1 files changed, 74 insertions, 0 deletions
diff --git a/area_windows.go b/area_windows.go
new file mode 100644
index 0000000..affdd9c
--- /dev/null
+++ b/area_windows.go
@@ -0,0 +1,74 @@
+// 24 march 2014
+
+package ui
+
+import (
+	"fmt"
+	"syscall"
+	"unsafe"
+	"sync"
+)
+
+const (
+	areastyle = 0 | controlstyle
+	areaxstyle = 0 | controlxstyle
+)
+
+const (
+	areaWndClassFormat = "gouiarea%X"
+)
+
+var (
+	areaWndClassNum uintptr
+	areaWndClassNumLock sync.Mutex
+)
+
+func areaWndProc(s *sysData) func(hwnd _HWND, uMsg uint32, wParam _WPARAM, lParam _LPARAM) _LRESULT {
+	return func(hwnd _HWND, uMsg uint32, wParam _WPARAM, lParam _LPARAM) _LRESULT {
+		switch uMsg {
+		default:
+			r1, _, _ := defWindowProc.Call(
+				uintptr(hwnd),
+				uintptr(uMsg),
+				uintptr(wParam),
+				uintptr(lParam))
+			return _LRESULT(r1)
+		}
+		panic(fmt.Sprintf("areaWndProc message %d did not return: internal bug in ui library", uMsg))
+	}
+}
+
+func registerAreaWndClass(s *sysData) (newClassName string, err error) {
+	const (
+		// from winuser.h
+		_CS_DBLCLKS = 0x0008
+	)
+
+	areaWndClassNumLock.Lock()
+	newClassName = fmt.Sprintf(areaWndClassFormat, areaWndClassNum)
+	areaWndClassNum++
+	areaWndClassNumLock.Unlock()
+
+	wc := &_WNDCLASS{
+		style:			_CS_DBLCLKS,		// needed to be able to register double-clicks
+		lpszClassName:	uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr(newClassName))),
+		lpfnWndProc:		syscall.NewCallback(areaWndProc(s)),
+		hInstance:		hInstance,
+		hIcon:			icon,
+		hCursor:			cursor,
+		hbrBackground:	_HBRUSH(_COLOR_BTNFACE + 1),
+	}
+
+	ret := make(chan uiret)
+	defer close(ret)
+	uitask <- &uimsg{
+		call:		_registerClass,
+		p:		[]uintptr{uintptr(unsafe.Pointer(wc))},
+		ret:		ret,
+	}
+	r := <-ret
+	if r.ret == 0 {		// failure
+		return "", r.err
+	}
+	return newClassName, nil
+}