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_scrollPos[wxWindow::ScrollDir_Horz] =
  34     m_win->m_scrollBar[wxWindow::ScrollDir_Horz]->adjustment->value = xPos;
  35     m_win->m_scrollPos[wxWindow::ScrollDir_Vert] =
  36     m_win->m_scrollBar[wxWindow::ScrollDir_Vert]->adjustment->value = yPos;
  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     GtkAdjustment* adj = range->adjustment;
  72     adj->step_increment = 1;
  73     adj->page_increment =
  74     adj->page_size = page_size;
  75     gtk_range_set_range(range, 0, upper);
  76
  77     // ensure that the scroll position is always in valid range
  78     if (*pos > *lines)
  79         *pos = *lines;
  80 }
  81
  82 void wxScrollHelper::AdjustScrollbars()
  83 {
  84     int vw, vh;
  85     m_targetWindow->GetVirtualSize(&vw, &vh);
  86
  87     int w, h;
  88     const wxSize availSize = GetSizeAvailableForScrollTarget(
  89         m_win->GetSize() - m_win->GetWindowBorderSize());
  90     if ( availSize.x >= vw && availSize.y >= vh )
  91     {
  92         w = availSize.x;
  93         h = availSize.y;
  94
  95         // we know that the scrollbars will be removed
  96         DoAdjustHScrollbar(w, vw);
  97         DoAdjustVScrollbar(h, vh);
  98
  99         return;
 100     }
 101
 102     m_targetWindow->GetClientSize(&w, NULL);
 103     DoAdjustHScrollbar(w, vw);
 104
 105     m_targetWindow->GetClientSize(NULL, &h);
 106     DoAdjustVScrollbar(h, vh);
 107
 108     const int w_old = w;
 109     m_targetWindow->GetClientSize(&w, NULL);
 110     if ( w != w_old )
 111     {
 112         // It is necessary to repeat the calculations in this case to avoid an
 113         // observed infinite series of size events, involving alternating
 114         // changes in visibility of the scrollbars.
 115         // At this point, GTK+ has already queued a resize, which will cause
 116         // AdjustScrollbars() to be called again. If the scrollbar visibility
 117         // is not correct before then, yet another resize will occur, possibly
 118         // leading to an unending series if the sizes are just right.
 119         DoAdjustHScrollbar(w, vw);
 120
 121         m_targetWindow->GetClientSize(NULL, &h);
 122         DoAdjustVScrollbar(h, vh);
 123     }
 124 }
 125
 126 void wxScrollHelper::DoScrollOneDir(int orient,
 127                                     int pos,
 128                                     int pixelsPerLine,
 129                                     int *posOld)
 130 {
 131     if ( pos != -1 && pos != *posOld && pixelsPerLine )
 132     {
 133         m_win->SetScrollPos(orient, pos);
 134         pos = m_win->GetScrollPos(orient);
 135
 136         int diff = (*posOld - pos)*pixelsPerLine;
 137         m_targetWindow->ScrollWindow(orient == wxHORIZONTAL ? diff : 0,
 138                                      orient == wxHORIZONTAL ? 0 : diff);
 139
 140         *posOld = pos;
 141     }
 142 }
 143
 144 void wxScrollHelper::DoScroll( int x_pos, int y_pos )
 145 {
 146     wxCHECK_RET( m_targetWindow != 0, wxT("No target window") );
 147
 148     DoScrollOneDir(wxHORIZONTAL, x_pos, m_xScrollPixelsPerLine, &m_xScrollPosition);
 149     DoScrollOneDir(wxVERTICAL, y_pos, m_yScrollPixelsPerLine, &m_yScrollPosition);
 150 }
 151
 152 // ----------------------------------------------------------------------------
 153 // scrollbars visibility
 154 // ----------------------------------------------------------------------------
 155
 156 namespace
 157 {
 158
 159 GtkPolicyType GtkPolicyFromWX(wxScrollbarVisibility visibility)
 160 {
 161     GtkPolicyType policy;
 162     switch ( visibility )
 163     {
 164         case wxSHOW_SB_NEVER:
 165             policy = GTK_POLICY_NEVER;
 166             break;
 167
 168         case wxSHOW_SB_DEFAULT:
 169             policy = GTK_POLICY_AUTOMATIC;
 170             break;
 171
 172         default:
 173             wxFAIL_MSG( wxS("unknown scrollbar visibility") );
 174             // fall through
 175
 176         case wxSHOW_SB_ALWAYS:
 177             policy = GTK_POLICY_ALWAYS;
 178             break;
 179     }
 180
 181     return policy;
 182 }
 183
 184 } // anonymous namespace
 185
 186 void wxScrollHelper::DoShowScrollbars(wxScrollbarVisibility horz,
 187                                       wxScrollbarVisibility vert)
 188 {
 189     GtkScrolledWindow * const scrolled = GTK_SCROLLED_WINDOW(m_win->m_widget);
 190     wxCHECK_RET( scrolled, "window must be created" );
 191
 192     gtk_scrolled_window_set_policy(scrolled,
 193                                    GtkPolicyFromWX(horz),
 194                                    GtkPolicyFromWX(vert));
 195 }