Version: (using KDE 4.1.0) Compiler: gcc 4.2.2 OS: Linux Installed from: Compiled From Sources When editing files with very long lines (like several hundred characters) containing lots of tabs, Kate slows down to a crawl. Cursor movement via arrow or page up/down keys takes several seconds per keypress on a fast dual core system.
Created attachment 27209 [details] Sample data file for PCGen application This is a data file that triggers the described problem.
*** This bug has been marked as a duplicate of bug 169549 ***
Bug 169549 is not exactly a duplicate, this file has several lines of line length about 700, it is not a one-line file.
Andreas: I disagree with this DUPE'ing as well. A single-line HTML file as in bug #169549 is not a realistic use case for a text _editor_; this however is an actual hand-edited data format used in connection with a relatively major FOSS application. Furthermore, it's a regression over KDE 3, where Kate used to handle the same files just fine.
Eike: Its still a file with rather long lines and as you can see in in the other bugreport thats something that simply won't ever be "quick and fast". Besides that, yes Kate in KDE4 is in general quite a bit slower than in KDE3, but I'm not sure its kate's fault - Qt itself also still is lacking performance-wise.
That is very unfortunate, as it is vital for me to edit this kind of files. It's basically a show-stopper for KDE4 for me. :(
*** Bug 210879 has been marked as a duplicate of this bug. ***
SVN commit 1036862 by pletourn: Render the tabstops non-antialiased Look as good as before and much faster (on X11) CCBUG:170322 M +12 -13 katerenderer.cpp WebSVN link: http://websvn.kde.org/?view=rev&revision=1036862
SVN commit 1037102 by dhaumann: backport SVN commit 1036862 by pletourn: Render the tabstops non-antialiased Look as good as before and much faster (on X11) CCBUG:170322 M +12 -13 katerenderer.cpp WebSVN link: http://websvn.kde.org/?view=rev&revision=1037102
I'v e built Kate with this fix, and it slightly improves the speed. however when handling lines of about 1000 characters length that contain many tabstops, it is still too slow to be of use in this mode; as an example, going to the end of the line from the start by using the End key still takes several seconds. However, this fix prompted me to try and switch off the display of the tabstop symbol, and as soon as this is done, Kate is as fast as ever. Having the tabstops visible would be nice though. It appears that the change of the tabstop symbol from the simple dot in KDE 3 to the "»" sign in KDE 4 actually causes this regression. Maybe it would be possible to add the old tabstop symbol back in as a third option besides just "on" and "off"?
No additional option. Maybe this can be solved by also solving bug #173699. If we still want characters instead of the three dots (KDE3), maybe it needs to be cached on a pixmap.
SVN commit 1038175 by pletourn: Optimize tabstop drawing Also remove a no longer needed workaround CCBUG:170322 M +5 -4 katerenderer.cpp WebSVN link: http://websvn.kde.org/?view=rev&revision=1038175
SVN commit 1038175 effects a noticeable improvement here. Moving from the start of a line (about 1500 colums with many tab stops) to the end of the line and back is still not as instantaneous as in the KDE 3 Kate, but this change makes Kate actually usable again. thanks!