I have made my own version of Tetris in Java and i have added the possibility of moving the shapes both with JButtons and with certain keyboard keys. The code snippet i used is the following:
leftButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent E) {
moveLeft();
}
});
rightButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent E) {
moveRight();
}
});
rotateButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent E) {
rotateMovingShape();
}
});
myPanel.addKeyListener(new KeyAdapter(){
public void keyPressed(KeyEvent event) {
int keyCode = event.getKeyCode();
if (keyCode == event.VK_A)
{
moveLeft();
}
if (keyCode == event.VK_D)
{
moveRight();
}
if (keyCode == event.VK_S)
{
rotateMovingShape();
}
}
});
The problem i have is that after i use the JButtons, i cannot longer control the shapes with the keyboard keys. I suspect it has something to do with gaining/losing focus, but i am not sure. Could anyone tell me what's going on?
You get that problem, because you use KeyListener, instead of that you need to use Key Bindings. For example:
component.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_A,0), "aPressed");
component.getActionMap().put("aPressed", new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("a key");
}
});
component.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_D,0), "dPressed");
component.getActionMap().put("dPressed", new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("d key");
}
});
// other bindings
where component is your JPanel.
A KeyListener only receives key events when the component has the keyboard focus. Clicking on the buttons transfers the focus to them and away from your panel, so you don't get the events. Any one of the following approaches will solve this:
Call setFocusable(false); on the buttons so that they won't steal the focus.
Add the KeyListener to the buttons too.
Use key bindings instead of a KeyListener, so that you can catch the key press whether the component has focus or not.
Related
I am Trying to make the program respond when the button ESC is clicked so that it will dispose the jframe. I am Not sure what the problem is but it seems to be in the if statement in the main menu.
*Note: te is the object name for the class (Text Editor)
This part is in the main method
f.add(text);
f.addKeyListener(te);
f.setVisible(true);
while(true){
if (exiting == true){
f.dispose();
}
}
This part is outside the main method
#Override
public void keyPressed(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_ESCAPE){
exiting = true;
}
}
Don't use KeyListeners, as a general rule, the component they are attached MUST have key board focus in order to be triggered.
Instead, use a key binding...
InputMap im = getRootPane().getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
ActionMap am = getRootPane().getActionMap();
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0), "cancel");
am.put("cancel", new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
dispose();
}
});
See How to Use Key Bindings for more details
Because of the power of the Action API, I would create a basic "dispose" action to start with:
public class DisposeWindowAction extends AbstractAction {
private Window window;
public DisposeWindowAction(Window window) {
this.window = window;
putValue(NAME, "Dispose");
putValue(ACCELERATOR_KEY, KeyStroke.getKeyStroke(KeyEvent.VK_EQUALS, 0));
}
public Window getWindow() {
return window;
}
#Override
public void actionPerformed(ActionEvent e) {
getWindow().dispose();
}
}
I'd then bind this to the ActionMap...
am.put("cancel", new DisposeWindowAction(this));
Why you ask? Because you can then use the same Action in JMenuItems and JButtons`....
JButton disposeButton = new JButton(new DisposeWindowAction(this));
...
(You can use the same instance of the Action, but you get the idea) and now the user has something like three more ways to dispose of the window...
See How to Use Actions for more details
there is an easier way to add a listener to the jframe. All you have to do is create a keylistener overriding keypressed and then check what type of object e.getComponent() is. If it is a window type you can call dispose on it when the escape key is pressed.
public void keyPressed(KeyEvent e){
If(e.getKeyCode() == KeyEvent.VK_ESCAPE){
If( e.getComponent() instanceof Window){
((Window)e.getComponent()).dispose();
}
}
}
You can of course change window to JFrame, and put the two if statements together.
Also you do not need the while loop.
How can I detect the Windows key modifier for KeyEvent? I have add the code:
textField.addKeyListener(new KeyAdapter() {
public void keyReleased(KeyEvent e) {
if ((e.getKeyCode() & KeyEvent.VK_ESCAPE) == KeyEvent.VK_ESCAPE) {
textField.setText("");
}
}
});
But the problem is, when I use the Windows zoom and try to exit from it using Win + Escape, if focus is in TextField, its content clears. I've tried filter by e.getModifiersEx(), but it returns 0. The only way I've found is to detect whether Windows pressed or not, is to create boolean field and change it's value when Windows pressed/released.
So, is there any way to get the Windows key pressure state from KeyEvent for ESCAPE released event?
The way I used for myself:
AbstractAction escapeAction = AbstractAction() {
public void actionPerfomed(ActionEvent e) {
setText("");
}
}
textField.addCaretListener(new CaretListener() {
#Override
public void caretUpdate(CaretEvent e) {
if (textField.getText() == null || textField.getText().isEmpty()) {
textField.getActionMap().remove("escape");
textField.getInputMap().remove(KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0));
} else {
textField.getActionMap().put("escape", escapeAction);
textField.getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0), escapeAction);
}
}
});
The title might be a little misleading, didnt know how to put my problem short.
Basically what im doing is im using keyboardlistener to find out which keys are down and according to that im moving my game character.
The problem is, when you click out of the window, while holding down a key my listener doesnt register the keyReleased event.
I tried to fix it by using mouse listener and the mouseExited event, but that doesnt fix it all the time, sometimes it does sometimes it doesnt.
