One of my favorite features in KWin is Window Switching (aka Alt+Tab) and it is not surprising that it’s also one of the areas I prefer to work on and love to see others working on.
This week our Window Switchers have received quite some love from various contributors. The compact layout got some usability improvements and the highlight in all layouts does no longer move around when pressing Alt+Tab for the first time. Navigation with cursor keys when the list of windows is open, is properly supported, now. That is in a horizontal layout the left/right keys can be used to navigate through the list, in a vertical the up/down keys are supported and in a grid all keys are supported. Of course the normal navigation is still Alt+Tab/Alt+Shift+Tab – navigation through cursor keys is just an additional useful feature for those who want to use it.
Speaking of grid based layouts: I implemented a new QML layout in a “Present Windows” style. It is a layout showing thumbnails of all windows in the list in a regular grid and taking the complete available screen estate. By that it is similar to the previous Alt+Tab mode inside the Present Windows Effect. The code related to Alt+Tab has been removed from the effect, but otherwise the effect is of course unchanged.
Having this mode as a QML layout has quite some advantages. E.g. it is no longer required to have desktop effects enabled, though it is still recommended 🙂 The layout follows the visual style of our primary Desktop Shell which makes it easier to use. Selection is indicated by the well known selection marker of the Desktop Shell Themeing. Last but not least the layout properly supports multiple screens, which has not been a pleasant experience with the old effect based implementation.
Overall the new grid layout is also incorporating some of the feedback we received for the new layouts introduced in 4.8. Our default layout replaced the BoxSwitch effect, but there has been a slight difference in behavior. The layout makes only use of the horizontal space and by that thumbnails can become so small that they cannot be recognized any more. In the new QML based layout the thumbnails always have the same size at the compromise that some of them are perhaps not visible.
A grid based layout provides here quite some advantages as the screen estate is used in a more efficient way to render high quality and good looking thumbnails even with a large amount of windows.
I like to remember that we are currently selecting ideas on how to improve our default settings and switching to the grid based layout may be one of those. Also I want to remember that all those changes are rather trivial and could easily be implemented by new contributors and are also listed in our ideas page and as milestones for 4.9.