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 // Copyright:   (c) Robert Roebling
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // For compilers that support precompilation, includes "wx.h".
  13 #include "wx/wxprec.h"
  14
  15 #ifdef __BORLANDC__
  16     #pragma hdrstop
  17 #endif
  18
  19 #include "wx/scrolwin.h"
  20
  21 #include <gtk/gtk.h>
  22 #include "wx/gtk/private/gtk2-compat.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     // prevent programmatic position changes from causing scroll events
  34     m_win->SetScrollPos(wxHORIZONTAL, xPos);
  35     m_win->SetScrollPos(wxVERTICAL, yPos);
  36
  37     base_type::SetScrollbars(
  38         pixelsPerUnitX, pixelsPerUnitY, noUnitsX, noUnitsY, xPos, yPos, noRefresh);
  39 }
  40
  41 void wxScrollHelper::DoAdjustScrollbar(GtkRange* range,
  42                                        int pixelsPerLine,
  43                                        int winSize,
  44                                        int virtSize,
  45                                        int *pos,
  46                                        int *lines,
  47                                        int *linesPerPage)
  48 {
  49     if (!range)
  50         return;
  51
  52     int upper;
  53     int page_size;
  54     if (pixelsPerLine > 0 && winSize > 0 && winSize < virtSize)
  55     {
  56         upper = (virtSize + pixelsPerLine - 1) / pixelsPerLine;
  57         page_size = winSize / pixelsPerLine;
  58         *lines = upper;
  59         *linesPerPage = page_size;
  60     }
  61     else
  62     {
  63         // GtkRange won't allow upper == lower, so for disabled state use [0,1]
  64         //   with a page size of 1. This will also clamp position to 0.
  65         upper = 1;
  66         page_size = 1;
  67         *lines = 0;
  68         *linesPerPage = 0;
  69     }
  70
  71     gtk_range_set_increments(range, 1, page_size);
  72     gtk_adjustment_set_page_size(gtk_range_get_adjustment(range), page_size);
  73     gtk_range_set_range(range, 0, upper);
  74
  75     // ensure that the scroll position is always in valid range
  76     if (*pos > *lines)
  77         *pos = *lines;
  78 }
  79
  80 void wxScrollHelper::AdjustScrollbars()
  81 {
  82     int vw, vh;
  83     m_targetWindow->GetVirtualSize(&vw, &vh);
  84
  85     int w, h;
  86     const wxSize availSize = GetSizeAvailableForScrollTarget(
  87         m_win->GetSize() - m_win->GetWindowBorderSize());
  88     if ( availSize.x >= vw && availSize.y >= vh )
  89     {
  90         w = availSize.x;
  91         h = availSize.y;
  92
  93         // we know that the scrollbars will be removed
  94         DoAdjustHScrollbar(w, vw);
  95         DoAdjustVScrollbar(h, vh);
  96
  97         return;
  98     }
  99
 100     m_targetWindow->GetClientSize(&w, NULL);
 101     DoAdjustHScrollbar(w, vw);
 102
 103     m_targetWindow->GetClientSize(NULL, &h);
 104     DoAdjustVScrollbar(h, vh);
 105
 106     const int w_old = w;
 107     m_targetWindow->GetClientSize(&w, NULL);
 108     if ( w != w_old )
 109     {
 110         // It is necessary to repeat the calculations in this case to avoid an
 111         // observed infinite series of size events, involving alternating
 112         // changes in visibility of the scrollbars.
 113         // At this point, GTK+ has already queued a resize, which will cause
 114         // AdjustScrollbars() to be called again. If the scrollbar visibility
 115         // is not correct before then, yet another resize will occur, possibly
 116         // leading to an unending series if the sizes are just right.
 117         DoAdjustHScrollbar(w, vw);
 118
 119         m_targetWindow->GetClientSize(NULL, &h);
 120         DoAdjustVScrollbar(h, vh);
 121     }
 122 }
 123
 124 void wxScrollHelper::DoScrollOneDir(int orient,
 125                                     int pos,
 126                                     int pixelsPerLine,
 127                                     int *posOld)
 128 {
 129     if ( pos != -1 && pos != *posOld && pixelsPerLine )
 130     {
 131         m_win->SetScrollPos(orient, pos);
 132         pos = m_win->GetScrollPos(orient);
 133
 134         int diff = (*posOld - pos)*pixelsPerLine;
 135         m_targetWindow->ScrollWindow(orient == wxHORIZONTAL ? diff : 0,
 136                                      orient == wxHORIZONTAL ? 0 : diff);
 137
 138         *posOld = pos;
 139     }
 140 }
 141
 142 void wxScrollHelper::DoScroll( int x_pos, int y_pos )
 143 {
 144     wxCHECK_RET( m_targetWindow != 0, wxT("No target window") );
 145
 146     DoScrollOneDir(wxHORIZONTAL, x_pos, m_xScrollPixelsPerLine, &m_xScrollPosition);
 147     DoScrollOneDir(wxVERTICAL, y_pos, m_yScrollPixelsPerLine, &m_yScrollPosition);
 148 }
 149
 150 // ----------------------------------------------------------------------------
 151 // scrollbars visibility
 152 // ----------------------------------------------------------------------------
 153
 154 namespace
 155 {
 156
 157 GtkPolicyType GtkPolicyFromWX(wxScrollbarVisibility visibility)
 158 {
 159     GtkPolicyType policy;
 160     switch ( visibility )
 161     {
 162         case wxSHOW_SB_NEVER:
 163             policy = GTK_POLICY_NEVER;
 164             break;
 165
 166         case wxSHOW_SB_DEFAULT:
 167             policy = GTK_POLICY_AUTOMATIC;
 168             break;
 169
 170         default:
 171             wxFAIL_MSG( wxS("unknown scrollbar visibility") );
 172             // fall through
 173
 174         case wxSHOW_SB_ALWAYS:
 175             policy = GTK_POLICY_ALWAYS;
 176             break;
 177     }
 178
 179     return policy;
 180 }
 181
 182 } // anonymous namespace
 183
 184 void wxScrollHelper::DoShowScrollbars(wxScrollbarVisibility horz,
 185                                       wxScrollbarVisibility vert)
 186 {
 187     GtkScrolledWindow * const scrolled = GTK_SCROLLED_WINDOW(m_win->m_widget);
 188     wxCHECK_RET( scrolled, "window must be created" );
 189
 190     gtk_scrolled_window_set_policy(scrolled,
 191                                    GtkPolicyFromWX(horz),
 192                                    GtkPolicyFromWX(vert));
 193 }