be more tolerant when no project is set

Author: ajungg

build.gradle

@@ -24,7 +24,7 @@ allprojects {
     }
 
     project.ext {
-        sdkVersion='0.9.0-beta10'
+        sdkVersion='0.9.0-beta11'
         versionCode=1
 
         compileSdkVersion=28

ui-integration/src/main/java/io/snabble/sdk/ui/integration/CheckoutFragment.java

@@ -7,6 +7,7 @@
 import android.view.ViewGroup;
 
 import io.snabble.sdk.Checkout;
+import io.snabble.sdk.Project;
 import io.snabble.sdk.ui.SnabbleUI;
 import io.snabble.sdk.ui.telemetry.Telemetry;
 
@@ -20,12 +21,16 @@ public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle sa
     public void onDestroyView() {
         super.onDestroyView();
 
-        Checkout checkout = SnabbleUI.getProject().getCheckout();
-        checkout.cancel();
+        Project project = SnabbleUI.getProject();
 
-        if(checkout.getState() != Checkout.State.PAYMENT_APPROVED
-                && checkout.getState() != Checkout.State.NONE) {
-            Telemetry.event(Telemetry.Event.CheckoutAbortByUser);
+        if(project != null) {
+            Checkout checkout = project.getCheckout();
+            checkout.cancel();
+
+            if (checkout.getState() != Checkout.State.PAYMENT_APPROVED
+                    && checkout.getState() != Checkout.State.NONE) {
+                Telemetry.event(Telemetry.Event.CheckoutAbortByUser);
+            }
         }
     }
 }