@Override
				public void keyPressed( KeyEvent e ) {
					switch( e.getKeyCode() ) {
						case KeyEvent.VK_ESCAPE: dispose(); pick( null ); break;

						// move mouse one pixel using arrow keys
						case KeyEvent.VK_LEFT:  robot.mouseMove( lastX - 1, lastY ); break;
						case KeyEvent.VK_RIGHT: robot.mouseMove( lastX + 1, lastY ); break;
						case KeyEvent.VK_UP:    robot.mouseMove( lastX, lastY - 1 ); break;
						case KeyEvent.VK_DOWN:  robot.mouseMove( lastX, lastY + 1 ); break;
					}
				}
An invisible window used to receive mouse and keyboard events for the whole screen.
flatlaf-theme-editor/src/main/java/com/formdev/flatlaf/themeeditor/FlatColorPipette.java