From edaeb17f3d416b2870032a5a91a82d4b39e4504b Mon Sep 17 00:00:00 2001
From: Tim Culverhouse <tim@timculverhouse.com>
Date: Sun, 30 Jun 2024 11:45:43 -0500
Subject: [PATCH] feat: implement mode 2048 in band resize reports

Implement mode 2048 for in-band window resize reports.

Reference: https://gist.github.com/rockorager/e695fb2924d36b2bcf1fff4a3704bd83
---
 README.md       |  1 +
 src/Loop.zig    |  9 ++++++++-
 src/Parser.zig  | 26 ++++++++++++++++++++++++++
 src/Vaxis.zig   |  6 ++++++
 src/ctlseqs.zig |  4 ++++
 5 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 2090b88..c80450c 100644
--- a/README.md
+++ b/README.md
@@ -32,6 +32,7 @@ Unix-likes.
 | Synchronized Output (DEC 2026) |     ✅     |
 | Unicode Core (DEC 2027)        |     ✅     |
 | Color Mode Updates (DEC 2031)  |     ✅     |
+| [In-Band Resize Reports](https://gist.github.com/rockorager/e695fb2924d36b2bcf1fff4a3704bd83)   |     ✅     |
 | Images (kitty)                 |     ✅     |
 
 ## Usage
diff --git a/src/Loop.zig b/src/Loop.zig
index b9bf030..ceea70b 100644
--- a/src/Loop.zig
+++ b/src/Loop.zig
@@ -89,6 +89,8 @@ pub fn Loop(comptime T: type) type {
 
         pub fn winsizeCallback(ptr: *anyopaque) void {
             const self: *Self = @ptrCast(@alignCast(ptr));
+            // We will be receiving winsize updates in-band
+            if (self.vaxis.state.in_band_resize) return;
 
             const winsize = Tty.getWinsize(self.tty.fd) catch return;
             if (@hasField(Event, "winsize")) {
@@ -286,7 +288,12 @@ pub fn handleEventGeneric(self: anytype, vx: *Vaxis, cache: *GraphemeCache, Even
                 .cap_da1 => {
                     std.Thread.Futex.wake(&vx.query_futex, 10);
                 },
-                .winsize => unreachable, // handled elsewhere for posix
+                .winsize => |winsize| {
+                    vx.state.in_band_resize = true;
+                    if (@hasField(Event, "winsize")) {
+                        self.postEvent(.{ .winsize = winsize });
+                    }
+                },
             }
         },
     }
diff --git a/src/Parser.zig b/src/Parser.zig
index 90244a2..a08761e 100644
--- a/src/Parser.zig
+++ b/src/Parser.zig
@@ -6,6 +6,7 @@ const Key = @import("Key.zig");
 const Mouse = @import("Mouse.zig");
 const code_point = @import("code_point");
 const grapheme = @import("grapheme");
+const Winsize = @import("main.zig").Winsize;
 
 const log = std.log.scoped(.parser);
 
@@ -470,6 +471,31 @@ inline fn parseCsi(input: []const u8, text_buf: []u8) Result {
                 else => return null_event,
             }
         },
+        't' => {
+            // XTWINOPS
+            // Split first into fields delimited by ';'
+            var iter = std.mem.splitScalar(u8, sequence[2 .. sequence.len - 1], ';');
+            const ps = iter.first();
+            if (std.mem.eql(u8, "48", ps)) {
+                // in band window resize
+                const width_char = iter.next() orelse return null_event;
+                const height_char = iter.next() orelse return null_event;
+                const width_pix = iter.next() orelse "0";
+                const height_pix = iter.next() orelse "0";
+
+                const winsize: Winsize = .{
+                    .rows = std.fmt.parseUnsigned(usize, height_char, 10) catch return null_event,
+                    .cols = std.fmt.parseUnsigned(usize, width_char, 10) catch return null_event,
+                    .x_pixel = std.fmt.parseUnsigned(usize, width_pix, 10) catch return null_event,
+                    .y_pixel = std.fmt.parseUnsigned(usize, height_pix, 10) catch return null_event,
+                };
+                return .{
+                    .event = .{ .winsize = winsize },
+                    .n = sequence.len,
+                };
+            }
+            return null_event;
+        },
         'u' => {
             // Kitty keyboard
             // CSI unicode-key-code:alternate-key-codes ; modifiers:event-type ; text-as-codepoints u
diff --git a/src/Vaxis.zig b/src/Vaxis.zig
index 284285a..18924a3 100644
--- a/src/Vaxis.zig
+++ b/src/Vaxis.zig
@@ -85,6 +85,7 @@ state: struct {
     mouse: bool = false,
     pixel_mouse: bool = false,
     color_scheme_updates: bool = false,
+    in_band_resize: bool = false,
     cursor: struct {
         row: usize = 0,
         col: usize = 0,
@@ -151,6 +152,10 @@ pub fn resetState(self: *Vaxis, tty: AnyWriter) !void {
         try tty.writeAll(ctlseqs.color_scheme_reset);
         self.state.color_scheme_updates = false;
     }
+    if (self.state.in_band_resize) {
+        try tty.writeAll(ctlseqs.in_band_resize_reset);
+        self.state.in_band_resize = false;
+    }
 }
 
 /// resize allocates a slice of cells equal to the number of cells
@@ -244,6 +249,7 @@ pub fn queryTerminalSend(_: Vaxis, tty: AnyWriter) !void {
     try tty.writeAll(ctlseqs.decrqm_sgr_pixels ++
         ctlseqs.decrqm_unicode ++
         ctlseqs.decrqm_color_scheme ++
+        ctlseqs.in_band_resize_set ++
         ctlseqs.xtversion ++
         ctlseqs.csi_u_query ++
         ctlseqs.kitty_graphics_query ++
diff --git a/src/ctlseqs.zig b/src/ctlseqs.zig
index a911f95..50f5e40 100644
--- a/src/ctlseqs.zig
+++ b/src/ctlseqs.zig
@@ -20,6 +20,10 @@ pub const mouse_set = "\x1b[?1002;1003;1004;1006h";
 pub const mouse_set_pixels = "\x1b[?1002;1003;1004;1016h";
 pub const mouse_reset = "\x1b[?1002;1003;1004;1006;1016l";
 
+// in-band window size reports
+pub const in_band_resize_set = "\x1b[?2048h";
+pub const in_band_resize_reset = "\x1b[?2048l";
+
 // sync
 pub const sync_set = "\x1b[?2026h";
 pub const sync_reset = "\x1b[?2026l";