Bug 25458 [Font] DBCS support: new SWT API
Last Friday we have included a new API in Font: public Font(Device device, FontData[] fds) { In order to have a more appropriate behavior on DBCS platforms Eclipse/UI should start using this API. Anyway, the best police still is never change the default font in the widget if you don't need to. (this new API is going to make difference in Eclipse/Motif only)
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/FontFieldEditor.java
* Sets the text of the change button.
 *
 * @param text the new text
 */
public void setChangeButtonText(String text) {
	Assert.isNotNull(text);
	changeButtonText = text;
	if (changeFontButton != null)
		changeFontButton.setText(text);
}
/**
 * Updates the change font button and the previewer to reflect the
 * newly selected font.
 */
private void updateFont(FontData font[]) {
	FontData bestFont = 
		JFaceResources.getFontRegistry().
			bestData(font,valueControl.getDisplay());
	
	if(bestFont == null)
		bestFont = getDefaultFontData();
		
	
	this.chosenFont = bestFont;
	
	if (valueControl != null) {
		valueControl.setText(StringConverter.asString(chosenFont));
	}
	if (previewer != null) {
		previewer.setFont(chosenFont);