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use io;
use unix::tty;
export type error = !(io::error | tty::error);
// A function that displays the widget.
export type print = fn(w: *widget) (void | error);
// A function that frees the resources associated to the widget.
export type finish = fn(w: *widget) void;
// An input listener on a widget. The returning value is intended to be used as
// a signal that will be returned by [[notify]] in order to trigger certain more
// global ui events (terminate the program, change widget focus, etc.). To
// register a listener with a widget, use [[addlistener]].
export type listener = *fn(w: *widget, r: rune) bool;
// A widget is an abstraction around a user-defined UI component. Custom widgets
// can be created through sub-typing:
//
// export type my_widget = struct {
// widget: widget::widget,
// lines: []str,
// };
//
// fn print(w: *widget::widget) (void | widget::error) = {
// const w = w: *my_widget;
// for (let i = 0z; i < len(w.lines); i += 1) {
// fmt::println(w.lines[i])!;
// };
// };
//
// fn finish(w: *widget::widget) void = {
// const w = w: *my_widget;
// free(w.lines);
// widget::finishcommon(w);
// };
//
// let list = my_widget {
// widget = widget::widget {
// print = &print,
// finish = &finish,
// ...
// };
// lines = strings::split("one,two,three", ","),
// };
// let l = layout::newlayout(list);
// layout::print(l)!;
export type widget = struct {
print: nullable *print,
finish: nullable *finish,
listeners: []listener,
};
// Add a listener to the given widget.
export fn addlistener(w: *widget, listener: listener) void = {
append(w.listeners, listener);
};
// Free the widget's listeners.
export fn finishcommon(w: *widget) void = {
free(w.listeners);
};
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