program/theme: Use GIO API directly Calling CLI has performance overhead and adds massive error cases such as non-zero exit code and signals.

Changes

4 changed files (+41/-33)

• flake.nix
  • @@ -219,6 +219,7 @@ name = system;
    value = pkgs.mkShell { packages = with pkgs; [ + glib zig go ];
• programs/theme/build.zig
  • @@ -27,6 +27,10 @@ .target = target,
    .optimize = optimize, }); + exe.linkLibC(); + exe.linkSystemLibrary2("gobject-2.0", .{}); + exe.linkSystemLibrary2("gio-2.0", .{}); + b.installArtifact(exe); // zig build run
• programs/theme/default.nix
  • @@ -14,14 +14,13 @@ # limitations under the License.
    # # SPDX-License-Identifier: Apache-2.0 - { pkgs, stdenvNoCC, installShellFiles, zig }: + { glib, pkg-config, stdenvNoCC, installShellFiles, zig }: stdenvNoCC.mkDerivation rec { pname = "my-theme"; version = "1.0.0"; - runtimeInputs = [ pkgs.glib ]; - - nativeBuildInputs = [ zig.hook installShellFiles ]; + buildInputs = [ glib ]; + nativeBuildInputs = [ pkg-config zig.hook installShellFiles ]; src = ./.;
• programs/theme/main.zig
  • @@ -18,6 +18,14 @@ //! Over-powered theme switcher.
    const std = @import("std"); + const gio = @cImport({ + @cInclude("gio/gio.h"); + }); + + const gobject = @cImport({ + @cInclude("glib-object.h"); + }); + const ExitCode = enum(u8) { ok = 0, generic_error = 1,
  • @@ -28,10 +36,10 @@ return @intFromEnum(self);
    } }; - const GnomeColorScheme = enum { - default, - @"prefer-dark", - @"prefer-light", + const GnomeColorScheme = enum(c_int) { + default = 0, + @"prefer-dark" = 1, + @"prefer-light" = 2, pub fn from_variant(variant: Variant) @This() { return switch (variant) {
  • @@ -85,34 +93,30 @@ std.log.err("Too many arguments.", .{});
    return ExitCode.incorrect_usage.to_u8(); } - const gnome_color_scheme = GnomeColorScheme.from_variant(variant); + gnome: { + const gnome_color_scheme = GnomeColorScheme.from_variant(variant); - { - const result = try std.process.Child.run(.{ - .allocator = allocator, - .argv = &.{ - "gsettings", - "set", - "org.gnome.desktop.interface", - "color-scheme", - @tagName(gnome_color_scheme), - }, - }); - defer allocator.free(result.stdout); - defer allocator.free(result.stderr); + const gsettings = gio.g_settings_new("org.gnome.desktop.interface"); + defer gobject.g_object_unref(gsettings); - switch (result.term) { - .Exited => |code| { - if (code != 0) { - std.log.err("gsettings command exited with non-zero code: {d}", .{code}); - return ExitCode.generic_error.to_u8(); - } - }, - else => { - std.log.err("gsettings command terminated unexpectedly.", .{}); - return ExitCode.generic_error.to_u8(); - }, + const gsettings_wrote = gio.g_settings_set_enum( + gsettings, + "color-scheme", + @intFromEnum(gnome_color_scheme), + ); + + if (gsettings_wrote == 0) { + std.log.warn( + "Unable to set GNOME color scheme to {s}", + .{@tagName(gnome_color_scheme)}, + ); + break :gnome; } + + // https://docs.gtk.org/gio/class.Settings.html#delay-apply-mode + // > ...these writes may not complete by the time that g_settings_set() + // > returns; see g_settings_sync()). + gio.g_settings_sync(); std.log.info("Set GNOME color scheme to {s}", .{@tagName(gnome_color_scheme)}); }