Bug 80429 [Preferences] [Dialogs] FieldEditors should relax requirements to support DialogPages
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/ide/dialogs/ResourceEncodingFieldEditor.java
Group group = super.createEncodingGroup(parent, numColumns);
		String byteOrderLabel = IDEEncoding.getByteOrderMarkLabel(getContentDescription());
		if (byteOrderLabel != null) {
			Label label = new Label(group, SWT.NONE);
			label.setText(IDEWorkbenchMessages.format(
					"WorkbenchPreference.encoding.encodingMessage", 
					new String[] { byteOrderLabel }));
			GridData layoutData = new GridData();
			layoutData.horizontalSpan = numColumns + 1;
			label.setLayoutData(layoutData);
		}
		return group;
	}
	/**
	 * Get the content description of the resource if it is 
	 * a file and it has a content description.
	 * @return IContentDescription or <code>null</code> if resource is
	 * not an IFile or it does not have a descrption.
	 */
	private IContentDescription getContentDescription() {
		try {
			if (resource instanceof IFile)
				return (((IFile) resource).getContentDescription());
		} catch (CoreException exception) {
			
		}
		return null;
	}
}