+
+// ----------------------------------------------------------------------------
+// scrolling
+// ----------------------------------------------------------------------------
+
+GtkAdjustment *wxTextCtrl::GetVAdj() const
+{
+ return HasFlag(wxTE_MULTILINE) ? GTK_TEXT(m_text)->vadj : NULL;
+}
+
+bool wxTextCtrl::DoScroll(GtkAdjustment *adj, int diff)
+{
+ float value = adj->value + diff;
+
+ if ( value < 0 )
+ value = 0;
+
+ float upper = adj->upper - adj->page_size;
+ if ( value > upper )
+ value = upper;
+
+ // did we noticeably change the scroll position?
+ if ( fabs(adj->value - value) < 0.2 )
+ {
+ // well, this is what Robert does in wxScrollBar, so it must be good...
+ return FALSE;
+ }
+
+ adj->value = value;
+
+ gtk_signal_emit_by_name(GTK_OBJECT(adj), "value_changed");
+
+ return TRUE;
+}
+
+bool wxTextCtrl::ScrollLines(int lines)
+{
+ GtkAdjustment *adj = GetVAdj();
+ if ( !adj )
+ return FALSE;
+
+ // this is hardcoded to 10 in GTK+ 1.2 (great idea)
+ static const int KEY_SCROLL_PIXELS = 10;
+
+ return DoScroll(adj, lines*KEY_SCROLL_PIXELS);
+}
+
+bool wxTextCtrl::ScrollPages(int pages)
+{
+ GtkAdjustment *adj = GetVAdj();
+ if ( !adj )
+ return FALSE;
+
+ return DoScroll(adj, (int)ceil(pages*adj->page_increment));
+}
+