Sample Android application

This is a sample Android application that can be built with gradle and buck.
It requires import_deps provided in facebook/buck#2706.

android/hello_world/.buckconfig

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+[cache]
+  mode = dir
+  dir_max_size = 1GB
+
+[android]
+  target = android-32
+
+[java]
+    src_roots = /java/
+    source_level = 8
+    target_level = 8

android/hello_world/.gitignore

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+*.iml
+.gradle
+/local.properties
+/.idea/caches
+/.idea/libraries
+/.idea/modules.xml
+/.idea/workspace.xml
+/.idea/navEditor.xml
+/.idea/assetWizardSettings.xml
+.DS_Store
+/build
+/app/build
+/captures
+.externalNativeBuild
+.cxx
+local.properties
+
+app/libs/*
+
+# Buck
+/.buckd
+/buck-out
+/buck-cache
+
+# Keystores
+# In Buck, all input files must live under the project root.
+# Therefore, you need to create the following files in this
+# project with your own keystore:
+keystore/debug.keystore
+# Most likely, you can use the standard debug keystore by running
+# the following:
+#
+#     cp ~/.android/debug.keystore keystore/debug.keystore
+
+third-party

android/hello_world/README.md

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+This is a sample Android app that can be built with gradle and buck.
+
+How to build
+-------------
+
+Define ANDROID_SDK environment variable
+```shell
+export ANDROID_SDK=/home/yourname/Android/Sdk
+```
+
+Generate a keystore:
+```shell
+cd keystore
+keytool -genkey -keystore debug.keystore -alias my_alias \
+>     -keyalg RSA -keysize 2048 -validity 10000
+```
+Update the keystore password in keystore/debug.keystore.properties.
+
+Create a list of project dependencies
+```shell
+cd ..
+mkdir buck-out
+./gradlew -q :app:dependencies --configuration debugCompileClasspath >  buck-out/deps.txt
+./gradlew -q :app:dependencies --configuration debugRuntimeClasspath >> buck-out/deps.txt
+./gradlew -q :app:dependencies --configuration debugAnnotationProcessorClasspath >> buck-out/deps.txt
+```
+
+Use the import_deps tool to download dependencies and generate BUCK files.
+```shell
+cd ../import_deps
+./importdeps.py --gdeps /Users/mdzyuba/whatsapp/android/tools/buck/hello_world/buck-out/deps.txt --libs third-party
+cd ../hello_world
+mv ../import_deps/third-party .
+```
+Verify the generated third-party BUCK
+```shell
+buck targets //third-party:
+buck build //third-party:core
+```
+Start an Android emulator or device. It could be based on SDK Platform v21 - v32.
+
+To build and install the app, run:
+```shell
+buck install //app:app
+```
+Then run Hello World app on the device.
+
+Hare is a list of sample buck targets:
+```shell
+buck build //app:deps
+buck build //app:lib
+buck build //keystore:debug_keystore
+buck build //app:app
+```
+

android/hello_world/app/BUCK

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+
+android_library(
+    name = "deps",
+    exported_deps = [
+        "//third-party/androidx/appcompat:appcompat",
+        "//third-party/com/google/android/material:material",
+        "//third-party/androidx/constraintlayout:constraintlayout"
+    ],
+    visibility = ["PUBLIC"],
+)
+
+android_build_config(
+    name = "build_config",
+    package = "com.example.helloworld",
+)
+
+android_resource(
+  name = 'res',
+  res = 'src/main/res',
+  package = 'com.example.helloworld',
+  visibility = [
+    "PUBLIC",
+  ],
+)
+
+android_library(
+  name = 'lib',
+  srcs = glob(['src/main/java/**/*.java']),
+  deps = [
+    ':res',
+    ':deps'
+  ],
+)
+
+android_binary(
+  name = 'app',
+  aapt_mode = 'aapt2',
+  manifest = 'src/main/AndroidManifest.xml',
+  manifest_entries = {
+    'version_code': 1,
+    'version_name': '1.0',
+    'min_sdk_version': 21,
+    'target_sdk_version': 32
+  },
+  keystore = '//keystore:debug_keystore',
+  deps = [
+    ':lib',
+    ':res',
+    ':deps',
+  ],
+)

