ptolemy.actor.gui

Class BrowserLauncher

java.lang.Object

ptolemy.actor.gui.BrowserLauncher

public class BrowserLauncher
extends java.lang.Object

BrowserLauncher is a class that provides one static method, openURL, which opens the default web browser for the current user of the system to the given URL. It may support other protocols depending on the system -- mailto, ftp, etc. -- but that has not been rigorously tested and is not guaranteed to work.

Yes, this is platform-specific code, and yes, it may rely on classes on certain platforms that are not part of the standard JDK. What we're trying to do, though, is to take something that's frequently desirable but inherently platform-specific -- opening a default browser -- and allow programmers (you, for example) to do so without worrying about dropping into native code or doing anything else similarly evil.

Anyway, this code is completely in Java and will run on all JDK 1.1-compliant systems without modification or a need for additional libraries. All classes that are required on certain platforms to allow this to run are dynamically loaded at runtime via reflection and, if not found, will not cause this to do anything other than returning an error when opening the browser.

There are certain system requirements for this class, as it's running through Runtime.exec(), which is Java's way of making a native system call. Currently, this requires that a Macintosh have a Finder which supports the GURL event, which is true for Mac OS 8.0 and 8.1 systems that have the Internet Scripting AppleScript dictionary installed in the Scripting Additions folder in the Extensions folder (which is installed by default as far as I know under Mac OS 8.0 and 8.1), and for all Mac OS 8.5 and later systems. On Windows, it only runs under Win32 systems (Windows 95, 98, and NT 4.0, as well as later versions of all). On other systems, this drops back from the inherently platform-sensitive concept of a default browser and simply attempts to launch Firefox via a shell command.

This code is Copyright 1999-2001 by Eric Albert (ejalbert@cs.stanford.edu) and may be redistributed or modified in any form without restrictions as long as the portion of this comment from this paragraph through the end of the comment is not removed. The author requests that he be notified of any application, applet, or other binary that makes use of this code, but that is more out of curiosity than anything and is not required. This software includes no warranty. The author is not responsible for any loss of data or functionality or any adverse or unexpected effects of using this software.

Credits:
Steven Spencer, JavaWorld magazine (Java//Tip 66)
Thanks also to Ron B. Yeh, Eric Shapiro, Ben Engber, Paul Teitlebaum, Andrea Cantatore, Larry Barowski, Trevor Bedzek, Frank Miedrich, and Ron Rabakukk

On November 3, 2003, BrowserLauncher was downloaded from http://browserlauncher.sourceforge.net/. That URL no longer exists, there is a replacement package which is LGPL'd. See http://web.archive.org/web/20031028032907/http://browserlauncher.sourceforge.net/ for the original web page.

Since:

Ptolemy II 3.0

Version:

$Id: BrowserLauncher.java 70402 2014-10-23 00:52:20Z cxh $, based on 1.4b1 (Released June 20, 2001)

Author:

Eric Albert (ejalbert@cs.stanford.edu)

Accepted Rating:

Red (cxh)

Proposed Rating:

Red (cxh)

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	delayExit Set to true if we copied a file out of a jar file so that the browser could display it.

Method Summary

Modifier and Type	Method and Description
static void	main(java.lang.String[] args) Launch the browser on the first argument.
static void	openURL(java.lang.String url) Attempts to open the default web browser to the given URL.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

delayExit

public static boolean delayExit

Set to true if we copied a file out of a jar file so that the browser could display it. The reason we need this flag is that the system will delete the temporary file on exit, and after openURL() is called, this Java process will exit unless we delay.

Method Detail

main

public static void main(java.lang.String[] args)
                 throws java.lang.Exception

Launch the browser on the first argument. If there is no first argument, then open http://ptolemy.eecs.berkeley.edu. Second and subsequent arguments are ignored. It is best if the first argument is an absolute URL as opposed to a relative URL.

For example, to open the user's default browser on http://www.eecs.berkeley.edu

  java -classpath $PTII ptolemy.actor.gui.BrowserLauncher http://www.eecs.berkeley.edu
  

Parameters:

args - An array of command line arguments. The first argument names a URL to be opened. If there is no first argument, then open http://ptolemy.eecs.berkeley.edu. Second and subsequent arguments are ignored.

Throws:

java.lang.Exception - If there is a problem launching the browser.

openURL

public static void openURL(java.lang.String url)
                    throws java.io.IOException

Attempts to open the default web browser to the given URL.

We use the following strategy to find URLs that may be inside jar files:
If the string does not start with "http": see if it is a file.
If the file cannot be found, look it up in the classpath.
If the file can be found in the classpath then use the found file instead of the given URL.
If the file cannot be found in the classpath, then pass the original given URL to the browser.

If the ptolemy.ptII.browser property is set, then its value is used as the value of the browser.
To always use Internet Explorer, one might invoke Ptolemy with:

 java -classpath $PTII -Dptolemy.ptII.browser=c:\\Program\ Files\\Internet\ Explorer\\iexplore.exe ptolemy.vergil.VergilApplication
 

To always use Firefox:

 java -classpath $PTII -Dptolemy.ptII.browser=c:\\Program\ Files\\Mozilla\ Firefox\\firefox ptolemy.vergil.VergilApplication
 

To preserve your browser choice set the ptolemy.ptII.browser property in $PTII/lib/ptII.properties. Note that each time $PTII/bin/configure is run, $PTII/lib/ptII.properties.in is read and $PTII/lib/ptII.properties is overwritten, so you may want to add your changes to co * $PTII/lib/ptII.properties.in.

Parameters:

url - The URL to open. It is best if the first argument is an absolute URL as opposed to a relative URL.

Throws:

java.io.IOException - If the web browser could not be located or does not run