htmlnewspapertablerenderer.java

一个使用struts+hibernate+spring开发的完的网站源代码。

/*
 * Copyright 2004 The Apache Software Foundation.
 * 
 * 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.apache.myfaces.custom.newspaper;

import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.component.html.HtmlDataTable;
import javax.faces.context.ResponseWriter;
import javax.faces.component.UIColumn;
import javax.faces.component.UIData;
import org.apache.myfaces.renderkit.JSFAttr;
import org.apache.myfaces.renderkit.RendererUtils;
import org.apache.myfaces.renderkit.html.HtmlRendererUtils;
import org.apache.myfaces.renderkit.html.HTML;
import org.apache.myfaces.renderkit.html.HtmlTableRendererBase;
import org.apache.myfaces.util.ArrayUtils;
import org.apache.myfaces.util.StringUtils;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Renderer for a table in multiple balanced columns.
 *
 * @author <a href="mailto:[e-mail]">Jesse Wilson</a>
 */
public class HtmlNewspaperTableRenderer
        extends HtmlTableRendererBase
{
    private static final Log log = LogFactory.getLog(HtmlNewspaperTableRenderer.class);

    public void encodeBegin(FacesContext facesContext, UIComponent uiComponent) throws IOException {
        RendererUtils.checkParamValidity(facesContext, uiComponent, UIData.class);
        ResponseWriter writer = facesContext.getResponseWriter();
        HtmlNewspaperTable newspaperTable = (HtmlNewspaperTable)uiComponent;
        
        // write out the table start tag
        HtmlRendererUtils.writePrettyLineSeparator(facesContext);
        writer.startElement(HTML.TABLE_ELEM, newspaperTable);
        writer.writeAttribute(HTML.ID_ATTR, newspaperTable.getClientId(facesContext), null);
        HtmlRendererUtils.renderHTMLAttributes(writer, newspaperTable, HTML.TABLE_PASSTHROUGH_ATTRIBUTES);

        // render the header
        renderFacet(facesContext, writer, newspaperTable, true);
    }
    
    public void encodeChildren(FacesContext facesContext, UIComponent uiComponent) throws IOException {
        RendererUtils.checkParamValidity(facesContext, uiComponent, UIData.class);
        ResponseWriter writer = facesContext.getResponseWriter();
        HtmlNewspaperTable newspaperTable = (HtmlNewspaperTable)uiComponent;
        
        // begin the table
        HtmlRendererUtils.writePrettyLineSeparator(facesContext);
        writer.startElement(HTML.TBODY_ELEM, newspaperTable);
        
        // get the CSS styles
        Styles styles = getStyles(newspaperTable);

        // count the number of actual rows
        int first = newspaperTable.getFirst();
        int rows = newspaperTable.getRows();
        int rowCount = newspaperTable.getRowCount();
        if(rows <= 0) {
            rows = rowCount - first;
        }
        int last = first + rows;
        if(last > rowCount) last = rowCount;
        
        // the number of slices to break the table up into */
        int newspaperColumns = newspaperTable.getNewspaperColumns();
        int newspaperRows;
        if((last - first) % newspaperColumns == 0) newspaperRows = (last - first) / newspaperColumns;
        else newspaperRows = ((last - first) / newspaperColumns) + 1;

        // walk through the newspaper rows
        for(int nr = 0; nr < newspaperRows; nr++) {

            // write the row start
            HtmlRendererUtils.writePrettyLineSeparator(facesContext);
            writer.startElement(HTML.TR_ELEM, newspaperTable);
            if(styles.hasRowStyle()) {
                String rowStyle = styles.getRowStyle(nr);
                writer.writeAttribute(HTML.CLASS_ATTR, rowStyle, null);
            }

            // walk through the newspaper columns
            for(int nc = 0; nc < newspaperColumns; nc++) {

                // the current row in the 'real' table
                int currentRow = nc * newspaperRows + nr + first;
                
                // if this row is not to be rendered
                if(currentRow >= last) continue;

                // bail if any row does not exist
                newspaperTable.setRowIndex(currentRow);
                if(!newspaperTable.isRowAvailable()) {
                    log.error("Row is not available. Rowindex = " + currentRow);
                    return;
                }
    
                // write each cell
                List children = newspaperTable.getChildren();
                for(int j = 0; j < newspaperTable.getChildCount(); j++) {
                    // skip this child if its not a rendered column 
                    UIComponent child = (UIComponent)children.get(j);
                    if(!(child instanceof UIColumn)) continue;
                    UIColumn column = (UIColumn)child;
                    if(!child.isRendered()) continue;
                    // draw the element's cell
                    writer.startElement(HTML.TD_ELEM, newspaperTable);
                    if(styles.hasColumnStyle()) writer.writeAttribute(HTML.CLASS_ATTR, styles.getColumnStyle(j), null);
                    RendererUtils.renderChild(facesContext, child);
                    writer.endElement(HTML.TD_ELEM);
                }

                // draw the spacer facet
                if(nc < newspaperColumns - 1) renderSpacerCell(facesContext, writer, newspaperTable);
            }
            // write the row end
            writer.endElement(HTML.TR_ELEM);
        }
        
        // write the end of the table's body
        writer.endElement(HTML.TBODY_ELEM);
    }
    
    /** 
     * Fetch the number of columns to divide the table into.
     */
    private int getNewspaperColumns() {
        return 3;
    }

    public void encodeEnd(FacesContext facesContext, UIComponent uiComponent) throws IOException {
        RendererUtils.checkParamValidity(facesContext, uiComponent, UIData.class);
        ResponseWriter writer = facesContext.getResponseWriter();
        HtmlNewspaperTable newspaperTable = (HtmlNewspaperTable)uiComponent;
        
        // render the footer
        renderFacet(facesContext, writer, newspaperTable, false);
        
        // write out the table end tag
        writer.endElement(HTML.TABLE_ELEM);
        HtmlRendererUtils.writePrettyLineSeparator(facesContext);
    }

    
    /**
     * Count the number of columns in the speicifed Newspaper table..
     */
    private int countColumns(HtmlNewspaperTable newspaperTable) {
        int columnCount = 0;
        for(Iterator it = newspaperTable.getChildren().iterator(); it.hasNext(); ) {
            UIComponent uiComponent = (UIComponent)it.next();
            if (uiComponent instanceof UIColumn && ((UIColumn)uiComponent).isRendered()) {
                columnCount++;
            }
        }
        return columnCount;
    }
    
    /**
     * Tests if the specified facet exists for the specified newspaper table.
     */
    private boolean hasFacet(HtmlNewspaperTable newspaperTable, boolean header) {
        for(Iterator it = newspaperTable.getChildren().iterator(); it.hasNext(); ) {
            // get the column
            UIComponent uiComponent = (UIComponent)it.next();
            if(!(uiComponent instanceof UIColumn)) continue;
            UIColumn column = (UIColumn)uiComponent;
            if(!column.isRendered()) continue;
            
            // test the facet
            if(header && ((UIColumn)uiComponent).getHeader() != null) return true;
            if(!header && ((UIColumn)uiComponent).getFooter() != null) return true;
        }
        return false;
    }

    /**