Using eSWT Browser in Java ME

Template:KBCS

ID		Creation date	May 20, 2008
Platform	S60 3rd Edition, FP2	Tested on devices	S60 3rd Ed. FP2 SDK
Category	Java	Subcategory	eSWT, Browsing

Keywords (APIs, classes, methods, functions): eSWT, Browser, QueryDialog, MobileShell, MessageBox

Overview

This code snippet demonstrates how to use eSWT's Browser class in Java ME. The Browser class instance implements the browser user interface metaphor and it allows the user to visualize and navigate through HTML documents. This example has also "Back", "Forward" and "Open URL" Commands for navigating to previous or next session history items and for opening desired html page. The MIDlet uses MobileShell, because it has a possibility to change the status pane size. The following section contains the complete code for compiling and running the example application.

Source code

import javax.microedition.midlet.MIDlet;
import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTError;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.ercp.swt.mobile.MobileShell;
import org.eclipse.swt.widgets.MessageBox;
import org.eclipse.swt.browser.Browser;
import org.eclipse.ercp.swt.mobile.QueryDialog;
import org.eclipse.ercp.swt.mobile.Command;
 
 
public class BrowserMIDlet extends MIDlet implements SelectionListener, Runnable {
    private Command exitCommand;
    private Command backCommand;
    private Command openCommand;
    private Command forwardCommand;
    private Command changeCommand;
    private Display display;
    private MobileShell shell;
    private Thread uiThread;
    private Browser browser = null;
    private boolean exiting = false;
    private int style = 2;  //MobileShell.SMALL_STATUS_PANE
    private String url = "http://forumnokia.mobi";
 
    public void startApp() {
        if(uiThread == null) {
            uiThread = new Thread(this);
            uiThread.start();
        }        
    }
 
    public void pauseApp() {
    }
 
    public void destroyApp(boolean unconditional) {
        exitEventLoop();
        try {
            uiThread.join();
        } 
        catch(InterruptedException e) {
        }        
    }
 
    void exitEventLoop() {
        exiting = true;
        Display.getDefault().wake();
    }
 
    public void run() {
        display = new Display();
        shell = new MobileShell(display, style);
        shell.setLayout(new FillLayout());        
        exitCommand = new Command(shell, Command.EXIT, 0);
        exitCommand.setText("Exit");
        exitCommand.addSelectionListener(this);        
        backCommand = new Command(shell, Command.BACK, 0);
        backCommand.setText("Back");
        backCommand.addSelectionListener(this);
        forwardCommand = new Command(shell, Command.OK, 0);
        forwardCommand.setText("Forward");
        forwardCommand.addSelectionListener(this);
        openCommand = new Command(shell, Command.OK, 1);
        openCommand.setText("Enter URL");
        openCommand.addSelectionListener(this);
        changeCommand = new Command(shell, Command.OK, 2);
        changeCommand.setText("Change status pane");
        changeCommand.addSelectionListener(this);
        try {
            browser = new Browser(shell, SWT.NONE);
        } catch (SWTError e) {
            MessageBox message = new MessageBox(shell, SWT.NONE);
            message.setText("SWTError: " + e.getMessage());
            message.open();
        }
        if (browser != null) {
            browser.setUrl(url);
        }
        shell.open();
        while(!exiting) {
            if(!display.readAndDispatch()) {
                display.sleep();
            }
        }
        shell.dispose();    // dispose objects
        display.dispose(); 
        notifyDestroyed();  // exit MIDlet                    
    }
 
    public void widgetSelected(SelectionEvent e) {
        if (e.widget.equals(exitCommand)) {
            exitEventLoop();
        }
        if (e.widget.equals(backCommand)) {
            browser.back();
        }
        if (e.widget.equals(forwardCommand)) {
            browser.forward();
        }
        if (e.widget.equals(openCommand)) {
            QueryDialog dialog = new QueryDialog(shell, SWT.NONE, QueryDialog.STANDARD);
            dialog.setPromptText("Enter URL:", "http://");
            url = dialog.open();
            if (url != null) {
                browser.setUrl(url);                
                shell.redraw();
            } else {}
        }
        if (e.widget.equals(changeCommand)) {
            if (style < 3) style = style + 1;
            else if (style == 3) style = 1;
            shell.changeTrim(SWT.SHELL_TRIM, style);
        }
    }
 
    public void widgetDefaultSelected(SelectionEvent arg0) {
    }    
}

Postconditions

When a BrowserMIDlet is opened, a browser window is shown on the screen. The browser will open the following URL: http://forumnokia.mobi.

See also

• eSWT