main: some minor cleanup

Very simplistic, but, and here's the key, it works.

src/main.zig

@@ -3,7 +3,6 @@ const builtin = @import("builtin");
 
 const vaxis = @import("vaxis");
 const xev = @import("xev");
-const Cell = vaxis.Cell;
 
 const networking = @import("./networking.zig");
 const rotctl = @import("./rotctl.zig");
@@ -132,6 +131,7 @@ pub const RotInt = struct {
             .get_position => |pos| {
                 self.current_posture = pos;
                 if (self.state == .rotator_connected) self.stateEvent(.rotator_ready);
+                self.draw() catch {};
             },
             .status => |code| if (code != .okay)
                 self.warn("rotctl error {s}", .{@tagName(code)}),
@@ -162,6 +162,7 @@ pub const RotInt = struct {
             .set_position => |pos| {
                 self.requested_posture = pos;
                 self.server.respond(self.loop, .okay);
+                self.draw() catch {};
             },
 
             .stop => self.server.respond(self.loop, .okay),
@@ -174,47 +175,92 @@ pub const RotInt = struct {
     }
 
     fn draw(self: *RotInt) !void {
-        const Static = struct {
-            const lower_limit: u8 = 30;
-            const next_ms: u64 = 8;
-            var color_idx: u8 = lower_limit;
-            var dir: enum { up, down } = .up;
-        };
-
-        const style: vaxis.Style = .{
-            .fg = .{ .rgb = [_]u8{ Static.color_idx, Static.color_idx, Static.color_idx } },
-        };
-
-        const segment: vaxis.Segment = .{
-            .text = "yeah ok",
-            .style = style,
-        };
         const win = self.vx.window();
         win.clear();
 
-        const y_off = (win.height / 2) -| (6 / 2);
-        const x_off = (win.width / 2) -| (30 / 2);
-        const center = win.child(.{
-            .x_off = x_off + win.x_off,
-            .y_off = y_off + win.y_off,
-            .width = .{ .limit = 30 },
-            .height = .{ .limit = 6 },
-            .border = .{ .where = .all, .style = style },
-        });
-        _ = try center.printSegment(segment, .{ .wrap = .grapheme });
-        switch (Static.dir) {
-            .up => {
-                Static.color_idx += 1;
-                if (Static.color_idx == 255) Static.dir = .down;
-            },
-            .down => {
-                Static.color_idx -= 1;
-                if (Static.color_idx == Static.lower_limit) Static.dir = .up;
-            },
-        }
+        var lines: [3][128]u8 = undefined;
+        const offsets: vaxis.Segment = .{ .text = try std.fmt.bufPrint(
+            lines[0][0..],
+            "Offsets:   Az: {d: >6.1}, El: {d: >6.1}",
+            .{ self.offsets.az, self.offsets.el },
+        ) };
+        const requested: vaxis.Segment = .{ .text = try std.fmt.bufPrint(
+            lines[1][0..],
+            "Requested: Az: {d: >6.1}, El: {d: >6.1}",
+            .{ self.requested_posture.az, self.requested_posture.el },
+        ) };
+        const current: vaxis.Segment = .{ .text = try std.fmt.bufPrint(
+            lines[2][0..],
+            "Current:   Az: {d: >6.1}, El: {d: >6.1}",
+            .{ self.current_posture.az, self.current_posture.el },
+        ) };
+
+        const center = vaxis.widgets.alignment.center(win, offsets.text.len, 1);
+        _ = try center.printSegment(offsets, .{});
+        const center_up = win.initChild(center.x_off, center.y_off + 1, .{ .limit = requested.text.len }, .{ .limit = 1 });
+        _ = try center_up.printSegment(requested, .{});
+        const center_down = win.initChild(center.x_off, center.y_off - 1, .{ .limit = current.text.len }, .{ .limit = 1 });
+        _ = try center_down.printSegment(current, .{});
+
         try self.vx.render(self.termbuffer.writer().any());
         try self.termbuffer.flush();
     }
+
+    fn terminalEvent(
+        self_: ?*RotInt,
+        loop: *xev.Loop,
+        watcher: *vaxis.xev.TtyWatcher(RotInt),
+        event: vaxis.xev.Event,
+    ) xev.CallbackAction {
+        const self = self_.?;
+        switch (event) {
+            .key_press => |key| keyp: {
+                var mods = key.mods;
+                mods.caps_lock = false;
+                mods.num_lock = false;
+                const scale: f64 = if (std.meta.eql(mods, .{ .shift = true })) 1 else 10;
+
+                const delta: AzEl = switch (key.codepoint) {
+                    vaxis.Key.left, vaxis.Key.kp_left => .{ .az = -0.1 * scale, .el = 0 },
+                    vaxis.Key.right, vaxis.Key.kp_right => .{ .az = 0.1 * scale, .el = 0 },
+                    vaxis.Key.up, vaxis.Key.kp_up => .{ .az = 0, .el = 0.1 * scale },
+                    vaxis.Key.down, vaxis.Key.kp_down => .{ .az = 0 * scale, .el = -0.1 * scale },
+                    'l' => {
+                        if (std.meta.eql(mods, .{ .ctrl = true }))
+                            self.vx.queueRefresh();
+                        break :keyp;
+                    },
+                    'c' => {
+                        if (std.meta.eql(mods, .{ .ctrl = true })) {
+                            loop.stop();
+                            return .disarm;
+                        }
+                        break :keyp;
+                    },
+                    'q' => {
+                        if (std.meta.eql(mods, .{})) {
+                            loop.stop();
+                            return .disarm;
+                        }
+                        break :keyp;
+                    },
+                    else => break :keyp,
+                };
+
+                self.offsets.az += delta.az;
+                self.offsets.el += delta.el;
+                self.draw() catch {
+                    self.warn("draw failure", .{});
+                };
+            },
+            .winsize => |ws| {
+                watcher.vx.resize(self.allocator, watcher.tty.anyWriter(), ws) catch
+                    return .disarm;
+            },
+            else => {},
+        }
+        return .rearm;
+    }
 };
 
