A program that asked for focus reports (1004) hears CSI I when its pane takes the keyboard and CSI O when it gives it up, to another pane, a tag or another window

The core has a window-focus event now, from SDL's window focus and from
the tty's own focus reports (vaxis turns 1004 on outside); the detached
wire carries it: version 10. The test shell's ESC]777;mouse;focus;<1|0>
fakes the window's.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 10 insertions, 4 deletions

diff --git a/src/tty/tty.zig b/src/tty/tty.zig
index 0b933065..67807cd5 100644
--- a/src/tty/tty.zig
+++ b/src/tty/tty.zig
@@ -1469,8 +1469,11 @@ const Shell = struct {
                 core.quit = true;
                 return true;
             },
-            .focus_in => {},
-            .focus_out => core.update(.pointer_leave),
+            .focus_in => core.update(.{ .focus = true }),
+            .focus_out => {
+                core.update(.pointer_leave);
+                core.update(.{ .focus = false });
+            },
             .winsize => |ws| {
                 s.vx.resize(s.gpa, s.tty.writer(), ws) catch {};
                 if (comptime pardes.pdf_enabled)
@@ -2674,8 +2677,11 @@ const Attach = struct {
         switch (event) {
             .nop, .wake, .fs_ready, .lsp_done, .lsp_status, .pipe_done, .pty_read, .pty_eof, .files_changed => {},
             .quit => return .none,
-            .focus_in => {},
-            .focus_out => return a.send(.pointer_leave),
+            .focus_in => return a.send(.{ .focus = true }),
+            .focus_out => {
+                if (a.send(.pointer_leave)) |end| return end;
+                return a.send(.{ .focus = false });
+            },
             .winsize => |ws| {
                 a.vx.resize(a.gpa, a.tty.writer(), ws) catch {};
                 a.dirty = true;