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     int w = noUnitsX * pixelsPerUnitX;
  53     int h = noUnitsY * pixelsPerUnitY;
  54     m_targetWindow->SetVirtualSize( w ? w : wxDefaultCoord,
  55                                     h ? h : wxDefaultCoord);
  56
  57     // Query view start after m_targetWindow->SetVirtualSize(...) since
  58     // that call can change the current=old scrolling position!
  59     int xs, ys;
  60     GetViewStart(& xs, & ys);
  61     int old_x = m_xScrollPixelsPerLine * xs;
  62     int old_y = m_yScrollPixelsPerLine * ys;
  63
  64     // If the target is not the same as the window with the scrollbars,
  65     // then we need to update the scrollbars here, since they won't have
  66     // been updated by SetVirtualSize().
  67     if (m_targetWindow != m_win)
  68     {
  69         AdjustScrollbars();
  70     }
  71
  72     if (!noRefresh)
  73     {
  74         int new_x = m_xScrollPixelsPerLine * m_xScrollPosition;
  75         int new_y = m_yScrollPixelsPerLine * m_yScrollPosition;
  76
  77         m_targetWindow->ScrollWindow( old_x - new_x, old_y - new_y );
  78     }
  79 }
  80
  81 void wxScrollHelper::DoAdjustScrollbar(GtkRange* range,
  82                                        int pixelsPerLine,
  83                                        int winSize,
  84                                        int virtSize,
  85                                        int *pos,
  86                                        int *lines,
  87                                        int *linesPerPage)
  88 {
  89     int upper;
  90     int page_size;
  91     if (pixelsPerLine > 0 && winSize > 0 && winSize < virtSize)
  92     {
  93         upper = (virtSize + pixelsPerLine - 1) / pixelsPerLine;
  94         page_size = winSize / pixelsPerLine;
  95         *lines = upper;
  96         *linesPerPage = page_size;
  97     }
  98     else
  99     {
 100         // GtkRange won't allow upper == lower, so for disabled state use [0,1]
 101         //   with a page size of 1. This will also clamp position to 0.
 102         upper = 1;
 103         page_size = 1;
 104         *lines = 0;
 105         *linesPerPage = 0;
 106     }
 107
 108     GtkAdjustment* adj = range->adjustment;
 109     adj->step_increment = 1;
 110     adj->page_increment =
 111     adj->page_size = page_size;
 112     gtk_range_set_range(range, 0, upper);
 113
 114     // ensure that the scroll position is always in valid range
 115     if (*pos > *lines)
 116         *pos = *lines;
 117 }
 118
 119 void wxScrollHelper::AdjustScrollbars()
 120 {
 121     int vw, vh;
 122     m_targetWindow->GetVirtualSize(&vw, &vh);
 123
 124     int w, h;
 125     const wxSize availSize = GetSizeAvailableForScrollTarget(
 126         m_win->GetSize() - m_win->GetWindowBorderSize());
 127     if ( availSize.x >= vw && availSize.y >= vh )
 128     {
 129         w = availSize.x;
 130         h = availSize.y;
 131
 132         // we know that the scrollbars will be removed
 133         DoAdjustHScrollbar(w, vw);
 134         DoAdjustVScrollbar(h, vh);
 135
 136         return;
 137     }
 138
 139     m_targetWindow->GetClientSize(&w, NULL);
 140     DoAdjustHScrollbar(w, vw);
 141
 142     m_targetWindow->GetClientSize(NULL, &h);
 143     DoAdjustVScrollbar(h, vh);
 144
 145     const int w_old = w;
 146     m_targetWindow->GetClientSize(&w, NULL);
 147     if ( w != w_old )
 148     {
 149         // It is necessary to repeat the calculations in this case to avoid an
 150         // observed infinite series of size events, involving alternating
 151         // changes in visibility of the scrollbars.
 152         // At this point, GTK+ has already queued a resize, which will cause
 153         // AdjustScrollbars() to be called again. If the scrollbar visibility
 154         // is not correct before then, yet another resize will occur, possibly
 155         // leading to an unending series if the sizes are just right.
 156         DoAdjustHScrollbar(w, vw);
 157
 158         m_targetWindow->GetClientSize(NULL, &h);
 159         DoAdjustVScrollbar(h, vh);
 160     }
 161 }
 162
 163 void wxScrollHelper::DoScrollOneDir(int orient,
 164                                     int pos,
 165                                     int pixelsPerLine,
 166                                     int *posOld)
 167 {
 168     if ( pos != -1 && pos != *posOld && pixelsPerLine )
 169     {
 170         m_win->SetScrollPos(orient, pos);
 171         pos = m_win->GetScrollPos(orient);
 172
 173         int diff = (*posOld - pos)*pixelsPerLine;
 174         m_targetWindow->ScrollWindow(orient == wxHORIZONTAL ? diff : 0,
 175                                      orient == wxHORIZONTAL ? 0 : diff);
 176
 177         *posOld = pos;
 178     }
 179 }
 180
 181 void wxScrollHelper::DoScroll( int x_pos, int y_pos )
 182 {
 183     wxCHECK_RET( m_targetWindow != 0, _T("No target window") );
 184
 185     DoScrollOneDir(wxHORIZONTAL, x_pos, m_xScrollPixelsPerLine, &m_xScrollPosition);
 186     DoScrollOneDir(wxVERTICAL, y_pos, m_yScrollPixelsPerLine, &m_yScrollPosition);
 187 }
 188
 189 // ----------------------------------------------------------------------------
 190 // scrollbars visibility
 191 // ----------------------------------------------------------------------------
 192
 193 namespace
 194 {
 195
 196 GtkPolicyType GtkPolicyFromWX(wxScrollbarVisibility visibility)
 197 {
 198     GtkPolicyType policy;
 199     switch ( visibility )
 200     {
 201         case wxSHOW_SB_NEVER:
 202             policy = GTK_POLICY_NEVER;
 203             break;
 204
 205         case wxSHOW_SB_DEFAULT:
 206             policy = GTK_POLICY_AUTOMATIC;
 207             break;
 208
 209         case wxSHOW_SB_ALWAYS:
 210             policy = GTK_POLICY_ALWAYS;
 211             break;
 212     }
 213
 214     return policy;
 215 }
 216
 217 } // anonymous namespace
 218
 219 void wxScrollHelper::DoShowScrollbars(wxScrollbarVisibility horz,
 220                                       wxScrollbarVisibility vert)
 221 {
 222     GtkScrolledWindow * const scrolled = GTK_SCROLLED_WINDOW(m_win->m_widget);
 223     wxCHECK_RET( scrolled, "window must be created" );
 224
 225     gtk_scrolled_window_set_policy(scrolled,
 226                                    GtkPolicyFromWX(horz),
 227                                    GtkPolicyFromWX(vert));
 228 }
 229