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 // For compilers that support precompilation, includes "wx.h".
  14 #include "wx/wxprec.h"
  15
  16 #ifdef __BORLANDC__
  17     #pragma hdrstop
  18 #endif
  19
  20 #include "wx/scrolwin.h"
  21
  22 #include <gtk/gtk.h>
  23
  24 // ----------------------------------------------------------------------------
  25 // wxScrollHelper implementation
  26 // ----------------------------------------------------------------------------
  27
  28 void wxScrollHelper::SetScrollbars(int pixelsPerUnitX, int pixelsPerUnitY,
  29                                    int noUnitsX, int noUnitsY,
  30                                    int xPos, int yPos,
  31                                    bool noRefresh)
  32 {
  33     m_win->m_scrollBar[wxWindow::ScrollDir_Horz]->adjustment->value = xPos;
  34     m_win->m_scrollBar[wxWindow::ScrollDir_Vert]->adjustment->value = yPos;
  35     base_type::SetScrollbars(
  36         pixelsPerUnitX, pixelsPerUnitY, noUnitsX, noUnitsY, xPos, yPos, noRefresh);
  37 }
  38
  39 void wxScrollHelper::DoAdjustScrollbar(GtkRange* range,
  40                                        int pixelsPerLine,
  41                                        int winSize,
  42                                        int virtSize,
  43                                        int *pos,
  44                                        int *lines,
  45                                        int *linesPerPage)
  46 {
  47     int upper;
  48     int page_size;
  49     if (pixelsPerLine > 0 && winSize > 0 && winSize < virtSize)
  50     {
  51         upper = (virtSize + pixelsPerLine - 1) / pixelsPerLine;
  52         page_size = winSize / pixelsPerLine;
  53         *lines = upper;
  54         *linesPerPage = page_size;
  55     }
  56     else
  57     {
  58         // GtkRange won't allow upper == lower, so for disabled state use [0,1]
  59         //   with a page size of 1. This will also clamp position to 0.
  60         upper = 1;
  61         page_size = 1;
  62         *lines = 0;
  63         *linesPerPage = 0;
  64     }
  65
  66     GtkAdjustment* adj = range->adjustment;
  67     adj->step_increment = 1;
  68     adj->page_increment =
  69     adj->page_size = page_size;
  70     gtk_range_set_range(range, 0, upper);
  71
  72     // ensure that the scroll position is always in valid range
  73     if (*pos > *lines)
  74         *pos = *lines;
  75 }
  76
  77 void wxScrollHelper::AdjustScrollbars()
  78 {
  79     int vw, vh;
  80     m_targetWindow->GetVirtualSize(&vw, &vh);
  81
  82     int w, h;
  83     const wxSize availSize = GetSizeAvailableForScrollTarget(
  84         m_win->GetSize() - m_win->GetWindowBorderSize());
  85     if ( availSize.x >= vw && availSize.y >= vh )
  86     {
  87         w = availSize.x;
  88         h = availSize.y;
  89
  90         // we know that the scrollbars will be removed
  91         DoAdjustHScrollbar(w, vw);
  92         DoAdjustVScrollbar(h, vh);
  93
  94         return;
  95     }
  96
  97     m_targetWindow->GetClientSize(&w, NULL);
  98     DoAdjustHScrollbar(w, vw);
  99
 100     m_targetWindow->GetClientSize(NULL, &h);
 101     DoAdjustVScrollbar(h, vh);
 102
 103     const int w_old = w;
 104     m_targetWindow->GetClientSize(&w, NULL);
 105     if ( w != w_old )
 106     {
 107         // It is necessary to repeat the calculations in this case to avoid an
 108         // observed infinite series of size events, involving alternating
 109         // changes in visibility of the scrollbars.
 110         // At this point, GTK+ has already queued a resize, which will cause
 111         // AdjustScrollbars() to be called again. If the scrollbar visibility
 112         // is not correct before then, yet another resize will occur, possibly
 113         // leading to an unending series if the sizes are just right.
 114         DoAdjustHScrollbar(w, vw);
 115
 116         m_targetWindow->GetClientSize(NULL, &h);
 117         DoAdjustVScrollbar(h, vh);
 118     }
 119 }
 120
 121 void wxScrollHelper::DoScrollOneDir(int orient,
 122                                     int pos,
 123                                     int pixelsPerLine,
 124                                     int *posOld)
 125 {
 126     if ( pos != -1 && pos != *posOld && pixelsPerLine )
 127     {
 128         m_win->SetScrollPos(orient, pos);
 129         pos = m_win->GetScrollPos(orient);
 130
 131         int diff = (*posOld - pos)*pixelsPerLine;
 132         m_targetWindow->ScrollWindow(orient == wxHORIZONTAL ? diff : 0,
 133                                      orient == wxHORIZONTAL ? 0 : diff);
 134
 135         *posOld = pos;
 136     }
 137 }
 138
 139 void wxScrollHelper::DoScroll( int x_pos, int y_pos )
 140 {
 141     wxCHECK_RET( m_targetWindow != 0, _T("No target window") );
 142
 143     DoScrollOneDir(wxHORIZONTAL, x_pos, m_xScrollPixelsPerLine, &m_xScrollPosition);
 144     DoScrollOneDir(wxVERTICAL, y_pos, m_yScrollPixelsPerLine, &m_yScrollPosition);
 145 }
 146
 147 // ----------------------------------------------------------------------------
 148 // scrollbars visibility
 149 // ----------------------------------------------------------------------------
 150
 151 namespace
 152 {
 153
 154 GtkPolicyType GtkPolicyFromWX(wxScrollbarVisibility visibility)
 155 {
 156     GtkPolicyType policy;
 157     switch ( visibility )
 158     {
 159         case wxSHOW_SB_NEVER:
 160             policy = GTK_POLICY_NEVER;
 161             break;
 162
 163         case wxSHOW_SB_DEFAULT:
 164             policy = GTK_POLICY_AUTOMATIC;
 165             break;
 166
 167         default:
 168             wxFAIL_MSG( wxS("unknown scrollbar visibility") );
 169             // fall through
 170
 171         case wxSHOW_SB_ALWAYS:
 172             policy = GTK_POLICY_ALWAYS;
 173             break;
 174     }
 175
 176     return policy;
 177 }
 178
 179 } // anonymous namespace
 180
 181 void wxScrollHelper::DoShowScrollbars(wxScrollbarVisibility horz,
 182                                       wxScrollbarVisibility vert)
 183 {
 184     GtkScrolledWindow * const scrolled = GTK_SCROLLED_WINDOW(m_win->m_widget);
 185     wxCHECK_RET( scrolled, "window must be created" );
 186
 187     gtk_scrolled_window_set_policy(scrolled,
 188                                    GtkPolicyFromWX(horz),
 189                                    GtkPolicyFromWX(vert));
 190 }