apprt/gtk-ng: abstract our alert vs msg dialog into a superclass (#7995)

This introduces a new `GhosttyDialog` class that either inherits from
`adw.MessageDialog` or `adw.AlertDialog`, depending on the version of
libadwaita we compile against. This is the same logic we used
previously.

This lets us have a single libadw 1.2 blueprint file for all dialogs and
we just do the right thing at compile time!

src/apprt/gtk-ng/build/gresource.zig

@@ -32,7 +32,6 @@ pub const icon_sizes: []const comptime_int = &.{ 16, 32, 128, 256, 512, 1024 };
 pub const blueprints: []const Blueprint = &.{
     .{ .major = 1, .minor = 2, .name = "config-errors-dialog" },
     .{ .major = 1, .minor = 2, .name = "surface" },
-    .{ .major = 1, .minor = 5, .name = "config-errors-dialog" },
     .{ .major = 1, .minor = 5, .name = "window" },
 };
 

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

@@ -7,18 +7,14 @@ const gresource = @import("../build/gresource.zig");
 const adw_version = @import("../adw_version.zig");
 const Common = @import("../class.zig").Common;
 const Config = @import("config.zig").Config;
+const Dialog = @import("dialog.zig").Dialog;
 
 const log = std.log.scoped(.gtk_ghostty_config_errors_dialog);
 
 pub const ConfigErrorsDialog = extern struct {
     const Self = @This();
     parent_instance: Parent,
-
-    pub const Parent = if (adw_version.supportsDialogs())
-        adw.AlertDialog
-    else
-        adw.MessageDialog;
-
+    pub const Parent = Dialog;
     pub const getGObjectType = gobject.ext.defineClass(Self, .{
         .name = "GhosttyConfigErrorsDialog",
         .instanceInit = &init,
@@ -76,19 +72,11 @@ pub const ConfigErrorsDialog = extern struct {
     }
 
     pub fn present(self: *Self, parent: ?*gtk.Widget) void {
-        switch (Parent) {
-            adw.AlertDialog => self.as(adw.Dialog).present(parent),
-            adw.MessageDialog => self.as(gtk.Window).present(),
-            else => comptime unreachable,
-        }
+        self.as(Dialog).present(parent);
     }
 
     pub fn close(self: *Self) void {
-        switch (Parent) {
-            adw.AlertDialog => self.as(adw.Dialog).forceClose(),
-            adw.MessageDialog => self.as(gtk.Window).close(),
-            else => comptime unreachable,
-        }
+        self.as(Dialog).close();
     }
 
     fn response(
@@ -147,23 +135,14 @@ pub const ConfigErrorsDialog = extern struct {
         pub const Instance = Self;
 
         fn init(class: *Class) callconv(.C) void {
+            gobject.ext.ensureType(Dialog);
             gtk.Widget.Class.setTemplateFromResource(
                 class.as(gtk.Widget.Class),
-                switch (Parent) {
-                    adw.AlertDialog => comptime gresource.blueprint(.{
-                        .major = 1,
-                        .minor = 5,
-                        .name = "config-errors-dialog",
-                    }),
-
-                    adw.MessageDialog => comptime gresource.blueprint(.{
-                        .major = 1,
-                        .minor = 2,
-                        .name = "config-errors-dialog",
-                    }),
-
-                    else => comptime unreachable,
-                },
+                comptime gresource.blueprint(.{
+                    .major = 1,
+                    .minor = 2,
+                    .name = "config-errors-dialog",
+                }),
             );
 
             // Properties
@@ -176,7 +155,7 @@ pub const ConfigErrorsDialog = extern struct {
 
             // Virtual methods
             gobject.Object.virtual_methods.dispose.implement(class, &dispose);
-            Parent.virtual_methods.response.implement(class, &response);
+            Dialog.virtual_methods.response.implement(class, &response);
         }
 
