Lobo Browser API Information

The Lobo Project

Lobo@SF

Lobo Browser API

This page explains how to use the Lobo browser JAR files as an API. We provide this API so that Swing applications that require web browser functionality can embed Lobo.

Requirements

The Browser API requires J2SE 5+ (JRE 1.5+). Direct JavaFX rendering in Lobo requires JRE (not JDK) 1.6+ at runtime.

Lobo vs. Cobra

The Cobra library and its dependencies are in charge of HTML and CSS parsing, rendering, plus Javascript processing – and not much else. Lobo, on the other hand, is a browser application that has been documented so that it can be used as an API. The Lobo browser API relies on the capabilities of Cobra as far as HTML is concerned. What the Lobo browser API provides are browser capabilities that are not HTML specific. These include:

Rendering content that is not necessarily HTML, such as images, text, JavaFX, Java, and any other content renderable via plugins.
A web request and HTTP engine supporting such features as HTTP authentication, HTTPS, cookies, caching, etc.
A navigation infrastructure.

Cobra, for the most part, expects developers to implement these features as they prefer, whereas Lobo implements them in specific ways (e.g. saving cached documents in $HOME/.lobo and so forth).

Cobra should be a more suitable solution in the following scenarios:

Only HTML parsing or simple rendering without browser-style navigation is required.
The developer wishes to have full control over how browser features are implemented and configured.
The developer requires a more compact framework.

API Documentation

JavaDoc for the Browser API may be found in the Lobo Browser API Documentation page.

Additionally, the Lobo Clientlet and Extensions API Documentation page can prove useful particularly in terms of extending the browser.

Setup

The JAR files required to use Lobo as an API may be found in the installation directory of Lobo. Note that JAR files under the ext directory must be present for many of the capabilities of the browser (including HTML) to work. Extension JAR files are expected to be in a directory named ext, which is a sibling of the Lobo executable JAR file.

In other words, lobo.jar, lobo-pub.jar and any other JAR files in the main installation directory should be added to the CLASSPATH. JAR files under the ext directory should not, as they are loaded dynamically. But they are expected to retain their placement relative to lobo.jar.

Size Note: JavaFX-related libraries (~ 10 Mb) are optional if you are only interested in the HTML capability. They are: javafxc.jar, javafxrt.jar and Scenario-*.jar.

Getting Started

A required first step is to call PlatformInit.getInstance().init to initialize security, protocols, look & feel, the console, the default window factory and extensions. If not all these features are required, at the very least initProtocols and initExtensions should be called.

The class FramePanel is a Swing component that can be used like any other Swing component. It renders HTML, images, text files and other content supported by browser extensions. To load a document in a FramePanel, invoke navigate or one of its variants.

Starting with Lobo 0.97.5, the class BrowserPanel can be used to embed a browser frame that has an optional toolbar, address bar, status bar (including a progress bar) and menu bar.

Examples

FramePanel example.
The following is a barebones program (requiring Lobo 0.98+) that embeds a FramePanel and loads the default Lobo home page.
LoboTestFrame.java
import org.lobobrowser.gui.*; import org.lobobrowser.main.*; import javax.swing.*; public class LoboTestFrame extends JFrame { public static void main(String[] args) throws Exception { // This optional step initializes logging so only warnings // are printed out. PlatformInit.getInstance().initLogging(false); // This step is necessary for extensions to work: PlatformInit.getInstance().init(false, false); // Create frame with a specific size. JFrame frame = new LoboTestFrame(); frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); frame.setSize(600, 400); frame.setVisible(true); } public LoboTestFrame() throws Exception { FramePanel framePanel = new FramePanel(); this.getContentPane().add(framePanel); framePanel.navigate("http://lobobrowser.org/browser/home.jsp"); } }
BrowserPanel example with browser toolbar.
The following program (requiring Lobo 0.98+) embeds a BrowserPanel instead. Hence, it has a toolbar and a status bar.
BrowserPanelTest.java
import java.awt.event.WindowEvent; import javax.swing.*; import javax.swing.border.*; import org.lobobrowser.gui.*; import org.lobobrowser.main.PlatformInit; public class BrowserPanelTest extends JFrame { public static void main(String[] args) throws Exception { // Initialize logging. PlatformInit.getInstance().initLogging(false); // This step is necessary for extensions to work: PlatformInit.getInstance().init(false, false); // Create frame with a specific size. JFrame frame = new BrowserPanelTest(); frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); frame.setSize(600, 400); frame.setVisible(true); } public BrowserPanelTest() throws Exception { this.setTitle("Lobo Demo"); final BrowserPanel bp = new BrowserPanel(); bp.setBorder(BorderFactory.createTitledBorder(new EtchedBorder(EtchedBorder.RAISED), "Embedded browser")); bp.navigate("http://lobobrowser.org/browser/home.jsp"); this.getContentPane().add(bp); this.addWindowListener(new java.awt.event.WindowAdapter() { public void windowClosing(WindowEvent e) { // This needs to be called in order // to inform extensions about the // window closing. bp.windowClosing(); } }); } }
The following is a screenshot of the BrowserPanelTest application GUI.

Licensing

Since Lobo, the application, is released under a GPL license, the Lobo browser API is also GPL licensed.

Help

If you require community assistance, please visit our Help Forum.

If you find something doesn't work quite the way it should, please submit a bug report or a feature request.