feat: remove linking to ColorSync (#713)

.changes/remove-colorsync-link.md

@@ -0,0 +1,5 @@
+---
+"tao": "patch"
+---
+
+On macOS, Remove linking to `ColorSync`

README.md

@@ -77,15 +77,6 @@ sudo apt install libappindicator3-dev
 sudo apt install libayatana-appindicator3-dev
 ```
 
-#### macOS
-
-To ensure compatibility with older macOS systems, TAO links to
-CGDisplayCreateUUIDFromDisplayID through the CoreGraphics framework.
-However, under certain setups this function is only available to be linked
-through the newer ColorSync framework. So, TAO provides the
-`TAO_LINK_COLORSYNC` environment variable which can be set to `1` or `true`
-while compiling to enable linking via ColorSync.
-
 ### Acknowledgement
 
 This is a fork of [winit](https://crates.io/crates/winit) which replaces Linux's port to Gtk.

build.rs

@@ -3,14 +3,6 @@
 // SPDX-License-Identifier: Apache-2.0
 
 fn main() {
-  // If building for macos and TAO_LINK_COLORSYNC is set to true
-  // use CGDisplayCreateUUIDFromDisplayID from ColorSync instead of CoreGraphics
-  if std::env::var("CARGO_CFG_TARGET_OS").map_or(false, |os| os == "macos")
-    && std::env::var("TAO_LINK_COLORSYNC")
-      .map_or(false, |v| v == "1" || v.eq_ignore_ascii_case("true"))
-  {
-    println!("cargo:rustc-cfg=use_colorsync_cgdisplaycreateuuidfromdisplayid");
-  }
   // link carbon hotkey on macOS
   {
     if std::env::var("CARGO_CFG_TARGET_OS").map_or(false, |os| os == "macos") {

src/platform_impl/macos/ffi.rs

@@ -182,16 +182,7 @@ pub type CGDisplayModeRef = *mut libc::c_void;
 // directly. Fortunately, it has always been available as a subframework of
 // `ApplicationServices`, see:
 // https://developer.apple.com/library/archive/documentation/MacOSX/Conceptual/OSX_Technology_Overview/SystemFrameworks/SystemFrameworks.html#//apple_ref/doc/uid/TP40001067-CH210-BBCFFIEG
-//
-// TODO: Remove the WINIT_LINK_COLORSYNC hack, it is probably not needed.
-#[cfg_attr(
-  not(use_colorsync_cgdisplaycreateuuidfromdisplayid),
-  link(name = "ApplicationServices", kind = "framework")
-)]
-#[cfg_attr(
-  use_colorsync_cgdisplaycreateuuidfromdisplayid,
-  link(name = "ColorSync", kind = "framework")
-)]
+#[link(name = "ApplicationServices", kind = "framework")]
 extern "C" {
   pub fn CGDisplayCreateUUIDFromDisplayID(display: CGDirectDisplayID) -> CFUUIDRef;
 }