Android alert display functionality using JNI

android/examples/triangle/build.gradle

@@ -1,9 +1,10 @@
 apply plugin: 'com.android.application'
+apply from: '../gradle/outputfilename.gradle'
 
 android {
     compileSdkVersion 26
     defaultConfig {
-        applicationId "de.saschawillems.vulkanTriangle"
+        applicationId "de.saschawillems.VulkanTriangle"
         minSdkVersion 19
         targetSdkVersion 26
         versionCode 1

android/examples/triangle/src/main/java/de/saschawillems/vulkanSample/VulkanActivity.java

@@ -5,10 +5,18 @@
  */
 package de.saschawillems.vulkanSample;
 
+import android.app.AlertDialog;
 import android.app.NativeActivity;
+import android.content.DialogInterface;
+import android.content.pm.ApplicationInfo;
 import android.os.Bundle;
 
+import java.util.concurrent.Semaphore;
+
 public class VulkanActivity extends NativeActivity {
+
+    VulkanActivity _activity;
+
     static {
         // Load native library
         System.loadLibrary("native-lib");
@@ -16,5 +24,36 @@ public class VulkanActivity extends NativeActivity {
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
+        _activity = this;
+    }
+
+    // Use a semaphore to create a modal dialog
+
+    private final Semaphore semaphore = new Semaphore(0, true);
+
+    public void showAlert(final String message)
+    {
+        ApplicationInfo applicationInfo = _activity.getApplicationInfo();
+        final String applicationName = applicationInfo.nonLocalizedLabel.toString();
+
+        this.runOnUiThread(new Runnable() {
+           public void run() {
+               AlertDialog.Builder builder = new AlertDialog.Builder(_activity, AlertDialog.THEME_HOLO_DARK);
+               builder.setTitle(applicationName);
+               builder.setMessage(message);
+               builder.setPositiveButton("Close", new DialogInterface.OnClickListener() {
+                   public void onClick(DialogInterface dialog, int id) {
+                       semaphore.release();
+                   }
+               });
+               builder.setCancelable(false);
+               AlertDialog dialog = builder.create();
+               dialog.show();
+           }
+        });
+        try {
+            semaphore.acquire();
+        }
+        catch (InterruptedException e) { }
     }
 }