[Java How-To] #4 "Splash" Screens without a Plugin (Servoy 4)

Java How-To's are intended to provide real-world examples of how Java can be used to easily extend Servoy in useful ways. I will try to post a new one as often as possible.

Description

Because of the excellent support Servoy provides for scripting Java (via Rhino), creating a custom splash screen is a relatively simple scripting task, and you don't need a plugin to do it. All you need instead is a little knowledge of Swing, and enough skill with Photoshop® to create a cool splash image. ;-)

The code below creates a new frame, undecorates it (which is what makes it look like a "splash"), sizes it, shapes it, centers it, adds a graphic and text component from the media library and then displays the newly created frame for a specified period of time. The frame is disposed automatically thereafter.

You don't need to modify this code at all to get it working. Just upload a PNG image named "splash.png" to your Servoy media library, and also upload a simple text document named credits.txt. If you do want to edit this code though you certainly can. An example of doing so might be adding a progress meter or adding a border to the components etc.

If you want to change how long the splash is displayed for, just change the value of application.sleep(...).

Try this! I think you will be surprised at how good it works/looks.

Java Classes Used

For more information about any of the Java classes used, click their corresponding link below.

• javax.swing.border.EmptyBorder
• javax.swing.ImageIcon
• javax.swing.JFrame
• javax.swing.JPanel
• javax.swing.JLabel
• javax.swing.JEditorPane
• java.awt.BorderLayout
• java.awt.Frame
• java.awt.Insets
• java.awt.GraphicsEnvironment
• java.awt.Point
• java.awt.Rectangle
• java.net.URL
  

Total Lines of Code

Around 50

The Servoy 4 Code

function showSplash()
{
var pkgs = new JavaImporter(Packages.javax.swing.border.EmptyBorder,
Packages.javax.swing.ImageIcon,
Packages.javax.swing.JFrame,
Packages.javax.swing.JPanel,
Packages.javax.swing.JLabel,
Packages.javax.swing.JEditorPane,

java.awt.BorderLayout,
java.awt.Frame,
java.awt.Insets,
java.awt.GraphicsEnvironment,
java.awt.Point,
java.awt.Rectangle,

java.net.URL);

with(pkgs) {

// Create the splash frame and its components
var splash_panel = new JPanel(new BorderLayout(0,0));

var splash_image = new JLabel(new ImageIcon(new URL("media:///splash.png")));

var splash_credits_pane = new JEditorPane(new URL("media:///credits.txt"));
splash_credits_pane.setEditable(false);
splash_credits_pane.setMargin(new Insets(20,20,20,20));

splash_panel.add(splash_image, BorderLayout.CENTER);
splash_panel.add(splash_credits_pane, BorderLayout.SOUTH);
splash_panel.setBorder(new EmptyBorder(0,0,0,0));

var splash_frame = new JFrame();
splash_frame.setUndecorated(true);
splash_frame.getContentPane().add(splash_panel);
splash_frame.pack();

/*
 Size/shape and center the splash frame

 The bulk of this code was borrowed from a public post on Sun's
 Java forum then converted to Servoy/JS.

 See: http://forums.sun.com/thread.jspa?threadID=508444
*/
var ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
var center = ge.getCenterPoint();
var bounds = ge.getMaximumWindowBounds();

var w = Math.max(bounds.width/2, Math.min(splash_frame.getWidth(), bounds.width)); // Using JS Math here, not Java Math
var h = Math.max(bounds.height/2, Math.min(splash_frame.getHeight(), bounds.height));
var x = center.x - w/2;
var y = center.y - h/2;

splash_frame.setBounds(x, y, w, h);

if (w == bounds.width && h == bounds.height)
{
 splash_frame.setExtendedState(Frame.MAXIMIZED_BOTH);
}

// splash_frame.pack(); Optionally pack here (instead of above) to have the splash resize to shape of image

splash_frame.validate();

splash_frame.show();

application.sleep(3000);

splash_frame.dispose();
}
}

IMPORTANT: Please be advised that you should always backup your Servoy solution before implementing or attempting any of the techniques described in this blog. None of the techniques described are guaranteed to work in any way shape or form, or for any specific purpose. Use them entirely at your own risk.