Bug 129214 [Field Assist] - Decorated Field attachments not centering images horizontally
DecoratedField is supposed to center decorations horizontally on each side. The current attachments are not doing so. Also consider whether grid would have been a better choice for internal implementation.
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/DecoratedField.java
label.setLayoutData(formData);
	}
	/*
	 * A decoration at the specified index has been added. Update the control's
	 * attachments if it has not previously been attached on that side or if it
	 * was attached to a decoration with a lesser width.
	 */
	private void updateControlAttachments(int index, FieldDecorationData decData) {
		FormData formData = (FormData) control.getLayoutData();
		int newWidth = widthOf(decData.decoration.getImage());
		switch (index) {
		case LEFT_TOP:
			if (decDatas[LEFT_BOTTOM] == null
					|| decDatas[LEFT_BOTTOM].data.width < newWidth) {
				formData.left = new FormAttachment(decData.label);
			} else
				formData = null;
			break;
		case LEFT_BOTTOM:
			if (decDatas[LEFT_TOP] == null
					|| decDatas[LEFT_TOP].data.width < newWidth) {
				formData.left = new FormAttachment(decData.label);
			} else
				formData = null;
			break;
		case RIGHT_TOP:
			if (decDatas[RIGHT_BOTTOM] == null
					|| decDatas[RIGHT_BOTTOM].data.width < newWidth) {
				formData.right = new FormAttachment(decData.label);
			} else