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Is there a standard Java interface for "implements addActionListener", "implements addChangeListener", etc.?

Posted on 2014-11-13
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Last Modified: 2014-11-13
Is there a standard Java interface for "implements addActionListener", "implements addChangeListener", "implements AddPropertyChangeListener"?

Say I create a new component, and this new component has a JButton and let's say a JSpinner configured to show numeric values, the JButton creates an Action, and the JSpinner is a property who's value changes, so I expect the user to call addActionListener to know when the button is pressed, and addPropertyChangeListener to know when the value of the JSpinner has changed.

Are there standard interfaces I should have my component implement that says, "This component supports addActionListener", and "This component supports addPropertyChangeListener"?

If the answer is "No", which I suspect is the case, then my next question is, "Why not?"

When I look at a class and I want to know what calls this class supports, I look at the interfaces. If there's no interface telling me "This class supports addActionListener", then it seems like I'm just supposed to magically "know" this (perhaps by reading the unwritten documentation?)

So, where am I going wrong in my thinking here?
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Question by:deleyd
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by:CPColin
ID: 40440342
So, where am I going wrong in my thinking here?
You're going wrong in thinking that the documentation is "unwritten." Here's the API documentation for JButton:

https://docs.oracle.com/javase/8/docs/api/javax/swing/JButton.html

It shows that addActionListener() is being inherited from AbstractButton. From that, you now know that everything that extends AbstractButton will support that addActionListener() call.

You ask, "How am I supposed to know what classes support addActionListener()?" Well, do you know you're supposed to use addActionListener() in the first place? You learned it when you started learning Swing, right? It's just part of what you have to learn when you learn how to use the JButton class.
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by:deleyd
ID: 40440526
So my error in thinking is looking at the interfaces to see what is implemented?

The "Unwritten documentation" I was referring to is the documentation not yet written for the new sample component I proposed that has a JButton and a JSpinner combined. I guess I just add comments to the top of the file for my new component explaining that it supports addActionListener for the JButton, and addPropertyChangeListener for the JSpinner?

(Or I just expect other programmers to wade through the code to discover what calls are available and figure it out for themselves?)
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CPColin earned 500 total points
ID: 40440569
If I encountered an unfamiliar component, I would expect that the Javadocs for that class would tell me how to use it, so adding that information to the class comment is probably the way to go.
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