core: con't copy App and apprt.App

Besides avoiding copying, this allows consumers to choose to allocate
these structs on the stack or to allocate on the heap. It also gives the
apprt.App a stable pointer sooner in the process.

src/App.zig

@@ -82,28 +82,23 @@ pub const CreateError = Allocator.Error || font.SharedGridSet.InitError;
 ///
 /// After calling this function, well behaved apprts should then call
 /// `focusEvent` to set the initial focus state of the app.
-pub fn create(
+pub fn init(
+    self: *App,
     alloc: Allocator,
-) CreateError!*App {
-    var app = try alloc.create(App);
-    errdefer alloc.destroy(app);
-
+) CreateError!void {
     var font_grid_set = try font.SharedGridSet.init(alloc);
     errdefer font_grid_set.deinit();
 
-    app.* = .{
+    self.* = .{
         .alloc = alloc,
         .surfaces = .{},
         .mailbox = .{},
         .font_grid_set = font_grid_set,
         .config_conditional_state = .{},
     };
-    errdefer app.surfaces.deinit(alloc);
-
-    return app;
 }
 
-pub fn destroy(self: *App) void {
+pub fn deinit(self: *App) void {
     // Clean up all our surfaces
     for (self.surfaces.items) |surface| surface.deinit();
     self.surfaces.deinit(self.alloc);
@@ -114,8 +109,6 @@ pub fn destroy(self: *App) void {
     // should gracefully close all surfaces.
     assert(self.font_grid_set.count() == 0);
     self.font_grid_set.deinit();
-
-    self.alloc.destroy(self);
 }
 
 /// Tick ticks the app loop. This will drain our mailbox and process those

src/apprt/embedded.zig

@@ -117,10 +117,11 @@ pub const App = struct {
     config: Config,
 
     pub fn init(
+        self: *App,
         core_app: *CoreApp,
         config: *const Config,
         opts: Options,
-    ) !App {
+    ) !void {
         // We have to clone the config.
         const alloc = core_app.alloc;
         var config_clone = try config.clone(alloc);
@@ -129,7 +130,7 @@ pub const App = struct {
         var keymap = try input.Keymap.init();
         errdefer keymap.deinit();
 
-        return .{
+        self.* = .{
             .core_app = core_app,
             .config = config_clone,
             .opts = opts,
@@ -1316,13 +1317,16 @@ pub const CAPI = struct {
         opts: *const apprt.runtime.App.Options,
         config: *const Config,
     ) !*App {
-        var core_app = try CoreApp.create(global.alloc);
-        errdefer core_app.destroy();
+        var core_app = try global.alloc.create(CoreApp);
+        errdefer {
+            core_app.deinit();
+            global.alloc.destroy(core_app);
+        }
 
         // Create our runtime app
         var app = try global.alloc.create(App);
         errdefer global.alloc.destroy(app);
-        app.* = try .init(core_app, config, opts.*);
+        try app.init(core_app, config, opts.*);
         errdefer app.terminate();
 
         return app;
@@ -1345,7 +1349,8 @@ pub const CAPI = struct {
         const core_app = v.core_app;
         v.terminate();
         global.alloc.destroy(v);
-        core_app.destroy();
+        core_app.deinit();
+        global.alloc.destroy(core_app);
     }
 
     /// Update the focused state of the app.

src/apprt/glfw.zig

@@ -50,7 +50,7 @@ pub const App = struct {
 
     pub const Options = struct {};
 
-    pub fn init(core_app: *CoreApp, _: Options) !App {
+    pub fn init(self: *App, core_app: *CoreApp, _: Options) !void {
         if (comptime builtin.target.os.tag.isDarwin()) {
             log.warn("WARNING WARNING WARNING: GLFW ON MAC HAS BUGS.", .{});
             log.warn("You should use the AppKit-based app instead. The official download", .{});
@@ -107,7 +107,7 @@ pub const App = struct {
         // We want the event loop to wake up instantly so we can process our tick.
         glfw.postEmptyEvent();
 
-        return .{
+        self.* = .{
             .app = core_app,
             .config = config,
             .darwin = darwin,

src/apprt/gtk/App.zig

@@ -110,7 +110,7 @@ quit_timer: union(enum) {
     expired: void,
 } = .{ .off = {} },
 
-pub fn init(core_app: *CoreApp, opts: Options) !App {
+pub fn init(self: *App, core_app: *CoreApp, opts: Options) !void {
     _ = opts;
 
     // Log our GTK version
@@ -424,7 +424,7 @@ pub fn init(core_app: *CoreApp, opts: Options) !App {
         gtk.STYLE_PROVIDER_PRIORITY_APPLICATION + 3,
     );
 
-    return .{
+    self.* = .{
         .core_app = core_app,
         .app = adw_app,
         .config = config,

src/main_ghostty.zig

@@ -98,11 +98,13 @@ pub fn main() !MainReturn {
     }
 
     // Create our app state
-    var app = try App.create(alloc);
-    defer app.destroy();
+    var app: App = undefined;
+    defer app.deinit();
+    try app.init(alloc);
 
     // Create our runtime app
-    var app_runtime = try apprt.App.init(app, .{});
+    var app_runtime: apprt.App = undefined;
+    try app_runtime.init(&app, .{});
     defer app_runtime.terminate();
 
     // Since - by definition - there are no surfaces when first started, the