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How Do I Get Rid Of All These Silly, Unnecessary Implementation Methods? [duplicate]

This question already has answers here:
How do I simplify MouseListener so that I don't have all these unused methods?
(2 answers)
Closed 4 years ago.
So I am making a class that is really simple. All it does is say when the mouse is clicked. So naturally I only want the mouseClicked override function. However, the IDE says I need to implement all of the methods. How do I make it so I don't need to implement all these silly, unnecessary methods?
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JFrame;
public class ME extends JFrame implements MouseListener{
public ME() {
this.setVisible(true);
this.setSize(100, 100);
// TODO Auto-generated constructor stub
}
public static void main(String[] args) {
ME Me = new ME();
Me.addMouseListener(Me);
}
#Override
public void mouseClicked(MouseEvent e) {
System.out.println(e);
}
#Override
public void mouseEntered(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseExited(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mousePressed(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseReleased(MouseEvent e) {
// TODO Auto-generated method stub
}
}

Implementing an interface is a promise to override the methods inside it.
You can't really get away with just implementing one, although you can refrain from completing the body of the method (however this is bad practice).

Java why is the key listener not working?

I do not know why this doesn't work. I have already read many posts, and added setFocusable but it just does not work.
public class Spiel {
public static void main(String[] args) {
Playground pg = new Playground();
pg.setLocation(0,0);
pg.setSize(1000,1000);
pg.setVisible(true);
pg.setFocusable(true);
}
}
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
public class Playground extends JFrame implements KeyListener {
Playground(){
}
#Override
public void keyTyped(KeyEvent e) {
System.exit(0);
}
#Override
public void keyPressed(KeyEvent e) {
System.exit(0);
}
#Override
public void keyReleased(KeyEvent e) {
// TODO Auto-generated method stub
}
}

You only implemented the KeyListener but if you want it to actually work you still need to register it to your frame.
Playground(){
addKeyListener(this); // should do the trick
}
Otherwise your frame wouldn't know that it actually has to listen and call the methods when a key is pressed.

KeyListener won't do anything

I'm trying to add a keylistener to JFrame but whenever I click a button, nothing happens. I am trying to get the keylistener to just print something basic but whenever i try to use an if statement nothing happens in the console.
package gui;
import java.awt.event.KeyEvent;
import java.util.ArrayList;
import javax.swing.*;
import javax.swing.JButton;
public class KeyListener implements java.awt.event.KeyListener {
ArrayList <JButton> _buttons;
JFrame _frame1;
public KeyListener(ArrayList <JButton> buttons, JFrame frame1){
_buttons = buttons;
_frame1 = frame1;
_frame1.addKeyListener(this);
_frame1.requestFocusInWindow();
_frame1.setFocusable(true);
this.keyTyped();
}
#Override
public void keyTyped(KeyEvent e) {
// TODO Auto-generated method stub
if (e.getKeyCode() == KeyEvent.VK_LEFT){
System.out.println("yes");
}
}
#Override
public void keyPressed(KeyEvent e) {
// TODO Auto-generated method stub
}
#Override
public void keyReleased(KeyEvent e) {
// TODO Auto-generated method stub
}
}
That is my keylistener class
This is my game class
package model;
import java.awt.event.KeyListener;
import javax.swing.*;
public class Game implements Runnable{
KeyListener _keylistener;
#Override
public void run() {
JFrame frame1 = new JFrame("KeyBricks");
frame1.setVisible(true);
JPanel panel1 = new JPanel();
frame1.addKeyListener(_keylistener);
model.Board board = new model.Board(panel1);
frame1.add(panel1);
frame1.pack();
frame1.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
}
}

You could register a KeyEventDispatcher:
KeyboardFocusManager.getCurrentKeyboardFocusManager().addKeyEventDispatcher(new KeyEventDispatcher() {
#Override
public boolean dispatchKeyEvent(KeyEvent e) {
System.out.println("dispatchKeyEvent: "+e);
return false;
}
});
Note that the registered KeyEventDispatchers will receive KeyEvents before they are dispatched to their targets, allowing to retarget the event, consume it, dispatch the event itself, or make other changes.

