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
* method at appropriate times. Subclasses may extend or reimplement.
	 * 
	 * @param e
	 *            the SWT modify event
	 */
	protected void editOccured(ModifyEvent e) {
		String value = text.getText();
		if (value == null)
			value = "";
		Object typedValue = value;
		boolean oldValidState = isValueValid();
		boolean newValidState = isCorrect(typedValue);
		if (typedValue == null && newValidState)
			Assert.isTrue(false,
					"Validator isn't limiting the cell editor's type range");
		if (!newValidState) {
			
			setErrorMessage(MessageFormat.format(getErrorMessage(),
					new Object[] { value }));
		}
		valueChanged(oldValidState, newValidState);
	}
	/**
	 * Since a text editor field is scrollable we don't set a minimumSize.
	 */
	public LayoutData getLayoutData() {
		return new LayoutData();
	}
	/**
	 * Return the modify listener.