Add update notification with automatic download & install option

.gitignore

@@ -17,3 +17,4 @@
 # but have a common checkstyle configuration
 !.idea/checkstyle-idea.xml
 *.iml
+*.lnk

app/build.gradle

@@ -40,6 +40,7 @@ dependencies {
     implementation 'androidx.swiperefreshlayout:swiperefreshlayout:1.1.0'
     implementation 'androidx.coordinatorlayout:coordinatorlayout:1.1.0'
     implementation 'com.google.android.material:material:1.2.1'
+    implementation 'com.squareup.okhttp:okhttp:2.5.0'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'androidx.test.ext:junit:1.1.2'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'

app/src/main/AndroidManifest.xml

@@ -6,6 +6,7 @@
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
+    <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
 
     <application
         android:allowBackup="true"

app/src/main/java/com/fmsys/snapdrop/MainActivity.java

@@ -15,6 +15,7 @@
 import android.net.NetworkInfo;
 import android.net.Uri;
 import android.net.wifi.WifiManager;
+import android.os.AsyncTask;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
@@ -30,6 +31,7 @@
 import android.widget.Toast;
 
 import androidx.annotation.RequiresApi;
+import androidx.appcompat.app.AlertDialog;
 import androidx.appcompat.widget.LinearLayoutCompat;
 import androidx.core.content.ContextCompat;
 import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
@@ -119,6 +121,7 @@ protected void onCreate(final Bundle savedInstanceState) {
         intentFilter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);
         registerReceiver(receiver, intentFilter);
 
+        new UpdateChecker().execute("");
     }
 
     private void refreshWebsite() {
@@ -278,4 +281,35 @@ public void run() {
 
     }
 
+    private class UpdateChecker extends AsyncTask<String, Void, String> {
+        @Override
+        protected String doInBackground(final String... params) {
+            try {
+                return UpdateUtils.checkUpdate();
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+            return null;
+        }
+
+        @Override
+        protected void onPostExecute(final String result) {
+            try {
+                if (result == null) {
+                    return;
+                }
+
+                final AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this, R.style.AlertDialogTheme)
+                        .setTitle(R.string.app_update)
+                        .setMessage(R.string.app_update_summary)
+                        .setPositiveButton(R.string.app_update_install, (dialog, id) -> UpdateUtils.runUpdate(MainActivity.this, result))
+                        .setNegativeButton(R.string.app_update_show_details, (dialog, id) -> UpdateUtils.showUpdatesInBrowserIntent(MainActivity.this));
+                builder.create().show();
+
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
 }

