org.metawidget.widgetprocessor.iface.AdvancedWidgetProcessor Maven / Gradle / Ivy
// Metawidget (licensed under LGPL)
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
package org.metawidget.widgetprocessor.iface;
/**
* Common interface implemented by all AdvancedWidgetProcessors. AdvancedWidgetProcessors can hook
* into additional lifecycle events.
*
* There are advantages to keeping the vanilla WidgetProcessor interface as a
* single-method interface: First, it alleviates the need for a BaseWidgetProcessor or
* WidgetProcessorAdapter class (to provide default implementations for subclasses who
* don't override all the methods); second, it makes WidgetProcessor an example of the
* Strategy pattern; third, it makes WidgetProcessor amenable to automatic function
* objects (part of closures in Java 7). This latter point is especially useful when using
* WidgetProcessors to attach event handlers.
*
* @author Richard Kennard
*/
public interface AdvancedWidgetProcessor
extends WidgetProcessor {
//
// Methods
//
/**
* Event called at the start of the widget building process, before the
* WidgetBuilder is called. WidgetProcessors may wish to act on this
* event to initialize themselves ready for processing. This event is only called once per
* inspection, not once per widget built.
*
* @param metawidget
* the parent Metawidget. Never null
*/
void onStartBuild( M metawidget );
/**
* Event called at the end of widget building, after all widgets have been built and added to
* the Layout. WidgetProcessors may wish to act on this event to clean
* themselves up after processing. This event is only called once per inspection, not once per
* widget built.
*
* @param metawidget
* the parent Metawidget. Never null
*/
void onEndBuild( M metawidget );
}