func DetachWindowEventHandler(hwnd win.HWND) {
key := HWND(hwnd)
if handler, exists := windowEventHandlers[hwnd]; exists {
tag := uintptr(unsafe.Pointer(handler))
if ret := HTMLayoutWindowDetachEventHandler(key, goElementProc, tag); ret != HLDOM_OK {
domPanic(C.HLDOM_RESULT(ret), "Failed to detach event handler from window")
}
delete(windowEventHandlers, hwnd)
}
}
func AttachWindowEventHandler(hwnd win.HWND, handler *EventHandler) {
key := HWND(hwnd)
tag := uintptr(unsafe.Pointer(handler))
if _, exists := windowEventHandlers[hwnd]; exists {
if ret := HTMLayoutWindowDetachEventHandler(key, goElementProc, tag); ret != HLDOM_OK {
domPanic(C.HLDOM_RESULT(ret), "Failed to detach event handler from window before adding the new one")
}
}
// Overwrite if it exists
windowEventHandlers[hwnd] = handler
// Don't let the caller disable ATTACH/DETACH events, otherwise we
// won't know when to throw out our event handler object
subscription := handler.Subscription()
subscription &= ^uint(DISABLE_INITIALIZATION & 0xffffffff)
if ret := HTMLayoutWindowAttachEventHandler(key, goElementProc, tag, subscription); ret != HLDOM_OK {
domPanic2(ret, "Failed to attach event handler to window")
}
}