Archived: This article is archived because it is not considered relevant for third-party developers creating commercial solutions today. If you think this article is still relevant, let us know by adding the template {{ReviewForRemovalFromArchive|write your reason here}}.

Overview

This snippet shows how to create a splash screen using eSWT. Example implements the splash screen as a window that is not maximized. Shows an image and also updates a ProgressBar. Follow the video link below to see how it works

Splash Screen Example Video

Source file

import javax.microedition.midlet.MIDlet;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.FormAttachment;
import org.eclipse.swt.layout.FormData;
import org.eclipse.swt.layout.FormLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.ProgressBar;
import org.eclipse.swt.widgets.Shell;
 
public class SplashScreenDemo extends MIDlet implements Runnable, SelectionListener {
 
  // A handle to the eSWT UI thread created by this MIDlet. 
  private Thread UIThread;
  // The eSWT Display created by this MIDlet in the eSWT UI thread.
  // When this is created the MIDlet gets connected to the native UI
  // functionality and eSWT UI toolkit is initialised for it. 
  private Display display;
  // A Shell widget created by this MIDlet. 
  private Shell shell;
  // A boolean to set when the event loop should exit. 
  private boolean exiting = false;
 
  public void startApp() {
    // Create the eSWT UI thread. 
    if(UIThread == null) {
      UIThread = new Thread(this);
      UIThread.start();
    }
  }
 
  public void pauseApp() {
    // Here we could reduce the resources but we should keep the Display 
    // instance and the eSWT UI Thread. 
  }
 
  // destroyApp is called when the MIDlet is terminated from the task list 
  // with the clear key, or the end key is pressed when the MIDlet is focused. 
  // It might also be called when the system needs to close applications 
  // e.g. in low memory conditions. 
  public void destroyApp(boolean unconditional) {
    // Make the event loop exit in the eSWT UI thread.
    exitEventLoop();
    // Wait for the eSWT UI thread to die. 
    try {
      UIThread.join();
    } catch(InterruptedException e) {
    }
  }
 
  // This method can be called from any thread to make the event loop to exit. 
  void exitEventLoop() {
    exiting = true;
    Display.getDefault().wake();
  }
 
  // The eSWT UI Thread. 
  public void run() {
    // Create the Display. 
    display = new Display();
 
    shell = new Shell(display);
 
 
    Rectangle screenSize = display.getBounds();
	final Image image = new Image(display, screenSize.width-50, screenSize.height/2);
	GC gc = new GC(image);
	gc.setBackground(display.getSystemColor(SWT.COLOR_CYAN));
	gc.fillRectangle(image.getBounds());
	gc.drawText("Splash Screen", 0, 5);
	gc.dispose();
	final Shell splash = new Shell(shell, SWT.ON_TOP);
	final ProgressBar bar = new ProgressBar(splash, SWT.SMOOTH);
	Label label = new Label(splash, SWT.BORDER);
	label.setImage(image);
	FormLayout layout = new FormLayout();
	splash.setLayout(layout);
	FormData labelData = new FormData ();
	labelData.right = new FormAttachment (100, 0);
	labelData.bottom = new FormAttachment (100, 0);
 
	label.setLayoutData(labelData);
	FormData progressData = new FormData ();
	progressData.left = new FormAttachment (0, 5);
	progressData.right = new FormAttachment (100, -5);
	progressData.bottom = new FormAttachment (100, -5);
	bar.setLayoutData(progressData);
	bar.setMaximum(10);
	splash.pack();
	Rectangle splashRect = splash.getBounds();
	Rectangle displayRect = display.getBounds();
	int x = (displayRect.width - splashRect.width) / 2;
	int y = (displayRect.height - splashRect.height) / 2;
	splash.setLocation(x, y);
	splash.open();
 
	display.asyncExec(new Runnable() {
		public void run() {
			for (int i = 0; i < 10; i++) {
				bar.setSelection(i+1);
				bar.update();
				try {Thread.sleep(1000);} catch (InterruptedException e) {
				}
			}
 
			splash.close();
			image.dispose();
			shell.setVisible(true);
		}
	});
 
 
    // Execute the eSWT event loop. 
    while(!exiting) {
      if(!display.readAndDispatch()) {
        display.sleep();
      }
    }
 
    // Clean up and destroy the MIDlet.
    display.dispose();
    notifyDestroyed();
  }
 
  public void widgetDefaultSelected(SelectionEvent e) {
  }
 
  public void widgetSelected(SelectionEvent e) {
    // Exit command selected, exit the event loop. 
    exitEventLoop();
  }
 
}

Postconditions

The splash screen will appear for 10 secs and update the ProgressBar every second. And will make the main application screen visible.

See also

• eSWT