From 12bc0d7b107ba35708d343c427b0826462ee2d9a Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <m@mitchellh.com>
Date: Tue, 12 Aug 2025 15:11:23 -0700
Subject: [PATCH] apprt/gtk-ng: window-subtitle

---
 src/apprt/gtk-ng/class/window.zig  | 18 ++++++++++++++++++
 src/apprt/gtk-ng/ui/1.5/tab.blp    |  2 +-
 src/apprt/gtk-ng/ui/1.5/window.blp |  7 +++++++
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/apprt/gtk-ng/class/window.zig b/src/apprt/gtk-ng/class/window.zig
index 3c818068b..fbee07801 100644
--- a/src/apprt/gtk-ng/class/window.zig
+++ b/src/apprt/gtk-ng/class/window.zig
@@ -1066,6 +1066,21 @@ pub const Window = extern struct {
         });
     }
 
+    fn closureSubtitle(
+        _: *Self,
+        config_: ?*Config,
+        pwd_: ?[*:0]const u8,
+    ) callconv(.c) ?[*:0]const u8 {
+        const config = if (config_) |v| v.get() else return null;
+        return switch (config.@"window-subtitle") {
+            .false => null,
+            .@"working-directory" => pwd: {
+                const pwd = pwd_ orelse return null;
+                break :pwd glib.ext.dupeZ(u8, std.mem.span(pwd));
+            },
+        };
+    }
+
     //---------------------------------------------------------------
     // Virtual methods
 
@@ -1789,6 +1804,8 @@ pub const Window = extern struct {
 
         fn init(class: *Class) callconv(.c) void {
             gobject.ext.ensureType(DebugWarning);
+            gobject.ext.ensureType(Surface);
+            gobject.ext.ensureType(Tab);
             gtk.Widget.Class.setTemplateFromResource(
                 class.as(gtk.Widget.Class),
                 comptime gresource.blueprint(.{
@@ -1838,6 +1855,7 @@ pub const Window = extern struct {
             class.bindTemplateCallback("notify_quick_terminal", &propQuickTerminal);
             class.bindTemplateCallback("notify_scale_factor", &propScaleFactor);
             class.bindTemplateCallback("titlebar_style_is_tabs", &closureTitlebarStyleIsTab);
+            class.bindTemplateCallback("computed_subtitle", &closureSubtitle);
 
             // Virtual methods
             gobject.Object.virtual_methods.dispose.implement(class, &dispose);
diff --git a/src/apprt/gtk-ng/ui/1.5/tab.blp b/src/apprt/gtk-ng/ui/1.5/tab.blp
index 32938c7c2..5c07209e8 100644
--- a/src/apprt/gtk-ng/ui/1.5/tab.blp
+++ b/src/apprt/gtk-ng/ui/1.5/tab.blp
@@ -8,7 +8,7 @@ template $GhosttyTab: Box {
   orientation: vertical;
   hexpand: true;
   vexpand: true;
-  tooltip: bind split_tree.active-surface as <$GhosttySurface>.pwd as <string>;
+  tooltip: bind split_tree.active-surface as <$GhosttySurface>.pwd;
 
   $GhosttySplitTree split_tree {
     notify::active-surface => $notify_active_surface();
diff --git a/src/apprt/gtk-ng/ui/1.5/window.blp b/src/apprt/gtk-ng/ui/1.5/window.blp
index 4ca90dfb5..b09c0d9b3 100644
--- a/src/apprt/gtk-ng/ui/1.5/window.blp
+++ b/src/apprt/gtk-ng/ui/1.5/window.blp
@@ -40,6 +40,13 @@ template $GhosttyWindow: Adw.ApplicationWindow {
 
         title-widget: Adw.WindowTitle {
           title: bind template.title;
+          // Blueprint auto-formatter won't let me split this into multiple
+          // lines. Let me explain myself. All parameters to a closure are used
+          // as notifications to recompute the value of the closure. All
+          // elements of a property chain are also subscribed to for changes.
+          // This one long, ugly line saves us from manually building up this
+          // massive notify chain in code.
+          subtitle: bind $computed_subtitle(template.config, tab_view.selected-page.child as <$GhosttyTab>.active-surface as <$GhosttySurface>.pwd) as <string>;
         };
 
         [start]