Prompt user to install OpenXR package if not installed

support/hololens/ServoApp/XRPkgChecker.cpp

@@ -0,0 +1,52 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#include "pch.h"
+#include "XRPkgChecker.h"
+#include "logs.h"
+#include "winrt/Windows.Management.Deployment.h"
+
+using namespace winrt::Windows::Management::Deployment;
+
+namespace winrt {
+
+void XRPkgChecker::OnInstalled(std::function<void()> callback,
+                               winrt::Windows::Foundation::TimeSpan interval) {
+  timer.Stop();
+  timer.Interval(interval);
+  installed_callback = std::make_unique<std::function<void()>>(callback);
+  timer.Tick({this, &XRPkgChecker::CheckXRPkgTick});
+  timer.Start();
+}
+
+void XRPkgChecker::StopTracking() {
+  installed_callback.reset();
+  timer.Stop();
+}
+
+void XRPkgChecker::CheckXRPkgTick(Windows::Foundation::IInspectable const &,
+                                  Windows::Foundation::IInspectable const &) {
+  if (IsInstalled()) {
+    (*installed_callback)();
+    StopTracking();
+  }
+}
+
+void XRPkgChecker::OpenStore() {
+  std::wstring url = L"ms-windows-store://pdp/?PFN=";
+  Windows::Foundation::Uri uri{url + OPENXR_PACKAGE_NAME};
+  Windows::System::Launcher::LaunchUriAsync(uri);
+}
+
+bool XRPkgChecker::IsInstalled() {
+  auto current_user = L"";
+  for (auto package : PackageManager().FindPackagesForUser(current_user)) {
+    if (package.Id().Name() == OPENXR_PACKAGE_SHORT_NAME) {
+      return true;
+    }
+  }
+  return false;
+}
+
+} // namespace winrt