Simple KeyListener not working

I'm working on a really simple project in Java to try to understand how to use KeyListener.
I've created a Main class and a KeyListener, MouseListener class. I want to get something to happen when I press a keyboard key. So far the only thing that is working is "Hello" when I click.
Here is my code:
import javax.swing.JFrame;
import javax.swing.JPanel;
public class KeyPractice{
public static void main(String[] args) {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
panel.addKeyListener(new KeyEar());
panel.addMouseListener(new KeyEar());
frame.add(panel);
frame.setVisible(true);
frame.setSize(400, 400);
}
}
And the Keylistener class....
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
public class KeyEar implements KeyListener, MouseListener {
public KeyEar(){
}
#Override
public void mouseClicked(MouseEvent arg0) {
System.out.println("Hello");
}
#Override
public void mouseEntered(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseExited(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mousePressed(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseReleased(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void keyPressed(KeyEvent arg0) {
System.out.println("Hello");
}
#Override
public void keyReleased(KeyEvent arg0) {
System.out.println("Hello");
}
#Override
public void keyTyped(KeyEvent arg0) {
System.out.println("Hello");
}
}

JPanel isn't focusable JComponent, have to add Object/JComponents that is focusable or interact with KeyEvents
KeyListener isn't proper listener for Swing JComponents, for Swing is replaced with KeyBindings

A JPanel cannot gain focus for KeyListener to work.
The preferred approach is to use Key Bindings for Swing. You can map an Action to a KeyStroke even when a component doesn't have focus.
Key Binding Example

I had similar problem but its so simple to solve but you have to found how to solve it witch is not so easy task :D
so how to solve this ? I just set all my buttons as focusable false.
instanceOfYourButton.setFocusable(false);
thats it

Prevent jLabel from losing focus when clicking on a nested jcombobox

I am making an app that will have some 'rectangles' (myLabel) with a text (rectangleName). Whenever I click on that rectangle, a combobox (nameComboBox) is shown to change the name of it.
So this is the declaration of that class.
public class myLabel extends JLabel implements MouseListener,FocusListener{
//this.panel;
JComboBox nameComboBox;
String rectangleName;
I added some focus stuff to that class as you can see it implements FocusListener.
I want to show the combobox only when the recangle is focused and hide it otherwise. The problem that I have is that when I select a rectangle and it shows the combobox because it's focused, when I click on the combobox, the rectangle loses its focus so it hides the combobox. Any way to prevent this?
Edit:
Replying to #mKorbel, This is my SSCCE
import java.awt.Color;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;
public class MyJLabel extends JLabel implements MouseListener,FocusListener{
JComboBox nameComboBox;
JPanel mainPanel;
String name;
public MyJLabel() {
this.setLocation(10,10);
this.setBounds(20, 20,200,200);
this.setBackground(Color.LIGHT_GRAY);
this.setFocusable(true);
setOpaque(true);
setHorizontalAlignment(SwingConstants.CENTER);
setFont(getFont());
setText(this.name);
this.nameComboBox= new JComboBox(new String[] { "option1","option2","option3" });
this.nameComboBox.setBounds(40,40,100,50);
this.nameComboBox.setVisible(false);
this.addMouseListener(this);
this.addFocusListener(this);
}
#Override
public void focusGained(FocusEvent e) {
System.out.println("focus gained");
this.nameComboBox.setVisible(true);
}
#Override
public void focusLost(FocusEvent e) {
System.out.println("focus lost");
this.nameComboBox.setVisible(false);
}
#Override
public void mouseClicked(MouseEvent e) {
this.requestFocus();
}
#Override
public void mousePressed(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseReleased(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseEntered(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseExited(MouseEvent e) {
// TODO Auto-generated method stub
}
public static void main(String[] args) {
MyJLabel myjl=new MyJLabel();
JFrame fr = new JFrame();
fr.setLayout(null);
fr.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JComboBox otherCombo = new JComboBox(new String[] { "otherOption1","otherOption2","otherOption3" });
otherCombo.setBounds(40,400,100,50);
fr.add(myjl.nameComboBox);
fr.add(myjl);
fr.add(otherCombo);
fr.setSize(300,500);
fr.setVisible(true);
}
}
You must start clicking on the combo at the bottom and you'll see in the console that the focus is lost. click on the gray rectangle and the focus will be gained. Click on the combo inside the rectangle and the rectangle will lose and gain the focus instantly, so it's impossible to choose an item. I would like to not change the focus of the rectangle while I am interacting with its combobox.