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.

Contribute to Kate

Currently we are at the Kate/KDevelop sprint in Vienna. Christoph and me took the time to look a bit around in the net for Kate, and more or less accidently stumbled over quite a lot of extensions by our users. Here are some examples:

Kate has just about 20 plugins written in C++. And, ironically, there are more plugins for Kate written in python. This is totally awesome, but still, the Kate developers didn’t even know about it ?¿? :-o

So we started contacting these potential contributors, and also asked why they e.g. upload it in some other git repository. One time, we got the answer, that they uploaded it somewhere to share it with other users. But really, the perfect way to share additions for Kate is to put it into the Kate git repository directly. This is how open source works…

So if you make additions or changes to Kate, please let us know, create a patch and send it to review board, come to our developer sprints, come to the annual KDE conferences… Talk to us, usually we are all pretty friendly and really happy about every single contribution!

Remove Trailing Spaces

Up to KDE 4.9, Kate Part had support to remove trailing spaces in two ways:

  1. Remove trailing spaces while editing
  2. Remove trailing spaces on save

The reasoning behind removing trailing spaces while editing is that when working on a document, we want to keep our own changes clean of trailing spaces. This way, we can for instance provide patches that are not cluttered with whitespace changes, and we just change lines that we really want to change.

The implementation of this feature unfortunately had quite some regressions that we were able to “fix” over time. For instance, you do not want to remove trailing spaces if the cursor is currently in the trailing spaces area. This alone means we have to kind of remember that we touched this line, and then remove it later. This was always hacky, and in fact, there are still corner cases that did not work.

For KDE 4.10, the both options were merged into just one option Remove trailing spaces with three possible values:

So we only support removing trailing spaces on save from KDE 4.10 on. The implementation is now very clean and based on the line modification system available since KDE 4.8: Thanks to this system we know exactly which lines in the document were changed. So if you choose “Modified Lines” in the configuration, trailing spaces of these modified lines are removed, and other lines remain untouched. If you choose “Entire Document”, then all trailing spaces in the document will be removed. And, needless to say, “Never” implies that trailing spaces are never removed.

For compatibility, the old mode-lines “remove-trailing-space” and “replace-trailing-spaces-save” are still supported, but you’ll get a kWarning() on the console. All these changes are also documented in the Kate handbook (once KDE 4.10 is released). From KDE 4.10 on, you should switch to the modelines

- remove-trailing-spaces none;
- remove-trailing-spaces modified;
- remove-trailing-spaces all;

Hope you like it…

How to remove a file with Kate

KDE has all these little nifty features, and – guess what – Kate has them, too. Here, we’ll have a look at how to delete a file with Kate. We’ll start with opening the file we want to delete. Example:

Next, we open the menu File > Open With and choose Other… as follows:

We’re almost done: Type ‘rm’ in the Open With dialog:

Now click OK to perform the action, et voila:

Now as you can see, Kate notifies you about the successful deletion. In case you change your mind, you can write it to disk again by clicking Overwrite. Reloading will tell you, that the file can indeed not be found, proving that Kate did exactly what you want. You can also ignore what you just did, which is probably the best choice. Don’t tell anyone :-)

PS: This tip comes from the KDevelop developers. So all Kudos and Cake go to them!
PPS: We are working hard at the Kate/KDevelop sprint in Vienna to provide the best tools for our users!