         pub fn as(class: *Class, comptime T: type) *T {

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

@@ -0,0 +1,93 @@
+const std = @import("std");
+const adw = @import("adw");
+const gobject = @import("gobject");
+const gtk = @import("gtk");
+
+const gresource = @import("../build/gresource.zig");
+const adw_version = @import("../adw_version.zig");
+const Common = @import("../class.zig").Common;
+const Config = @import("config.zig").Config;
+
+const log = std.log.scoped(.gtk_ghostty_dialog);
+
+/// Dialog is a simple abstraction over the `adw.AlertDialog` and
+/// `adw.MessageDialog` widgets, chosen at comptime based on the linked
+/// Adwaita version.
+///
+/// Once we drop support for Adwaita <= 1.2, this can be fully removed
+/// and we can use `adw.AlertDialog` directly.
+pub const Dialog = extern struct {
+    const Self = @This();
+    parent_instance: Parent,
+
+    pub const Parent = if (adw_version.supportsDialogs())
+        adw.AlertDialog
+    else
+        adw.MessageDialog;
+
+    pub const getGObjectType = gobject.ext.defineClass(Self, .{
+        .name = "GhosttyDialog",
+        .classInit = &Class.init,
+        .parent_class = &Class.parent,
+    });
+
+    pub const virtual_methods = struct {
+        /// Forwarded from parent so subclasses can reference this
+        /// directly. This will make it easier to remove Dialog in the future.
+        pub const response = Parent.virtual_methods.response;
+    };
+
+    pub fn present(self: *Self, parent: ?*gtk.Widget) void {
+        switch (Parent) {
+            adw.AlertDialog => self.as(adw.Dialog).present(parent),
+
+            adw.MessageDialog => {
+                // Reset the previous parent window
+                self.as(gtk.Window).setTransientFor(null);
+
+                // We need to get the window for the parent in order
+                // to set the transient-for property on the MessageDialog.
+                if (parent) |widget| parent: {
+                    const root = gtk.Widget.getRoot(widget) orelse break :parent;
+                    const window = gobject.ext.cast(
+                        gtk.Window,
+                        root,
+                    ) orelse break :parent;
+                    self.as(gtk.Window).setTransientFor(window);
+                }
+
+                self.as(gtk.Window).present();
+            },
+
+            else => comptime unreachable,
+        }
+    }
+
+    pub fn close(self: *Self) void {
+        switch (Parent) {
+            adw.AlertDialog => self.as(adw.Dialog).forceClose(),
+            adw.MessageDialog => self.as(gtk.Window).close(),
+            else => comptime unreachable,
+        }
+    }
+
+    const C = Common(Self, null);
+    pub const as = C.as;
+    pub const ref = C.ref;
+    pub const unref = C.unref;
+    const private = C.private;
+
+    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 {
+            _ = class;
+        }
+
+        pub fn as(class: *Class, comptime T: type) *T {
+            return gobject.ext.as(T, class);
+        }
+    };
+};

src/apprt/gtk-ng/ui/1.2/config-errors-dialog.blp

@@ -1,7 +1,8 @@
 using Gtk 4.0;
+// This is unused but if we remove it we get a blueprint-compiler error.
 using Adw 1;
 
-template $GhosttyConfigErrorsDialog: Adw.MessageDialog {
+template $GhosttyConfigErrorsDialog: $GhosttyDialog {
   heading: _("Configuration Errors");
   body: _("One or more configuration errors were found. Please review the errors below, and either reload your configuration or ignore these errors.");
 

src/apprt/gtk-ng/ui/1.5/config-errors-dialog.blp

@@ -1,27 +0,0 @@
-using Gtk 4.0;
-using Adw 1;
-
-template $GhosttyConfigErrorsDialog: Adw.AlertDialog {
-  heading: _("Configuration Errors");
-  body: _("One or more configuration errors were found. Please review the errors below, and either reload your configuration or ignore these errors.");
-
-  responses [
-    ignore: _("Ignore"),
-    reload: _("Reload Configuration") suggested,
-  ]
-
-  extra-child: ScrolledWindow {
-    min-content-width: 500;
-    min-content-height: 100;
-
-    TextView {
-      editable: false;
-      cursor-visible: false;
-      top-margin: 8;
-      bottom-margin: 8;
-      left-margin: 8;
-      right-margin: 8;
-      buffer: bind (template.config as <$GhosttyConfig>).diagnostics-buffer;
-    }
-  };
-}