1 files changed, 145 insertions, 0 deletions
diff --git a/libtui/libtui.ha b/libtui/libtui.ha
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+++ b/libtui/libtui.ha
@@ -0,0 +1,145 @@
+// License: MPL-2.0
+// (c) 2022 Julian Hurst <ark@mansus.space>
+
+use fmt;
+use os;
+use io;
+use unix::tty;
+use errors;
+use bufio;
+use encoding::utf8;
+use strings;
+
+export type key = (rune | specialkey);
+
+// A listener on a rune input that returns if the ui needs to terminate or not
+export type listener = *fn(ui: *ttyui, r: key) bool;
+
+export type ttyui = struct {
+	term: tty::termios,
+	f: io::file,
+	listeners: []listener,
+};
+
+// Initializes the UI and returns a ttyui.
+export fn init() ttyui = {
+	let f = match (tty::open()) {
+	case let f: io::file =>
+		yield f;
+	case let e: tty::error =>
+		fmt::fatal(tty::strerror(e));
+	};
+	if (!tty::isatty(f)) {
+		fmt::fatal("stream is not a tty");
+	};
+	let term = match (tty::termios_query(f)) {
+	case let t: tty::termios =>
+		yield t;
+	case let e: errors::error =>
+		fmt::fatal(errors::strerror(e));
+	};
+	tty::makeraw(&term)!;
+	//tty::noecho(&term)!;
+
+	let ui = ttyui {
+		term = term,
+		f = f,
+		listeners = [],
+	};
+	hidecursor(ui);
+	return ui;
+};
+
+export fn hidecursor(ui: ttyui) void = {
+	print(ui, "\x1B[?25l");
+};
+
+export fn showcursor(ui: ttyui) void = {
+	print(ui, "\x1B[?25h");
+};
+
+// Returns the window size for the given ttyui.
+export fn getwinsize(ui: ttyui) (tty::ttysize | tty::error) = {
+	return tty::winsize(ui.f);
+};
+
+// Suspend the UI. To restore it, use [[resume]].
+export fn suspend(ui: *ttyui) void = {
+	showcursor(*ui);
+	tty::termios_restore(&ui.term);
+};
+
+// Resumes the UI after a [[suspend]].
+export fn resume(ui: *ttyui) void = {
+	tty::makeraw(&ui.term)!;
+	tty::noecho(&ui.term)!;
+	hidecursor(*ui);
+};
+
+// Restores the UI state and closes and frees the resources associated with the
+// given ttyui.
+export fn finish(ui: *ttyui) void = {
+	showcursor(*ui);
+	tty::termios_restore(&ui.term);
+	io::close(ui.f)!;
+	free(ui.listeners);
+};
+
+// Scans a rune. A convenience function for [[bufio::scanrune]].
+export fn scan(ui: ttyui) (key | utf8::invalid | io::EOF | io::error) = {
+	//const r = bufio::scanrune(ui.f)?;
+	const r = match (bufio::scanrune(ui.f)?) {
+	case let r: rune =>
+		yield r;
+	case =>
+		return io::EOF;
+	};
+	return getkey(r);
+};
+
+// Notify (call) the ttyui's listeners with the ttyui and r as a parameter.
+// Returns true if a listener returned true, false otherwise.
+export fn notify(ui: *ttyui, r: (rune | specialkey)) bool = {
+	for (let i = 0z; i < len(ui.listeners); i += 1) {
+		if (ui.listeners[i](ui, r)) {
+			return true;
+		};
+	};
+	return false;
+};
+
+fn loop(ui: *ttyui) void = {
+	for (true) {
+		let r = match (bufio::scanrune(ui.f)) {
+		case let r: rune =>
+			yield r;
+		case utf8::invalid =>
+			fmt::fatal("Invalid utf8 sequence found");
+		case io::EOF =>
+			fmt::fatal("EOF");
+		case let e: io::error =>
+			fmt::fatal(io::strerror(e));
+		};
+		for (let i = 0z; i < len(ui.listeners); i += 1) {
+			if (ui.listeners[i](ui, r)) {
+				return;
+			};
+		};
+	};
+};
+
+// Add a listener to the given ttyui.
+export fn addlistener(ui: *ttyui, l: listener) void = {
+	append(ui.listeners, l);
+};
+
+// Print a string or rune to the ttyui.
+export fn print(ui: ttyui, arg: (str | rune)) void = {
+	fmt::fprint(ui.f, arg)!;
+	//fmt::fprintf(ui.f, "{}\r", arg)!;
+};
+
+// Clear the ttyui.
+export fn clear(ui: ttyui) void = {
+	fmt::fprintf(ui.f, "\x1B[2J\x1B[1;1H\r")!;
+};