Decide which GUI technology we'd like to stick with

[kosarev]

Part of #3.

General directions to consider:

• No-GUI libraries: Cairo, PyGame, probably strengthened with SDL.
  It might be, our needs in terms of GUI are not very vast, in which case drawing icons manually (like we currently do on tape start/pause for example) may be considered acceptable or even desired.
• "Classic" widget libraries: Qt, GTK/tkinter, wxWidgets, etc.
  Time-proven solutions, but not very appealing and may take a lot of time to implement desired GUI things.
• Browser/JS-based solutions: Electron, NW.js, Flexx, etc.
  Relatively easy to use and allow great looking interfaces, though binding with Python and C++ and displaying pixel textures at acceptable FPS would be a pain.
• A custom GUI on top of a low-level library like Skia.
  I wonder how much effort this approach would take.
• A third-party GUI solution on top of other low-level libraries, such as ImGUI, Kivy, NanoVG, etc.
  Both seem like they do well with shaders/animations and generally look like a good fit for an emulator's interface.

[ArjunNair]

May I suggest IMGUI? I've used it for a chip8 emulator I wanted to run as cross platform on Linux, windows and mac. It works quite well and has many language bindings too.

[kosarev]

Thanks a lot, @ArjunNair! Added ImGUI to the list, and also found a similar project, Kivy. The first seems to be a popular choice for games, thus promising good performance, and the latter is itself written in Python. I'm going to see if there are more libraries of this kind, but I think at this point it's more or less clear that for this project any of these two would be a better choice comparing to solutions like Qt/wxWidgets/... and Electron/NW.js.

As to Skia, the library itself seems impressive, but the only GUI library built on top of it I found so far is https://github.com/skui-org/skui, and I would say the screenshots at http://www.thomthom.net/thoughts/2013/07/skui-a-gui-framework-for-sketchup/ look somewhat archaic. :-) So either there's a better alternative to Skui or we would need to write our own widgets, and I'm not sure how much time it would take given our needs...

[kosarev]

A good overview of the topic:

UIs in Python
https://livingthing.danmackinlay.name/python_gui.html

Among other options, mentions this:
https://github.com/vurtun/nuklear

[boriel]

I use pygame directly (which is on top of SDL), not a gui itself. This list is pretty interesting!! :)

[kosarev]

@boriel Thanks, Jose. Added PyGame and Cairo to the list. It indeed might be that no-GUI is just enough for our needs. :-)