diff --git a/.travis.yml b/.travis.yml
index 250aa4fde..3b031b1af 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -15,7 +15,7 @@ android:
     - tools
     - build-tools-28.0.3
     - android-24
-    - android-26
+    - android-28
     - extra
     - extra-android-m2repository
     - sys-img-armeabi-v7a-android-24
diff --git a/dependencies.gradle b/dependencies.gradle
index 670f36adb..0019aa218 100644
--- a/dependencies.gradle
+++ b/dependencies.gradle
@@ -1,13 +1,12 @@
-def support_lib_version = '26.1.0'
 def jems_version = '1.18'
 def contentpal_version = 'a7fbc62eef' //  a7fbc62eef -> 2018-08-19
-def support_test_runner_version = '0.5'
+def androidx_test_runner_version = '1.1.1'
 
 ext.deps = [
         // Support & Google libraries
-        support_appcompat  : "com.android.support:appcompat-v7:$support_lib_version",
-        support_annotations: "com.android.support:support-annotations:$support_lib_version",
-        support_design     : "com.android.support:design:$support_lib_version",
+        support_appcompat  : 'androidx.appcompat:appcompat:1.0.2',
+        support_annotations: 'androidx.annotation:annotation:1.0.0',
+        support_design     : 'com.google.android.material:material:1.0.0',
         android_dashclock  : 'com.google.android.apps.dashclock:dashclock-api:2.0.0',
 
         // dmfs
@@ -26,10 +25,10 @@ ext.deps = [
         // Testing
         junit              : 'junit:junit:4.12',
         hamcrest           : 'org.hamcrest:hamcrest-all:1.3',
-        mockito            : 'org.mockito:mockito-core:2.10.0',
+        mockito            : 'org.mockito:mockito-core:2.27.0',
         robolectric        : 'org.robolectric:robolectric:3.5.1',
-        support_test_runner: "com.android.support.test:runner:$support_test_runner_version",
-        support_test_rules : "com.android.support.test:rules:$support_test_runner_version",
+        support_test_runner: "androidx.test:runner:$androidx_test_runner_version",
+        support_test_rules : "androidx.test:rules:$androidx_test_runner_version",
 
         // dmfs testing
         jems_testing       : "org.dmfs:jems-testing:$jems_version",
diff --git a/gradle.properties b/gradle.properties
index 6ce1f33d3..1d081ca71 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,4 +1,6 @@
-COMPILE_SDK_VERSION=26
+COMPILE_SDK_VERSION=28
 MIN_SDK_VERSION=15
 TARGET_SDK_VERSION=26
 VERSION_OVERRIDE=0
+android.enableJetifier=true
+android.useAndroidX=true
diff --git a/opentasks-contract/build.gradle b/opentasks-contract/build.gradle
index 65ac00f53..674316aae 100644
--- a/opentasks-contract/build.gradle
+++ b/opentasks-contract/build.gradle
@@ -7,7 +7,7 @@ android {
         minSdkVersion MIN_SDK_VERSION.toInteger()
         targetSdkVersion TARGET_SDK_VERSION.toInteger()
 
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
 
     }
     buildTypes {
diff --git a/opentasks-provider/build.gradle b/opentasks-provider/build.gradle
index f2ac7ac72..9deaf7295 100644
--- a/opentasks-provider/build.gradle
+++ b/opentasks-provider/build.gradle
@@ -7,7 +7,7 @@ android {
         minSdkVersion MIN_SDK_VERSION.toInteger()
         targetSdkVersion TARGET_SDK_VERSION.toInteger()
 
