/* scroll a bar in a given direction */
static void
scroll (GtkAdjustment* bar, GArray *argv) {
- gdouble amount;
gchar *end;
+ gdouble max_value;
- amount = g_ascii_strtod(g_array_index(argv, gchar*, 0), &end);
- if (*end == '%') amount = gtk_adjustment_get_page_size(bar) * amount * 0.01;
- gtk_adjustment_set_value (bar, gtk_adjustment_get_value(bar)+amount);
+ gdouble page_size = gtk_adjustment_get_page_size(bar);
+ gdouble value = gtk_adjustment_get_value(bar);
+ gdouble amount = g_ascii_strtod(g_array_index(argv, gchar*, 0), &end);
+
+ if (*end == '%')
+ value += page_size * amount * 0.01;
+ else
+ value += amount;
+
+ max_value = gtk_adjustment_get_upper(bar) - page_size;
+
+ if (value > max_value)
+ value = max_value; /* don't scroll past the end of the page */
+
+ gtk_adjustment_set_value (bar, value);
}
static void