 pub fn main() !void {
@@ -245,7 +291,7 @@ pub fn main() !void {
     try app.initInPlace();
 
     var vx_loop: vaxis.xev.TtyWatcher(RotInt) = undefined;
-    try vx_loop.init(&tty, &vx, &loop, &app, eventCallback);
+    try vx_loop.init(&tty, &vx, &loop, &app, RotInt.terminalEvent);
 
     try vx.enterAltScreen(tty.anyWriter());
     try vx.queryTerminalSend(tty.anyWriter());
@@ -256,72 +302,3 @@ pub fn main() !void {
 
     try loop.run(.until_done);
 }
-
-fn eventCallback(
-    self_: ?*RotInt,
-    loop: *xev.Loop,
-    watcher: *vaxis.xev.TtyWatcher(RotInt),
-    event: vaxis.xev.Event,
-) xev.CallbackAction {
-    const self = self_.?;
-    switch (event) {
-        .key_press => |key| keyp: {
-            var mods = key.mods;
-            mods.caps_lock = false;
-            mods.num_lock = false;
-            const scale: f64 = if (std.meta.eql(mods, .{ .shift = true })) 1 else 10;
-
-            const delta: AzEl = switch (key.codepoint) {
-                vaxis.Key.left, vaxis.Key.kp_left => .{ .az = -0.1 * scale, .el = 0 },
-                vaxis.Key.right, vaxis.Key.kp_right => .{ .az = 0.1 * scale, .el = 0 },
-                vaxis.Key.up, vaxis.Key.kp_up => .{ .az = 0, .el = 0.1 * scale },
-                vaxis.Key.down, vaxis.Key.kp_down => .{ .az = 0 * scale, .el = -0.1 * scale },
-                'l' => {
-                    if (std.meta.eql(mods, .{ .ctrl = true }))
-                        self.vx.queueRefresh();
-                    break :keyp;
-                },
-                'c' => {
-                    if (std.meta.eql(mods, .{ .ctrl = true })) {
-                        loop.stop();
-                        return .disarm;
-                    }
-                    break :keyp;
-                },
-                'q' => {
-                    if (std.meta.eql(mods, .{})) {
-                        loop.stop();
-                        return .disarm;
-                    }
-                    break :keyp;
-                },
-                else => break :keyp,
-            };
-
-            self.offsets.az += delta.az;
-            self.offsets.el += delta.el;
-        },
-        .winsize => |ws| {
-            watcher.vx.resize(self.allocator, watcher.tty.anyWriter(), ws) catch
-                return .disarm;
-        },
-        else => {},
-    }
-    return .rearm;
-}
-
-fn timerCallback(
-    ud: ?*RotInt,
-    loop: *xev.Loop,
-    completion: *xev.Completion,
-    err: xev.Timer.RunError!void,
-) xev.CallbackAction {
-    _ = err catch @panic("timer error");
-
-    var app = ud orelse return .disarm;
-    app.draw() catch @panic("couldn't draw");
-
-    const timer = xev.Timer.init() catch unreachable;
-    timer.run(loop, completion, 8, RotInt, app, timerCallback);
-    return .disarm;
-}