Support (new posts)

Cannot run Kojo:

Thu, 21 Jul 2022 12:23:51 +0000

Hello,
I have just downloaded and installed Kojo (2.9.22) on my Macbook pro (Mac Os Monterey 12.5). No problems in installation.

I am trying to open the app, but it keeps loading without opening.
What can I do?

Thank you very much!

Cannot run Kojo:

Sun, 03 Jun 2018 09:15:45 +0000

Wow merci beaucoup

Tout fonctionne à merveille.

Cannot run Kojo:

Sun, 03 Jun 2018 00:10:47 +0000

Ah, please run Kojo with Java 8. To do so, just modify the java line in $KOJO_HOME/bin/kojo to point to your java 8 install.

You can get Java 8 from Oracle, IntelliJ, or from Ubuntu repos.

Cannot run Kojo:

Sat, 02 Jun 2018 23:55:00 +0000

Hello
I got this message when i try to lunch kojo2 on kubuntu 18.04.

Exception in thread "main" java.lang.ExceptionInInitializerError
at net.kogics.kojo.lite.DesktopMain.main(DesktopMain.scala)
Caused by: java.lang.RuntimeException: classloader (jdk.internal.loader.ClassLoaders$AppClassLoader@255316f2) is not a URLClassLoader
at scala.sys.package$.error(package.scala:27)
at net.kogics.kojo.lite.DesktopMain$.(DesktopMain.scala:23)
at net.kogics.kojo.lite.DesktopMain$.(DesktopMain.scala)
… 1 more

Thank you for your hard work.

Kojo och chrombooks: Re: Kojo och chrombooks IN ENGLISH Kojo and Chromebooks with ChromeOS

Thu, 24 Aug 2017 10:18:45 +0000

Yes you can, after liberating your student's machines: ChromeOS is actually prepared for running a Linux Ubuntu subsystem! Programming is all about controlling your computer so when teaching programming it makes perfect sense to unlock your Chromebook and use developer mode and then install what is called "Crouton" on your Chromebook.

Here is one of many guides on the net on how to do that:
http://www.androidauthority.com/crouton-turn-your-chromebook-into-far-more-than-a-glorified-web-browser-663044

The you install Java with this terminal command in your Ubuntu subsystem:

sudo apt-get install default-jdk

And then install Kojo as described for Linux on the Kojo download page. And ready to go!

BTW: This means that the sysadmin of your school should support your very important pedagogical ambitions in allowing your students to do "real" programing! :)

Hope this helped?

Good luck!

Kojo och chrombooks: Kojo och chrombooks

Thu, 24 Aug 2017 06:50:23 +0000

Mina elever har chromebooks. Går det att jobba med Kojo?

Kojo in DiDPI monitor:

Fri, 05 Feb 2016 18:31:23 +0000

I have started to play with this, and I have a new Kojo-Web build out there (http://www.kogics.net/webkojo). Let me know if you see any font size improvements with this build.

Msi-file: Re: Msi-file

Tue, 24 Nov 2015 05:50:38 +0000

Sorry, we currently only have an exe installer. Is there a problem with using the exe installer? Or is it an IT policy thing?

Msi-file: Msi-file

Mon, 23 Nov 2015 17:33:29 +0000

I would like to use Kojo with my pupils at school. Our IT-support wants a msi-file so that they can install Kojo with UpKeeper. Can anyone help me to find a msi-file?

javax.swing question: Re: javax.swing question

Thu, 22 Oct 2015 15:45:53 +0000

Try:
import javax.swing.WindowConstants
frame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE)

DISPOSE_ON_CLOSE is defined in WindowConstants. JFrame implements WindowConstants, but DISPOSE_ON_CLOSE is not visible via JFrame in Scala (can't remember why off the top of my head).

javax.swing question: javax.swing question

Thu, 22 Oct 2015 13:35:31 +0000

hi
I'm goofing around using Kojo to explore different things, and wanted to explore Swing. Having a problem because Frame.DISPOSE_ON_CLOSE is claimed not to be a member of java.swing.JFrame? No problem with EXIT_ON_CLOSE but I don't want to use that, because Kojo gets killed every time I close the window.

import java.awt.Graphics import java.awt.image.BufferedImage import javax.swing.JComponent import javax.swing.JFrame val frame: JFrame = new JFrame("Fractal") frame.setSize(640,320) frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE) frame.setVisible(true)

Results in:

Error[9,39]: value DISPOSE_ON_CLOSE is not a member of object javax.swing.JFrame

I realise Kojo isn't necessarily meant to be used in this way, but for my better understanding, I am curious why DISPOSE_ON_CLOSE doesn't show up!

