Added the initial Windows Spinbox code.

basicctrls_windows.c

@@ -160,3 +160,6 @@ void setGroupSubclass(HWND hwnd, void *data)
 	if ((*fv_SetWindowSubclass)(hwnd, groupSubProc, 0, (DWORD_PTR) data) == FALSE)
 		xpanic("error subclassing Group to give it its own event handler", GetLastError());
 }
+
+// provided for cgo's benefit
+LPWSTR xUPDOWN_CLASSW = UPDOWN_CLASSW;

comctl32_windows.c

@@ -17,6 +17,7 @@ BOOL (*WINAPI fv_ImageList_Destroy)(HIMAGELIST);
 	ICC_PROGRESS_CLASS |		/* progress bars */		\
 	ICC_TAB_CLASSES |			/* tabs */				\
 	ICC_LISTVIEW_CLASSES |		/* list views */			\
+	ICC_UPDOWN_CLASS |		/* spinboxes */		\
 	0)
 
 // note that this is an 8-bit character string we're writing; see the encoding clause

spinbox_windows.go

@@ -0,0 +1,62 @@
+// 28 october 2014
+
+package ui
+
+import (
+	"unsafe"
+)
+
+// #include "winapi_windows.h"
+import "C"
+
+// TODO do we have to manually monitor user changes to the edit control?
+
+type spinbox struct {
+	hwndEdit			C.HWND
+	hwndUpDown		C.HWND
+}
+
+func newSpinbox() Spinbox {
+	s := new(spinbox)
+	s.hwndEdit = C.newControl(editclass,
+		C.textfieldStyle | C.ES_NUMBER,
+		C.textfieldExtStyle)
+	s.hwndUpDown = C.newControl(C.xUPDOWN_CLASSW,
+		C.UDS_ALIGNRIGHT | C.UDS_ARROWKEYS | C.UDS_HOTTRACK | C.UDS_NOTHOUSANDS | C.UDS_SETBUDDYINT,
+		0)
+	C.SendMessageW(s.hwndUpDown, C.UDM_SETBUDDY, C.WPARAM(uintptr(unsafe.Pointer(s.hwndEdit))), 0)
+	C.SendMessageW(s.hwndUpDown, C.UDM_SETRANGE32, 0, 100)
+	C.SendMessageW(s.hwndUpDown, C.UDM_SETPOS32, 0, 0)
+	return s
+}
+
+func (s *spinbox) setParent(p *controlParent) {
+	C.controlSetParent(s.hwndEdit, p.hwnd)
+	C.controlSetParent(s.hwndUpDown, p.hwnd)
+}
+
+func (s *spinbox) preferredSize(d *sizing) (width, height int) {
+	// TODO
+	return 20, 20
+}
+
+func (s *spinbox) resize(x int, y int, width int, height int, d *sizing) {
+	C.moveWindow(s.hwndEdit, C.int(x), C.int(y), C.int(width), C.int(height))
+}
+
+func (s *spinbox) nTabStops() int {
+	// TODO does the up-down control count?
+	return 1
+}
+
+// TODO be sure to modify this when we add Show()/Hide()
+func (s *spinbox) containerShow() {
+	C.ShowWindow(s.hwndEdit, C.SW_SHOW)
+	C.ShowWindow(s.hwndUpDown, C.SW_SHOW)
+}
+
+// TODO be sure to modify this when we add Show()/Hide()
+func (s *spinbox) containerHide() {
+	C.ShowWindow(s.hwndEdit, C.SW_HIDE)
+	C.ShowWindow(s.hwndUpDown, C.SW_HIDE)
+}

winapi_windows.h

@@ -75,6 +75,7 @@ extern void setTextFieldSubclass(HWND, void *);
 extern void textfieldSetAndShowInvalidBalloonTip(HWND, WCHAR *);
 extern void textfieldHideInvalidBalloonTip(HWND);
 extern void setGroupSubclass(HWND, void *);
+extern LPWSTR xUPDOWN_CLASSW;
 
 // init_windows.c
 extern HINSTANCE hInstance;