macOS: Implement Refresh (#742)

* macOS: Implement Refresh

* drawRect should take NSRect

CHANGELOG.md

@@ -17,6 +17,7 @@
 - On X11, `WindowBuilder::with_min_dimensions` and `WindowBuilder::with_max_dimensions` now correctly account for DPI.
 - Added support for generating dummy `DeviceId`s and `WindowId`s to better support unit testing.
 - On macOS, fixed unsoundness in drag-and-drop that could result in drops being rejected.
+- On macOS, implemented `WindowEvent::Refresh`.
 
 # Version 0.18.0 (2018-11-07)
 

src/platform/macos/util.rs

@@ -2,6 +2,7 @@ use cocoa::appkit::NSWindowStyleMask;
 use cocoa::base::{id, nil};
 use cocoa::foundation::{NSRect, NSUInteger};
 use core_graphics::display::CGDisplay;
+use objc::runtime::{Class, Object};
 
 use platform::platform::ffi;
 use platform::platform::window::IdRef;
@@ -39,6 +40,11 @@ pub unsafe fn toggle_style_mask(window: id, view: id, mask: NSWindowStyleMask, o
     window.makeFirstResponder_(view);
 }
 
+pub unsafe fn superclass<'a>(this: &'a Object) -> &'a Class {
+    let superclass: id = msg_send![this, superclass];
+    &*(superclass as *const _)
+}
+
 pub unsafe fn create_input_context(view: id) -> IdRef {
     let input_context: id = msg_send![class!(NSTextInputContext), alloc];
     let input_context: id = msg_send![input_context, initWithClient:view];

src/platform/macos/view.rs

@@ -71,6 +71,10 @@ lazy_static! {
             sel!(initWithWinit:),
             init_with_winit as extern fn(&Object, Sel, *mut c_void) -> id,
         );
+        decl.add_method(
+            sel!(drawRect:),
+            draw_rect as extern fn(&Object, Sel, NSRect),
+        );
         decl.add_method(sel!(hasMarkedText), has_marked_text as extern fn(&Object, Sel) -> BOOL);
         decl.add_method(
             sel!(markedRange),
@@ -154,6 +158,27 @@ extern fn init_with_winit(this: &Object, _sel: Sel, state: *mut c_void) -> id {
     }
 }
 
+extern fn draw_rect(this: &Object, _sel: Sel, rect: NSRect) {
+    unsafe {
+        let state_ptr: *mut c_void = *this.get_ivar("winitState");
+        let state = &mut *(state_ptr as *mut ViewState);
+
+        if let Some(shared) = state.shared.upgrade() {
+            let window_event = Event::WindowEvent {
+                window_id: WindowId(get_window_id(state.window)),
+                event: WindowEvent::Refresh,
+            };
+            shared.pending_events
+                .lock()
+                .unwrap()
+                .push_back(window_event);
+        }
+
+        let superclass = util::superclass(this);
+        let () = msg_send![super(this, superclass), drawRect:rect];
+    }
+}
+
 extern fn has_marked_text(this: &Object, _sel: Sel) -> BOOL {
     //println!("hasMarkedText");
     unsafe {