Update and improve android_gradle (#965)

* Update CMakeLists.txt files so we can build libamber_ndk.so for
Android via CMake.

* `android_gradle/`:

  * Update Gradle version, settings, and build files to match the latest
  Android sample. Importantly, this removes the use of jcenter and
  bintray repositories, which were shut down.

  * Specify NDK version so that Gradle can install required native build
  tools automatically.

  * Define externalNativeBuild so Gradle can perform the Android CMake
  build automatically.

* Replace `main` with `android_main` when building the Amber tool as a
library for Android to avoid compiler warnings, and rename other
Android-related symbols to avoid confusion.

Fixes #964

4 files changed, 33 insertions, 16 deletions

diff --git a/android_gradle/app/build.gradle b/android_gradle/app/build.gradle
index 40c4c54..b756f6b 100644
--- a/android_gradle/app/build.gradle
+++ b/android_gradle/app/build.gradle
@@ -1,26 +1,37 @@
-apply plugin: 'com.android.application'
+plugins {
+    id 'com.android.application'
+}
 
 android {
-    compileSdkVersion 29
-    buildToolsVersion "29.0.2"
+    compileSdk 30
+    buildToolsVersion "30.0.2"
+    ndkVersion "21.4.7075529"
 
     defaultConfig {
         applicationId "com.google.amber"
         minSdkVersion 24
-        targetSdkVersion 29
+        targetSdkVersion 30
         versionCode 1
         versionName "1.0"
 
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+
+        externalNativeBuild {
+            cmake {
+                arguments "-DAMBER_USE_LOCAL_VULKAN=1"
+                targets "amber_ndk"
+            }
+        }
     }
 
-    sourceSets {
-        androidTest.manifest.srcFile "src/androidTest/AndroidManifest.xml"
+    externalNativeBuild {
+        cmake {
+            path "../../CMakeLists.txt"
+        }
     }
 
-    dependencies {
-        androidTestImplementation 'androidx.test:runner:1.1.0'
-        androidTestImplementation 'androidx.test:rules:1.1.0'
+    sourceSets {
+        androidTest.manifest.srcFile "src/androidTest/AndroidManifest.xml"
     }
 
     buildTypes {
@@ -29,6 +40,10 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt')
         }
     }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
 
     sourceSets {
         main {
@@ -41,9 +56,10 @@ android {
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
 
-    implementation 'androidx.appcompat:appcompat:1.1.0'
-    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
-    testImplementation 'junit:junit:4.12'
-    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
-    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
+    implementation 'androidx.appcompat:appcompat:1.3.1'
+    implementation 'com.google.android.material:material:1.4.0'
+    implementation 'androidx.constraintlayout:constraintlayout:2.1.1'
+    testImplementation 'junit:junit:4.13.2'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.3'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
 }
diff --git a/android_gradle/app/src/androidTest/java/com/google/amber/AmberLauncher.java b/android_gradle/app/src/androidTest/java/com/google/amber/AmberLauncher.java
index 4864843..ad92154 100644
--- a/android_gradle/app/src/androidTest/java/com/google/amber/AmberLauncher.java
+++ b/android_gradle/app/src/androidTest/java/com/google/amber/AmberLauncher.java
@@ -54,7 +54,7 @@ public class AmberLauncher {
     String stdout_file = args.getString("stdout", new File(outputDir, "amber_stdout.txt").toString());
     String stderr_file = args.getString("stderr", new File(outputDir, "amber_stderr.txt").toString());
 
-    int res = Amber.androidMain(args_list.toArray(new String[0]), stdout_file, stderr_file);
+    int res = Amber.androidHelper(args_list.toArray(new String[0]), stdout_file, stderr_file);
 
     // If the process crashes during the above call or we call System.exit below, the output
     // from `adb shell am instrument ...` will be:
diff --git a/android_gradle/app/src/main/AndroidManifest.xml b/android_gradle/app/src/main/AndroidManifest.xml
index 0ab9856..c74c390 100644
--- a/android_gradle/app/src/main/AndroidManifest.xml
+++ b/android_gradle/app/src/main/AndroidManifest.xml
@@ -4,6 +4,7 @@
 
     <application
         android:allowBackup="true"
+        android:fullBackupOnly="true"
         android:label="Amber"
         android:supportsRtl="true">
         <meta-data
diff --git a/android_gradle/app/src/main/java/com/google/amber/Amber.java b/android_gradle/app/src/main/java/com/google/amber/Amber.java
index 8319ccf..008c528 100644
--- a/android_gradle/app/src/main/java/com/google/amber/Amber.java
+++ b/android_gradle/app/src/main/java/com/google/amber/Amber.java
@@ -19,5 +19,5 @@ public class Amber {
     System.loadLibrary("amber_ndk");
   }
 
-  public static native int androidMain(String[] args, String stdout_file, String stderr_file);
+  public static native int androidHelper(String[] args, String stdout_file, String stderr_file);
 }