switch to using Fragments and ViewModel

app/build.gradle

@@ -1,4 +1,5 @@
 apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android'
 
 android {
     compileSdkVersion 29
@@ -34,8 +35,14 @@ android {
 
 dependencies {
     implementation fileTree(include: ['*.jar'], dir: 'libs')
-    implementation 'androidx.appcompat:appcompat:1.1.0'
-    implementation 'com.google.android.material:material:1.1.0'
+    implementation 'androidx.appcompat:appcompat:1.2.0'
+    implementation 'com.google.android.material:material:1.2.0'
+    implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0'
+    implementation "androidx.core:core-ktx:1.3.1"
+    implementation "androidx.fragment:fragment:1.3.0-alpha08"
+    implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:2.2.0"
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
+    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9"
 }
 
 def props = new Properties()
@@ -61,3 +68,6 @@ if (propFile.canRead()) {
     println 'signing.properties not found'
     android.buildTypes.release.signingConfig = null
 }
+repositories {
+    mavenCentral()
+}

app/src/debug/res/values/strings.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="app_name">PDF Viewer Debug</string>
+</resources>

app/src/main/AndroidManifest.xml

@@ -1,29 +1,38 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-        package="org.grapheneos.pdfviewer"
-        android:targetSandboxVersion="2">
-    <application android:icon="@mipmap/ic_launcher"
-            android:roundIcon="@mipmap/ic_launcher_round"
-            android:label="@string/app_name"
-            android:theme="@style/AppTheme"
-            android:allowBackup="true">
-        <activity android:name=".PdfViewer"
-                android:label="@string/app_name">
+    package="org.grapheneos.pdfviewer"
+    android:targetSandboxVersion="2">
+
+    <application
+        android:allowBackup="true"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:theme="@style/AppTheme">
+        <activity
+            android:name=".PdfViewerActivity"
+            android:label="@string/app_name">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
+
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
             <intent-filter>
                 <action android:name="android.intent.action.VIEW" />
+
                 <category android:name="android.intent.category.DEFAULT" />
                 <category android:name="android.intent.category.BROWSABLE" />
+
                 <data android:mimeType="application/pdf" />
             </intent-filter>
         </activity>
 
-        <meta-data android:name="android.webkit.WebView.MetricsOptOut"
-                android:value="true" />
-        <meta-data android:name="android.webkit.WebView.EnableSafeBrowsing"
-                android:value="false" />
+        <meta-data
+            android:name="android.webkit.WebView.MetricsOptOut"
+            android:value="true" />
+        <meta-data
+            android:name="android.webkit.WebView.EnableSafeBrowsing"
+            android:value="false" />
     </application>
-</manifest>
+
+</manifest>

app/src/main/java/org/grapheneos/pdfviewer/PdfViewerActivity.java

@@ -0,0 +1,24 @@
+package org.grapheneos.pdfviewer;
+
+import android.os.Bundle;
+
+import androidx.appcompat.app.AppCompatActivity;
+
+public class PdfViewerActivity extends AppCompatActivity {
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_pdf_viewer);
+
+        if (savedInstanceState == null) {
+            PdfViewerFragment fragment = PdfViewerFragment.newInstance();
+            getSupportFragmentManager()
+                    .beginTransaction()
+                    .setPrimaryNavigationFragment(fragment)
+                    .add(R.id.pdf_fragment_container, fragment)
+                    .commit();
+        }
+
+    }
+}