From 65d79f295fe60cdad99429fcbfdea9e967dff10f Mon Sep 17 00:00:00 2001
From: Elias Naur <mail@eliasnaur.com>
Date: Sun, 17 May 2020 11:58:42 +0200
Subject: [PATCH] app/internal/app: introduce runOnMain for main thread
 callbacks

Signed-off-by: Elias Naur <mail@eliasnaur.com>
---
 app/internal/window/os_darwin.go | 30 ++++++++++++++++++++++++++++++
 app/internal/window/os_darwin.h  |  3 +++
 app/internal/window/os_darwin.m  | 12 ++++++++++++
 3 files changed, 45 insertions(+)
 create mode 100644 app/internal/window/os_darwin.go
 create mode 100644 app/internal/window/os_darwin.h
 create mode 100644 app/internal/window/os_darwin.m

diff --git a/app/internal/window/os_darwin.go b/app/internal/window/os_darwin.go
new file mode 100644
index 00000000..5d84b47c
--- /dev/null
+++ b/app/internal/window/os_darwin.go
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package window
+
+/*
+#include "os_darwin.h"
+*/
+import "C"
+
+var mainFuncs = make(chan func(), 1)
+
+// runOnMain runs the function on the main thread.
+func runOnMain(f func()) {
+	go func() {
+		mainFuncs <- f
+		C.gio_wakeupMainThread()
+	}()
+}
+
+//export gio_dispatchMainFuncs
+func gio_dispatchMainFuncs() {
+	for {
+		select {
+		case f := <-mainFuncs:
+			f()
+		default:
+			return
+		}
+	}
+}
diff --git a/app/internal/window/os_darwin.h b/app/internal/window/os_darwin.h
new file mode 100644
index 00000000..cb56b440
--- /dev/null
+++ b/app/internal/window/os_darwin.h
@@ -0,0 +1,3 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+__attribute__ ((visibility ("hidden"))) void gio_wakeupMainThread(void);
diff --git a/app/internal/window/os_darwin.m b/app/internal/window/os_darwin.m
new file mode 100644
index 00000000..8c7b6eb3
--- /dev/null
+++ b/app/internal/window/os_darwin.m
@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+@import Dispatch;
+
+#include "os_darwin.h"
+#include "_cgo_export.h"
+
+void gio_wakeupMainThread(void) {
+	dispatch_async(dispatch_get_main_queue(), ^{
+		gio_dispatchMainFuncs();
+	});
+}