Heres my implementation:
Keyboard:
public void mouseLeftWindow()
{
for(int i =0;i<KEY_COUNT;i++)
{
keys[i] = false;
}
}
#Override
public void keyPressed(KeyEvent e)
{
int keyCode = e.getKeyCode();
if(keyCode>=0 && keyCode<KEY_COUNT)
{
keys[keyCode] = true;
}
}
#Override
public void keyReleased(KeyEvent e)
{
int keyCode = e.getKeyCode();
if(keyCode>=0 && keyCode<KEY_COUNT)
{
keys[keyCode] = false;
}
}
where keys[] is a boolean[] describing, which codes are pressed
mouse:
#Override
public void mouseExited(MouseEvent e)
{
mouseMoved(e);
keyboard.mouseLeftWindow();
}
Your program will listen for further key events even when your mouse exited the component. That means you set everything to false on exit but if a key is still pressed it will be set to true immediately again. I think you are looking for a FocusListener instead of a MouseListener.
addFocusListener(new FocusListener() {
#Override
public void focusGained(FocusEvent e) {
}
#Override
public void focusLost(FocusEvent e) {
keyboard.mouseLeftWindow();
}
});
I am writing a game and I have just tried to add the KeyListener. I have experience with java including KeyListeners but I for some reason cannot figure out why this code only works some of the time.
Here is my listener function:
public void Listener() {
System.out.println("[INFO] Listener() Ran.");
KeyListener kl = new KeyListener() {
public void keyPressed(KeyEvent e) {
if(e.getKeyChar()=='a'){
System.out.println("[DEBUG] A Pressed.");
}
}
public void keyReleased(KeyEvent e) {
}
public void keyTyped(KeyEvent e) {
}
};
panel.addKeyListener(kl);
System.out.println("[DEBUG] panel added KeyListener.");
}
This code works probably only 1 out of 10 times that I run it. Maybe even less. Any ideas on why this is?
The getKeyChar should be called in the keyTyped. The getKeyCode() == KeyEvent.VK_A in the other both methods.
I am trying to write a Minesweeper clone in Java for fun. I have a grid of JButtons whose labels I will change to represent the danger count, flags, etc.
My problem is, I don't know how to get a right click on a JButton to depress the button. I've done the following:
button.addMouseListener(new MouseAdapter(){
public void mouseClicked(MouseEvent e){
boolean mine = field.isMine(x, y);
if (e.isPopupTrigger()) {
button.setText("F");
}
else {
if (mine) {
button.setText("X");
}
}
}
});
This doesn't seem to be working at all; the "F" is never shown, only the "X" part. But more importantly, this does nothing for depressing the button.
EDIT: Macs have popup trigger happen on mousePress, not mouseClick.
EDIT: Here's the solution I worked out based off of accepted answer:
button.addMouseListener(new MouseAdapter(){
boolean pressed;
#Override
public void mousePressed(MouseEvent e) {
button.getModel().setArmed(true);
button.getModel().setPressed(true);
pressed = true;
}
#Override
public void mouseReleased(MouseEvent e) {
//if(isRightButtonPressed) {underlyingButton.getModel().setPressed(true));
button.getModel().setArmed(false);
button.getModel().setPressed(false);
if (pressed) {
if (SwingUtilities.isRightMouseButton(e)) {
button.setText("F");
}
else {
button.setText("X");
}
}
pressed = false;
}
#Override
public void mouseExited(MouseEvent e) {
pressed = false;
}
#Override
public void mouseEntered(MouseEvent e) {
pressed = true;
}
});
add(button);
Minesweeper clone http://grab.by/1y9z
Button can't be pressed by right click. Add such a lines to you mouse listener
mousePressed:
if(isRightButtonPressed) {underlyingButton.getModel().setPressed(true));
mouseReleased:
if(needReset) {underlyingButton.getModel().setPressed(false));
or do there whatever want.
I wouldn't use isPopupTrigger but directly check for the right button:
button.addMouseListener(new MouseAdapter(){
public void mouseClicked(MouseEvent e){
boolean mine = field.isMine(x, y);
if (e.getButton() == MouseEvent.BUTTON2) {
button.setText("F");
}
...
Just a small addition: the simplest way to check for the right button is SwingUtilities.isRightMouseButton
As you have mentioned that checking for "mousePressed" solved your issue. And the Javadoc of isPopupTrigger would explain the need for this:
public boolean isPopupTrigger()
...
Note: Popup menus are triggered differently on different systems. Therefore, isPopupTrigger should be checked in both mousePressed and mouseReleased for proper cross-platform functionality.
Also see the section on The Mouse Listener API in the Java Swing tutorial.
MouseEvent has some properties
static int BUTTON1
static int BUTTON2
static int BUTTON3
among others. Check those when your event fires.
EDIT
public int getButton()
Returns which, if any, of the mouse buttons has changed state.
The button being visibly depressed on right click isn't part of the "normal" behavior of buttons. You may be able to fake it using JToggleButtons, or simply changing the button's background color and maybe border while the right mouse button is being held down.
If you are certain that the event is properly being triggered (debug FTW!) and that the button.setText("F") is happening, then perhaps you simply need to repaint.
Repaint the button.
http://java.sun.com/javase/6/docs/api/javax/swing/JComponent.html#repaint(java.awt.Rectangle)
This works for me fine on Mac:
import java.awt.event.*;
import javax.swing.*;
public class ButtonTest extends JFrame {
JButton button;
public ButtonTest() {
button = new JButton("W");
button.addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent e) {
if (e.getButton() == 3) { // if right click
button.setText("F");
button.getModel().setPressed(false);
// button.setEnabled(true);
} else {
button.setText("X");
button.getModel().setPressed(true);
// button.setEnabled(false);
}
}
});
this.add(button);
this.setVisible(true);
}
public static void main(String[] args) {
new ButtonTest();
}
}
You might as well check for e.getButton() == 2 but I don't know when this one is triggered on Macs.