Figure 15.1. The Count Words preferences sheet

A preferences sheet does not have to implement the AppPart interface. A preferences sheet is simply a specialized component contained in a PreferencesEditor.

In XMLmind XML Editor, user preferences such as displayScaling, lastOpenedFiles, etc^[7] are stored in a Preferences object. This object is accessed using App.getPreferences.

Action EditPreferencesAction (declared as "editPreferencesAction" in DesktopApp.xxe_gui) creates a PreferencesEditor.

There are two kinds of preferences sheet:

The custom preferences sheet we are going to describe here belong to this second kind.

Excerpts from CountWordsOptions.java:

public class CountWordsOptions extends AppPreferencesSheet {
    private SpinnerNumberModel countedWordMinCharsModel;
    private JSpinner countedWordMinChars;
    
    public CountWordsOptions() {
        super("countWords", "Count Words");
    }

    protected PreferencesSheetPane createPane() {
        PreferencesSheetPane form = 
            new PreferencesSheetPane(new FlowLayout(FlowLayout.LEFT, 5, 2));

        JLabel label = new JLabel("Do not count words having less than");
        form.add(label);

        countedWordMinCharsModel = new SpinnerNumberModel(1, 1, 1000, 1);
        countedWordMinChars = new JSpinner(countedWordMinCharsModel);
        form.add(countedWordMinChars);

        label = new JLabel("characters");
        form.add(label);

        return form;
    }

    public void focusPane() {
        countedWordMinChars.requestFocus();
    }

    public void fillPane(Preferences prefs) {
        int count = prefs.getInt("countedWordMinChars", 1, 1000, 1);
        countedWordMinCharsModel.setValue(new Integer(count));
    }

    public boolean validatePane(Preferences prefs) {
        int count = countedWordMinCharsModel.getNumber().intValue();
        prefs.putInt("countedWordMinChars", count);

        return true;
    }

    public void applyPreferences(Preferences prefs) {
        AppPart part = app.getPart("countWordsTool");
        if (part != null) {
            part.applyPreferences();
        }
    }
}