUnitY,
  40                                    int noUnitsX, int noUnitsY,
  41                                    int xPos, int yPos,
  42                                    bool noRefresh)
  43 {
  44     m_xScrollPixelsPerLine = pixelsPerUnitX;
  45     m_yScrollPixelsPerLine = pixelsPerUnitY;
  46
  47     m_win->m_scrollBar[wxWindow::ScrollDir_Horz]->adjustment->value =
  48     m_xScrollPosition = xPos;
  49     m_win->m_scrollBar[wxWindow::ScrollDir_Vert]->adjustment->value =
  50     m_yScrollPosition = yPos;
  51
  52     // Setting hints here should arguably be deprecated, but without it
  53     // a sizer might override this manual scrollbar setting in old code.
  54     // m_targetWindow->SetVirtualSizeHints( noUnitsX * pixelsPerUnitX, noUnitsY * pixelsPerUnitY );
  55
  56     int w = noUnitsX * pixelsPerUnitX;
  57     int h = noUnitsY * pixelsPerUnitY;
  58     m_targetWindow->SetVirtualSize( w ? w : wxDefaultCoord,
  59                                     h ? h : wxDefaultCoord);
  60
  61     // Query view start after m_targetWindow->SetVirtualSize(...) since
  62     // that call can change the current=old scrolling position!
  63     int xs, ys;
  64     GetViewStart(& xs, & ys);
  65     int old_x = m_xScrollPixelsPerLine * xs;
  66     int old_y = m_yScrollPixelsPerLine * ys;
  67
  68     // If the target is not the same as the window with the scrollbars,
  69     // then we need to update the scrollbars here, since they won't have
  70     // been updated by SetVirtualSize().
  71     if (m_targetWindow != m_win)
  72     {
  73         AdjustScrollbars();
  74     }
  75
  76     if (!noRefresh)
  77     {
  78         int new_x = m_xScrollPixelsPerLine * m_xScrollPosition;
  79         int new_y = m_yScrollPixelsPerLine * m_yScrollPosition;
  80
  81         m_targetWindow->ScrollWindow( old_x - new_x, old_y - new_y );
  82     }
  83 }
  84
  85 void wxScrollHelper::DoAdjustScrollbar(GtkRange* range,
  86                                        int pixelsPerLine,
  87                                        int winSize,
  88                                        int virtSize,
  89                                        int *pos,
  90                                        int *lines,
  91                                        int *linesPerPage)
  92 {
  93     int upper;
  94     int page_size;
  95     if (pixelsPerLine > 0 && winSize > 0 && winSize < virtSize)
  96     {
  97         upper = (virtSize + pixelsPerLine - 1) / pixelsPerLine;
  98         page_size = winSize / pixelsPerLine;
  99         *lines = upper;
 100         *linesPerPage = page_size;
 101     }
 102     else
 103     {
 104         // GtkRange won't allow upper == lower, so for disabled state use [0,1]
 105         //   with a page size of 1. This will also clamp position to 0.
 106         upper = 1;
 107         page_size = 1;
 108         *lines = 0;
 109         *linesPerPage = 0;
 110     }
 111
 112     GtkAdjustment* adj = range->adjustment;
 113     adj->step_increment = 1;
 114     adj->page_increment =
 115     adj->page_size = page_size;
 116     gtk_range_set_range(range, 0, upper);
 117
 118     // ensure that the scroll position is always in valid range
 119     if (*pos > *lines)
 120         *pos = *lines;
 121 }
 122
 123 void wxScrollHelper::AdjustScrollbars()
 124 {
 125     int vw, vh;
 126     m_targetWindow->GetVirtualSize(&vw, &vh);
 127
 128     int w, h;
 129     const wxSize availSize = GetSizeAvailableForScrollTarget(
 130         m_win->GetSize() - m_win->GetWindowBorderSize());
 131     if ( availSize.x >= vw && availSize.y >= vh )
 132     {
 133         w = availSize.x;
 134         h = availSize.y;
 135
 136         // we know that the scrollbars will be removed
 137         DoAdjustHScrollbar(w, vw);
 138         DoAdjustVScrollbar(h, vh);
 139
 140         return;
 141     }
 142
 143     m_targetWindow->GetClientSize(&w, NULL);
 144     DoAdjustHScrollbar(w, vw);
 145
 146     m_targetWindow->GetClientSize(NULL, &h);
 147     DoAdjustVScrollbar(h, vh);
 148
 149     const int w_old = w;
 150     m_targetWindow->GetClientSize(&w, NULL);
 151     if ( w != w_old )
 152     {
 153         // It is necessary to repeat the calculations in this case to avoid an
 154         // observed infinite series of size events, involving alternating
 155         // changes in visibility of the scrollbars.
