Leave a comment Posted on by Leo Ufimtsev gtk, swt

[swt/gtk development] Why you should type the odd /*int*/ comment after long

You might have noticed that a lot of code in SWT/GTK has that odd /*int*/ comment after a long declaration.

long /*int*/ list

I turns out the comment is needed for backwards 32 bit support.

So in general you should put it in parameter declarations and in variable declarations:

//Parameter declaration:
Control [] _getChildren (long /*int*/ parentHandle)

//Variable declaration:
long /*int*/ list = OS.gtk_container_get_children (parentHandle);

This is especially important in OS.java which is used to generate C code.

Leave a comment Posted on by Leo Ufimtsev swt

SWT Bug Triage

If you are a GTK/SWT developer and want to be involved in SWT Triage,
Then you should read:
https://www.eclipse.org/swt/triage.php

It is also useful to subscribe to the swt-platform email in bugzilla.
This way you’ll get emails for new SWT bugs and comment update on un-assigned bugs.
To do this, go to bugzilla, -> Preferences -> Email preferences
-> “Add users to my watch list” , add: platform-swt-inbox@eclipse.org
The only trouble is that you’ll get emails for all platforms (Windows/Mac/Linux) and you’ll have to create some filters for sorting things out. But in general I found that it’s good to be ‘aware’ of the issues that happen on windows/mac, as those sometimes occur on Linux also, or a bug labeled as ‘windows’ often impacts linux swt also.

 

 

21 Comments Posted on by Leo Ufimtsev Eclipse, gtk

How to tell if you are running Eclipse on Gtk2 or on Gtk3

When troubleshooting Eclipse bugs, I sometimes ask if you are running eclipse on gtk2 or gtk3.

Usually I can tell visually if Eclipse is running on Gtk2 or Gtk3, but this changes depending on your system theme.

In the about section

As Alexander Kurtakov pointed out and described in Lar’s article ,

Help -> About -> Installation Details -> Configuration Tab.

Look for something like:
org.eclipse.swt.internal.gtk.version=3.14.12

It’s usually somewhere near line 84 ish. But you can copy the text and search for it in your text editor.

Note, if this line is missing altogether, you’re (very most likely) running Eclipse on Gtk2.

See what version is on your system

You can find out which version of gtk is installed on your system by running pkg-config (you might need to install it first). This gives you an indication of which version of gtk eclipse might be using.

pkg-config --modversion gtk+-3.0

Force Eclipse to use either gtk2 / gtk3

You can force Eclipse to use a certain version of gtk:

#Gtk3 forced:
export SWT_GTK3=1
eclipse

#Gtk2 forced:
export SWT_GTK3=0
eclipse

Under gtk3, the entry in the about section should be present like: org.eclipse.swt.internal.gtk.version=3.14.12

 

[edit 2016-09Sep-08Thu]
This is actually by far the most visited blog entry on my blog (20k+ views)
I reference this page quite often, I made a short/memorable url for it: http://bit.ly/gtk2orgtk3

Leave a comment Posted on by Leo Ufimtsev Eclipse, swt

Correct SWT code style for widget development and using Eclipse’s regex to fix your code style.

When doing SWT Development, if you submit code with the wrong style, you might get some code-comments from other contributors advising you to fix your style.

Luckily there is an Eclipse-SWT-formatted profile that one can use or one can fix them with some Regex.

Note: I will update this article as I find out more about SWT style.
Continue reading →

2 Comments Posted on by Leo Ufimtsev Eclipse, Fedora, Linux, OS X, swt

How to create cross-platform SWT applications packaged in a single jar in Eclipse

The deal with SWT is that you geneally create a jar that runs nativley on a single platform.

This means that if you want to create an application that works on windows/mac/linux in both 32/64 bit, then you need to compile/package jar 6 files and distribute one file per platform.

This is very cumbersome for small projects where you want a single file that runs on every platform.

The solution is to bundle the jars and load them dynamically with Mchr3k’s SWT Jar loader.

The next challenge is how to get this business working in Eclipse. Well, there is a guide for this.

Basically, you create a project with the name “HelloWorld”, you have to
download the swt jar’s and rename them to match os/version and then you
have to add a build.xml file. This takes about 30 minutes.

I followed the guide and actually got it to work.

To make life easier, I created a git-repo with a template project.  You can clone it and start a SWT project with that.

I used swt 4.4 in the project. In the future you might want to update it. To do so:

  • Download the latest jar files from Eclipse’s download site .
    • click on the most recent version, e.g ‘4’4,
    • then search for “SWT Binary and Source”
    • download the Windows 32/64 Versions,   linux x86/x86_64/GTK+ versions, Mac OS X versions
    • open the archives and extract the ‘swt.jar’ files
    • match the jar files to the jar files in the project ./gui folder. But append new version. (4.4 -> 4.x)
  • Edit the build.xml file,
    • change the “swtversion=”4.4″” to the newer version.
    • Also update <fileset dir=”./gui” includes=”swt-*-4.4.jar” />

Screen shots:

Linux

crossSwt1

You can run the generated jar file with ‘java -jar crossSWT.jar”:

crossSWT jar

OS X

Here I had to launch the jar with a special paramater:
java -jar -XstartOnFirstThread crossSWT.jar
os x

Windows

I don’t use windows :-), but rumors has it works on windows also.