I have created an undecorated transparent stage with the always on top flag set to true and wish to use this as an overlay for a game. The game is in windowed fullscreen mode, and this is on Windows 10.
When the game window is active without the JavaFX overlay over the game, there's no taskbar showing. But as soon as i place the JavaFX overlay over the game, the taskbar pops up.
I was wondering if there's any way to use this as an overlay for the game without having the taskbar showing.
You may be able to achieve what you want (overlay in a fullscreen game) but not the way you are trying (undecorated transparent stage with the always on top flag set to true).
If you want something similar to what Steam or Fraps overlays are, then you have to implement some dll injection. Java alone does not allow you to do so, you'll have to use a C/C++ module for it.
Here are some explanations of how Xfire's overlay works, to help you understand the process behind it. Also, here is a DX9 overlay library that could help you as it does include a Java wrapper and some examples. But keep in mind that it might not work on more recent versions of DirectX and OpenGL thus not on all games, but can still help you as an example.
