Develop Reference

JCEF (Java Chromium Embedded Framework) Browser does not load content; only blank screen on Eclipse

I have been trying to get the Java version of Chromium Embedded Framework (JCEF) to work on Eclipse for some time. I am able to verify that the library files are working correctly, since if I run the included sample class files on the VM, the program runs and some webpage is displayed. However, if I run the program from Eclipse, the program will always display a blank window. I am able to verify that the library binary jcef_helper.exe is successfully run, but not matter how I link the .jar files and other library files, the webpage will not generate and there will always be a blank screen. I cannot pinpoint the issue here. I tried specifying path, adding the JCEF library path of my OS environment variables PATH field to no avail. I have followed the documentation, even sample files behave the same way when I have anything to do with compilation/ run. One note of interest, my Eclipse console will display this during run:
initialize on Thread[AWT-EventQueue-0,6,main]
Perhaps there is a thread issue?
Code in question:
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Toolkit;
import javax.swing.JFrame;
import javax.swing.WindowConstants;
import org.cef.CefApp;
import org.cef.CefApp.CefAppState;
import org.cef.CefClient;
import org.cef.CefSettings;
import org.cef.browser.CefBrowser;
import org.cef.handler.CefAppHandlerAdapter;
public class WebV
{
public static void main(String args[])
{
Dimension dispDimension = Toolkit.getDefaultToolkit().getScreenSize();
int width = (int)Math.round(dispDimension.getWidth() / 2);
int height = (int)Math.round(dispDimension.getHeight() / 2);
CefApp.addAppHandler(new CefAppHandlerAdapter(null)
{
#Override
public void stateHasChanged(CefAppState state)
{
if(state == CefAppState.TERMINATED)
{
System.exit(0);
}
}
});
CefSettings settings = new CefSettings();
settings.windowless_rendering_enabled = false;
CefApp cefApp = CefApp.getInstance(settings);
CefClient client = cefApp.createClient();
CefBrowser browser = client.createBrowser("http://www.google.com", false, false);
Component browserComponent = browser.getUIComponent();
JFrame frame = new JFrame();
frame.setTitle("WebV");
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.setSize(width, height);
frame.setResizable(true);
frame.setLocationRelativeTo(null);
frame.add(browserComponent);
frame.setVisible(true);
}
}
Tested with both Java 17 and Java 8.
Run on Eclipse, with VM args:
-Djava.library.path=./bin/lib/win64
Any inupt would be greatly appreicated.

This answer was kindly provided by 'Yanovsky' at the JCEF forums.
The simple example provided by the JCEF package is incomplete.
We need to add a CefMessageRouter instance to our browser client. This is demonstrated in the detailed examples, but not the simple one. This code should be added before we create our CefBrowser instance and after we have created a CefClient object:
CefMessageRouter msgRouter = CefMessageRouter.create();
msgRouter.addHandler(new MessageRouterHandler(), true);
msgRouter.addHandler(new MessageRouterHandlerEx(client), false);
client.addMessageRouter(msgRouter);
For reference, this is my post in the JCEF forum:
https://magpcss.org/ceforum/viewtopic.php?f=17&t=18834&sid=45381db639d1621f2f8b38b4d8848800

I just copied and pasted your code in eclipse and added the jars and ran the code and voila, google.com opened without any issues.
I didnt have to add any more new lines as suggested by mindoverflow.
The webpage was visible in the window after a few secs and not immediately.
Here's what popped up after running the code.
And in the eclipse console, I see this
initialize on Thread[AWT-EventQueue-0,6,main] with library path C:\path\to\dlls

Java error: "Can't open input server /Library/InputManagers/Inquisitor"

I'm just now getting into GUI's in Java and when experimenting with JFrame I get the following error:
java[3126:71534] Can't open input server /Library/InputManagers/Inquisitor
Despite the error the program runs fine, but I'd like to know what this is about as I couldn't find much about Inquisitor anywhere.
Running Netbeans 8.0.2 and Java 8 Update 40 on OS X Yosemite (10.10.2). The java code being run is:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Ikkuna extends JFrame implements ActionListener{
JTextField syöte;
JLabel vastaus;
JButton painike;
public void setTitle(String string){
super.setTitle(string);
}
public Ikkuna(){
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
setTitle("Celsius / Fahrenheit -muunnos");
this.setSize(400, 200);
this.setResizable(false);
JPanel paneeli = (JPanel) getContentPane();
syöte = new JTextField(10);
vastaus = new JLabel("tuntematon");
painike = new JButton("Laske");
painike.addActionListener(this);
syöte.addActionListener(this);
paneeli.setLayout(new FlowLayout(FlowLayout.LEFT, 10,10));
paneeli.add(syöte);
paneeli.add(vastaus);
paneeli.add(painike);
setVisible(true);
}
public void actionPerformed(ActionEvent e){
vastaus.setText("" + ((Integer.parseInt(syöte.getText())*1.8+32)));
}
public static void main(String[] args){
Ikkuna i = new Ikkuna();
}
}

