On Windows and macOS, add API to enable/disable window controls (#2537)

* On Windows and macOS, add API to enable/disable window controls

* fix build

* missing import

* use `WindowButtons` flags

* rename to `[set_]enabled_buttons`

* add example, fix windows impl for minimize

* macOS: Fix button enabling close/minimize while disabling maximized

* Update src/platform_impl/windows/window.rs

Co-authored-by: Kirill Chibisov <contact@kchibisov.com>

* compose the flags on a sep line, use `bool::then`

Co-authored-by: Mads Marquart <mads@marquart.dk>
Co-authored-by: Kirill Chibisov <contact@kchibisov.com>

src/platform_impl/macos/appkit/control.rs

@@ -1,5 +1,5 @@
 use objc2::foundation::NSObject;
-use objc2::{extern_class, ClassType};
+use objc2::{extern_class, extern_methods, ClassType};
 
 use super::{NSResponder, NSView};
 
@@ -12,3 +12,13 @@ extern_class!(
         type Super = NSView;
     }
 );
+
+extern_methods!(
+    unsafe impl NSControl {
+        #[sel(setEnabled:)]
+        pub fn setEnabled(&self, enabled: bool);
+
+        #[sel(isEnabled)]
+        pub fn isEnabled(&self) -> bool;
+    }
+);

src/platform_impl/macos/appkit/window.rs

@@ -180,6 +180,12 @@ extern_methods!(
         #[sel(isResizable)]
         pub fn isResizable(&self) -> bool;
 
+        #[sel(isMiniaturizable)]
+        pub fn isMiniaturizable(&self) -> bool;
+
+        #[sel(hasCloseBox)]
+        pub fn hasCloseBox(&self) -> bool;
+
         #[sel(isMiniaturized)]
         pub fn isMiniaturized(&self) -> bool;