CODEWITHSUNDEEP
javaswinguser-interfaceinterfaceabstract-class
nullByteMe
nullByteMe

Reputation: 6391

How can I update a GUI from multiple classes?

Let's say I have a class that builds a GUI and has a method updateMainUI(String text) that appends text to a JTextArea. Currently, I'm using abstract classes and methods to update the field from a different class, but I'm wondering if this is the 'right' way to do it?

I now have three abstract classes that have an protected abstract updateUI(String text) method that I override in my GUI class to update the field whenever I need to, but I'm doing the same thing in multiple classes and now I feel like I need another class that does the exact same thing.

Is there a better or more acceptable way of doing this?

Upvotes: 0

Views: 170

Answers (1)

MadProgrammer
MadProgrammer

Reputation: 347184

From you question, it's difficult to be 100% sure, but, it is generally encouraged to use a Model–view–controller approach to these types of problems.

This is, the model defines the "virtual" state, the view represents this state to the user and the controller controls changes to the model initiated from the view...

The view is notified, by the model, when it changes, so it can update the state and the view notifies the controller when some part of its view/state has changed and may be reflected in the model.

To this end, I would encourage you to define some kind of model, which is normally described by a interface which can be used by the various aspects of your program. Updates to the model don't need to come from the user/UI, but you will need to ensure that you clearly document when notifications might come from a different thread other than the Event Dispatching Thread, so your UI code can take correct actions and synchronise the updates.

So, based on you example, your model might have a method call setText (or some such), which triggers some kind of event notification to registered listeners.

This instance of the model would be shared amongst the various classes of your application

You main UI would be one of these classes listening for a change in the models state, when it detected a change, it would update its state accordingly.

This is an example of the observer pattern and you see this in use all over Swing (via it's listener/event API)

Upvotes: 1

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