Sunday, February 15, 2009

Announce: DesignGridLayout 1.1 released!

Two weeks after the fourth release candidate of DesignGridLayout 1.1 (1.1-rc4), I have decided to release the official final 1.1 release.

Compared with previous official 1.0 release, this version brings the multiple rows span components feature, in addition to a few enhancement and bugs fixes:
  • fixed several problems with baseline alignment (only on Java 5): issues #3 and #27
  • fixed a problem with smart vertical resize of JList (issue #28)
  • fixed an exception with multi-grid feature (issue #26)
  • fixed an exception when creating a row but adding no component to it (issue #30)
  • fixed a bad look with grids having just a label but no component (issue #31)
  • optimized the size of the example jar (removed all screenshots that are used during automatic tests)
  • completely refactored the examples application
  • added an option to disable "smart vertical resize" feature (issue #34)
Now I can go back to work on next release (1.2). Future version 1.2 will have two major features:
  1. Synchronization of several layouts: with this feature it will be possible to ensure correct alignments (vertical or horizontal) across several panels using DesignGridLayout. This will be particularly useful for use inside JTabbedPanes or in Wizard dialogs.
  2. Extension API to customize policies related to components vertical resize (the current -internal- policy recognizes only vertical JSliders and JScrollPanes as variable height components, but some users have expressed the need to recognize also other specialized components)
First enhancement is on the way but will take some more time since it is a quite complex feature. I intend to release a 1.2-beta with this feature only, for users to check if it fits their needs well in synchronizing alignments. 1.2-beta is expected by mid-March if I can progress well.

If you're not afraid of using a "work-in-progress" version, you can get it from Subversion trunk, build it according to the instructions on the web site, then take a look at the new Synchronizer class.

I hope to have a first 1.2 release candidate by end of March or early April.

Saturday, February 07, 2009

JInternalFrame lesson learned

I am not a big fan of MDI (Multiple Document Interface) UI in general. I much prefer SDI or, better, UIs with docking capability.

Hence I don't have much experience with Swing JDesktopPane & JInternalFrame (the basic building bricks for creating an MDI UI in Swing).

However, a few days ago, an engineer from my company, developing a sample MDI UI (for an exercise related to a "GUI training"), was using DesignGridLayout LayoutManager and found a strange behavior in one of his windows, as demonstrated in the following screenshot, taken after a few pixels increase of the frame height (note the table overlapping the "Open" button):

The layout code is there:
UIHelper.addGroup(layout, "Criteria");
layout.row().center().add(searchButton, resetButton);

UIHelper.addGroup(layout, "Results");
I found it strange because I had never faced this bug with DesignGridLayout before. Hence I have started investigating. The first surprise to me was that I could not reproduce this problem in a JFrame or a JDialog!

Hence I've written the simplest Test Case application, using JInternalFrame, to reproduce this problem:
JFrame mainFrame = new JFrame();
mainFrame.setBounds(30, 30, 800, 600);

JDesktopPane desktop = new JDesktopPane();

JInternalFrame frame = new JInternalFrame("", true, true, true, true);
frame.setLocation(30, 30);

JPanel top = new JPanel();
setTableHeight(table, 3);
DesignGridLayout layout = new DesignGridLayout(top);
layout.row().center().fill().add(new JScrollPane(table));
layout.row().center().add(new JButton("OK"));

catch (java.beans.PropertyVetoException e)
Here is the screenshot (at preferred size):

After a long debugging session, I found out that the preferred height of the JScrollPane in the above example was incorrect at the time Swing calls LayoutManager.preferredSize(); but when the frame is displayed (LayoutManager.layoutContainer() is called), the height of the JScrollPane is correct!

Further investigation (and pixels counting on the screen!) has shown me that during the call to pack(), the preferred height of the JScrollPane is equal to the preferred height of the embedded JTable, plus the JScrollPane borders, but it does not include the JTableHeader!

After checking Swing source code and trying to change slightly the code that packs and shows the JInternalFrame, I found out that the problem is that pack() is called too early!

The following change just removed the problem:
// Order of calling desktop.add() is important wrt frame.pack() call!

The rant

This problem is specified nowhere in JDesktop or JInternalFrame javadoc! In addition, the JInternalFrame section of the Swing tutorial is totally unclear and even misleading about that point!

Well that's a lesson learned for me:
Always make sure you add JInternalFrame to the JDesktopPane before calling pack().

Event better: avoid MDI like the plague (I remember, a long time ago, being allergic to Swing MDI because of various other problems...)

Thursday, February 05, 2009

Why I do open source and how I came to it

As prompted by Alex Ruiz (himself prompted by Kirill), I will explain in this post my reasons for doing open source.