TLDR: Don't worry about it, it has nothing to do with your code, although you're probably better of removing Inquisitor extension as there's a good chance that it's not working properly.
InputManagers are intended to be Keyboard/Mouse extensions for applications. The idea is that the code is loaded into applications and can change their behavior in relation to Mouse/Keyboard input, but are generally used as a mechanism for extending applications. They became more restricted in 10.5, where they had to be in the system supported location only (/Library/InputManagers), and stopped being loaded entirely on 64bit mode.
Java 8 is a 64bit only application, so if you're seeing this error, then it's probably because the extension is not being loaded because it's a 64bit application and the system doesn't load extensions in this case.
The extension Inquisitor doesn't look to have been updated in a long time, and was used to extend the functionality of Safari, adding auto-complete to the search bar. The default search functionality of Safari now includes auto-complete, so I would consider it obsoleted.
If you want extended functionality for Safari, there are other plugins which extend the behaviour, such as Glims (I used to use it, but stopped because I felt it destabilized safari more than usual).
Opening the /Library/InputManagers folder (open a Finder window, hit Command-G to get a location field and type in the directory, then hit enter) will allow you to see what input managers are present on the system.

ClassNotFoundException using Processing's PApplet with Arduino Tool

I developer a basic Processing PApplet to run as a Tool in the Arduino IDE and that ran fine until Arduino 1.5.8. The problem I have is that in Arduino 1.6.0 some of the code got refactored and this happened on the Arduino side:
" In order to provide a better command line, IDE has been refactored
into app and arduino-core which is the old core In order to avoid
conflicts between classes, PApplet was moved from
processing.core.PApplet to processing.app.legacy.PApplet "
This explanation came from one of the Arduino IDE developers. It's worth noting that processing.app.legacy.PApplet is a (very)stripped down version of PApplet, discarding all graphics capabilities which I need.
Initially I was getting this error:
Uncaught exception in main method: java.lang.NoClassDefFoundError: processing/core/PApplet
Placing Processing's core.jar in the same location as the eclipse exported tool jar fixed this issues, but let to another:
Exception in thread "AWT-EventQueue-0" java.lang.RuntimeException: You need to use "Import Library" to add processing.core.PGraphicsJava2D to your sketch.
at processing.core.PApplet.makeGraphics(Unknown Source)
at processing.core.PApplet.init(Unknown Source)
The part that is confusing is I've used Processing's library source java files instead of the core.jar compiled library to avoid this issue, but it didn't change anything.
I've gone through PApplet's source code and found the graphics/renderer class gets loaded and instantiated at runtime here like so:
Class<?> rendererClass =
Thread.currentThread().getContextClassLoader().loadClass(renderer);
Constructor<?> constructor = rendererClass.getConstructor(new Class[] { });
PGraphics pg = (PGraphics) constructor.newInstance();
and this is where the ClassNotFoundException is caught throwing the Runtime exception:
catch (ClassNotFoundException cnfe) {
// if (cnfe.getMessage().indexOf("processing.opengl.PGraphicsOpenGL") != -1) {
// throw new RuntimeException(openglError +
// " (The library .jar file is missing.)");
// } else {
if (external) {
throw new RuntimeException("You need to use \"Import Library\" " +
"to add " + renderer + " to your sketch.");
} else {
throw new RuntimeException("The " + renderer +
" renderer is not in the class path.");
}
}
I'm getting more comfortable with java, but I don't have enough experience to figure this one out. It looks like a classpath issue, but I'm not sure why this happens and how I should tell java where to find the classes it needs to load.
Here is the code test I'm using based on the Arduino Tool sample that comes with the IDE. Currently I'm exporting the jar file (not runnable) from eclipse:
/*
Part of the Processing project - http://processing.org
Copyright (c) 2008 Ben Fry and Casey Reas
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package com.transformers.supermangletron;
import java.awt.Color;
import java.awt.Dimension;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import processing.core.PApplet;
import processing.app.Editor;
import processing.app.tools.Tool;
//import processing.app.legacy.PApplet;
/**
* Example Tools menu entry.
*/
public class Mangler implements Tool {
private Editor editor;
public void init(Editor editor) {
this.editor = editor;
}
private void setupSketch(){
int w = 255;
int h = 255;
// PApplet ui = new PApplet();
TestApp ui = new TestApp();
JFrame window = new JFrame(getMenuTitle());
window.setPreferredSize(new Dimension(w,h+20));
window.add(ui);
window.invalidate();
window.pack();
window.setVisible(true);
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
ui.init();
System.out.println("setup complete");
}
public String getMenuTitle() {
return "Mangle Selection";
}
public void run() {
setupSketch();
}
}
and here's the basic test Applet I'm trying to display:
package com.transformers.supermangletron;
import processing.core.PApplet;
public class TestApp extends PApplet {
public void setup(){
size(100,100);
}
public void draw(){
background((1.0f+sin(frameCount * .01f)) * 127);
}
}
How can I fix this ClassNotFoundException with my setup?
Any hints on what I should double check regarding class paths?

