com.edgenius.wiki.gwt.client.render.RenderPanel.java Source code

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Here is the source code for com.edgenius.wiki.gwt.client.render.RenderPanel.java

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/* 
 * =============================================================
 * Copyright (C) 2007-2011 Edgenius (http://www.edgenius.com)
 * =============================================================
 * License Information: http://www.edgenius.com/licensing/edgenius/2.0/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2.0
 * as published by the Free Software Foundation.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * http://www.gnu.org/licenses/gpl.txt
 *  
 * ****************************************************************
 */
package com.edgenius.wiki.gwt.client.render;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.HTMLPanel;
import com.google.gwt.user.client.ui.Widget;

/**
 * @author Dapeng.Ni
 */
public abstract class RenderPanel extends FlowPanel {
    private List content = new ArrayList();
    private String panelID;

    /**
     * All RenderPanel instance must have an unique id value. This is useful for renderCallback(id) to 
     * look up the specified RenderPanel scripts and eval them.
     * @param id
     */
    public RenderPanel() {
        panelID = HTMLPanel.createUniqueId();
        DOM.setElementAttribute(this.getElement(), "id", panelID);
    }

    public void insert(Widget widget, int beforeIndex) {
        if (beforeIndex > content.size())
            return;

        content.add(beforeIndex, widget);
    }

    public void insert(String text, int beforeIndex) {
        if (beforeIndex > content.size())
            return;

        content.add(beforeIndex, text);
    }

    public void add(String text) {
        content.add(text);
    }

    public void add(Widget widget) {
        content.add(widget);
    }

    public int getContentWidgetCount() {
        return content.size();
    }

    /**
     * @return
     */
    public Iterator<Object> iteratorContent() {
        return new Iterator() {
            Iterator iter = content.iterator();

            public boolean hasNext() {
                return iter.hasNext();
            }

            public Object next() {
                return iter.next();
            }

            public void remove() {
                iter.remove();
            }
        };
    }

    public Object getContentWidget(int idx) {
        return content.get(idx);
    }

    public boolean removeCotentWidget(int idx) {
        if (idx >= content.size())
            return false;

        content.remove(idx);
        return true;
    }

    public void clear() {
        clearPanel();
        content.clear();
    }

    /**
     * I don't remember exactly as old bug database is hacked and removed. The reason why use this method to 
     * add render content is because HTML DOM Hierarchy model. If simply use FlowPanel.add(), it may break DOM hierarchy in 
     * some case.
     * Submit the latest content, must be call after any modify content method, such as remove(), add(), insert()
     * or iterator.remove() etc.
     */
    public void submit() {
        StringBuffer render = new StringBuffer();
        Map<String, Widget> widgetMap = new HashMap<String, Widget>();

        int size = content.size();
        if (size == 0) {
            //IE issue, if content is blank, the right size author info panel will 100% width to occupy entire page
            render.append("&nbsp;");
        } else {
            for (int idx = 0; idx < size; idx++) {
                Object obj = content.get(idx);
                if (obj instanceof String) {
                    render.append((String) obj);
                } else if (obj instanceof Widget) {
                    String uid = HTMLPanel.createUniqueId();
                    widgetMap.put(uid, (Widget) obj);
                    //surround with <![CDATA[]]>: This is fix bug when render something like: {html}<!{html}{feedback}
                    //Render content "!<<span id=123></span>" in FF and IE will break document.getElementById()
                    //This means the HTMLPanel can't work as the span element can not be found out.
                    //use <![CDATA[]]> rather than <!----> is because if "<![" is before text, then <!----> won't work.
                    //but <![CDATA[]]> work both <! or <![ before the macro widget.
                    render.append("<![CDATA[]]><span id='" + uid + "'></span><![CDATA[]]>");
                }
            }
        }

        HTMLPanel panel = new HTMLPanel(render.toString());

        for (Entry<String, Widget> entry : widgetMap.entrySet()) {
            panel.add(entry.getValue(), entry.getKey());

        }
        //reset panel to empty, then render new content
        clearPanel();

        super.add(panel);
        Scheduler.get().scheduleDeferred(new ScheduledCommand() {
            public void execute() {
                renderCallback(panelID);
            }
        });
    }

    /**
     * clean all widget from this panel
     */
    private void clearPanel() {
        //cannot call super.clear directly, because Panel.clear() execute iterator.remove(), it already overwrite by this class
        Iterator it = super.iterator();
        while (it.hasNext()) {
            Widget w = (Widget) it.next();
            super.remove(w);
        }
    }

    private native void renderCallback(String panelID) /*-{
                                                       $wnd.renderCallback(panelID);
                                                       }-*/;

}