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
 
     }
     buildTypes {
diff --git a/opentasks-provider/src/androidTest/java/org/dmfs/provider/tasks/TaskProviderInstancesTest.java b/opentasks-provider/src/androidTest/java/org/dmfs/provider/tasks/TaskProviderInstancesTest.java
index 6d09a96a5..8bfb9836e 100644
--- a/opentasks-provider/src/androidTest/java/org/dmfs/provider/tasks/TaskProviderInstancesTest.java
+++ b/opentasks-provider/src/androidTest/java/org/dmfs/provider/tasks/TaskProviderInstancesTest.java
@@ -21,8 +21,8 @@
 import android.content.OperationApplicationException;
 import android.os.Build;
 import android.os.RemoteException;
-import android.support.test.InstrumentationRegistry;
-import android.support.test.runner.AndroidJUnit4;
+import androidx.test.InstrumentationRegistry;
+import androidx.test.runner.AndroidJUnit4;
 
 import org.dmfs.android.contentpal.Operation;
 import org.dmfs.android.contentpal.OperationsQueue;
diff --git a/opentasks-provider/src/androidTest/java/org/dmfs/provider/tasks/TaskProviderTest.java b/opentasks-provider/src/androidTest/java/org/dmfs/provider/tasks/TaskProviderTest.java
index eae186bb2..c26d05b85 100644
--- a/opentasks-provider/src/androidTest/java/org/dmfs/provider/tasks/TaskProviderTest.java
+++ b/opentasks-provider/src/androidTest/java/org/dmfs/provider/tasks/TaskProviderTest.java
@@ -21,8 +21,8 @@
 import android.content.ContentValues;
 import android.content.Context;
 import android.os.Build;
-import android.support.test.InstrumentationRegistry;
-import android.support.test.runner.AndroidJUnit4;
+import androidx.test.InstrumentationRegistry;
+import androidx.test.runner.AndroidJUnit4;
 
 import org.dmfs.android.contentpal.Operation;
 import org.dmfs.android.contentpal.OperationsQueue;
diff --git a/opentasks/build.gradle b/opentasks/build.gradle
index 842ecc203..af8ec1acc 100644
--- a/opentasks/build.gradle
+++ b/opentasks/build.gradle
@@ -21,7 +21,7 @@ android {
         // spread version code to allow inserting versions if necessary
         versionCode gitCommitNo('refs/remotes/origin/master') * 99 + gitCommitNo('HEAD') + Integer.parseInt(VERSION_OVERRIDE)
         versionName version
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
     if (project.hasProperty("DMFS_RELEASE_KEYSTORE")) {
         signingConfigs {
@@ -74,7 +74,6 @@ dependencies {
     }
     implementation(deps.android_carrot) {
         exclude module: 'carrot'
-        exclude group: 'com.android.support'
         exclude module: 'iterators'
         exclude module: 'jems'
     }
@@ -86,12 +85,8 @@ dependencies {
     testImplementation deps.robolectric
     testImplementation deps.jems_testing
 
-    androidTestImplementation(deps.support_test_runner) {
-        exclude group: 'com.android.support', module: 'support-annotations'
-    }
-    androidTestImplementation(deps.support_test_rules) {
-        exclude group: 'com.android.support', module: 'support-annotations'
-    }
+    androidTestImplementation deps.support_test_runner
+    androidTestImplementation deps.support_test_rules
     implementation project(path: ':opentaskspal')
 }
 
diff --git a/opentasks/src/androidTest/java/org/dmfs/tasks/utils/DateTimeToTimeConversionTest.java b/opentasks/src/androidTest/java/org/dmfs/tasks/utils/DateTimeToTimeConversionTest.java
index 2319050af..657575ac7 100644
--- a/opentasks/src/androidTest/java/org/dmfs/tasks/utils/DateTimeToTimeConversionTest.java
+++ b/opentasks/src/androidTest/java/org/dmfs/tasks/utils/DateTimeToTimeConversionTest.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.tasks.utils;
 
-import android.support.test.runner.AndroidJUnit4;
+import androidx.test.runner.AndroidJUnit4;
 import android.text.format.Time;
 
