Create Eclipse RAP Widget from ClientScripting-based widget

package org.o7planning.customwidget.logcomposite;

import java.io.IOException;
import java.io.InputStream;

import org.eclipse.rap.json.JsonObject;
import org.eclipse.rap.json.JsonValue;
import org.eclipse.rap.rwt.RWT;
import org.eclipse.rap.rwt.client.service.JavaScriptLoader;
import org.eclipse.rap.rwt.remote.AbstractOperationHandler;
import org.eclipse.rap.rwt.remote.Connection;
import org.eclipse.rap.rwt.remote.OperationHandler;
import org.eclipse.rap.rwt.remote.RemoteObject;
import org.eclipse.rap.rwt.service.ResourceManager;
import org.eclipse.rap.rwt.widgets.WidgetUtil;
import org.eclipse.swt.widgets.Composite;

public class LogComposite extends Composite {


   private static final long serialVersionUID = -8590973451146216709L;

   private RemoteObject remoteObject;


   // The directory containing the file js, css.
   private static final String REAL_RESOURCE_PATH = "logjsresources";

   private static final String REGISTER_PATH = "logjs";

   private static final String REMOTE_TYPE = "o7planning.LogComposite";

   private final String[] FILENAMES = { "logjs.css", "logjs.js" ,"load-css-file.js" , "rap-handler.js" };

   private final OperationHandler operationHandler = new AbstractOperationHandler() {

       private static final long serialVersionUID = -1979566336567602883L;

       @Override
       public void handleSet(JsonObject properties) {
           System.out.println("##### handleSet ..:");
           JsonValue textValue = properties.get("text");
           if (textValue != null) {
               // text = textValue.asString();
           }
       }

       @Override
       public void handleCall(String method, JsonObject parameters) {
           System.out.println("##### handleCall ..:" + method);
       }

       @Override
       public void handleNotify(String event, JsonObject properties) {
           System.out.println("##### handleNotify ..:" + event);
           if (event.equals("dirty")) {
           }
       }

   };

   /**
    * Create the composite.
    *
    * @param parent
    * @param style
    */
   public LogComposite(Composite parent, int style) {
       super(parent, style);

       // Note: Catching error when viewed on WindowBuilder
       try {
           registerResources();
           loadJavaScript();

           Connection connection = RWT.getUISession().getConnection();
           remoteObject = connection.createRemoteObject(REMOTE_TYPE);
           remoteObject.setHandler(operationHandler);

           //
           remoteObject.set("parent", WidgetUtil.getId(this));

       } catch (Exception e) {
           e.printStackTrace();
           // throw new RuntimeException(e);
       }
   }
   

   @Override
   public void dispose()  {
       super.dispose();        

       // Call destroy() function in rap-handler.js
       remoteObject.destroy();
   }


   // Load the js files required at Client.
   private void loadJavaScript() {
       JavaScriptLoader jsLoader = RWT.getClient().getService(
               JavaScriptLoader.class);
       ResourceManager resourceManager = RWT.getResourceManager();

       // Load file logjs.js into page
 
       jsLoader.require(resourceManager.getLocation(REGISTER_PATH + "/"
               + "logjs.js"));

       // Load file load-css-file.js into page
   
       jsLoader.require(resourceManager.getLocation(REGISTER_PATH + "/"
               + "load-css-file.js"));
       
       // Load file rap-handler.js into page.

        jsLoader.require(resourceManager.getLocation(REGISTER_PATH + "/"
                  + "rap-handler.js"));
   }

   private void registerResources() throws IOException {
       ResourceManager resourceManager = RWT.getResourceManager();

       for (String fileName : FILENAMES) {

           // After registering, you can access on your browser:
           
           // (http://localhost:port/rwt-resources/logjs/abc.js )
           // logjs/abc.js            
           String path = REGISTER_PATH + "/" + fileName;

            // Check this resource has been registered yet.
           boolean isRegistered = resourceManager.isRegistered(path);

           if (!isRegistered) {
               ClassLoader classLoader = LogComposite.class.getClassLoader();
               // Real Path (in src)
               
               // logjsresources/abc.js
               String realPath = REAL_RESOURCE_PATH + "/" + fileName;

               InputStream inputStream = classLoader
                       .getResourceAsStream(realPath);
               if (inputStream == null) {
                   throw new IOException("File not found " + realPath);
               }
               try {
                   // Register resource                    
                   resourceManager.register(path, inputStream);
               } finally {
                   inputStream.close();
               }
           }
       }
   }

   @Override
   protected void checkSubclass() {
   }

   public void appendWarn(String text) {
       System.out.println("appendWarn");
       JsonObject obj= new JsonObject();
       obj.add("text", text);
       this.remoteObject.call("appendWarn", obj);
   }
   
   public void appendErr(String text) {
       System.out.println("appendErr");
       JsonObject obj= new JsonObject();
       obj.add("text", text);
       this.remoteObject.call("appendErr", obj);
   }
   
   public void appendInfo(String text) {
       System.out.println("appendInfo");
       JsonObject obj= new JsonObject();
       obj.add("text", text);
       this.remoteObject.call("appendInfo", obj);
   }
   
   public void clearAll() {
       System.out.println("clearAll");
       this.remoteObject.call("clearAll", new JsonObject());
   }
}

    @Override
    protected void createContents(Composite parent) {
        
        // Change code, to enable open with WindowBuilder.
        parent.setLayout(new FillLayout());
        Composite main = new Composite(parent, SWT.NONE);
    }

package simplerapapplication;

import org.eclipse.rap.rwt.application.AbstractEntryPoint;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.layout.RowLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.o7planning.customwidget.logcomposite.LogComposite;


public class BasicEntryPoint extends AbstractEntryPoint {
   private LogComposite logComposite;

   /**
    * @wbp.parser.entryPoint
    */
   @Override
   protected void createContents(Composite parent) {
       
       parent.setLayout(new FillLayout());
       Composite main = new Composite(parent, SWT.NONE);
       main.setLayout(new GridLayout(1, false));
       
       logComposite = new LogComposite(main, SWT.BORDER);
       logComposite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true, 1, 1));
       
       Composite composite = new Composite(main, SWT.NONE);
       composite.setLayout(new RowLayout(SWT.HORIZONTAL));
       composite.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false, 1, 1));
       
       Button btnNewButton = new Button(composite, SWT.NONE);
       btnNewButton.addSelectionListener(new SelectionAdapter() {
           @Override
           public void widgetSelected(SelectionEvent e) {
               allErrorLine();
           }
       });
       btnNewButton.setText("Add Error Line");
       
       Button btnNewButton_1 = new Button(composite, SWT.NONE);
       btnNewButton_1.addSelectionListener(new SelectionAdapter() {
           @Override
           public void widgetSelected(SelectionEvent e) {
               addWarningLine();
           }
       });
       btnNewButton_1.setText("Add Warning Line");
       
       Button btnNewButton_2 = new Button(composite, SWT.NONE);
       btnNewButton_2.addSelectionListener(new SelectionAdapter() {
           @Override
           public void widgetSelected(SelectionEvent e) {
               clearAll();
           }
       });
       btnNewButton_2.setText("Clear ALL");
   }
   
   
   private void allErrorLine()  {
       logComposite.appendErr("Starting Servlet Engine: Apache Tomcat/7.0.23");
   }
   
   
   private void addWarningLine()  {
       logComposite.appendWarn("Starting Servlet Engine: Apache Tomcat/7.0.23");
   }
   
   private void clearAll()  {
       logComposite.clearAll();
   }

}