From 3257203b6c0b1e9d415ee6f6c3e9a19fc6b2ae0b Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <m@mitchellh.com>
Date: Wed, 16 Jul 2025 09:29:33 -0700
Subject: [PATCH] apprt/gtk-ng: start basic window

---
 src/apprt/gtk-ng/build/gresource.zig   | 35 +++++++++++++--
 src/apprt/gtk-ng/class/application.zig |  6 +++
 src/apprt/gtk-ng/class/window.zig      | 59 ++++++++++++++++++++++++++
 src/apprt/gtk-ng/ui/1.5/window.blp     |  8 ++--
 4 files changed, 101 insertions(+), 7 deletions(-)
 create mode 100644 src/apprt/gtk-ng/class/window.zig

diff --git a/src/apprt/gtk-ng/build/gresource.zig b/src/apprt/gtk-ng/build/gresource.zig
index 6f9245de5..db5c2cf6e 100644
--- a/src/apprt/gtk-ng/build/gresource.zig
+++ b/src/apprt/gtk-ng/build/gresource.zig
@@ -29,12 +29,14 @@ pub const icon_sizes: []const comptime_int = &.{ 16, 32, 128, 256, 512, 1024 };
 /// setup in the build system.
 ///
 /// These will be asserted to exist at runtime.
-pub const blueprints: []const struct {
+pub const blueprints: []const Blueprint = &.{
+    .{ .major = 1, .minor = 5, .name = "window" },
+};
+
+pub const Blueprint = struct {
     major: u16,
     minor: u16,
     name: []const u8,
-} = &.{
-    .{ .major = 1, .minor = 5, .name = "window" },
 };
 
 /// The list of filepaths that we depend on. Used for the build
@@ -60,6 +62,33 @@ pub const file_inputs = deps: {
     break :deps deps;
 };
 
+/// Returns the matching blueprint resource path for the given blueprint
+/// definition. This will fail at compile time if the blueprint is not
+/// found.
+///
+/// Must be called at comptime.
+pub fn blueprint(comptime bp: Blueprint) [:0]const u8 {
+    // The comptime block around this whole thing forces an error if
+    // the caller attempts to call this function at runtime.
+    comptime {
+        for (blueprints) |candidate| {
+            if (candidate.major == bp.major and
+                candidate.minor == bp.minor and
+                std.mem.eql(u8, candidate.name, bp.name))
+            {
+                return std.fmt.comptimePrint("{s}/ui/{d}.{d}/{s}.ui", .{
+                    prefix,
+                    candidate.major,
+                    candidate.minor,
+                    candidate.name,
+                });
+            }
+        }
+
+        @compileError("invalid blueprint");
+    }
+}
+
 pub fn main() !void {
     var debug_allocator: std.heap.DebugAllocator(.{}) = .init;
     defer _ = debug_allocator.deinit();
diff --git a/src/apprt/gtk-ng/class/application.zig b/src/apprt/gtk-ng/class/application.zig
index 2c807a8f9..a2fd05a67 100644
--- a/src/apprt/gtk-ng/class/application.zig
+++ b/src/apprt/gtk-ng/class/application.zig
@@ -5,6 +5,7 @@ const adw = @import("adw");
 const gio = @import("gio");
 const glib = @import("glib");
 const gobject = @import("gobject");
+const gtk = @import("gtk");
 
 const build_config = @import("../../../build_config.zig");
 const apprt = @import("../../../apprt.zig");
@@ -13,6 +14,8 @@ const CoreApp = @import("../../../App.zig");
 const configpkg = @import("../../../config.zig");
 const Config = configpkg.Config;
 
+const GhosttyWindow = @import("window.zig").GhosttyWindow;
+
 const log = std.log.scoped(.gtk_ghostty_application);
 
 /// The primary entrypoint for the Ghostty GTK application.
@@ -380,6 +383,9 @@ pub const GhosttyApplication = extern struct {
             Class.parent,
             self.as(Parent),
         );
+
+        const win = GhosttyWindow.new(self);
+        gtk.Window.present(win.as(gtk.Window));
     }
 
     fn finalize(self: *GhosttyApplication) callconv(.C) void {
diff --git a/src/apprt/gtk-ng/class/window.zig b/src/apprt/gtk-ng/class/window.zig
new file mode 100644
index 000000000..df8b99cee
--- /dev/null
+++ b/src/apprt/gtk-ng/class/window.zig
@@ -0,0 +1,59 @@
+const std = @import("std");
+const adw = @import("adw");
+const gobject = @import("gobject");
+const gtk = @import("gtk");
+
+const gresource = @import("../build/gresource.zig");
+const GhosttyApplication = @import("application.zig").GhosttyApplication;
+
+const log = std.log.scoped(.gtk_ghostty_window);
+
+pub const GhosttyWindow = extern struct {
+    const Self = @This();
+    parent_instance: Parent,
+    pub const Parent = adw.ApplicationWindow;
+    pub const getGObjectType = gobject.ext.defineClass(Self, .{
+        .instanceInit = &init,
+        .classInit = &Class.init,
+        .parent_class = &Class.parent,
+        .private = .{ .Type = Private, .offset = &Private.offset },
+    });
+
+    const Private = struct {
+        _todo: u8 = 0,
+        var offset: c_int = 0;
+    };
+
+    pub fn new(app: *GhosttyApplication) *Self {
+        return gobject.ext.newInstance(Self, .{ .application = app });
+    }
+
+    fn init(win: *GhosttyWindow, _: *Class) callconv(.C) void {
+        gtk.Widget.initTemplate(win.as(gtk.Widget));
+    }
+
+    pub fn as(win: *Self, comptime T: type) *T {
+        return gobject.ext.as(T, win);
+    }
+
+    pub const Class = extern struct {
+        parent_class: Parent.Class,
+        var parent: *Parent.Class = undefined;
+        pub const Instance = Self;
+
+        fn init(class: *Class) callconv(.C) void {
+            gtk.Widget.Class.setTemplateFromResource(
+                class.as(gtk.Widget.Class),
+                comptime gresource.blueprint(.{
+                    .major = 1,
+                    .minor = 5,
+                    .name = "window",
+                }),
+            );
+        }
+
+        pub fn as(class: *Class, comptime T: type) *T {
+            return gobject.ext.as(T, class);
+        }
+    };
+};
diff --git a/src/apprt/gtk-ng/ui/1.5/window.blp b/src/apprt/gtk-ng/ui/1.5/window.blp
index 22ba886ff..d6321537e 100644
--- a/src/apprt/gtk-ng/ui/1.5/window.blp
+++ b/src/apprt/gtk-ng/ui/1.5/window.blp
@@ -1,8 +1,8 @@
 using Gtk 4.0;
 using Adw 1;
 
-Adw.Window {
-  Label {
-    label: "Hello";
-  }
+template $GhosttyWindow: Adw.ApplicationWindow {
+  content: Label {
+    label: "Hello, Ghostty!";
+  };
 }