 import org.dmfs.rfc5545.DateTime;
diff --git a/opentasks/src/main/java/com/jmedeisis/draglinearlayout/DragLinearLayout.java b/opentasks/src/main/java/com/jmedeisis/draglinearlayout/DragLinearLayout.java
index b80e0c9bd..4c1613012 100644
--- a/opentasks/src/main/java/com/jmedeisis/draglinearlayout/DragLinearLayout.java
+++ b/opentasks/src/main/java/com/jmedeisis/draglinearlayout/DragLinearLayout.java
@@ -36,8 +36,8 @@ of this software and associated documentation files (the "Software"), to deal
 import android.graphics.Canvas;
 import android.graphics.Rect;
 import android.graphics.drawable.BitmapDrawable;
-import android.support.annotation.NonNull;
-import android.support.v4.view.MotionEventCompat;
+import androidx.annotation.NonNull;
+import androidx.core.view.MotionEventCompat;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.util.SparseArray;
diff --git a/opentasks/src/main/java/org/dmfs/android/widgets/ColoredShapeCheckBox.java b/opentasks/src/main/java/org/dmfs/android/widgets/ColoredShapeCheckBox.java
index 7d69e6cf3..abbf6181c 100644
--- a/opentasks/src/main/java/org/dmfs/android/widgets/ColoredShapeCheckBox.java
+++ b/opentasks/src/main/java/org/dmfs/android/widgets/ColoredShapeCheckBox.java
@@ -24,7 +24,7 @@
 import android.graphics.drawable.Drawable;
 import android.graphics.drawable.GradientDrawable;
 import android.graphics.drawable.LayerDrawable;
-import android.support.v7.widget.AppCompatCheckBox;
+import androidx.appcompat.widget.AppCompatCheckBox;
 import android.util.AttributeSet;
 
 import org.dmfs.tasks.R;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/AppSettingsFragment.java b/opentasks/src/main/java/org/dmfs/tasks/AppSettingsFragment.java
index 3b6ebeb26..d184e7f33 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/AppSettingsFragment.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/AppSettingsFragment.java
@@ -18,7 +18,7 @@
 
 import android.os.Bundle;
 import android.preference.PreferenceFragment;
-import android.support.annotation.Nullable;
+import androidx.annotation.Nullable;
 
 
 /**
diff --git a/opentasks/src/main/java/org/dmfs/tasks/EditTaskActivity.java b/opentasks/src/main/java/org/dmfs/tasks/EditTaskActivity.java
index bf48970a0..024e873da 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/EditTaskActivity.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/EditTaskActivity.java
@@ -18,9 +18,9 @@
 
 import android.content.Intent;
 import android.os.Bundle;
-import android.support.v4.app.Fragment;
-import android.support.v4.app.NavUtils;
-import android.support.v7.app.ActionBar;
+import androidx.fragment.app.Fragment;
+import androidx.core.app.NavUtils;
+import androidx.appcompat.app.ActionBar;
 import android.view.Menu;
 import android.view.MenuItem;
 
diff --git a/opentasks/src/main/java/org/dmfs/tasks/EditTaskFragment.java b/opentasks/src/main/java/org/dmfs/tasks/EditTaskFragment.java
index 8124a8787..d371b8666 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/EditTaskFragment.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/EditTaskFragment.java
@@ -25,12 +25,12 @@
 import android.net.Uri;
 import android.os.Build.VERSION;
 import android.os.Bundle;
-import android.support.v4.app.FragmentActivity;
-import android.support.v4.app.LoaderManager;
-import android.support.v4.content.CursorLoader;
-import android.support.v4.content.Loader;
-import android.support.v7.app.ActionBar;
-import android.support.v7.app.AppCompatActivity;
+import androidx.fragment.app.FragmentActivity;
+import androidx.loader.app.LoaderManager;
+import androidx.loader.content.CursorLoader;
+import androidx.loader.content.Loader;
+import androidx.appcompat.app.ActionBar;
+import androidx.appcompat.app.AppCompatActivity;
 import android.text.TextUtils;
 import android.util.Log;
 import android.view.LayoutInflater;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/EmptyTaskFragment.java b/opentasks/src/main/java/org/dmfs/tasks/EmptyTaskFragment.java
index 52ef0a74f..b9791348a 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/EmptyTaskFragment.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/EmptyTaskFragment.java
@@ -18,7 +18,7 @@
 
