I have just returned from the Qt World Summit and had my laptop connected to two different projectors there.

This was the first time I had a presentation using a Plasma 5 based desktop and in general it worked nicely (projector detected, etc).

I experiences some rather annoying snags with the config UI though, especially with the drag behavior of the screen rectangles.

kcm_screen's plugin info says it is at version 5.4.1 so this might have been fixed already (didn't find any open bug report on this with a quick simple search).

a) There is no snapping, it was impossible to correctly align the edges.
On the first day I tried for ~15 minutes, trying to move the mouse as diligently as possible, but in the end there was alway some 5-10 pixel offset in at least one direction.
With the touch pad even that would have been even harder.

b) During this repeated trying I ran into one occasion where the rectangle representing the external screen was drawn behind the one for the internal screen. Since it was smaller it was basically not accessible anymore.


Reproducible: Always

Steps to Reproduce:
Step by step my setup was like this:

1) connect HDMI cable. all fine at this point, screen config showing both rectangles side by side

2) reduce the resolution of the external device (e.g. internal at 1920x1080, external at 1024x768)

3) move the rectangle of the external device to the top left corner of the internal device, to share the top left overlapping portion of the screen


Actual Results:  
There was always some offset either vertically, horziontally or both between the two screens' top left corners.


Expected Results:  
Having the top edge of the smaller external screen perfectly aligned with the top edge of the internal screen and also having the left edges aligned.
Or in other words, have 0/0 offset on the top left corner between the two screens

kcm_kscreen seems to be missing from the component selection options