apprt/gtk: write StringList for boxed type of strings

src/apprt/gtk/ext.zig

@@ -12,6 +12,8 @@ const gobject = @import("gobject");
 const gtk = @import("gtk");
 
 pub const actions = @import("ext/actions.zig");
+const slice = @import("ext/slice.zig");
+pub const StringList = slice.StringList;
 
 /// Wrapper around `gobject.boxedCopy` to copy a boxed type `T`.
 pub fn boxedCopy(comptime T: type, ptr: *const T) *T {
@@ -64,4 +66,5 @@ pub fn gValueHolds(value_: ?*const gobject.Value, g_type: gobject.Type) bool {
 
 test {
     _ = actions;
+    _ = slice;
 }

src/apprt/gtk/ext/slice.zig

@@ -0,0 +1,106 @@
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+const ArenaAllocator = std.heap.ArenaAllocator;
+const glib = @import("glib");
+const gobject = @import("gobject");
+
+/// A boxed type that holds a list of string slices.
+pub const StringList = struct {
+    arena: ArenaAllocator,
+    strings: []const [:0]const u8,
+
+    pub fn create(
+        alloc: Allocator,
+        strings: []const [:0]const u8,
+    ) Allocator.Error!*StringList {
+        var arena: ArenaAllocator = .init(alloc);
+        errdefer arena.deinit();
+        const arena_alloc = arena.allocator();
+        var stored = try arena_alloc.alloc([:0]const u8, strings.len);
+        for (strings, 0..) |s, i| stored[i] = try arena_alloc.dupeZ(u8, s);
+
+        const ptr = try alloc.create(StringList);
+        errdefer alloc.destroy(ptr);
+        ptr.* = .{ .arena = arena, .strings = stored };
+
+        return ptr;
+    }
+
+    pub fn deinit(self: *StringList) void {
+        self.arena.deinit();
+    }
+
+    pub fn destroy(self: *StringList) void {
+        const alloc = self.arena.child_allocator;
+        self.deinit();
+        alloc.destroy(self);
+    }
+
+    pub const getGObjectType = gobject.ext.defineBoxed(
+        StringList,
+        .{
+            .name = "GhosttyStringList",
+            .funcs = .{
+                .copy = &struct {
+                    fn copy(self: *StringList) callconv(.c) *StringList {
+                        return StringList.create(
+                            self.arena.child_allocator,
+                            self.strings,
+                        ) catch @panic("OOM");
+                    }
+                }.copy,
+                .free = &struct {
+                    fn free(self: *StringList) callconv(.c) void {
+                        self.destroy();
+                    }
+                }.free,
+            },
+        },
+    );
+};
+
+test "StringList create and destroy" {
+    const testing = std.testing;
+    const alloc = testing.allocator;
+
+    const input: []const [:0]const u8 = &.{ "hello", "world" };
+    const list = try StringList.create(alloc, input);
+    defer list.destroy();
+
+    try testing.expectEqual(@as(usize, 2), list.strings.len);
+    try testing.expectEqualStrings("hello", list.strings[0]);
+    try testing.expectEqualStrings("world", list.strings[1]);
+}
+
+test "StringList create empty list" {
+    const testing = std.testing;
+    const alloc = testing.allocator;
+
+    const input: []const [:0]const u8 = &.{};
+    const list = try StringList.create(alloc, input);
+    defer list.destroy();
+
+    try testing.expectEqual(@as(usize, 0), list.strings.len);
+}
+
+test "StringList boxedCopy and boxedFree" {
+    const testing = std.testing;
+    const alloc = testing.allocator;
+
+    const input: []const [:0]const u8 = &.{ "foo", "bar", "baz" };
+    const original = try StringList.create(alloc, input);
+    defer original.destroy();
+
+    const copied: *StringList = @ptrCast(@alignCast(gobject.boxedCopy(
+        StringList.getGObjectType(),
+        original,
+    )));
+    defer gobject.boxedFree(StringList.getGObjectType(), copied);
+
+    try testing.expectEqual(@as(usize, 3), copied.strings.len);
+    try testing.expectEqualStrings("foo", copied.strings[0]);
+    try testing.expectEqualStrings("bar", copied.strings[1]);
+    try testing.expectEqualStrings("baz", copied.strings[2]);
+
+    try testing.expect(original.strings.ptr != copied.strings.ptr);
+}