All posts by Dominik

Dominik is a PhD student at the Control Theory and Robotics Lab, TU Darmstadt, as part of the Research Training Group GKMM (GRK1362). My research focuses on state estimation in distributed systems. As hobby, I contribute to the KDE project and work on the Kate application and editor component.

Highlight Selected Text

Kate has a new plugin called “Highlight Selection”. Since it is a KTextEditor plugin, it is available for all apps using KatePart (e.g.: Kile, Kate, KWrite, KDevelop etc). What does it do? If you select a whole word, all occurrences of this word are highlighted as well:

You can jump to the next occurrence with ctrl+h (btw: ctrl+h works already since KDE 4.2 or so). The plugin will be included in KDE 4.6. If you can’t wait, you can use it already now by building Kate from the sources.

(Side note: Be careful with enabling this plugin in KDevelop, since KDevelop itself is already doing extensive highlighting)

Recent Files Menu in Kate

As many other applications Kate has the menu File > Recent Files, which lists all files you recently used. This recent file list right now is per session, i.e., each session has its own entries listed as recent files. Now there is a request to change it such that there is just one single global recent file list. I think having two recent files menus (one for the session and one global) is a bad solution. Further, adding an option for that also sounds wrong.

To change or not to change, that’s the question?! :) What do you think?

Encoding Detection Revised

In recent KDE releases up to version 4.4 Kate unfortunately very often selected the wrong encoding. The result is that e.g. german umlauts (öäü) show up as cryptic signs in the text editor. What I’ve seen lots of times is that in this case people start to fix those characters manually for the entire document. In other words: They totally do not get at all that the text document simply was opened with the wrong encoding. In fact, the users usually do not even know what encoding is at all. While this is of course kind of sad, this certainly won’t change…

Given this fact, the only correct “fix” is a very good automatic encoding detection, such that the encoding is usually chosen correctly. In the rewrite of Kate’s text buffer for KDE 4.5, Christoph also rewrote the file loader including the encoding detection. The detection now works as follows:

  1. try selected encoding by the user (through the open-file-dialog or the console)
  2. try encoding detection (some intelligent trial & error method)
  3. use fallback encoding

In step 1, Kate tries to use the encoding specified in the open-file-dialog or the one given when launching Kate from the console. On success, we are done.

The encoding detection in step 2 first tries unicode encoding by looking for a Byte Order Mark (BOM). If found, it is certain that the text document is unicode encoded.  If there is no BOM, Kate next uses a tool from KDElibs (KEncodingProber) to detect the correct encoding. This is basically trial & error: Try encoding A, if there are characters in the document the encoding is not able to represent, try encoding B. Then C and so on… Unfortunately, this also doesn’t always work, because a byte sequence might be valid in several encodings and represent different characters. This is why it’s more or less impossible to get the encoding always right. There is simply no way…

If the encoding detection fails, Kate uses a fallback encoding. You can configure this fallback encoding in the editor component settings in the “Open/Save” category. If the fallback encoding fails as well, the document is marked as read-only and a warning is shown.

What about Kile and KDevelop?

One of the applications that heavily suffered of the wrong encoding detection in the past was the LaTeX editor Kile. The same holds probably for KDevelop (although it’s usually less critical with source code). The good news is, that with KDE >= 4.5 the problems with respect to wrong encoding should be gone. So it’s certainly worth to update if you are affected by this issue.

Featured Articles

Looking back at the last month, migrating our Kate homepage over to WordPress was a vast success. The useful content we had on our old Drupal was copied over. The benefit of WordPress is that we now have a nice blog software as well with which we even aggregate some external blogs related to Kate. The new homepage is also more structured by having a list of featured articles showing useful resources, such as links to user or developer documentation.

The idea behind of the featured articles is to provide links to blog entries explaining in more depth what you can do with Kate. There are lots of useful tricks probably even some KDE developers aren’t aware of. If you have further hints of how to efficiently use Kate, please contact us and write a blog entry on kate-editor.org.

Besides that, thanks to all contributors for our awesome release in 4.5! :)