如何在JTextField上删除MouseListener / ActionListener

Question

I have the following code adding an ActionListener to a JTextField:

chatInput.addMouseListener(new java.awt.event.MouseAdapter() {
    public void mouseClicked(java.awt.event.MouseEvent evt) {
       chatInputMouseClicked(evt);
    }
});

Now how do I remove this MouseListener using chatInput.removeMouseListener() , since this function needs an argument?

Answer 1

You can consider 3 approaches:

1) Save reference to your listener before adding it so you can remove it later:

MouseListener ml = new MouseAdapter() {
    public void mouseClicked(java.awt.event.MouseEvent evt) {
        chatInputMouseClicked(evt);
    }
};
chatInput.addMouseListener (ml);
...
chatInput.removeMouseListener (ml);

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2) You can get all certain event listeners with correspondent methods like:

public MouseListener[] getMouseListeners()  

or

public EventListener[] getListeners(Class listenerType)

Here are the javadocs for the first and second methods. If you can identify among all listeners the one which you want to remove or if you want to remove all listeners this approach may help.

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3) You can use some boolean variable which will 'turn off' your listener. But you should notice that the variable should be a field of outer class:

private boolean mouseListenerIsActive;

public void doSmthWithMouseListeners () {
    mouseListenerIsActive = true;

    chatInput.addMouseListener(new MouseAdapter() {
        public void mouseClicked(MouseEvent evt) {
            if (mouseListenerIsActive) {
               chatInputMouseClicked(evt);
            }
        }
    });
}

public void stopMouseListner () {
    mouseListenerIsActive = false;
}

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I would prefer the third one because it gives some flexibility and if I want to turn on mouse listener again I will not need to create new object.