With Raspberry Pi2, we are using QT with eglfs support from this repository: https://github.com/pbouda/buildroot-qt-dev
Normally we were running single gui application written in QT and showing fullscreen user interface. However, now a second gui application needs to work in background and popup a window from time to time when there is user interaction. But whenever background application pops up its gui it shows it fullscreen on top of the default window regardless of its dimensions is 1/3 of the whole screen.
So the question is, when using eglfs, how can I pop up a second small window from a different process while default window is still visible in the background?