android/hello_world/app/build.gradle

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+plugins {
+    id 'com.android.application'
+}
+
+android {
+    compileSdk 32
+
+    defaultConfig {
+        applicationId "com.example.helloworld"
+        minSdk 21
+        targetSdk 32
+        versionCode 1
+        versionName "1.0"
+
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+    }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+}
+
+dependencies {
+    implementation 'androidx.appcompat:appcompat:1.4.1'
+    implementation 'com.google.android.material:material:1.5.0'
+    implementation 'androidx.constraintlayout:constraintlayout:2.1.3'
+    testImplementation 'junit:junit:4.13.2'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.3'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
+}
+
+configurations {
+    toCopy
+}
+
+dependencies {
+    toCopy 'androidx.appcompat:appcompat:1.4.1'
+    toCopy 'com.google.android.material:material:1.5.0'
+    toCopy 'androidx.constraintlayout:constraintlayout:2.1.3'
+}
+
+task download(type: Copy) {
+    from configurations.toCopy
+    into 'libs'
+}
+
+

android/hello_world/app/proguard-rules.pro

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+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile

android/hello_world/app/src/androidTest/java/com/example/helloworld/ExampleInstrumentedTest.java

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+package com.example.helloworld;
+
+import static org.junit.Assert.*;
+
+import android.content.Context;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.platform.app.InstrumentationRegistry;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+@RunWith(AndroidJUnit4.class)
+public class ExampleInstrumentedTest {
+  @Test
+  public void useAppContext() {
+    // Context of the app under test.
+    Context appContext = InstrumentationRegistry.getInstrumentation().getTargetContext();
+    assertEquals("com.example.helloworld", appContext.getPackageName());
+  }
+}

android/hello_world/app/src/main/AndroidManifest.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.example.helloworld">
+
+    <application
+        android:allowBackup="true"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/Theme.HelloWorld">
+        <activity
+            android:name=".MainActivity"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>

android/hello_world/app/src/main/java/com/example/helloworld/MainActivity.java

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+package com.example.helloworld;
+
+import android.os.Bundle;
+import androidx.appcompat.app.AppCompatActivity;
+
+public class MainActivity extends AppCompatActivity {
+
+  @Override
+  protected void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    setContentView(R.layout.activity_main);
+  }
+}

android/hello_world/app/src/main/res/drawable-v24/ic_launcher_foreground.xml

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+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <path android:pathData="M31,63.928c0,0 6.4,-11 12.1,-13.1c7.2,-2.6 26,-1.4 26,-1.4l38.1,38.1L107,108.928l-32,-1L31,63.928z">
+        <aapt:attr name="android:fillColor">
+            <gradient
+                android:endX="85.84757"
+                android:endY="92.4963"
+                android:startX="42.9492"
+                android:startY="49.59793"
+                android:type="linear">
+                <item
+                    android:color="#44000000"
+                    android:offset="0.0" />
+                <item
+                    android:color="#00000000"
+                    android:offset="1.0" />
+            </gradient>
+        </aapt:attr>
+    </path>
+    <path
+        android:fillColor="#FFFFFF"
+        android:fillType="nonZero"
+        android:pathData="M65.3,45.828l3.8,-6.6c0.2,-0.4 0.1,-0.9 -0.3,-1.1c-0.4,-0.2 -0.9,-0.1 -1.1,0.3l-3.9,6.7c-6.3,-2.8 -13.4,-2.8 -19.7,0l-3.9,-6.7c-0.2,-0.4 -0.7,-0.5 -1.1,-0.3C38.8,38.328 38.7,38.828 38.9,39.228l3.8,6.6C36.2,49.428 31.7,56.028 31,63.928h46C76.3,56.028 71.8,49.428 65.3,45.828zM43.4,57.328c-0.8,0 -1.5,-0.5 -1.8,-1.2c-0.3,-0.7 -0.1,-1.5 0.4,-2.1c0.5,-0.5 1.4,-0.7 2.1,-0.4c0.7,0.3 1.2,1 1.2,1.8C45.3,56.528 44.5,57.328 43.4,57.328L43.4,57.328zM64.6,57.328c-0.8,0 -1.5,-0.5 -1.8,-1.2s-0.1,-1.5 0.4,-2.1c0.5,-0.5 1.4,-0.7 2.1,-0.4c0.7,0.3 1.2,1 1.2,1.8C66.5,56.528 65.6,57.328 64.6,57.328L64.6,57.328z"
+        android:strokeWidth="1"
+        android:strokeColor="#00000000" />
+</vector>