I am using KDE Plasma on Kubuntu 17.10 and I am searching for a way to make a window fit the height of the screen, preserving its current width and horizontal position.
For example, on Windows, one can drag the top edge of the window to the top of the screen, while resizing, and the window will be resized this way. Double clicking on the top (or bottom) edge also achieves this.
I have a very large monitor and the ability to resize a Window in this way is rather vital. Otherwise, the only alternative is snapping to the left or right half of the screen.