Added widget

app/src/main/AndroidManifest.xml

@@ -11,6 +11,10 @@
     <uses-permission android:name="android.permission.WAKE_LOCK" />
     <uses-permission android:name="com.android.vending.BILLING" />
 
+    <uses-feature
+        android:name="android.software.app_widgets"
+        android:required="false" />
+
     <application
         android:name=".ApplicationEx"
         android:allowBackup="false"
@@ -103,6 +107,17 @@
                 android:resource="@xml/fileprovider_paths" />
         </provider>
 
+        <receiver
+            android:name=".Widget"
+            android:label="@string/app_name">
+            <intent-filter>
+                <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
+            </intent-filter>
+            <meta-data
+                android:name="android.appwidget.provider"
+                android:resource="@xml/widget" />
+        </receiver>
+
         <receiver android:name=".ReceiverAutostart">
             <intent-filter>
                 <action android:name="android.intent.action.BOOT_COMPLETED" />

app/src/main/java/eu/faircode/email/ServiceSynchronize.java

@@ -215,6 +215,8 @@ public class ServiceSynchronize extends LifecycleService {
 
         serviceManager.onLost(null);
 
+        Widget.update(this, -1);
+
         stopForeground(true);
 
         NotificationManager nm = getSystemService(NotificationManager.class);
@@ -339,6 +341,8 @@ public class ServiceSynchronize extends LifecycleService {
         // https://developer.android.com/training/notify-user/group
         List<Notification> notifications = new ArrayList<>();
 
+        Widget.update(this, messages.size());
+
         if (messages.size() == 0)
             return notifications;
 

app/src/main/java/eu/faircode/email/Widget.java

@@ -0,0 +1,53 @@
+package eu.faircode.email;
+
+/*
+    This file is part of FairEmail.
+
+    FairEmail is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    NetGuard is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with NetGuard.  If not, see <http://www.gnu.org/licenses/>.
+
+    Copyright 2018 by Marcel Bokhorst (M66B)
+*/
+
+import android.app.PendingIntent;
+import android.appwidget.AppWidgetManager;
+import android.appwidget.AppWidgetProvider;
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.Intent;
+import android.widget.RemoteViews;
+
+public class Widget extends AppWidgetProvider {
+    @Override
+    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
+        update(appWidgetIds, appWidgetManager, context, -1);
+    }
+
+    static void update(Context context, int count) {
+        AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(context);
+        int appWidgetIds[] = AppWidgetManager.getInstance(context).getAppWidgetIds(new ComponentName(context, Widget.class));
+        update(appWidgetIds, appWidgetManager, context, count);
+    }
+
+    private static void update(int[] appWidgetIds, AppWidgetManager appWidgetManager, Context context, int count) {
+        Intent intent = new Intent(context, ActivityView.class);
+        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+        PendingIntent pi = PendingIntent.getActivity(context, ActivityView.REQUEST_UNIFIED, intent, PendingIntent.FLAG_UPDATE_CURRENT);
+        for (int id : appWidgetIds) {
+            RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.widget);
+            views.setOnClickPendingIntent(R.id.widget, pi);
+            views.setTextViewText(R.id.tvCount, count < 0 ? "?" : Integer.toString(count));
+            appWidgetManager.updateAppWidget(id, views);
+        }
+    }
+}

app/src/main/res/layout/widget.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/widget"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content"
+    android:background="@color/colorWidgetBackground"
+    android:orientation="vertical"
+    android:padding="6dp">
+
+    <ImageView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center_horizontal"
+        android:src="@drawable/baseline_mail_24"
+        android:tint="@color/colorWidgetForeground" />
+
+    <TextView
+        android:id="@+id/tvCount"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center_horizontal"
+        android:text="?"
+        android:textColor="@color/colorWidgetForeground"
+        android:textSize="15sp"
+        android:textStyle="bold" />
+</LinearLayout>

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

@@ -7,6 +7,9 @@
     <color name="colorActionForeground">#fff</color>
     <color name="colorActionForegroundDisabled">#ccc</color>
 
+    <color name="colorWidgetForeground">#fff</color>
+    <color name="colorWidgetBackground">#3f000000</color>
+
     <color name="lightColorUnread">#000</color>
     <color name="lightColorItemSelected">#ccc</color>
     <color name="lightColorSeparator">#aaa</color>

app/src/main/res/xml/widget.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
+    android:initialLayout="@layout/widget"
+    android:minWidth="40dp"
+    android:minHeight="40dp"
+    android:previewImage="@drawable/baseline_mail_24"
+    android:resizeMode="none"
+    android:updatePeriodMillis="0" />