CODEWITHSUNDEEP
javamultithreadingswing
D-Dᴙum
D-Dᴙum

Reputation: 7890

Is This Bad Programming Practice

Please consider the following code:

public class MyClass extends javax.swing.JFrame {

    private JTree jTree;
    //Code ommited for clarity

    public void methodCalledByAnotherThread(){

       final DefaultTreeModel t = new DefaultTreeModel();
       //Do some thing with t

       SwingUtilities.invokeLater(new Runnable(){
            public void Run(){
               jTree.setModel(t);
            }
       });
   }
}

MyClass is created and executed on the Swing thread. Some time during its execution it starts a second thread which will eventually call the methodCalledByAnotherThread(). Not this method will NEVER be called on the Swing thread.

methodCalledByAnotherThread() creates a (local) DefaultTreeModel object and does some work with it but because this is NOT on the Swing thread it cannot set the model into jTree hence the call to SwingUtilities.invokeLater(). In the Runnable object , which is executed on the Swing thread, it sets the LOCAL DefaultTreeModel t into the JTree.

My question is (and I haven't actually compiled and run this code yet so it may not work).. is the above BAD programming practice? If so how can I set a TreeModel created on a NON-Swing thread into a Swing object?

Upvotes: 3

Views: 284

Answers (2)

mKorbel
mKorbel

Reputation: 109813

1) don't extends javax.swing.JFrame more in Composition versus Inheritance, e.i.

2) better would be getModel from currnet JTree instance rathen than recreate DefaultTreeModel on runtime and maybe with un_know life cycle

3) correct is that you adding model by wrapping into invokeLater, sugestion easiest way is from Runnable#Thread, better from SwingWorker,

Upvotes: 3

John Vint
John Vint

Reputation: 40256

That looks fine (in fact its the best way to do it). So long as //Do some thing with t does not include any elements that are already displayed on the UI.

Upvotes: 3

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