Added the window creation code. Now let's hope this works...

sysdata_windows.go

@@ -2,6 +2,7 @@
 package main
 
 import (
+	"fmt"
 	"syscall"
 	"unsafe"
 )
@@ -11,6 +12,7 @@ type sysData struct {
 
 	hwnd			_HWND
 	cid				_HMENU
+	shownAlready		bool
 }
 
 type classData struct {
@@ -25,8 +27,8 @@ type classData struct {
 var classTypes = [nctypes]*classData{
 	c_window:	&classData{
 		name:	uintptr(unsafe.Pointer(stdWndClass)),
-		style:	xxxx,
+		style:	_WS_OVERLAPPEDWINDOW,
-		xstyle:	xxxx,
+		xstyle:	0,
 	},
 //	c_button:		&classData{
 //		name:	uintptr(unsafe.Pointer("BUTTON"))
@@ -36,21 +38,76 @@ var classTypes = [nctypes]*classData{
 }
 
 func (s *sysData) make() (err error) {
-	
+	ret := make(chan uiret)
+	defer close(ret)
+	ct := classTypes[s.ctype]
+	uitask <- &uimsg{
+		call:		_createWindowEx,	
+		p:		[]uintptr{
+			uintptr(ct.xstyle),
+			ct.name,
+			uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr(s.title))),
+			uintptr(ct.style),
+			uintptr(_CW_USEDEFAULT),		// TODO
+			uintptr(_CW_USEDEFAULT),
+			uintptr(_CW_USEDEFAULT),
+			uintptr(_CW_USEDEFAULT),
+			uintptr(_NULL),					// TODO parent
+			uintptr(s.cid),
+			uintptr(hInstance),
+			uintptr(_NULL),
+		},
+		ret:	ret
+	}
+	r := <-ret
+	if r.err != nil {
+		return r.err
+	}
+	s.hwnd = _HWND(r.ret)
+	return nil
 }
 
+var (
+	_updateWindow = user32.NewProc("UpdateWindow")
+)
+
+// if the object is a window, we need to do the following the first time
+// 	ShowWindow(hwnd, nCmdShow);
+// 	UpdateWindow(hwnd);
+// otherwise we go ahead and show the object normally with SW_SHOW
 func (s *sysData) show() (err error) {
+	if s.ctype != c_window {		// don't do the init ShowWindow/UpdateWindow chain on non-windows
+		s.shownAlready = true
+	}
+	show := uintptr(_SW_SHOW)
+	if !s.shownAlready {
+		show = uintptr(nCmdShow)
+	}
 	ret := make(chan uiret)
 	defer close(ret)
 	uitask <- &uimsg{
 		call:		_showWindow,
-		p:		[]uintptr{uintptr(s.hwnd, _SW_SHOW},
+		p:		[]uintptr{uintptr(s.hwnd, show},
 		ret:		ret,
 	}
 	r := <-ret
-	close(ret)
+	if r.err != nil {
 		return r.err
 	}
+	if !s.shownAlready {
+		uitask <- &uimsg{
+			call:		_updateWindow,
+			p:		[]uintptr{uintptr(s.hwnd)},
+			ret:		ret,
+		}
+		r = <-ret
+		if r.ret == 0 {		// failure
+			return fmt.Errorf("error updating window for the first time: %v", r.err)
+		}
+		s.shownAlready = true
+	}
+	return nil
+}
 
 func (s *sysData) hide() (err error) {
 	ret := make(chan uiret)

unmigrated/painting_windows.go

@@ -1,20 +0,0 @@
-// 9 february 2014
-package main
-
-import (
-//	"syscall"
-//	"unsafe"
-)
-
-var (
-	updateWindow = user32.NewProc("UpdateWindow")
-)
-
-// TODO is error handling valid here? MSDN just says zero on failure; syscall.LazyProc.Call() always returns non-nil
-func UpdateWindow(hWnd HWND) (err error) {
-	r1, _, err := updateWindow.Call(uintptr(hWnd))
-	if r1 == 0 {		// failure
-		return err
-	}
-	return nil
-}