App copy source is incorrect if copy source window closes shortly after copying

[CoreParadox]

For example, using the 1Password launcher to copy passwords, the launcher disappears after copying and focuses the window under it, causing pastebar to think the copied text came from the current focused application. This also makes the app ignore rule not work, as it doesn't see the copied password coming from 1Password.

Reproduction:

1. Open PasteBar and 1Password
2. Optionally add an app filter for 1Password
3. Press the 1Password quick access hotkey (ctrl+shift+space by default)
4. Copy a password with the hotkey (ctrl+shift+c by default)
5. Check PasteBar source for the copied text, it will show the wrong app name, and the filter failed to trigger because of that.

[kurdin]

@CoreParadox
Thank you for reporting, but unfortunately there is nothing I can do about that. Some apps open windows that can't be traceable from other apps as they have no main app context in the OS. It's the same if you copy, for example, something from the task menu on Windows or menu bar on Mac.

I was trying to find a solution, but I could not. PasteBar is open source, so maybe somebody else with better knowledge can help to create code to detect copying from special, non-main app windows.