[macos] add NSWindow.hasShadow support (#1637)

* [macos] add NSWindow.hasShadow

* change log

* cargo fmt

* Update CHANGELOG.md

* Update src/platform_impl/macos/window.rs

* Update src/platform/macos.rs

* set_has_shadow() with cuter format

* adjust code

* cargo fmt

* changelog

src/platform_impl/macos/window.rs

@@ -60,7 +60,7 @@ pub fn get_window_id(window_cocoa_id: id) -> Id {
     Id(window_cocoa_id as *const Object as _)
 }
 
-#[derive(Clone, Default)]
+#[derive(Clone)]
 pub struct PlatformSpecificWindowBuilderAttributes {
     pub activation_policy: ActivationPolicy,
     pub movable_by_window_background: bool,
@@ -71,6 +71,25 @@ pub struct PlatformSpecificWindowBuilderAttributes {
     pub fullsize_content_view: bool,
     pub resize_increments: Option<LogicalSize<f64>>,
     pub disallow_hidpi: bool,
+    pub has_shadow: bool,
+}
+
+impl Default for PlatformSpecificWindowBuilderAttributes {
+    #[inline]
+    fn default() -> Self {
+        Self {
+            activation_policy: Default::default(),
+            movable_by_window_background: false,
+            titlebar_transparent: false,
+            title_hidden: false,
+            titlebar_hidden: false,
+            titlebar_buttons_hidden: false,
+            fullsize_content_view: false,
+            resize_increments: None,
+            disallow_hidpi: false,
+            has_shadow: true,
+        }
+    }
 }
 
 fn create_app(activation_policy: ActivationPolicy) -> Option<id> {
@@ -224,6 +243,10 @@ fn create_window(
                 }
             }
 
+            if !pl_attrs.has_shadow {
+                ns_window.setHasShadow_(NO);
+            }
+
             ns_window.center();
             ns_window
         });
@@ -1094,6 +1117,19 @@ impl WindowExtMacOS for UnownedWindow {
             }
         }
     }
+
+    #[inline]
+    fn has_shadow(&self) -> bool {
+        unsafe { self.ns_window.hasShadow() == YES }
+    }
+
+    #[inline]
+    fn set_has_shadow(&self, has_shadow: bool) {
+        unsafe {
+            self.ns_window
+                .setHasShadow_(if has_shadow { YES } else { NO })
+        }
+    }
 }
 
 impl Drop for UnownedWindow {