gtk-ng: add ipc infrastructure and connect +new-window ipcs (#8069)

src/apprt/gtk-ng/App.zig

@@ -3,6 +3,7 @@
 const App = @This();
 
 const std = @import("std");
+const builtin = @import("builtin");
 const Allocator = std.mem.Allocator;
 const adw = @import("adw");
 const gio = @import("gio");
@@ -16,6 +17,7 @@ const Application = @import("class/application.zig").Application;
 const Surface = @import("Surface.zig");
 const gtk_version = @import("gtk_version.zig");
 const adw_version = @import("adw_version.zig");
+const ipcNewWindow = @import("ipc/new_window.zig").newWindow;
 
 const log = std.log.scoped(.gtk);
 
@@ -24,6 +26,18 @@ const log = std.log.scoped(.gtk);
 /// because GTK's `GLArea` does not support drawing from a different thread.
 pub const must_draw_from_app_thread = true;
 
+/// GTK application ID
+pub const application_id = switch (builtin.mode) {
+    .Debug, .ReleaseSafe => "com.mitchellh.ghostty-debug",
+    .ReleaseFast, .ReleaseSmall => "com.mitchellh.ghostty",
+};
+
+/// GTK object path
+pub const object_path = switch (builtin.mode) {
+    .Debug, .ReleaseSafe => "/com/mitchellh/ghostty_debug",
+    .ReleaseFast, .ReleaseSmall => "/com/mitchellh/ghostty",
+};
+
 /// The GObject Application instance
 app: *Application,
 
@@ -67,16 +81,21 @@ pub fn performAction(
     return try self.app.performAction(target, action, value);
 }
 
+/// Send the given IPC to a running Ghostty. Returns `true` if the action was
+/// able to be performed, `false` otherwise.
+///
+/// Note that this is a static function. Since this is called from a CLI app (or
+/// some other process that is not Ghostty) there is no full-featured apprt App
+/// to use.
 pub fn performIpc(
     alloc: Allocator,
     target: apprt.ipc.Target,
     comptime action: apprt.ipc.Action.Key,
     value: apprt.ipc.Action.Value(action),
 ) !bool {
-    _ = alloc;
-    _ = target;
-    _ = value;
-    return false;
+    switch (action) {
+        .new_window => return try ipcNewWindow(alloc, target, value),
+    }
 }
 
 /// Redraw the inspector for the given surface.

src/apprt/gtk-ng/class/application.zig

@@ -227,8 +227,7 @@ pub const Application = extern struct {
                 }
             }
 
-            const default_id = comptime build_config.bundle_id;
-            break :app_id if (builtin.mode == .Debug) default_id ++ "-debug" else default_id;
+            break :app_id ApprtApp.application_id;
         };
 
         const display: *gdk.Display = gdk.Display.getDefault() orelse {
@@ -781,8 +780,23 @@ pub const Application = extern struct {
 
     /// Setup our action map.
     fn startupActionMap(self: *Self) void {
+        const t_variant_type = glib.ext.VariantType.newFor(u64);
+        defer t_variant_type.free();
+
+        const as_variant_type = glib.VariantType.new("as");
+        defer as_variant_type.free();
+
+        // The set of actions. Each action has (in order):
+        // [0] The action name
+        // [1] The callback function
+        // [2] The glib.VariantType of the parameter
+        //
+        // For action names:
+        // https://docs.gtk.org/gio/type_func.Action.name_is_valid.html
         const actions = .{
             .{ "quit", actionQuit, null },
+            .{ "new-window", actionNewWindow, null },
+            .{ "new-window-command", actionNewWindow, as_variant_type },
         };
 
         const action_map = self.as(gio.ActionMap);
@@ -1013,6 +1027,52 @@ pub const Application = extern struct {
         };
     }
 
+    /// Handle `app.new-window` and `app.new-window-command` GTK actions
+    pub fn actionNewWindow(
+        _: *gio.SimpleAction,
+        parameter_: ?*glib.Variant,
+        self: *Self,
+    ) callconv(.c) void {
+        log.debug("received new window action", .{});
+
+        parameter: {
+            // were we given a parameter?
+            const parameter = parameter_ orelse break :parameter;
+
+            const as_variant_type = glib.VariantType.new("as");
+            defer as_variant_type.free();
+
+            // ensure that the supplied parameter is an array of strings
+            if (glib.Variant.isOfType(parameter, as_variant_type) == 0) {
+                log.warn("parameter is of type {s}", .{parameter.getTypeString()});
+                break :parameter;
+            }
+
+            const s_variant_type = glib.VariantType.new("s");
+            defer s_variant_type.free();
+
+            var it: glib.VariantIter = undefined;
+            _ = it.init(parameter);
+
+            while (it.nextValue()) |value| {
+                defer value.unref();
+
+                // just to be sure
+                if (value.isOfType(s_variant_type) == 0) continue;
+
+                var len: usize = undefined;
+                const buf = value.getString(&len);
+                const str = buf[0..len];
+
+                log.debug("new-window command argument: {s}", .{str});
+            }
+        }
+
+        _ = self.core().mailbox.push(.{
+            .new_window = .{},
+        }, .{ .forever = {} });
+    }
+
     //----------------------------------------------------------------
     // Boilerplate/Noise
 

