if (cmd.button() == mouse_button::button1) {
LCursor & bvcur = cur.bv().cursor();
if (abs(cmd.x - first_x) + abs(cmd.y - first_y) > 4
if (cmd.button() == mouse_button::button1) {
LCursor & bvcur = cur.bv().cursor();
if (abs(cmd.x - first_x) + abs(cmd.y - first_y) > 4