Older blog entries for Kay (starting at number 52)

Java has no integrated event system but most classes in the Java Runtime uses the Listener Pattern for this. This pattern is pretty powerful and (when using Generics) completely type-safe but in the end it is still pain-in-the-ass. Think of a class which wants to send five different events. You have to write five listener interfaces and write at least 15 methods (five register methods, five unregister methods and five fire-event methods) and collections for all the listener objects which are registered. Depending on the type of events you may want to write five event classes which are used as containers for the event data. Lazy programmers therefor put all five events into the same listener interface so they only need one register/unregister/fire tripplet. But this requires the event receivers to implement all five listener methods even if they are interested in only one of them. So some genius invented the Adapter classes which already provide empty listener methods which can be extended by the event receiver. The whole thing is pretty annoying because it's so complicated to implement and to use.

So lets take a look at a different approach...

Because I'm currently playing Guild Wars pretty often and I was too lazy to switch between Windows and Linux when I switched between playing and working I installed lots of development software on Windows so I can work there, too. But after Windows crashed and shredded some of my source files while doing this I decided to ditch Windows completely. So I installed Guild Wars on Linux (using Wine) and after some configuration changes it works well enough. It never runs as fast as on Windows but it is fully playable.

In Delphi I used TActionList with lots of TAction items to implement the various actions in an application. These actions can then be linked to menu items and buttons. An action can have an OnUpdate event handler which is responsible for activating and deactivating the action depending on the current state of the application. This is a very useful feature which is also available in Lazarus but unfortunately it is somewhat broken in current Lazarus version (At least up to daily snapshot 20081231) because the OnUpdate event handlers are not called correctly for actions which are only linked to menu items. This bug is already reported and hopefully it will be fixed soon. But for now I have created a little workaround for it.

It's pretty difficult to find information about how to write a multi-lingual application with Lazarus. I've been through this and I hope that this article helps others to get on the right way. I'm not 100% sure the way I found is the right way but at least it works great for me. So it can't be totally wrong.

Currently I'm again involved in developing GUI software for Windows. In the past I always did this with Delphi so I thought it would be nice to use it again. I searched for a free version of it which was quite hard. How the hell is it called today? Borland Delphi? Code Gears Delphi? Turbo Delphi? Which is the newest version? Delphi 2006? Delphi 10? Where are the Personal Editions? Is there still a Kylix out there for cross-platform development? Wasn't there an announcement that Borland will switch to Eclipse for Delphi development? Very confusing situation...

I noticed that GTK1 applications have a rather large and ugly font on my system. I searched the internet for a solution and found references to files like .gtkrc-1.2-gnome and .gtkrc-mine and some font definitions I have to put in there. But none of these solutions worked out for me. I found another reference to the program xfontsel and with all these partial information I was able to find a nice working solution. I hope it will also work for others.