If you're getting this error when you run from eclipse, you have to add the library jars to your classpath. You do this by right-clicking your project, going to properties, then to Java Build Path. Make sure the library jars are listed under the Libraries tab.
If you're getting this error when you run an exported jar, then you need to do one of two things:
Either make sure you export a runnable jar with the library jars embedded inside the main jar. Do this from eclipse by right-clicking the project, going to Export, then choosing "runnable jar" from the list.
Or, make sure you set the classpath as a JVM argument. You do this using the -cp option from the command line.

UnsatisfiedLinkError no jogl in java.library.path

I'm trying to build a jogl app. I downloaded the jars and the native dll files. I have included them in my buildpath but when I run my code I get a the error from the title
Here is my vm file:
-server
-Xms128m
-Xmx512m
-XX:MaxPermSize=250m
-XX:ReservedCodeCacheSize=64m
-ea
-Dsun.io.useCanonCaches=false
-Djava.net.preferIPv4Stack=true
-XX:+UseCodeCacheFlushing
-XX:+UseConcMarkSweepGC
-XX:SoftRefLRUPolicyMSPerMB=50
-Djava.library.path="C:\Users\Vlad\Documents\dev\jogamp-all-platforms\lib\windows-amd64"
Here is that folder:
Here are the jars that I have in my build path:
And finally if there is any need for the actual code here it is:
import javax.media.opengl.GLCanvas;
import javax.media.opengl.GLCapabilities;
import javax.swing.*;
/**
* on 20/02/14.
*/
public class Demo extends JFrame {
static Demo app = new Demo();
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
app.setVisible(true);
}
});
}
public Demo(){
super("This is my first jogl app");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
GLCapabilities caps = new GLCapabilities();
GLCanvas canvas = new GLCanvas(caps);
canvas.addGLEventListener(new MyGLListener());
getContentPane().add(canvas);
}
}
EDIT
I have changed the libraries to match the new ones:
As you can see I have the natives and the jogl-all.jar and even the gluegen-rt.jar library.
The error that I get now is a compiler error:
This is the piece of code that's causing it:
GLCanvas canvas = new GLCanvas(new GLCapabilities());
It says that GLCapabilites (GLProfiles) in GLCapabilties cannot be applied to ();

You may also need to include gluegen-rt.jar in your build path. You should be able to obtain this from the same place where you found jogl-all.jar (JOGL 2).
Regarding your edit, for simplicity, you can use:
GLCanvas canvas = new GLCanvas(new GLCapabilities(null));
This will allow you to use the default GLProfile.

Your source code uses JOGL 1 whereas you try to use JOGL 2 JARs with it. Rather look at my simple example on Wikipedia. You can find the instructions to install JOGL in our Wiki here.

Swing on OSX: How to Trap command-Q?

After being convinced ("schooled") that Swing apps on Mac do look native, I'm trying to make mine look as native as possible. Everything looks great, but when I hit command+Q or do it from the menu, my windowStateChanged(WindowEvent e) is not firing on my main JFrame (if I exit in any other way, it does fire). How can I respond to the real Apple quit?

