hi

.gitignore

@@ -0,0 +1,2 @@
+dws
+

main.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/jordanorelli/dws/ui"
+)
+
+func exit(status int, t string, args ...interface{}) {
+	if !strings.HasSuffix(t, "\n") {
+		t = t + "\n"
+	}
+	if status == 0 {
+		fmt.Fprintf(os.Stdout, t, args...)
+	} else {
+		fmt.Fprintf(os.Stderr, t, args...)
+	}
+	os.Exit(status)
+}
+
+type failable func() error
+
+func must(fn failable, status int, msg string) {
+	msg = strings.TrimSpace(msg)
+	if err := fn(); err != nil {
+		exit(status, "%s: %s", msg, err)
+	}
+}
+
+func main() {
+	ui, err := ui.NewDesktop()
+	if err != nil {
+		exit(1, "unable to create desktop ui: %s", err)
+	}
+	must(ui.Init, 1, "unable to initialize desktop ui")
+	must(ui.Run, 1, "unable to run desktop ui")
+}

ui/ui.go

@@ -0,0 +1,6 @@
+package ui
+
+type UI interface {
+	Init() error
+	Run() error
+}

ui/ui_darwin.go

@@ -0,0 +1,30 @@
+package ui
+
+import (
+	"runtime"
+)
+
+/*
+#cgo CFLAGS: -x objective-c
+#cgo LDFLAGS: -framework Cocoa
+#include "ui_darwin.h"
+*/
+import "C"
+
+func NewDesktop() (UI, error) {
+	runtime.LockOSThread()
+	return new(cocoaUI), nil
+}
+
+type cocoaUI struct {
+}
+
+func (ui *cocoaUI) Init() error {
+	C.Initialize()
+	return nil
+}
+
+func (ui *cocoaUI) Run() error {
+	C.Run()
+	return nil
+}

ui/ui_darwin.h

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+void Initialize(void);
+int Run(void);

ui/ui_darwin.m

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+#include <Cocoa/Cocoa.h>
+
+void
+Initialize(void) {
+    [NSAutoreleasePool new];
+    [NSApplication sharedApplication];
+    [NSApp setActivationPolicy:NSApplicationActivationPolicyRegular];
+}
+
+int
+Run(void) {
+    id menubar = [[NSMenu new] autorelease];
+    id appMenuItem = [[NSMenuItem new] autorelease];
+    [menubar addItem:appMenuItem];
+    [NSApp setMainMenu:menubar];
+
+    id appMenu = [[NSMenu new] autorelease];
+    id appName = [[NSProcessInfo processInfo] processName];
+    id quitTitle = [@"Quit " stringByAppendingString:appName];
+    id quitMenuItem = [[[NSMenuItem alloc] initWithTitle:quitTitle
+        action:@selector(terminate:) keyEquivalent:@"q"]
+              autorelease];
+    [appMenu addItem:quitMenuItem];
+    [appMenuItem setSubmenu:appMenu];
+
+    id window = [[[NSWindow alloc] initWithContentRect:NSMakeRect(0, 0, 200, 200)
+        styleMask:NSTitledWindowMask backing:NSBackingStoreBuffered defer:NO]
+            autorelease];
+    [window cascadeTopLeftFromPoint:NSMakePoint(20,20)];
+    [window setTitle:appName];
+    [window makeKeyAndOrderFront:nil];
+    [NSApp activateIgnoringOtherApps:YES];
+    [NSApp run];
+    return 0;
+}