Bug 126527 [Field Assist] - API - Field Decoration alignment issues are different for cell editors
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/DecoratedTextCellEditor.java
public boolean isCopyEnabled() {
		if (text == null || text.isDisposed())
			return false;
		return text.getSelectionCount() > 0;
	}
	/**
	 * The <code>TextCellEditor</code> implementation of this
	 * <code>CellEditor</code> method returns <code>true</code> if the
	 * current selection is not empty.
	 */
	public boolean isCutEnabled() {
		if (text == null || text.isDisposed())
			return false;
		return text.getSelectionCount() > 0;
	}
	/**
	 * The <code>TextCellEditor</code> implementation of this
	 * <code>CellEditor</code> method returns <code>true</code> if there is
	 * a selection or if the caret is not positioned at the end of the text.
	 */
	public boolean isDeleteEnabled() {
		if (text == null || text.isDisposed())
			return false;
		return text.getSelectionCount() > 0
				|| text.getCaretPosition() < text.getCharCount();
	}
	/**
	 * The <code>TextCellEditor</code> implementation of this
	 * <code>CellEditor</code> method always returns <code>true</code>.
	 */