tkmod

Overview ¶

Package tkmod is the native module "tk": desktop windows with Tk widgets whose event handlers are Kukel functions (TODO.md Q67).

use tk; use events;
main() {
    local w = new tk::Window("Kukel"), n = 0;
    local label = new tk::Label(w, "clicked 0 times");
    local button = new tk::Button(w, "Click me");
    button->onclick(fn() { n++; label->settext("clicked " + str(n) + " times"); });
    label->pack();
    button->pack();
    events::run();          // until the window is closed
}

It uses modernc.org/tk9.0, Tk without cgo: Tcl/Tk are embedded in kukel and unpacked to the user's cache directory the first time. Tk runs on the main thread of the process, so only an interpreter running in the main goroutine can use it (kukel's own, not a worker; a Go program that embeds kukel calls Run there). events::run() asks Tk for its events every 10 milliseconds, so handlers run one at a time like all handlers of the event loop.

The module adds about 19 MB, so it is only in a kukel built with the build tag tk (go build -tags tk); its code is in the files with the build constraint tk.