Commit 0aead42fdf ("navigation: Add is available (#1847)") added the
ability to draw the app icon in grey and in a disabled state when some
prerequisits were not met. Only the Navigation app was using this mechanism
due to its icons being stored in the external memory and possibly missing.
Commit 63e0c4f4ef ("Application selection at build time") broke this by
always setting the state as true:
for (const auto& userApp : userApps) {
apps[i++] = Screens::Tile::Applications {userApp.icon, userApp.app, true};
}
Fix this by creating an isAvailable() strcuture in the app classes, similar
to how the Watchfaces handle the same problem of checking availability.
A list of "user applications" is built at compile time. It contains all the info needed to create the application at runtime (ptr to a create() function) and to display the app in the application menu. All applications declare a TypeTrait with these information.
When a new app must be loaded, DisplayApp first check if this app is a System app (in which case it creates it like it did before). If it's not a System app, it looks for the app in the list of User applications and creates it if it found it.
Those changes allow to more easily add new app and to select which app must be built into the firmware.
Switch to C++20 (and fix a few issues in SpiMaster.cpp and Watchdog.cpp.
Don't use relative imports like `../foo.h` as those depend on the
relative position of both files. Rather than that use imports relative
to the `src` directory, which explicitly is part of the include
directories.
Previously, pressing the back button would close the alarm app anyway. Now if you press on it and the popup with information is open, it will first close and the second press will close the application
