+static bool wxScrollAdjust(GtkAdjustment* adj, double change)
+{
+ double value_start = adj->value;
+ double value = value_start + change;
+ double upper = adj->upper - adj->page_size;
+ if (value > upper)
+ {
+ value = upper;
+ }
+ // Lower bound will be checked by gtk_adjustment_set_value
+ gtk_adjustment_set_value(adj, value);
+ return adj->value != value_start;
+}
+
+bool wxWindowGTK::ScrollLines(int lines)
+{
+ return
+ m_vAdjust != NULL &&
+ wxScrollAdjust(m_vAdjust, lines * m_vAdjust->step_increment);
+}
+
+bool wxWindowGTK::ScrollPages(int pages)
+{
+ return
+ m_vAdjust != NULL &&
+ wxScrollAdjust(m_vAdjust, pages * m_vAdjust->page_increment);
+}
+
+void wxWindowGTK::SetVScrollAdjustment(GtkAdjustment* adj)
+{
+ wxASSERT(m_vAdjust == NULL);
+ m_vAdjust = adj;
+}