 156         // At this point, GTK+ has already queued a resize, which will cause
 157         // AdjustScrollbars() to be called again. If the scrollbar visibility
 158         // is not correct before then, yet another resize will occur, possibly
 159         // leading to an unending series if the sizes are just right.
 160         DoAdjustHScrollbar(w, vw);
 161
 162         m_targetWindow->GetClientSize(NULL, &h);
 163         DoAdjustVScrollbar(h, vh);
 164     }
 165 }
 166
 167 void wxScrollHelper::DoScrollOneDir(int orient,
 168                                     int pos,
 169                                     int pixelsPerLine,
 170                                     int *posOld)
 171 {
 172     if ( pos != -1 && pos != *posOld && pixelsPerLine )
 173     {
 174         m_win->SetScrollPos(orient, pos);
 175         pos = m_win->GetScrollPos(orient);
 176
 177         int diff = (*posOld - pos)*pixelsPerLine;
 178         m_targetWindow->ScrollWindow(orient == wxHORIZONTAL ? diff : 0,
 179                                      orient == wxHORIZONTAL ? 0 : diff);
 180
 181         *posOld = pos;
 182     }
 183 }
 184
 185 void wxScrollHelper::DoScroll( int x_pos, int y_pos )
 186 {
 187     wxCHECK_RET( m_targetWindow != 0, _T("No target window") );
 188
 189     DoScrollOneDir(wxHORIZONTAL, x_pos, m_xScrollPixelsPerLine, &m_xScrollPosition);
 190     DoScrollOneDir(wxVERTICAL, y_pos, m_yScrollPixelsPerLine, &m_yScrollPosition);
 191 }
 192
 193 // ----------------------------------------------------------------------------
 194 // scrollbars visibility
 195 // ----------------------------------------------------------------------------
 196
 197 namespace
 198 {
 199
 200 GtkPolicyType GtkPolicyFromWX(wxScrollbarVisibility visibility)
 201 {
 202     GtkPolicyType policy;
 203     switch ( visibility )
 204     {
 205         case wxSHOW_SB_NEVER:
 206             policy = GTK_POLICY_NEVER;
 207             break;
 208
 209         case wxSHOW_SB_DEFAULT:
 210             policy = GTK_POLICY_AUTOMATIC;
 211             break;
 212
 213         case wxSHOW_SB_ALWAYS:
 214             policy = GTK_POLICY_ALWAYS;
 215             break;
 216     }
 217
 218     return policy;
 219 }
 220
 221 } // anonymous namespace
 222
 223 void wxScrollHelper::DoShowScrollbars(wxScrollbarVisibility horz,
 224                                       wxScrollbarVisibility vert)
 225 {
 226     GtkScrolledWindow * const scrolled = GTK_SCROLLED_WINDOW(m_win->m_widget);
 227     wxCHECK_RET( scrolled, "window must be created" );
 228
 229     gtk_scrolled_window_set_policy(scrolled,
 230                                    GtkPolicyFromWX(horz),
 231                                    GtkPolicyFromWX(vert));
 232 }
 233