K's cluttered loft - Howtos

CSS box model hacks

nospam@example.com (Klaus Reimer) — Tue, 17 Nov 2009 11:20:34 +0100

Consider that you want to display some DIV inside another DIV where the inner DIV always fills out the outer DIV completely:

<style type="text/javascript">
  #outer { width: 256px; height: 256px; }
  #inner { background: red; height: 100%; }
</style>
<div id="outer">
  <div id="inner"></div>
</div>

Width is already correct because the default value of auto keeps the inner DIV at maximum width. So only the height:100% style is needed for this scenario. But what if the inner DIV also has some padding or a border? Then the percent values will not work because according to the W3C box model the border and the padding is added to the width and height. So the inner DIV gets too large. In standard compliant browsers (Even in IE7) this can be solved pretty easy. IE6 needs a little hack. Read on...

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Stop supporting IE7?

nospam@example.com (Klaus Reimer) — Fri, 21 Aug 2009 08:07:03 +0200

As already written in my Stop supporting IE6 article I hoped for IE8 supporting media specifiers in CSS @import statements. The benefit would be to lock out IE6 and IE7 from seeing the CSS definitions without using proprietary IE conditional comments. Fortunately Microsoft really did it, they support this syntax in IE8!

So if a website is going to drop support for IE7 (which may be a good idea because IE7 is still a pain-in-the-ass when it comes to web standards) then it can be done like this:

<style type="text/css">
  @import "common.css" screen;
</style>

Using Microsoft's Browser Test VMs in Virtual Box

nospam@example.com (Klaus Reimer) — Fri, 12 Jun 2009 20:07:00 +0200

If you are a web developer like me then you most likely must test your web pages in at least three incarnations of the evil Internet Explorer. And if you are a linux user like me then you will most likely not use native windows installations to do this. And if you are a Microsoft hater like me then you may have no Windows installation CDs at all. So how are you going to test your stuff in Internet Explorer?

Fortunately Microsoft is so kind to provide some Virtual Machine Images for testing purposes. Unfortunately they are only available for Virtual PC but with some work they can be used in Virtual Box as well. In this article I will describe how to get these images running on Ubuntu Linux 9.04.

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Events in Java (Second try)

nospam@example.com (Klaus Reimer) — Wed, 03 Jun 2009 00:14:00 +0200

Well, I'm not that satisfied with the Signal/Slot system I described in a previous article. The reflection part of it makes me itch. So I gave it a second try...

First of all lets summarize the problems with the listener pattern:

Two classes (The data container for the event and the listener interface) must be created for each event.
At least three methods must be created for each event (Register, Unregister and Fire) in each class which is going to fire the event

So it's simply too much boiler-plate code and the goal is to put as much as possible of it into some library classes without losing any type-safety and without using reflection. I'm going to describe my solution in this article and again I will use the nonsense example of a citizen which drinks some beverage and a Big Brother which monitors it.

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Events in Java

nospam@example.com (Klaus Reimer) — Mon, 01 Jun 2009 15:23:00 +0200

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...

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Lazarus TActionList

nospam@example.com (Klaus Reimer) — Wed, 31 Dec 2008 19:23:47 +0100

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.

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I18N with Lazarus

nospam@example.com (Klaus Reimer) — Wed, 31 Dec 2008 17:36:23 +0100

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.

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Lazarus

nospam@example.com (Klaus Reimer) — Thu, 25 Dec 2008 15:00:00 +0100

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...

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Nice GTK1 fonts in Ubuntu

nospam@example.com (Klaus Reimer) — Mon, 15 Dec 2008 10:05:24 +0100

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.

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Stop supporting IE6

nospam@example.com (Klaus Reimer) — Mon, 06 Oct 2008 09:08:00 +0200

Lately I came to the conclusion that it is time to stop support for IE6 on new websites. I'm getting sick of using all those CSS hacks and I finally want to use new CSS selectors everywhere. IE7 is still a bad browser but at least it supports these selectors and (in most cases) even alpha-transparent graphics. It still needs some hacks but it's acceptable for now.

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Dell firmware problems with TSSTCorp TS-L632D DVD drive

nospam@example.com (Klaus Reimer) — Sat, 01 Mar 2008 22:49:58 +0100

If you own a Dell notebook with a TS-L632D CD/DVD drive and use it with Ubuntu Linux then you may have the same problem as me: You can't select the write speed in Nautilus. After hours of research I puzzled together various information I found on the net and now I got it working.

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Linux on Dell Latitude D820

nospam@example.com (Klaus Reimer) — Wed, 24 May 2006 21:08:00 +0200

Commercial ATI Linux Display Driver

nospam@example.com (Klaus Reimer) — Sun, 07 May 2006 16:02:00 +0200

A lot of people say ATI is doing a lousy job in providing good linux drivers for linux. Maybe this is true. But the situation is not that bad. With a little work it's possible to configure linux so you can really enjoy your ATI hardware. At least this is true for my current notebook: A Dell Latitide D810 which comes with a ATI Mobility X600.

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Ubuntu Linux on Dell Latitude D810

nospam@example.com (Klaus Reimer) — Sat, 06 May 2006 11:17:00 +0200

I already had this Notebook running with Ubuntu Linux for some months but never have written an installation report. I've switched to the newer Dell Latitude D820 but this machine has now it's second hardware failure so I've switched back to the Dell Latitude D810 and I think now it's a good time to write the missing installation report.

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OOP with JavaScript

nospam@example.com (Klaus Reimer) — Wed, 11 Jan 2006 21:41:00 +0100

First of all it should be said that OOP with JavaScript is a real pain. I have read documents on the net where JavaScript is held high for its simple OOP design but that's nonsense. Yes, JavaScript knows objects. And yes, it is possible to create custom objects in a very simple way. But one of the main reasons for OOP is inheritance and this is something which is possible but absolutely dirty in JavaScript. But ok, here you are, so you may be willing to learn it. Or maybe you know it better and can teach me a more clean approach. Feel free to contact me.

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