apprt/embedded: do not depend on macOS APIs on non-macOS

src/apprt/embedded.zig

@@ -1664,6 +1664,9 @@ pub const CAPI = struct {
         ptr: *Surface,
         window: *anyopaque,
     ) void {
+        // This is only supported on macOS
+        if (comptime builtin.target.os.tag != .macos) return;
+
         const config = ptr.app.config;
 
         // Do nothing if we don't have background transparency enabled

src/input.zig

@@ -17,8 +17,8 @@ pub const SplitResizeDirection = Binding.Action.SplitResizeDirection;
 // Keymap is only available on macOS right now. We could implement it
 // in theory for XKB too on Linux but we don't need it right now.
 pub const Keymap = switch (builtin.os.tag) {
-    .ios, .macos => @import("input/KeymapDarwin.zig"),
-    else => struct {},
+    .macos => @import("input/KeymapDarwin.zig"),
+    else => @import("input/KeymapNoop.zig"),
 };
 
 test {

src/input/KeymapNoop.zig

@@ -0,0 +1,38 @@
+//! A noop implementation of the keymap interface so that the embedded
+//! library can compile on non-macOS platforms.
+const KeymapNoop = @This();
+
+const Mods = @import("key.zig").Mods;
+
+pub const State = struct {};
+pub const Translation = struct {
+    text: []const u8,
+    composing: bool,
+};
+
+pub fn init() !KeymapNoop {
+    return .{};
+}
+
+pub fn deinit(self: *const KeymapNoop) void {
+    _ = self;
+}
+
+pub fn reload(self: *KeymapNoop) !void {
+    _ = self;
+}
+
+pub fn translate(
+    self: *const KeymapNoop,
+    out: []u8,
+    state: *State,
+    code: u16,
+    mods: Mods,
+) !Translation {
+    _ = self;
+    _ = out;
+    _ = state;
+    _ = code;
+    _ = mods;
+    return .{ .text = "", .composing = false };
+}