 import android.app.Activity;
 import android.os.Bundle;
-import android.support.v4.app.Fragment;
+import androidx.fragment.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/InputTextDialogFragment.java b/opentasks/src/main/java/org/dmfs/tasks/InputTextDialogFragment.java
index 0640f62b3..82c8959a2 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/InputTextDialogFragment.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/InputTextDialogFragment.java
@@ -22,7 +22,7 @@
 import android.content.DialogInterface;
 import android.content.DialogInterface.OnKeyListener;
 import android.os.Bundle;
-import android.support.v4.app.Fragment;
+import androidx.fragment.app.Fragment;
 import android.view.ContextThemeWrapper;
 import android.view.KeyEvent;
 import android.view.LayoutInflater;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/JobIds.java b/opentasks/src/main/java/org/dmfs/tasks/JobIds.java
index b9a9c9304..ca94dbd54 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/JobIds.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/JobIds.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.tasks;
 
-import android.support.v4.app.JobIntentService;
+import androidx.core.app.JobIntentService;
 
 
 /**
diff --git a/opentasks/src/main/java/org/dmfs/tasks/ManageListActivity.java b/opentasks/src/main/java/org/dmfs/tasks/ManageListActivity.java
index b89dc11ca..bcc939850 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/ManageListActivity.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/ManageListActivity.java
@@ -25,7 +25,7 @@
 import android.database.Cursor;
 import android.net.Uri;
 import android.os.Bundle;
-import android.support.v7.app.AlertDialog;
+import androidx.appcompat.app.AlertDialog;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.WindowManager.LayoutParams;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/QuickAddDialogFragment.java b/opentasks/src/main/java/org/dmfs/tasks/QuickAddDialogFragment.java
index 331b49cd9..174542cc8 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/QuickAddDialogFragment.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/QuickAddDialogFragment.java
@@ -23,9 +23,9 @@
 import android.graphics.Color;
 import android.net.Uri;
 import android.os.Bundle;
-import android.support.v4.app.LoaderManager;
-import android.support.v4.content.CursorLoader;
-import android.support.v4.content.Loader;
+import androidx.loader.app.LoaderManager;
+import androidx.loader.content.CursorLoader;
+import androidx.loader.content.Loader;
 import android.text.Editable;
 import android.text.TextWatcher;
 import android.view.ContextThemeWrapper;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/SettingsListFragment.java b/opentasks/src/main/java/org/dmfs/tasks/SettingsListFragment.java
index b776010b2..14d785186 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/SettingsListFragment.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/SettingsListFragment.java
@@ -27,12 +27,12 @@
 import android.database.Cursor;
 import android.os.Bundle;
 import android.os.RemoteException;
-import android.support.v4.app.ListFragment;
-import android.support.v4.app.LoaderManager;
-import android.support.v4.content.CursorLoader;
-import android.support.v4.content.Loader;
-import android.support.v4.widget.CursorAdapter;
-import android.support.v7.app.AlertDialog;
+import androidx.fragment.app.ListFragment;
+import androidx.loader.app.LoaderManager;
+import androidx.loader.content.CursorLoader;
+import androidx.loader.content.Loader;
+import androidx.cursoradapter.widget.CursorAdapter;
+import androidx.appcompat.app.AlertDialog;
 import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuInflater;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/SyncSettingsActivity.java b/opentasks/src/main/java/org/dmfs/tasks/SyncSettingsActivity.java
index 5eb5b1d14..6f36181f4 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/SyncSettingsActivity.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/SyncSettingsActivity.java
@@ -16,8 +16,8 @@
 package org.dmfs.tasks;
 
 import android.os.Bundle;
-import android.support.v4.app.FragmentActivity;
-import android.support.v4.app.FragmentManager;
+import androidx.fragment.app.FragmentActivity;
+import androidx.fragment.app.FragmentManager;
 import android.view.View;
 import android.widget.Button;
 
diff --git a/opentasks/src/main/java/org/dmfs/tasks/TaskGroupPagerAdapter.java b/opentasks/src/main/java/org/dmfs/tasks/TaskGroupPagerAdapter.java
index 4155d84a6..09ebe4e30 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/TaskGroupPagerAdapter.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/TaskGroupPagerAdapter.java
@@ -18,9 +18,9 @@
 
