Category Archives: Developers

Kate needs BiDi/Unicode aware developers ;)

During our long bug hunting and fixing sprint I came along some nasty BiDi or Unicode related bugs.

I and most others in the Kate team are not really able to fix such issues :( We lack both the knowledge of the underlying techniques and are not able to write/read any language that really uses complex unicode chars or BiDi text.

Therefore: If you know Qt and you want to help out with fixing BiDi/Unicode related bugs, please provide patches for them in the KDE Bugzilla!

Here are the relevant bugs:

Any help here is highly appreciated! If you have questions about the internals of KatePart needed to fix such an issue, just ask in the bug or kwrite-devel@kde.org.

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…