corundum-framework-package

A desktop app as a Velopack package, for Windows, macOS and Linux.

start is the first thing the app's main runs. Started by the Windows installer or uninstaller for a hook, it runs the app's hook and exits; otherwise it tells the app whether this start is its first, the first after an update, or neither, from the version the app last ran with. Not in a package (cargo run), it says so and does nothing else.

use corundum_framework_package::{PackageSpec, Services, Start, start};

static SPEC: PackageSpec = PackageSpec {
    app_name: "my-app",
    on_installed: None,
    on_uninstalling: None,
    before_apply: None,
    cli: None,
    services: Services::NONE,
};

fn main() {
    if let Start::Updated { from, to } = start(&SPEC) {
        println!("updated from {from} to {to}");
    }
}

The crate's other parts:

• Updater finds and downloads the app's updates on a thread of its own, and applies one only when asked, after the app's before_apply has stopped its background processes. apply hands the update to Velopack's updater: with After::Exit (a daemon, a command) it exits the process; with a restart it returns, and the app ends the process itself, a GUI by closing its window. apply_pending_at_start applies, at a GUI's start, an update downloaded earlier and never applied.
• cli_path puts the app's command line on PATH: the user Path on Windows, from the install hook; a link in /usr/local/bin on macOS and in ~/.local/bin on Linux, when the user asks. Another program's command of the same name is left alone.
• console is the Windows console shim: a GUI binary has no console, so a small console binary on PATH starts it with the terminal's arguments and streams.

Background services

PackageSpec::services names the app's background services: Services::NONE, or with the service feature Services::new(&[my_service]), each a function building the service's corundum_framework_service::ServiceSpec. With them:

• Updater::apply and apply_pending_at_start stop the services that are running after the app's before_apply, and note them in services-to-restart in the app's data directory first. A service whose state cannot be read is stopped and noted all the same; only a note that cannot be written refuses the update. When the apply fails, they are started again at once.
• start starts the services an update stopped, on every start, packaged or not, and removes the note: whichever of the app's programs starts first after the update does it.
• On Windows, the uninstall hook uninstalls each service before the files go. On macOS and Linux nothing runs at uninstall: remove the background service first (Settings › About › Remove), or its unit is left pointing at a program that is gone.

Packaging

The command on PATH (CliSpec::command) need not be the cargo binary's name. On macOS and Linux it links to the running executable, whatever vpk --mainExe named it; on Windows it is the shim <command>.exe beside the GUI executable in current\.

Cargo cannot build two binaries of one name in a workspace (cargo#6313), so an app's desktop package is built as <app>-desktop, while its headless build keeps <app>. Pack it so:

• macOS and Linux: rename the desktop binary to <app> in the pack directory, and run vpk pack --mainExe <app>.
• Windows: keep the GUI executable's name, add the console shim as <app>.exe, and run vpk pack --mainExe <app>-desktop.exe. The shim calls console::forward("<app>-desktop.exe"). Without the shim (cargo install, or before packaging) the GUI executable prints in the terminal through corundum_framework_platform::console::attach_parent, which the shell does not wait for: no exit code, no typed input.
• --packTitle equals LauncherSpec::name, so the installer's shortcut and the launcher's path coincide.
• Velopack's Update.exe (UpdateMac on macOS) stays beside the executable; vpk puts it there, and the package's detection looks for it.

On iOS and Android the crate is empty: the store installs and updates the app there.

License

Licensed under either of the Apache License, Version 2.0 or the MIT license, at your option.