Kojo in DiDPI monitor:

Tue, 20 Oct 2015 12:48:15 +0000

Both of these IDEs have customized themes; netbeans is closer to the default windows look and feel but it is not the standard one that ships with Swing.

Kojo in DiDPI monitor:

Sat, 17 Oct 2015 14:22:10 +0000

Does Netbeans use the 'Windows Look and Feel' on Surface Pro? And Intellij IDEA?

Kojo in DiDPI monitor:

Thu, 15 Oct 2015 01:41:21 +0000

Surface Pro 3 is 216 PPI, while the new Surface Pro 4 and Surface Book are 267 PPI. I noticed that the newer Netbeans is a bit better at handling high DPI, so Kojo may be able to leverage some of it perhaps?

Kojo in DiDPI monitor: Re: Kojo in DiDPI monitor

Mon, 12 Oct 2015 17:44:29 +0000

Noted:
https://bitbucket.org/lalit_pant/kojo/issues/4/kojo-in-didpi-monitor

Will investigate as soon as I get access to a high DPI monitor. What's the DPI/Resolution on Surface Pro 3?

- Lalit

Kojo in DiDPI monitor: Kojo in DiDPI monitor

Sat, 10 Oct 2015 13:09:50 +0000

Running Kojo under high DPI monitors like Surface Pro 3, the UI appears too small to be usable and the text size used in the editor and menu are tiny and unusable. Other Java programs like IntelliJ appears to respect the system text scale better; is it possible for Kojo to adapt the UI for the high DPI screens?

Problem with the Scala Tutorial and perhaps Kojo itself.:

Sun, 02 Aug 2015 05:13:41 +0000

FYI, Scala uses integer division from the Java world.

Problem with the Scala Tutorial and perhaps Kojo itself.:

Sat, 01 Aug 2015 21:13:10 +0000

This is an update on the above issue. I think I figured out what's wrong with Kojo/Scala. In the expression 3.5*9.4+7/5 the 7/5 isn't being converted into a floating point or real number before it is added to product of 3.5*9.4. This can be illustrated in the following script:

println(3.5*9.4+7/5) // Returns 33.9
println(3.5*9.4+7.0/5) // Returns 34.3 which is the correct product!
println(3.5*9.4+7/5.0) // Also returns 34.3 which is also correct!

So it appears that the 7 isn't being converted into a float. I can live with this bug, but just wanted to let everyone know that to be on the safe bet not to mix floats with integers until this gets correct. Take care now and have a good day!

Problem with the Scala Tutorial and perhaps Kojo itself.: Problem with the Scala Tutorial and perhaps Kojo itself.

Sat, 01 Aug 2015 18:33:11 +0000

Kojo 2.4 Beta Version: 2.4.06 r41 Build date: 20 Apr 2015 Java version: 1.8.0_51-64bit. Scala version: 2.11.6

Following "Expressions" section under the Scala tutorial, which is under Kojo's Help menu and ran the expression 3.5*9.4+7/5, which returned 33.9, I've repeated tried this expression using both Windows 7 calculator and Google search and the number I am getting from them is 34.3, which means either Kojo has a problem or the world as a problem. I have also tried just running it like this: println((3.5*9.4)+(7/5)), but again the result Kojo returns is 33.9. Perhaps I do not understand how the "order of operation" Kojo is performing, but I've tried it several ways got different results of course, but never got 33.9. Please look into this issue and let me know whether I am not understanding something or if there is a bug in Kojo. I really think Kojo is a great system overall, but if it's a calculation bug then it needs to be address. Thanks and have a great day!

Kojo hangs on loading screen in Ubuntu 15.04:

Sun, 12 Jul 2015 03:09:19 +0000

Good to know.

A similar looking problem was reported here: https://groups.google.com/forum/#!topic/kojo-dev/u1jbahCiu-0

I will update that thread.

Thanks,
- Lalit