Description Ben Rowlands 2011-02-09 06:48:26 EST

Build Identifier: 20100917-0705

FontFieldEditor is used to select a font in a preference page. Code that reacts to font changes register an IPropertyChangeListener with the PreferenceStore. When a new font is chosen this listener is invoked with a FontData[] instance as the new value. But when the "Restore Defaults" button is clicked on the preference page, the listener is called with a String representation of the default font.

Note, I use PreferenceConverter.setDefault(store, FONT, defaultFont) to initialized the default font in the preference store.

Stack trace showing the call path:

  ...
  at org.eclipse.jface.preference.PreferenceStore$1.run(PreferenceStore.java:136)
  at org.eclipse.jface.util.SafeRunnable$1.run(SafeRunnable.java:128)
  at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
  at org.eclipse.jface.preference.PreferenceStore.firePropertyChangeEvent(PreferenceStore.java:133)
  at org.eclipse.jface.preference.PreferenceStore.setToDefault(PreferenceStore.java:565)
  at org.eclipse.jface.preference.FieldEditor.store(FieldEditor.java:678)
  at org.eclipse.jface.preference.FieldEditorPreferencePage.performOk(FieldEditorPreferencePage.java:343)
  at org.eclipse.jface.preference.PreferencePage.performApply(PreferencePage.java:432)
  ...

When FieldEditor.store() is called it does this:

  ...
  if (isDefaultPresented) {
    preferenceStore.setToDefault(preferenceName);
  } else {
    doStore();
  }
  ...

Note, FontFieldEditor#setToDefault() does do the right thing. But I don't see anyone calling it. I think the fix would be to call instead of calling setToDefault above:

  protected void setToDefault() {
     FontData[] defaultFontData = PreferenceConverter.getDefaultFontDataArray(getPreferenceStore(), getPreferenceName());
     PreferenceConverter.setValue(getPreferenceStore(), getPreferenceName(), defaultFontData);
  }

Easy enough (but ugly) to workaround by checking argument type and re-parsing String into FontData instance.

Reproducible: Always