would it be possible to implement a draggable DocumentWindow on Android similar to the desktop counterpart?
AFAIK Android does not have a concept of draggable windows. You would have to implement this yourself. I tried to do something similar a few years ago: implement a draggable component in an Android JUCE app. It was slow and jerky (even with OpenGL). I tried to get it working smoothly and gave up in the end.
do you think you could share the project if you still have it?
as i tried doing something similar for my AndroidCompositor
however i never got it… as fast as the native compositor (since im trying to render a compositor inside of a compositor) mainly the issue is texture transfer speed
never got around to implementing draggability and such as i was too focused on improving the transfer speed of textures from the command line programs to the application compositor
for example: ./MovingWindows -> Android Compositor.apk
GUI application (Client):
GUI (client) uploads to Compositor (Server) via IPC, and if directly integrated (eg render directly via shared memory such that the client and server are compiled into the application) then it can render pretty quickly (or at least it is currently the fastest way of texture transfer i have since it can write directly into the client)
but yea, in general it is slow
tho i am moving literally pixel by pixel with no graphically accelerated movements such as skipping certain pixels depending on how fast the animation is to be like modern compositors do
but in general, i believe we should be able to achieve decent animation speed if we directly use a draggable, resizable View, as i am working a form of vst system in https://github.com/mgood7123/VSTDEMO and so far i can render everything except for OpenGL (as i get memory leaks in view.hide() and view().show and thus would be unstable, i have not worked out the cause of those memory leaks yet)