void
CancelVibrate(const WindowIdentifier &id)
{
AssertMainThread();
// Although only active windows may start vibrations, a window may
// cancel its own vibration even if it's no longer active.
//
// After a window is marked as inactive, it sends a CancelVibrate
// request. We want this request to cancel a playing vibration
// started by that window, so we certainly don't want to reject the
// cancellation request because the window is now inactive.
//
// But it could be the case that, after this window became inactive,
// some other window came along and started a vibration. We don't
// want this window's cancellation request to cancel that window's
// actively-playing vibration!
//
// To solve this problem, we keep track of the id of the last window
// to start a vibration, and only accepts cancellation requests from
// the same window. All other cancellation requests are ignored.
if (InSandbox() || (gLastIDToVibrate && *gLastIDToVibrate == id.AsArray())) {
// Don't forward our ID if we are not in the sandbox, because hal_impl
// doesn't need it, and we don't want it to be tempted to read it. The
// empty identifier will assert if it's used.
PROXY_IF_SANDBOXED(CancelVibrate(InSandbox() ? id : WindowIdentifier()));
}
}
void
CancelVibrate(nsIDOMWindow* window)
{
CancelVibrate(WindowIdentifier(window));
}
