Checking if a JEditorPane has been edited

While I was looking for a way to check if a JEditorPane's text had been changed since the last save, I found a site that actually wanted me to pay for the answer. Bloody cheek. It isn't that tough, but it took a bit of reading. All that is needed is to install a DocumentListener into the editor pane's document. You can download a complete example which includes an ant build file. Just type "ant run" at the shell prompt to run it. You will need ant and JDK >= 1.5 (it may work in older JDKs, but I used 1.5 so I can't be sure).

  1. public class SwingEditor extends JEditorPane {
  2.     private boolean dirty = false;
  3.  
  4.     public SwingEditor() {
  5. 	super("text/plain", "");
  6. 	setFont(new Font("Monospaced", Font.PLAIN, 12));
  7. 	getDocument().addDocumentListener(
  8.             new EditDocumentListener());
  9.     }
  10.  
  11.     public boolean isDirty() {
  12. 	return dirty;
  13.     }
  14.  
  15.     public void setDirty(boolean newDirty) {
  16. 	dirty = newDirty;
  17.     }
  18.  
  19.     private class EditDocumentListener implements
  21.  
  22. 	public void changedUpdate(DocumentEvent ev) {
  23. 	    dirty = true;
  24. 	}
  25.  
  26. 	public void insertUpdate(DocumentEvent ev) {
  27. 	    dirty = true;
  28. 	}
  29.  
  30. 	public void removeUpdate(DocumentEvent ev) {
  31. 	    dirty = true;
  32. 	}
  33.     }
  34. }

Source download: swing-editor-src-0_1.jar