feat: add a simple clock status bar widget

src/tui/status/clock.zig

@@ -0,0 +1,101 @@
+const std = @import("std");
+const tp = @import("thespian");
+const log = @import("log");
+const zeit = @import("zeit");
+
+const Plane = @import("renderer").Plane;
+
+const Widget = @import("../Widget.zig");
+const MessageFilter = @import("../MessageFilter.zig");
+const tui = @import("../tui.zig");
+const mainview = @import("../mainview.zig");
+const logview = @import("../logview.zig");
+
+allocator: std.mem.Allocator,
+plane: Plane,
+tick_timer: ?tp.Cancellable = null,
+on_event: ?Widget.EventHandler,
+tz: zeit.timezone.TimeZone,
+
+const message_display_time_seconds = 2;
+const error_display_time_seconds = 4;
+const Self = @This();
+
+const Level = enum {
+    info,
+    err,
+};
+
+pub fn create(a: std.mem.Allocator, parent: Plane, event_handler: ?Widget.EventHandler) @import("widget.zig").CreateError!Widget {
+    var env = std.process.getEnvMap(a) catch |e| return tp.exit_error(e, @errorReturnTrace());
+    defer env.deinit();
+    const self: *Self = try a.create(Self);
+    self.* = .{
+        .allocator = a,
+        .plane = try Plane.init(&(Widget.Box{}).opts(@typeName(Self)), parent),
+        .on_event = event_handler,
+        .tz = zeit.local(a, &env) catch |e| return tp.exit_error(e, @errorReturnTrace()),
+    };
+    try tui.current().message_filters.add(MessageFilter.bind(self, receive_tick));
+    self.update_tick_timer();
+    return Widget.to(self);
+}
+
+pub fn deinit(self: *Self, a: std.mem.Allocator) void {
+    tui.current().message_filters.remove_ptr(self);
+    if (self.tick_timer) |*t| {
+        t.cancel() catch {};
+        t.deinit();
+        self.tick_timer = null;
+    }
+    self.tz.deinit();
+    self.plane.deinit();
+    a.destroy(self);
+}
+
+pub fn receive(self: *Self, from: tp.pid_ref, m: tp.message) error{Exit}!bool {
+    var btn: u32 = 0;
+    if (try m.match(.{ "D", tp.any, tp.extract(&btn), tp.more })) {
+        if (self.on_event) |h| h.send(from, m) catch {};
+        return true;
+    }
+    return false;
+}
+
+pub fn layout(_: *Self) Widget.Layout {
+    return .{ .static = 5 };
+}
+
+pub fn render(self: *Self, theme: *const Widget.Theme) bool {
+    self.plane.set_base_style(" ", theme.statusbar);
+    self.plane.erase();
+    self.plane.home();
+
+    const now = zeit.instant(.{}) catch return false;
+    const now_local = now.in(&self.tz);
+    const dt = now_local.time();
+    _ = self.plane.print("{d:0>2}:{d:0>2}", .{ dt.hour, dt.minute }) catch {};
+    return false;
+}
+
+fn receive_tick(self: *Self, _: tp.pid_ref, m: tp.message) error{Exit}!bool {
+    if (try m.match(.{"CLOCK"})) {
+        tui.need_render();
+        self.update_tick_timer();
+        return true;
+    }
+    return false;
+}
+
+fn update_tick_timer(self: *Self) void {
+    const current_time: usize = @intCast(std.time.milliTimestamp());
+    const ms_delay_until_tick = current_time % std.time.ms_per_s;
+    const s_delay_until_tick = current_time % std.time.ms_per_min;
+    const delay = s_delay_until_tick + ms_delay_until_tick;
+    if (self.tick_timer) |*t| {
+        t.cancel() catch {};
+        t.deinit();
+        self.tick_timer = null;
+    }
+    self.tick_timer = tp.self_pid().delay_send_cancellable(self.allocator, delay, .{"CLOCK"}) catch null;
+}