android- multi onClick listener in one button

Question

I have made a custom component like Mybutton.java and I have set an onclick listener in Mybutton.java.

Now, in my new activity, I have to call a Mybutton and add content in onclick listener.

However, if I use OnClickListener mClickListener = new OnClickListener(){...... it will replace the old content. I hope it can do the old and new listener together.

I have searched for some information, found out i can implement this method. After many attempts, I'm still getting errors.

Can anyone give me a simple example that i can learn to modify it?

Answer 1

I don't think there's an API in the Android API that allows multiple onClick listeners. You'd need some custom class that handles a single onClick() and pass in handlers for it to call. Something like this:

private class CompositeOnClickListener implements View.OnClickListener{
    List<View.OnClickListener> listeners;

    public CompositeOnClickListener(){
        listeners = new ArrayList<View.OnClickListener>();
    }

    public void addOnClickListener(View.OnClickListener listener){
        listeners.add(listener);
    }

    @Override
    public void onClick(View v){
       for(View.OnClickListener listener : listeners){
          listener.onClick(v);
       }
    }
}

When your setting your buttons, do:

CompositeOnClickListener groupListener = new CompositeOnClickListener();
myButton.setOnClickListener(groupListener);

Then, whenever you want to add another listener, just call

groupListener.addOnClickListener(new View.OnClickListener(){
   @Override
   public void onClick(View v){
      **** Custom implementation ****
   }
});