But as a way to explain my motivation, I will draw a history of my involvement into open source.
I have to admit that remembering that history was not easy, thanks Google I could find quite a lot of facts I had almost forgotten about my own past;-)

Let's start with my first projects, actually never open sourced, some even never released "in the wild"!
  • ObjectBase: never completed (only reached specification stage in 1993)
  • EasyMage: released in 1994 (C++, MacOS, shareware actually, source code never disclosed). At that time I developed this application as a passionate. And as a dreamer, I also hoped making some money out of it (IIRC, I did not pass over 100 licenses sold;-))
  • SCADA (C++ & Java 1.2, around year 1997-2000): never released. But this project helped me a lot learning Java along with CORBA.
  • CORBA WhiteBoard (Java 1.4, around years 2000-2003): never released. But this project gave me more experience with Java Swing. And more impotantly, it has served as inspiration roots for my second Open Source project, HiveBoard.
All projects above have brought me a lot in terms of pure technical knowledge (C++ & Java languages, CORBA technologies, Swing GUIs). However, the whole process to implement these projects was quite awkward. Open Source has helped me getting more "professional" in the whole software lifecycle (in particular in the areas of automated testing, planning, issues management).

Now let's go further into my progressive involvement into Open Source. First of all, all projects above were developed with a spirit of "implement everything from scratch" (the DRY principle did not really exist in these times;-) and using only little third-party -open source- libraries)

My first involvement in Open Source can be traced back to 1999, it was quite limited: I have reported bugs to the omniORB library and then contributed some answers to questions in the forum. I also evangelized omniORB to my students in 1999 (I was a part-time IT professor in Vietnam at that time).

This may not look much but actually, this is very important in Open Source: contribution doesn't have to be just committing code, but also using open source code in your own projects, reporting problems, suggesting enhancements, helping other users when you can, evangelizing the products you use and like...

At that period, I have also contributed problems reports to ORBACUS/Java (which was open source at that time).

Then, much later on (mid 2004), at this time Spring started to take off seriously, I was interested in Dependency Injection but hated Spring because of its too verbose XML configuration. Then I discovered HiveMind (it was in beta at that time) and found it much more interesting than Spring. However, it was lacking all that Spring had which is not DI-related (integration with persistence libraries in particular). I found HiveMind so good a DI framework that I wanted to evangelize it, but it always failed in comparison to Spring because of the lack of 3rd-party integration. That's why I decided, late 2004, to start HiveTranse my first OSS project. Unfortunately it seems it didn't help wider adoption of HiveMind. But at least it has served me to start my second OSS project, HiveBoard, at the end of 2004.

Both projects have really absorbed my time during several years and they have helped me improving my skills in:
  • Java technical area: I started to get acquainted with Hibernate, iBatis, securityfilter... I also worked with useful products like Tomcat and Jetty.
  • Software lifecycle process: I have learned to use tools to help me build (ant, el4ant), and test (JUnit, jmock, dbunit, abbot). I also got used to managing issues. I had to perform quite a bunch of efforts in terms of documentation (good for changing a "standard" developer's bad habits;-))
  • Soft skills: when you commit into Open Source, you have to be careful about not growing too big an ego, and rather be humble towards the mistakes you make (and the remarks you get about these mistakes). You have to listen to what others tell you and accept criticism on your project. In other words, you have to "open up", this is one quality I believe I have grown during my Open Source years (although I am far from perfect to this regard;-))
More recently (mid 2008), I have joined the DesignGridLayout project. The reason why I did so was that because I found this library excellent, I had started to use it in HiveBoard, and I wanted to "give back" some of my efforts to the community, from which I had already benefited a lot (I would be very embarrassed to enumerate the exhaustive list of OSS libraries and tools I have use in the past 10 years).

What I have learned from DesignGridLayout is:
  • how to design a good API (I believe)
  • how to "market" the project (although the results don't seem compelling so far)
  • how to keep my cool (or at least, try to;-)) when facing some "attacks" from other people
I consider the third point important because, although Open Source contribution is generally very rewarding, it can also bring you some problems you would never have imagined. I consider it a positive point however: most often, attacks arise from some fear of competition, which in a way means that what I have done so far is probably not too bad;-) Anyway, I believe the only response to attacks is "go ahead, don't listen, try to do better and show it".

To sum up with the reasons I do open source:
  • learn more about new technologies (very important in our profession where technology evolves at a fast pace) without any external constraint (you can choose the latest "cool stuff" to try and integrate in your work)
  • learn more about tools to help the release management process (these tools I can later on push them in a professional environment in my daily job)
  • give back to the community what the community has given me
  • hopefully help the others by giving away something you consider useful to other people
  • get some visibility (open sourcing the projects you originally used for yourself brings some extra "cost" in terms of time, so you definitely want to have these efforts "paid back": the reward here is the kind comments on your projects, the bugs reports, the suggestions for improvements...)
  • get some "technical respect" in my daily job (engineers in my company respect me, not just because I'm older than them and I am their boss, but because they can see that I have a proven record of technical background and I am not just a stupid manager who understands nothing to software development)
To summarize further I could reduce this to just one word "Passion" of everything related to IT (not just coding but all tools and practices around software engineering).

Actually I think that's not very far from what Kirill and Alex have mentioned: such a long post to say the same as others already have! Promised, next time I blog I'll try to talk only about new stuff;-)

For those who have read until there to see who would be the next ones to be prompted for the reasons they do open source, sorry guys, you have read all my prose for nothing, I have nobody left on my list (or contrarily I have potentially too many to enumerate);-)