src/gtk/scrolwin.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/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 #include "wx/gtk/private/gtk2-compat.h"
  24
  25 // ----------------------------------------------------------------------------
  26 // wxScrollHelper implementation
  27 // ----------------------------------------------------------------------------
  28
  29 void wxScrollHelper::SetScrollbars(int pixelsPerUnitX, int pixelsPerUnitY,
  30                                    int noUnitsX, int noUnitsY,
  31                                    int xPos, int yPos,
  32                                    bool noRefresh)
  33 {
  34     // prevent programmatic position changes from causing scroll events
  35     m_win->SetScrollPos(wxHORIZONTAL, xPos);
  36     m_win->SetScrollPos(wxVERTICAL, yPos);
  37
  38     base_type::SetScrollbars(
  39         pixelsPerUnitX, pixelsPerUnitY, noUnitsX, noUnitsY, xPos, yPos, noRefresh);
  40 }
  41
  42 void wxScrollHelper::DoAdjustScrollbar(GtkRange* range,
  43                                        int pixelsPerLine,
  44                                        int winSize,
  45                                        int virtSize,
  46                                        int *pos,
  47                                        int *lines,
  48                                        int *linesPerPage)
  49 {
  50     if (!range)
  51         return;
  52
  53     int upper;
  54     int page_size;
  55     if (pixelsPerLine > 0 && winSize > 0 && winSize < virtSize)
  56     {
  57         upper = (virtSize + pixelsPerLine - 1) / pixelsPerLine;
  58         page_size = winSize / pixelsPerLine;
  59         *lines = upper;
  60         *linesPerPage = page_size;
  61     }
  62     else
  63     {
  64         // GtkRange won't allow upper == lower, so for disabled state use [0,1]
  65         //   with a page size of 1. This will also clamp position to 0.
  66         upper = 1;
  67         page_size = 1;
  68         *lines = 0;
  69         *linesPerPage = 0;
  70     }
  71
  72     gtk_range_set_increments(range, 1, page_size);
  73     gtk_adjustment_set_page_size(gtk_range_get_adjustment(range), page_size);
  74     gtk_range_set_range(range, 0, upper);
  75
  76     // ensure that the scroll position is always in valid range
  77     if (*pos > *lines)
  78         *pos = *lines;
  79 }
  80
  81 void wxScrollHelper::AdjustScrollbars()
  82 {
  83     int vw, vh;
  84     m_targetWindow->GetVirtualSize(&vw, &vh);
  85
  86     int w, h;
  87     const wxSize availSize = GetSizeAvailableForScrollTarget(
  88         m_win->GetSize() - m_win->GetWindowBorderSize());
  89     if ( availSize.x >= vw && availSize.y >= vh )
  90     {
  91         w = availSize.x;
  92         h = availSize.y;
  93
  94         // we know that the scrollbars will be removed
  95         DoAdjustHScrollbar(w, vw);
  96         DoAdjustVScrollbar(h, vh);
  97
  98         return;
  99     }
 100
 101     m_targetWindow->GetClientSize(&w, NULL);
 102     DoAdjustHScrollbar(w, vw);
 103
 104     m_targetWindow->GetClientSize(NULL, &h);
 105     DoAdjustVScrollbar(h, vh);
 106
 107     const int w_old = w;
 108     m_targetWindow->GetClientSize(&w, NULL);
 109     if ( w != w_old )
 110     {
 111         // It is necessary to repeat the calculations in this case to avoid an
 112         // observed infinite series of size events, involving alternating
 113         // changes in visibility of the scrollbars.
 114         // At this point, GTK+ has already queued a resize, which will cause
 115         // AdjustScrollbars() to be called again. If the scrollbar visibility
 116         // is not correct before then, yet another resize will occur, possibly
 117         // leading to an unending series if the sizes are just right.
 118         DoAdjustHScrollbar(w, vw);
 119
 120         m_targetWindow->GetClientSize(NULL, &h);
 121         DoAdjustVScrollbar(h, vh);
 122     }
 123 }
 124
 125 void wxScrollHelper::DoScrollOneDir(int orient,
 126                                     int pos,
 127                                     int pixelsPerLine,
 128                                     int *posOld)
 129 {
 130     if ( pos != -1 && pos != *posOld && pixelsPerLine )
 131     {
 132         m_win->SetScrollPos(orient, pos);
 133         pos = m_win->GetScrollPos(orient);
 134
 135         int diff = (*posOld - pos)*pixelsPerLine;
 136         m_targetWindow->ScrollWindow(orient == wxHORIZONTAL ? diff : 0,
 137                                      orient == wxHORIZONTAL ? 0 : diff);
 138
 139         *posOld = pos;
 140     }
 141 }
 142
 143 void wxScrollHelper::DoScroll( int x_pos, int y_pos )
 144 {
 145     wxCHECK_RET( m_targetWindow != 0, wxT("No target window") );
 146
 147     DoScrollOneDir(wxHORIZONTAL, x_pos, m_xScrollPixelsPerLine, &m_xScrollPosition);
 148     DoScrollOneDir(wxVERTICAL, y_pos, m_yScrollPixelsPerLine, &m_yScrollPosition);
 149 }
 150
 151 // ----------------------------------------------------------------------------
 152 // scrollbars visibility
 153 // ----------------------------------------------------------------------------
 154
 155 namespace
 156 {
 157
 158 GtkPolicyType GtkPolicyFromWX(wxScrollbarVisibility visibility)
 159 {
 160     GtkPolicyType policy;
 161     switch ( visibility )
 162     {
 163         case wxSHOW_SB_NEVER:
 164             policy = GTK_POLICY_NEVER;
 165             break;
 166
 167         case wxSHOW_SB_DEFAULT:
 168             policy = GTK_POLICY_AUTOMATIC;
 169             break;
 170
 171         default:
 172             wxFAIL_MSG( wxS("unknown scrollbar visibility") );
 173             // fall through
 174
 175         case wxSHOW_SB_ALWAYS:
 176             policy = GTK_POLICY_ALWAYS;
 177             break;
 178     }
 179
 180     return policy;
 181 }
 182
 183 } // anonymous namespace
 184
 185 void wxScrollHelper::DoShowScrollbars(wxScrollbarVisibility horz,
 186                                       wxScrollbarVisibility vert)
 187 {
 188     GtkScrolledWindow * const scrolled = GTK_SCROLLED_WINDOW(m_win->m_widget);
 189     wxCHECK_RET( scrolled, "window must be created" );
 190
 191     gtk_scrolled_window_set_policy(scrolled,
 192                                    GtkPolicyFromWX(horz),
 193                                    GtkPolicyFromWX(vert));
 194 }