SequentialPager.java

/*
 * Copyright 2014 cruxframework.org.
 * 
 * Licensed 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.cruxframework.crux.smartfaces.client.pager;

import org.cruxframework.crux.smartfaces.client.backbone.common.FacesBackboneResourcesCommon;
import org.cruxframework.crux.smartfaces.client.button.Button;
import org.cruxframework.crux.smartfaces.client.panel.NavPanel;

import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.SimplePanel;

/**
 * A pager which does not know the total number of pages. So, it can only move the cursor to next or to previous page.  
 * @author Thiago da Rosa de Bustamante
 */
public class SequentialPager<T> extends NavigationButtonsPager<T>
{
	public static final String DEFAULT_STYLE_NAME = "faces-SequentialPager";
	private static final String STYLE_CURRENT_PAGE_LABEL = "currentPage";
	
	private SimplePanel infoPanel;
	private Button nextButton = createNextButton();
	private NavPanel panel;
	private Button previousButton = createPreviousButton();
	
	/**
	 * Constructor
	 */
	public SequentialPager()
	{
		this.panel = new NavPanel();
		this.infoPanel = new SimplePanel();
		this.infoPanel.setWidget(createCurrentPageLabel("" + 0));
		
		this.panel.add(previousButton);
		this.panel.add(infoPanel);
		this.panel.add(nextButton);		
		
		initWidget(this.panel);		

		setStyleName(DEFAULT_PAGER_STYLE_NAME);
		this.panel.addStyleName(DEFAULT_STYLE_NAME);
	}

	@Override
	public void setStyleName(String style)
	{
	    super.setStyleName(style);
	    super.addStyleName(FacesBackboneResourcesCommon.INSTANCE.css().facesSequentialPager());
	}
	
	
	@Override
	public void setStyleName(String style, boolean add)
	{
		super.setStyleName(style, add);
		if (!add)
		{
		    super.addStyleName(FacesBackboneResourcesCommon.INSTANCE.css().facesSequentialPager());
		}
	}
	
	/**
	 * @see org.cruxframework.crux.widgets.client.paging.AbstractPager#hideLoading()
	 */
	@Override
	protected void hideLoading()
	{
		// does nothing
	}

	@Override
	protected void onUpdate()
	{
		Label currentPageLabel = createCurrentPageLabel("" + getCurrentPage());
		this.infoPanel.clear();
		this.infoPanel.add(currentPageLabel);
	}
	
	@Override
	protected void setInteractionEnabled(boolean enabled) 
	{
		previousButton.setEnabled(enabled);
		nextButton.setEnabled(enabled);
	}
	
	/**
	 * @see org.cruxframework.crux.widgets.client.paging.AbstractPager#showLoading()
	 */
	@Override
	protected void showLoading()
	{
		this.infoPanel.clear();
		this.infoPanel.add(createCurrentPageLabel("..."));
	}
	
	/**
	 * Creates the label that shows the current showing page
	 * @param currentPageNumber
	 * @return
	 */
	private Label createCurrentPageLabel(String currentPageNumber)
	{
		Label label = new Label(currentPageNumber);
		label.setStyleName(STYLE_CURRENT_PAGE_LABEL);
		return label;
	}
}