1 files changed, 43 insertions, 2 deletions
diff --git a/redo/controls_windows.go b/redo/controls_windows.go
index 3b73b48..dd4b8c9 100644
--- a/redo/controls_windows.go
+++ b/redo/controls_windows.go
@@ -5,6 +5,7 @@ package ui
 import (
 	"fmt"
 	"syscall"
+	"unsafe"
 )
 
 type widgetbase struct {
@@ -73,8 +74,20 @@ func (w *widgetbase) settext(text string, results ...t_LRESULT) *Request {
 	}
 }
 
+// all controls that have events receive the events themselves through subclasses
+// to do this, all windows (including the message-only window; see http://support.microsoft.com/default.aspx?scid=KB;EN-US;Q104069) forward WM_COMMAND to each control with this function
+func forwardCommand(hwnd uintptr, uMsg t_UINT, wParam t_WPARAM, lParam t_LPARAM) t_LRESULT {
+	control := uintptr(lParam)
+	// don't generate an event if the control (if there is one) is unparented (a child of the message-only window)
+	if control != hNULL && f_IsChild(msgwin, control) == 0 {
+		return f_SendMessageW(control, msgCOMMAND, wParam, lParam)
+	}
+	return f_DefWindowProcW(hwnd, uMsg, wParam, lParam)
+}
+
 type button struct {
 	*widgetbase
+	clicked		*event
 }
 
 var buttonclass = syscall.StringToUTF16Ptr("BUTTON")
@@ -89,6 +102,7 @@ func newButton(text string) *Request {
 			setWindowText(w.hwnd, text, []t_LRESULT{c_FALSE})
 			c <- &button{
 				widgetbase:	w,
+				clicked:		newEvent(),
 			}
 		},
 		resp:		c,
@@ -96,8 +110,14 @@ func newButton(text string) *Request {
 }
 
 func (b *button) OnClicked(e func(c Doer)) *Request {
-	// TODO
-	return nil
+	c := make(chan interface{})
+	return &Request{
+		op:		func() {
+			b.clicked.set(e)
+			c <- struct{}{}
+		},
+		resp:		c,
+	}
 }
 
 func (b *button) Text() *Request {
@@ -107,3 +127,24 @@ func (b *button) Text() *Request {
 func (b *button) SetText(text string) *Request {
 	return b.settext(text)
 }
+
+var buttonsubprocptr = syscall.NewCallback(buttonSubProc)
+
+func buttonSubProc(hwnd uintptr, uMsg t_UINT, wParam t_WPARAM, lParam t_LPARAM, id t_UINT_PTR, data t_DWORD_PTR) t_LRESULT {
+	b := (*button)(unsafe.Pointer(uintptr(data)))
+	switch uMsg {
+	case msgCOMMAND:
+		if wParam.HIWORD() == c_BN_CLICKED {
+			b.clicked.fire()
+			println("button clicked")
+			return 0
+		}
+		// TODO return
+	case c_WM_NCDESTROY:
+		// TODO remove
+		// TODO return
+	default:
+		// TODO return
+	}
+	panic(fmt.Errorf("Button message %d does not return a value (bug in buttonSubProc())", uMsg))
+}