add hide_application on macos (#1364)

Co-authored-by: Osspial <osspial@gmail.com>
Co-authored-by: Bogaevsky <vbogaevsky@gmail.com>

CHANGELOG.md

@@ -1,5 +1,6 @@
 # Unreleased
 
+- On macOS, add `hide_application` to `EventLoopWindowTarget` via a new `EventLoopWindowTargetExtMacOS` trait. `hide_application` will hide the entire application by calling `-[NSApplication hide: nil]`.
 - On macOS, fix not sending ReceivedCharacter event for specific keys combinations.
 - On macOS, fix `CursorMoved` event reporting the cursor position using logical coordinates.
 - On macOS, fix issue where unbundled applications would sometimes open without being focused.

src/platform/macos.rs

@@ -4,6 +4,7 @@ use std::os::raw::c_void;
 
 use crate::{
     dpi::LogicalSize,
+    event_loop::{EventLoop, EventLoopWindowTarget},
     monitor::MonitorHandle,
     window::{Window, WindowBuilder},
 };
@@ -209,3 +210,17 @@ impl MonitorHandleExtMacOS for MonitorHandle {
         self.inner.ns_screen().map(|s| s as *mut c_void)
     }
 }
+
+/// Additional methods on `EventLoopWindowTarget` that are specific to macOS.
+pub trait EventLoopWindowTargetExtMacOS {
+    /// Hide the entire application. In most applications this is typically triggered with Command-H.
+    fn hide_application(&self);
+}
+
+impl<T> EventLoopWindowTargetExtMacOS for EventLoopWindowTarget<T> {
+    fn hide_application(&self) {
+        let cls = objc::runtime::Class::get("NSApplication").unwrap();
+        let app: cocoa::base::id = unsafe { msg_send![cls, sharedApplication] };
+        unsafe { msg_send![app, hide: 0] }
+    }
+}