Fix for old devices

They can't use vector drawables in notifications. Also, groups can not
be used, see http://stackoverflow.com/a/34953411.

app/build.gradle

@@ -184,6 +184,7 @@ android {
         versionCode 102050
         versionName getVersionName()
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        vectorDrawables.useSupportLibrary = true
     }
 
     testOptions {

app/src/main/java/org/fdroid/fdroid/FDroidApp.java

@@ -37,6 +37,7 @@ import android.os.Build;
 import android.os.Environment;
 import android.os.StrictMode;
 import android.preference.PreferenceManager;
+import android.support.v7.app.AppCompatDelegate;
 import android.text.TextUtils;
 import android.util.Log;
 import android.widget.Toast;
@@ -78,6 +79,10 @@ import sun.net.www.protocol.bluetooth.Handler;
 )
 public class FDroidApp extends Application {
 
+    static {
+        AppCompatDelegate.setCompatVectorFromResourcesEnabled(true);
+    }
+
     private static final String TAG = "FDroidApp";
 
     public static final String SYSTEM_DIR_NAME = Environment.getRootDirectory().getAbsolutePath();

app/src/main/java/org/fdroid/fdroid/NotificationHelper.java

@@ -15,6 +15,7 @@ import android.os.Build;
 import android.support.graphics.drawable.VectorDrawableCompat;
 import android.support.v4.app.NotificationCompat;
 import android.support.v4.app.NotificationManagerCompat;
+import android.support.v4.content.ContextCompat;
 import android.support.v4.content.LocalBroadcastManager;
 import android.text.SpannableStringBuilder;
 import android.text.Spanned;
@@ -251,14 +252,14 @@ class NotificationHelper {
         if (entry.intent != null) {
             switch (entry.status) {
                 case UpdateAvailable:
-                    return new NotificationCompat.Action(R.drawable.ic_notify_update_24dp, context.getString(R.string.notification_action_update), entry.intent);
+                    return new NotificationCompat.Action(R.drawable.ic_file_download, context.getString(R.string.notification_action_update), entry.intent);
 
                 case Downloading:
                 case Installing:
-                    return new NotificationCompat.Action(R.drawable.ic_notify_cancel_24dp, context.getString(R.string.notification_action_cancel), entry.intent);
+                    return new NotificationCompat.Action(R.drawable.ic_cancel, context.getString(R.string.notification_action_cancel), entry.intent);
 
                 case ReadyToInstall:
-                    return new NotificationCompat.Action(R.drawable.ic_notify_install_24dp, context.getString(R.string.notification_action_install), entry.intent);
+                    return new NotificationCompat.Action(R.drawable.ic_file_install, context.getString(R.string.notification_action_install), entry.intent);
             }
         }
         return null;
@@ -333,9 +334,15 @@ class NotificationHelper {
                         .setLargeIcon(iconLarge)
                         .setLocalOnly(true)
                         .setVisibility(NotificationCompat.VISIBILITY_SECRET)
-                        .setGroup(GROUP_UPDATES)
                         .setContentIntent(entry.intent);
 
+        /* If using stacked notifications, use groups. Note that this would not work prior to Lollipop,
+           because of http://stackoverflow.com/a/34953411, but currently not an issue since stacked
+           notifications are used only on >= Nougat.
+        */
+        if (useStackedNotifications()) {
+            builder.setGroup(GROUP_UPDATES);
+        }
 
         // Handle actions
         //
@@ -430,9 +437,12 @@ class NotificationHelper {
                         .setContentText(context.getString(R.string.notification_content_single_installed))
                         .setLocalOnly(true)
                         .setVisibility(NotificationCompat.VISIBILITY_SECRET)
-                        .setGroup(GROUP_INSTALLED)
                         .setContentIntent(entry.intent);
 
+        if (useStackedNotifications()) {
+            builder.setGroup(GROUP_INSTALLED);
+        }
+
         Intent intentDeleted = new Intent(BROADCAST_NOTIFICATIONS_INSTALLED_CLEARED);
         intentDeleted.putExtra(EXTRA_NOTIFICATION_KEY, entry.getUniqueKey());
         PendingIntent piDeleted = PendingIntent.getBroadcast(context, 0, intentDeleted, 0);