app/src/main/java/com/fmsys/snapdrop/UpdateUtils.java

@@ -0,0 +1,112 @@
+package com.fmsys.snapdrop;
+
+import android.app.Activity;
+import android.app.DownloadManager;
+import android.app.ProgressDialog;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.net.Uri;
+import android.os.Build;
+import android.os.Environment;
+
+import androidx.core.content.FileProvider;
+
+import com.squareup.okhttp.OkHttpClient;
+import com.squareup.okhttp.Request;
+import com.squareup.okhttp.Response;
+
+import java.io.File;
+import java.io.IOException;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+
+public final class UpdateUtils {
+
+    private UpdateUtils() {
+        // utility class
+    }
+
+    public static String checkUpdate() throws JSONException, IOException {
+
+        final OkHttpClient client = new OkHttpClient();
+        final Request request = new Request.Builder()
+                .url("https://fm-sys.github.io/snapdrop-android/output-metadata.json")
+                .build();
+
+        final Response response = client.newCall(request).execute();
+        final JSONObject obj = new JSONObject(response.body().string());
+        final JSONObject recentApp = obj.getJSONArray("elements").getJSONObject(0);
+        final int versionCode = recentApp.getInt("versionCode");
+
+        if (BuildConfig.VERSION_CODE < versionCode) {
+            return recentApp.getString("outputFile");
+        }
+
+        return null;
+    }
+
+    public static void runUpdate(final Activity context, final String fileName) {
+
+        final String downloadLink = "https://github.com/fm-sys/snapdrop-android/releases/latest/download/" + fileName;
+
+        final File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS), fileName);
+        if (file.exists()) {
+            launchInstallIntent(context, file);
+            return;
+        }
+
+        final ProgressDialog progressdialog = new ProgressDialog(context, R.style.AlertDialogTheme);
+        progressdialog.setMessage(context.getString(R.string.app_update_download_text));
+        progressdialog.setTitle(R.string.app_update_download_info);
+        progressdialog.setCancelable(false);
+        progressdialog.show();
+
+        //set downloadManager
+        final DownloadManager.Request downloadRequest = new DownloadManager.Request(Uri.parse(downloadLink))
+                .setDescription(context.getString(R.string.app_update_download_info))
+                .setTitle(fileName)
+                .setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE)
+                .setDestinationUri(Uri.fromFile(file));
+
+        // get download service and enqueue file
+        final DownloadManager manager = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);
+        final long downloadId = manager.enqueue(downloadRequest);
+
+        //set BroadcastReceiver to install app when .apk is downloaded
+        final BroadcastReceiver onComplete = new BroadcastReceiver() {
+            public void onReceive(final Context cntxt, final Intent intent) {
+                progressdialog.dismiss();
+                context.unregisterReceiver(this);
+                launchInstallIntent(context, file);
+            }
+        };
+        //register receiver for when .apk download is compete
+        context.registerReceiver(onComplete, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));
+
+
+    }
+
+    private static void launchInstallIntent(final Activity context, final File file) {
+
+        final Intent install = new Intent(Intent.ACTION_INSTALL_PACKAGE);
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            install.setData(FileProvider.getUriForFile(context, context.getApplicationContext().getPackageName() + ".provider", file));
+            install.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
+        } else {
+            install.setData(Uri.fromFile(file));
+        }
+        context.startActivity(install);
+    }
+
+    public static void showUpdatesInBrowserIntent(final Activity context) {
+        final Intent i = new Intent(Intent.ACTION_VIEW);
+        i.setData(Uri.parse("https://github.com/fm-sys/snapdrop-android/releases/latest"));
+        context.startActivity(i);
+    }
+
+}

app/src/main/res/values-de-rDE/strings.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="app_name">Snapdrop</string>
+    <string name="app_update">Update verfügbar</string>
+    <string name="app_update_summary">Updates enthalten in der Regel wichtige Fehlerbehebungen und tolle neue Funktionen. Die Installation wird empfohlen…</string>
+    <string name="app_update_install">Installieren</string>
+    <string name="app_update_show_details">Weitere Informationen</string>
+    <string name="app_update_download_info">Update wird heruntergeladen</string>
+    <string name="app_update_download_text">Dies sollte nur wenige Sekunden in Anspruch nehmen…</string>
+</resources>

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

@@ -1,3 +1,10 @@
 <resources>
     <string name="app_name">Snapdrop</string>
+
+    <string name="app_update">Update available</string>
+    <string name="app_update_summary">Updates usually contain important bug fixes and great new features. Installation is recommended…</string>
+    <string name="app_update_install">Install</string>
+    <string name="app_update_show_details">More details</string>
+    <string name="app_update_download_info">Downloading update</string>
+    <string name="app_update_download_text">This should only take a few seconds…</string>
 </resources>

app/src/main/res/values/styles.xml

@@ -25,4 +25,9 @@
         <item name="colorPrimary">@color/colorPrimary</item>
     </style>
 
+    <style name="AlertDialogTheme" parent="Theme.MaterialComponents.Light.Dialog.Alert">
+        <item name="colorPrimary">@color/colorAccent</item>
+        <item name="colorAccent">@color/colorAccent</item>
+    </style>
+
 </resources>