You can implement com.apple.eawt.ApplicationListener and respond to the Quit event. An example may be found in the Mac OS X Reference Library example, OSXAdapter.
Addendum: See Java for Mac OS X 10.6 Update 3 and 10.5 Update 8 Release Notes for information on deprecation, the redesigned com.apple.eawt.Application class, and the location of API documentation for the Apple Java extensions. Control-click or right-click on the .jdk file to Show Package Contents. You can browse the classes of com.apple.eawt among the OpenJDK sources.
As shown in this complete example, you can specify the desired
QuitStrategy; a WindowListener will respond to ⌘Q:
Application.getApplication().setQuitStrategy(QuitStrategy.CLOSE_ALL_WINDOWS);
As noted here, you can set the property from the command line
java -Dapple.eawt.quitStrategy=CLOSE_ALL_WINDOWS -cp build/classes gui.QuitStrategyTest
or early in the program, before posting any GUI events:
System.setProperty("apple.eawt.quitStrategy", "CLOSE_ALL_WINDOWS");
EventQueue.invokeLater(new QuitStrategyTest()::display);
Console, after ⌘Q:
java.vendor: Oracle Corporation
java.version: 1.8.0_60
os.name: Mac OS X
os.version: 10.11
apple.eawt.quitStrategy: CLOSE_ALL_WINDOWS
java.awt.event.WindowEvent[WINDOW_CLOSING,opposite=null,oldState=0,newState=0] on frame0
Code:
package gui;
import java.awt.EventQueue;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JFrame;
import javax.swing.JTextArea;
/**
* #see https://stackoverflow.com/a/7457102/230513
*/
public class QuitStrategyTest {
private void display() {
JFrame f = new JFrame("QuitStrategyTest");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.addWindowListener(new WindowAdapter() {
#Override
public void windowClosing(WindowEvent e) {
System.out.println(e);
}
});
f.add(new JTextArea(getInfo()));
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
private String getInfo() {
String[] props = {
"java.vendor",
"java.version",
"os.name",
"os.version",
"apple.eawt.quitStrategy"
};
StringBuilder sb = new StringBuilder();
for (String prop : props) {
sb.append(prop);
sb.append(": ");
sb.append(System.getProperty(prop));
sb.append(System.getProperty("line.separator"));
}
System.out.print(sb);
return sb.toString();
}
public static void main(String[] args) {
System.setProperty("apple.eawt.quitStrategy", "CLOSE_ALL_WINDOWS");
EventQueue.invokeLater(new QuitStrategyTest()::display);
}
}

The top voted answer is excellent but just to fill in the "best way":
System.setProperty("apple.eawt.quitStrategy", "CLOSE_ALL_WINDOWS");
This will trigger the standard window closing callback event which should work really nicely for portable code.
As a result of the discussion below it seems that its crucial to do this really early in the app. I wrote this early in the static initializer of the main class before any UI code was executed.

This is a pretty good question, and I must admit I don't have the answer. However, a couple years ago when I was working on a Java app and faced this problem, I solved it by registering a shutdown hook with the runtime that would do what I wanted the app to do before quitting. It's a heavy-handed solution but it worked. You can take a look at my code and see if it helps.

I was originally seeing a 'access restriction' violation when trying to access the com.apple.eawt.Application and com.apple.eawt.* subclasses.
(Note: I'm programming on a MAC, using Eclipse, with Java 1.6 using Swing)
So I needed to modify my java build path to allow access to the apple subclasses by adding "com/apple/eawt/**" access rule. After that this code below was able to compile and work for me:
//NOTE: This code only works for MAC OS. If you run this on Windows
//the application never starts (so you literally need to remove this block of code)
import com.apple.eawt.*;
import com.apple.eawt.QuitHandler;
Application a = Application.getApplication();
a.setQuitHandler(new QuitHandler() {
#Override
public void handleQuitRequestWith(com.apple.eawt.AppEvent.QuitEvent qe, com.apple.eawt.QuitResponse qr) {
// TODO Auto-generated method stub
int res = JOptionPane.showConfirmDialog(frame, "Are you sure you want to exit the program?", "Quit ?", JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE);
if (res == JOptionPane.YES_OPTION)
qr.performQuit();
else
qr.cancelQuit();
}
});

Have you tried setting up command-Q as an accelerator in your menu? Can you make your app respond to it?
I'm not positive, but I think this works in Linux and probably Windows with the equivalent Alt-F4. My app responds to the "killing" keystroke, I process some cleanup code and then I do a programmatic System.exit().
If you're "just" after graceful exit handling, you may also want to catch the WindowEvent WINDOW_CLOSING, where traditionally "are you sure?" stuff gets done.

Looking at the link to Java for Mac OS X 10.6 Update 3 and 10.5 Update 8 Release Notes I noticed that there is a section on Default Quit Action. This describes a system property to request that all windows are closed in response to the "Quit" menu item, which sounds like exactly what is needed? I have used this in my own application (using Info.plist to set the property on OS X only), and it seems to work as described. This would presumably only work on recent Java/OS X versions, but for those platforms seems like a neat solution, and doesn't require any code changes.