Fix the error comment shown for old systems at the beginning of FusionTables.

The previous code did not work, because it killed the activity immediately,
without waiting for user response.

Change-Id: I9cd611ad7ca51cdc38244444118d22cc0b2f5bbd

appinventor/components/src/com/google/appinventor/components/runtime/FusiontablesControl.java

@@ -30,10 +30,11 @@ import com.google.appinventor.components.runtime.util.OAuth2Helper;
 import com.google.appinventor.components.runtime.util.SdkLevel;
 
 import android.app.Activity;
+import android.app.AlertDialog;
 import android.app.ProgressDialog;
+import android.content.DialogInterface;
 import android.os.AsyncTask;
 import android.util.Log;
-import android.widget.Toast;
 
 import org.apache.http.HttpResponse;
 import org.apache.http.client.ClientProtocolException;
@@ -173,12 +174,42 @@ public class FusiontablesControl extends AndroidNonvisibleComponent implements C
     this.activity = componentContainer.$context();
     requestHelper = createClientLoginHelper(DIALOG_TEXT, FUSIONTABLES_SERVICE);
     query = DEFAULT_QUERY;
+    
     if (SdkLevel.getLevel() < SdkLevel.LEVEL_ECLAIR) {
-      Toast.makeText(activity, "Sorry. The Fusiontables component is not compatible with your phone. Exiting.", Toast.LENGTH_LONG).show();
-      activity.finish();
+      showNoticeAndDie(
+          "Sorry. The Fusiontables component is not compatible with this phone.",
+          "This application must exit.",
+          "Rats!");      
     }
+    
+    // comment: The above code was originally
+    //    Toast.makeText(activity,
+    //        "Sorry. The Fusiontables component is not compatible with your phone. Exiting.",
+    //        Toast.LENGTH_LONG).show();
+    //    activity.finish();
+    // I'm leaving this here for the edification of future developers.  The code does not work
+    // because Toasts do not block: The activity will finish immediately, regardless of
+    // the length of the toast, and the message will not be readable. The new version isn't
+    // quite right either because the app will execute Screen.Initialize while the message
+    // is being shown.
+ 
   }
   
+  // show a notification and kill the app when the button is pressed
+  private void showNoticeAndDie(String message, String title, String buttonText){
+    AlertDialog alertDialog = new AlertDialog.Builder(activity).create();
+    alertDialog.setTitle(title);
+    // prevents the user from escaping the dialog by hitting the Back button
+    alertDialog.setCancelable(false);
+    alertDialog.setMessage(message);
+    alertDialog.setButton(buttonText, new DialogInterface.OnClickListener() {
+      public void onClick(DialogInterface dialog, int which) {
+        activity.finish();
+      }});
+    alertDialog.show();
+  }
+
+  
   /**
    * Setter for the app developer's API key.
    */