vaxis: add mode 2027 query parsing, wcwidth measurement

Signed-off-by: Tim Culverhouse <tim@timculverhouse.com>

src/Parser.zig

@@ -281,20 +281,19 @@ pub fn parse(self: *Parser, input: []const u8) !Result {
                             'u' => blk: {
                                 if (seq.private_indicator) |priv| {
                                     // response to our kitty query
-                                    // TODO: kitty query handling
                                     if (priv == '?') {
                                         return .{
                                             .event = .cap_kitty_keyboard,
                                             .n = i + 1,
                                         };
-                                    }
+                                    } else {
-
                                         log.warn("unhandled csi: CSI {s}", .{input[start + 1 .. i + 1]});
                                         return .{
                                             .event = null,
                                             .n = i + 1,
                                         };
                                     }
+                                }
                                 if (seq.param_idx == 0) {
                                     log.warn("unhandled csi: CSI {s}", .{input[start + 1 .. i + 1]});
                                     return .{
@@ -313,6 +312,51 @@ pub fn parse(self: *Parser, input: []const u8) !Result {
                             'O' => { // focus out
                                 return .{ .event = .focus_out, .n = i + 1 };
                             },
+                            'y' => { // DECRQM response
+                                const priv = seq.private_indicator orelse {
+                                    log.warn("unhandled csi: CSI {s}", .{input[start + 1 .. i + 1]});
+                                    return .{ .event = null, .n = i + 1 };
+                                };
+                                if (priv != '?') {
+                                    log.warn("unhandled csi: CSI {s}", .{input[start + 1 .. i + 1]});
+                                    return .{ .event = null, .n = i + 1 };
+                                }
+                                const intm = seq.intermediate orelse {
+                                    log.warn("unhandled csi: CSI {s}", .{input[start + 1 .. i + 1]});
+                                    return .{ .event = null, .n = i + 1 };
+                                };
+                                if (intm != '$') {
+                                    log.warn("unhandled csi: CSI {s}", .{input[start + 1 .. i + 1]});
+                                    return .{ .event = null, .n = i + 1 };
+                                }
+                                if (seq.param_idx != 2) {
+                                    log.warn("unhandled csi: CSI {s}", .{input[start + 1 .. i + 1]});
+                                    return .{ .event = null, .n = i + 1 };
+                                }
+                                // We'll get two fields, the first is the mode
+                                // we requested, the second is the status of the
+                                // mode
+                                // 0: not recognize
+                                // 1: set
+                                // 2: reset
+                                // 3: permanently set
+                                // 4: permanently reset
+                                switch (seq.params[0]) {
+                                    2027 => {
+                                        switch (seq.params[1]) {
+                                            0, 4 => return .{ .event = null, .n = i + 1 },
+                                            else => return .{ .event = .cap_unicode, .n = i + 1 },
+                                        }
+                                    },
+                                    2031 => {},
+                                    else => {
+                                        log.warn("unhandled DECRPM: CSI {s}", .{input[start + 1 .. i + 1]});
+                                        return .{ .event = null, .n = i + 1 };
+                                    },
+                                }
+                                log.warn("unhandled csi: CSI {s}", .{input[start + 1 .. i + 1]});
+                                return .{ .event = null, .n = i + 1 };
+                            },
                             else => {
                                 log.warn("unhandled csi: CSI {s}", .{input[start + 1 .. i + 1]});
                                 return .{

src/Tty.zig

@@ -187,6 +187,11 @@ pub fn run(
                         vx.postEvent(.cap_rgb);
                     }
                 },
+                .cap_unicode => {
+                    if (@hasField(EventType, "cap_unicode")) {
+                        vx.postEvent(.cap_unicode);
+                    }
+                },
             }
         }
     }

src/event.zig

@@ -12,4 +12,5 @@ pub const Event = union(enum) {
     // these are delivered as discovered terminal capabilities
     cap_kitty_keyboard,
     cap_rgb,
+    cap_unicode,
 };

src/gwidth.zig

@@ -0,0 +1,51 @@
+const std = @import("std");
+const unicode = std.unicode;
+const testing = std.testing;
+const ziglyph = @import("ziglyph");
+
+/// the method to use when calculating the width of a grapheme
+pub const Method = enum {
+    unicode,
+    wcwidth,
+};
+
+/// returns the width of the provided string, as measured by the method chosen
+pub fn gwidth(str: []const u8, method: Method) !usize {
+    switch (method) {
+        .unicode => {
+            return try ziglyph.display_width.strWidth(str, .half);
+        },
+        .wcwidth => {
+            var total: usize = 0;
+            const utf8 = try unicode.Utf8View.init(str);
+            var iter = utf8.iterator();
+
+            while (iter.nextCodepoint()) |cp| {
+                const w = ziglyph.display_width.codePointWidth(cp, .half);
+                if (w < 0) continue;
+                total += @intCast(w);
+            }
+            return total;
+        },
+    }
+}
+
+test "gwidth: a" {
+    try testing.expectEqual(1, try gwidth("a", .unicode));
+    try testing.expectEqual(1, try gwidth("a", .wcwidth));
+}
+
+test "gwidth: emoji with ZWJ" {
+    try testing.expectEqual(2, try gwidth("👩‍🚀", .unicode));
+    try testing.expectEqual(4, try gwidth("👩‍🚀", .wcwidth));
+}
+
+test "gwidth: emoji with skin tone selector" {
+    try testing.expectEqual(2, try gwidth("👋🏿", .unicode));
+    try testing.expectEqual(4, try gwidth("👋🏿", .wcwidth));
+}
+
+test "gwidth: invalid string" {
+    try testing.expectError(error.InvalidUtf8, gwidth("\xc3\x28", .unicode));
+    try testing.expectError(error.InvalidUtf8, gwidth("\xc3\x28", .wcwidth));
+}

src/main.zig

@@ -27,6 +27,7 @@ test {
     _ = @import("cell.zig");
     _ = @import("ctlseqs.zig");
     _ = @import("event.zig");
+    _ = @import("gwidth.zig");
     _ = @import("queue.zig");
     _ = @import("vaxis.zig");
 }