filterform.java

Wicket一个开发Java Web应用程序框架。它使得开发web应用程序变得容易而轻松。 Wicket利用一个POJO data beans组件使得它可以与任何持久层技术相结合。

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.wicket.extensions.markup.html.repeater.data.table.filter;

import org.apache.wicket.Component;
import org.apache.wicket.behavior.AbstractBehavior;
import org.apache.wicket.markup.ComponentTag;
import org.apache.wicket.markup.MarkupStream;
import org.apache.wicket.markup.html.WebMarkupContainer;
import org.apache.wicket.markup.html.form.Form;
import org.apache.wicket.markup.html.form.FormComponent;
import org.apache.wicket.markup.html.form.HiddenField;
import org.apache.wicket.model.Model;
import org.apache.wicket.util.string.AppendingStringBuffer;

/**
 * A form with filter-related special functionality for its form components.
 * 
 * @author igor
 * 
 */
public class FilterForm extends Form
{
	private static final long serialVersionUID = 1L;

	private final HiddenField hidden;
	private final IFilterStateLocator locator;

	/**
	 * @param id
	 *            component id
	 * @param locator
	 *            filter state locator
	 */
	public FilterForm(String id, IFilterStateLocator locator)
	{
		super(id, new FilterStateModel(locator));

		this.locator = locator;

		// add hidden field used for managing current focus
		hidden = new HiddenField("focus-tracker", new Model());

		hidden.add(new AbstractBehavior()
		{
			private static final long serialVersionUID = 1L;

			public void onComponentTag(Component component, ComponentTag tag)
			{
				tag.put("id", getFocusTrackerFieldCssId());
				super.onComponentTag(component, tag);
			}
		});
		add(hidden);

		// add javascript to restore focus to a filter component
		add(new WebMarkupContainer("focus-restore")
		{
			private static final long serialVersionUID = 1L;

			protected void onComponentTagBody(MarkupStream markupStream, ComponentTag openTag)
			{
				AppendingStringBuffer script = new AppendingStringBuffer(
						"<script>_filter_focus_restore('").append(getFocusTrackerFieldCssId())
						.append("');</script>");
				replaceComponentTagBody(markupStream, openTag, script);
			}
		});
	}

	/**
	 * @return css id of the hidden form input that keeps track of the focused input field
	 */
	public final String getFocusTrackerFieldCssId()
	{
		return hidden.getPageRelativePath();
	}


	/**
	 * @return IFilterStateLocator passed to this form
	 */
	public final IFilterStateLocator getStateLocator()
	{
		return locator;
	}

	/**
	 * Adds behavior to the form component to allow this form to keep track of the component's focus
	 * which will be restored after a form submit.
	 * 
	 * @param fc
	 *            form component
	 */
	public final void enableFocusTracking(FormComponent fc)
	{
		fc.add(new AbstractBehavior()
		{
			private static final long serialVersionUID = 1L;

			public void onComponentTag(Component component, ComponentTag tag)
			{
				tag.put("id", component.getMarkupId());
				tag.put("onfocus", getFocusTrackingHandler(component));
				super.onComponentTag(component, tag);
			}
		});
	}

	/**
	 * Returns the javascript focus handler necessary to notify the form of focus tracking changes
	 * on the component
	 * 
	 * Useful when components want to participate in focus tracking but want to add the handler
	 * their own way.
	 * 
	 * A unique css id is required on the form component for focus tracking to work.
	 * 
	 * @param component
	 *            component to
	 * @return the javascript focus handler necessary to notify the form of focus tracking changes
	 *         on the component
	 */
	public final String getFocusTrackingHandler(Component component)
	{
		return ("_filter_focus(this, '" + getFocusTrackerFieldCssId() + "');");
	}

	/**
	 * Model that uses filter state locator as a passthrough for model objects
	 * 
	 * @author Igor Vaynberg (ivaynberg)
	 * 
	 */
	private static class FilterStateModel extends Model
	{
		private static final long serialVersionUID = 1L;

		private IFilterStateLocator locator;

		/**
		 * Constructor
		 * 
		 * @param locator
		 *            IFilterStateLocator implementation used to provide model object for this model
		 */
		public FilterStateModel(IFilterStateLocator locator)
		{
			if (locator == null)
			{
				throw new IllegalArgumentException("argument [locator] cannot be null");
			}
			this.locator = locator;
		}

		/**
		 * @see org.apache.wicket.model.IModel#getObject()
		 */
		public Object getObject()
		{
			return locator.getFilterState();
		}

		/**
		 * @see org.apache.wicket.model.IModel#setObject(java.lang.Object)
		 */
		public void setObject(Object object)
		{
			locator.setFilterState(object);
		}

	}

}