+ }
+ else if (keycode == left_code)
+ {
+ shift = PAN * (x_max - x_min);
+ x_min += shift;
+ x_max += shift;
+ }
+ else if (keycode == right_code)
+ {
+ shift = PAN * (x_max - x_min);
+ x_min -= shift;
+ x_max -= shift;
+ }
+ else if (keycode == plus_code ||
+ keycode == equal_code)
+ {
+ shift = ZOOM * (x_max - x_min);
+ x_min += shift;
+ x_max -= shift;
+ }
+ else if (keycode == minus_code)
+ {
+ shift = (1- 2*ZOOM) * (x_max - x_min);
+ x_min -= shift;
+ x_max += shift;
+ }
+ else if (keycode == home_code)
+ {
+ acre_get_x_axis_data_range (acre, &x_min, &x_max);
+ }
+ need_redraw = 1;
+ break;