src/apprt/gtk-ng/ipc/new_window.zig

@@ -0,0 +1,170 @@
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+
+const gio = @import("gio");
+const glib = @import("glib");
+
+const apprt = @import("../../../apprt.zig");
+const ApprtApp = @import("../App.zig");
+
+// Use a D-Bus method call to open a new window on GTK.
+// See: https://wiki.gnome.org/Projects/GLib/GApplication/DBusAPI
+//
+// `ghostty +new-window` is equivalent to the following command (on a release build):
+//
+// ```
+// gdbus call --session --dest com.mitchellh.ghostty --object-path /com/mitchellh/ghostty --method org.gtk.Actions.Activate new-window [] []
+// ```
+//
+// `ghostty +new-window -e echo hello` would be equivalent to the following command (on a release build):
+//
+// ```
+// gdbus call --session --dest com.mitchellh.ghostty --object-path /com/mitchellh/ghostty --method org.gtk.Actions.Activate new-window-command '[<@as ["echo" "hello"]>]' []
+// ```
+pub fn newWindow(alloc: Allocator, target: apprt.ipc.Target, value: apprt.ipc.Action.NewWindow) (Allocator.Error || std.posix.WriteError || apprt.ipc.Errors)!bool {
+    const stderr = std.io.getStdErr().writer();
+
+    // Get the appropriate bus name and object path for contacting the
+    // Ghostty instance we're interested in.
+    const bus_name: [:0]const u8, const object_path: [:0]const u8 = switch (target) {
+        .class => |class| result: {
+            // Force the usage of the class specified on the CLI to determine the
+            // bus name and object path.
+            const object_path = try std.fmt.allocPrintZ(alloc, "/{s}", .{class});
+
+            std.mem.replaceScalar(u8, object_path, '.', '/');
+            std.mem.replaceScalar(u8, object_path, '-', '_');
+
+            break :result .{ class, object_path };
+        },
+        .detect => .{ ApprtApp.application_id, ApprtApp.object_path },
+    };
+    defer {
+        switch (target) {
+            .class => alloc.free(object_path),
+            .detect => {},
+        }
+    }
+
+    if (gio.Application.idIsValid(bus_name.ptr) == 0) {
+        try stderr.print("D-Bus bus name is not valid: {s}\n", .{bus_name});
+        return error.IPCFailed;
+    }
+
+    if (glib.Variant.isObjectPath(object_path.ptr) == 0) {
+        try stderr.print("D-Bus object path is not valid: {s}\n", .{object_path});
+        return error.IPCFailed;
+    }
+
+    const dbus = dbus: {
+        var err_: ?*glib.Error = null;
+        defer if (err_) |err| err.free();
+
+        const dbus_ = gio.busGetSync(.session, null, &err_);
+        if (err_) |err| {
+            try stderr.print(
+                "Unable to establish connection to D-Bus session bus: {s}\n",
+                .{err.f_message orelse "(unknown)"},
+            );
+            return error.IPCFailed;
+        }
+
+        break :dbus dbus_ orelse {
+            try stderr.print("gio.busGetSync returned null\n", .{});
+            return error.IPCFailed;
+        };
+    };
+    defer dbus.unref();
+
+    // use a builder to create the D-Bus method call payload
+    const payload = payload: {
+        const payload_variant_type = glib.VariantType.new("(sava{sv})");
+        defer glib.free(payload_variant_type);
+
+        // Initialize our builder to build up our parameters
+        var builder: glib.VariantBuilder = undefined;
+        builder.init(payload_variant_type);
+        errdefer builder.clear();
+
+        // action
+        if (value.arguments == null) {
+            builder.add("s", "new-window");
+        } else {
+            builder.add("s", "new-window-command");
+        }
+
+        // parameters
+        {
+            const av_variant_type = glib.VariantType.new("av");
+            defer av_variant_type.free();
+
+            var parameters: glib.VariantBuilder = undefined;
+            parameters.init(av_variant_type);
+            errdefer parameters.clear();
+
+            if (value.arguments) |arguments| {
+                // If `-e` was specified on the command line, the first
+                // parameter is an array of strings that contain the arguments
+                // that came after `-e`, which will be interpreted as a command
+                // to run.
+                {
+                    const as = glib.VariantType.new("as");
+                    defer as.free();
+
+                    var command: glib.VariantBuilder = undefined;
+                    command.init(as);
+                    errdefer command.clear();
+
+                    for (arguments) |argument| {
+                        command.add("s", argument.ptr);
+                    }
+
+                    parameters.add("v", command.end());
+                }
+            }
+
+            builder.addValue(parameters.end());
+        }
+
+        {
+            const platform_data_variant_type = glib.VariantType.new("a{sv}");
+            defer platform_data_variant_type.free();
+
+            builder.open(platform_data_variant_type);
+            defer builder.close();
+
+            // we have no platform data
+        }
+
+        break :payload builder.end();
+    };
+
+    {
+        var err_: ?*glib.Error = null;
+        defer if (err_) |err| err.free();
+
+        const result_ = dbus.callSync(
+            bus_name,
+            object_path,
+            "org.gtk.Actions",
+            "Activate",
+            payload,
+            null, // We don't care about the return type, we don't do anything with it.
+            .{}, // no flags
+            -1, // default timeout
+            null, // not cancellable
+            &err_,
+        );
+        defer if (result_) |result| result.unref();
+
+        if (err_) |err| {
+            try stderr.print(
+                "D-Bus method call returned an error err={s}\n",
+                .{err.f_message orelse "(unknown)"},
+            );
+            return error.IPCFailed;
+        }
+    }
+
+    return true;
+}