Add Light, Dark Gray, and Dark themes along with the System theme.

[cristian64]

The following themes are offered:

• System: Purely based on Qt's Fusion built-in style
• Light: Qt's Fusion built-in style + custom light palette
• Dark Gray: Qt's Fusion built-in style + custom dark gray palette
• Dark: Qt's Fusion built-in style + custom dark palette

Light	Dark Gray	Dark

[dreamsyntax]

Lint failed.

Im fine with this if we extend to be part of the theme switcher which is currently Windows only.

Since default linux/mac already has dark mode iff using appropriate Qt theme selection on your system.

[dreamsyntax]

Light:

Dark:

--

I think for Linux/Mac platforms we should probably specify that 'Light' is actually your default Qt theme- so in my case of using EndeavourOS Cinnamon with Dark Mode Qt / Dark themes looks as above for each option.

[cristian64]

[...]

I think for Linux/Mac platforms we should probably specify that 'Light' is actually your default Qt theme- so in my case of using EndeavourOS Cinnamon with Dark Mode Qt / Dark themes looks as above for each option.

This is the part I mentioned I'd like to discuss. Right now, the naked use of the Fusion built-in style means "use the system's". Isn't that the case on Windows too? I would have thought a user having the light theme on Windows would still see a light theme in DME when the current Dark mode is selected.

We could offer the following options for the Theme setting:

• Default (or System): the Fusion built-in style as-is
• Dark: Fusion + custom dark palette
• Light: Fusion + custom light palette

This would guarantee that the Dark and Light styles look alike in all platforms.

[dreamsyntax]

Right now, the naked use of the Fusion built-in style means "use the system's". Isn't that the case on Windows too? I would have thought a user having the light theme on Windows would still see a light theme in DME when the current Dark mode is selected.

You are correct, just tested this. It does follow system theme.

[dreamsyntax]

Minor nitpick, can we make the names expose the theme names? Like how DuckStation/PCSX2 do it?

The system dark on Windows for example is Fusion Dark,
Where the "Dark" option is actually Dark Fusion (Gray)

DuckStation/PCSX2 example:

[dreamsyntax]

LGTM.
Note this will drop WindowsVistaTheme, but I think it doesn't look that different compared to Fusion Light anyway.

Tested on Linux and on Windows