Key press event not working in date picker

Question

I need key press event for date picker in Java Swing. I had tried this, but it is not working.

if (evt.getKeyCode()==evt.VK_ENTER)
{
   txttotal.requestFocus();
}

Answer 1

You can find inner components by using popup in the base UI same as this code. But you must find components by name instead of constant indexes.

public class MainClass {
    public static void main(String [] args) {
        JFrame jFrame=new JFrame();
        jFrame.setLayout(null);
        jFrame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
        jFrame.setBounds(10,10,500,500);
        JInternalFrame frame=new JInternalFrame("test",false,true,false,true);
        frame.setLayout(null);
        frame.setBounds(100, 100, 200, 200);
        frame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);

        frame.setVisible(true);
        DatePicker datePicker=new DatePicker() {

        };

        datePicker.setBounds(10,10,100,20);
        frame.add(datePicker);
        jFrame.add(frame);
        jFrame.setVisible(true);

        datePicker.showPopup();
        datePicker.hidePopup();
        BasicDatePickerUI datePickerUI= (BasicDatePickerUI )datePicker.getUI();
        datePicker.getComponent(1).addKeyListener(new KeyListener() {
            @Override
            public void keyTyped(KeyEvent e) {
                if(e.getKeyCode()==e.VK_ENTER) {
                    System.out.println("TYPE OK ON BUTTON!");
                }
            }

            @Override
            public void keyPressed(KeyEvent e) {
                if(e.getKeyCode()==e.VK_ENTER) {
                    System.out.println("PRESS OK ON BUTTON!");
                }
            }

            @Override
            public void keyReleased(KeyEvent e) {
                if(e.getKeyCode()==e.VK_ENTER) {
                    System.out.println("RELEASE OK ON BUTTON!");
                }
            }
        });

        datePicker.getComponent(0).addKeyListener(new KeyListener() {
            @Override
            public void keyTyped(KeyEvent e) {
                if(e.getKeyCode()==e.VK_ENTER) {
                    System.out.println("TYPE OK ON TEXT!");
                }
            }

            @Override
            public void keyPressed(KeyEvent e) {
                if(e.getKeyCode()==e.VK_ENTER) {
                    System.out.println("PRESS OK ON TEXT!");
                }
            }

            @Override
            public void keyReleased(KeyEvent e) {
                if(e.getKeyCode()==e.VK_ENTER) {
                    System.out.println("RELEASE OK ON TEXT!");
                }
            }
        });
        try {
            Field field=BasicDatePickerUI.class.getDeclaredField("popup");
            field.setAccessible(true);
            JPopupMenu popup=(JPopupMenu)field.get(datePickerUI);
            ((JComponent) ((JComponent) popup.getComponent(0)).getComponent(2)).addKeyListener(new KeyListener() {
                @Override
                public void keyTyped(KeyEvent e) {
                    if(e.getKeyCode()==e.VK_ENTER) {
                        System.out.println("TYPE OK ON POPUP!");
                    }

                }

                @Override
                public void keyPressed(KeyEvent e) {
                    if(e.getKeyCode()==e.VK_ENTER) {
                        System.out.println("PRESS OK ON POPUP!");
                    }

                }

                @Override
                public void keyReleased(KeyEvent e) {
                    if(e.getKeyCode()==e.VK_ENTER) {
                        System.out.println("RELEASE OK ON POPUP!");
                    }

                }
            });
            System.out.println("wait for ENTER key...");
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }

    }

}

You can see PRESS OK ON POPUP and PRESS OK ON TEXT in the console output if you press ENTER key on DatePicker Text or Popup.