 import android.annotation.SuppressLint;
 import android.content.Context;
-import android.support.v4.app.Fragment;
-import android.support.v4.app.FragmentManager;
-import android.support.v4.app.FragmentStatePagerAdapter;
+import androidx.fragment.app.Fragment;
+import androidx.fragment.app.FragmentManager;
+import androidx.fragment.app.FragmentStatePagerAdapter;
 
 import org.dmfs.tasks.groupings.AbstractGroupingFactory;
 import org.dmfs.tasks.groupings.TabConfig;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/TaskListActivity.java b/opentasks/src/main/java/org/dmfs/tasks/TaskListActivity.java
index 247fb7ace..2eaa724d6 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/TaskListActivity.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/TaskListActivity.java
@@ -26,20 +26,20 @@
 import android.os.Bundle;
 import android.os.Handler;
 import android.provider.Settings;
-import android.support.annotation.ColorInt;
-import android.support.annotation.NonNull;
-import android.support.design.widget.AppBarLayout;
-import android.support.design.widget.FloatingActionButton;
-import android.support.design.widget.TabLayout;
-import android.support.v4.app.Fragment;
-import android.support.v4.app.FragmentManager;
-import android.support.v4.view.MenuItemCompat;
-import android.support.v4.view.MenuItemCompat.OnActionExpandListener;
-import android.support.v4.view.ViewPager;
-import android.support.v4.view.ViewPager.OnPageChangeListener;
-import android.support.v7.widget.SearchView;
-import android.support.v7.widget.SearchView.OnQueryTextListener;
-import android.support.v7.widget.Toolbar;
+import androidx.annotation.ColorInt;
+import androidx.annotation.NonNull;
+import com.google.android.material.appbar.AppBarLayout;
+import com.google.android.material.floatingactionbutton.FloatingActionButton;
+import com.google.android.material.tabs.TabLayout;
+import androidx.fragment.app.Fragment;
+import androidx.fragment.app.FragmentManager;
+import androidx.core.view.MenuItemCompat;
+import androidx.core.view.MenuItemCompat.OnActionExpandListener;
+import androidx.viewpager.widget.ViewPager;
+import androidx.viewpager.widget.ViewPager.OnPageChangeListener;
+import androidx.appcompat.widget.SearchView;
+import androidx.appcompat.widget.SearchView.OnQueryTextListener;
+import androidx.appcompat.widget.Toolbar;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/TaskListFragment.java b/opentasks/src/main/java/org/dmfs/tasks/TaskListFragment.java
index 853e392ae..48c41f878 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/TaskListFragment.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/TaskListFragment.java
@@ -33,10 +33,10 @@
 import android.os.AsyncTask;
 import android.os.Bundle;
 import android.os.Handler;
-import android.support.annotation.NonNull;
-import android.support.design.widget.Snackbar;
-import android.support.v4.app.LoaderManager;
-import android.support.v4.content.Loader;
+import androidx.annotation.NonNull;
+import com.google.android.material.snackbar.Snackbar;
+import androidx.loader.app.LoaderManager;
+import androidx.loader.content.Loader;
 import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuInflater;
@@ -59,8 +59,6 @@
 import org.dmfs.tasks.contract.TaskContract;
 import org.dmfs.tasks.contract.TaskContract.Instances;
 import org.dmfs.tasks.contract.TaskContract.Tasks;
-import org.dmfs.tasks.groupings.ByDueDate;
-import org.dmfs.tasks.groupings.ByList;
 import org.dmfs.tasks.groupings.filters.AbstractFilter;
 import org.dmfs.tasks.groupings.filters.ConstantFilter;
 import org.dmfs.tasks.model.Model;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/ViewTaskActivity.java b/opentasks/src/main/java/org/dmfs/tasks/ViewTaskActivity.java
index 8cd7378b8..2a9b0e66c 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/ViewTaskActivity.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/ViewTaskActivity.java
@@ -22,9 +22,9 @@
 import android.os.Build.VERSION;
 import android.os.Bundle;
 import android.os.Handler;
-import android.support.annotation.ColorInt;
-import android.support.annotation.NonNull;
-import android.support.v4.app.Fragment;
+import androidx.annotation.ColorInt;
+import androidx.annotation.NonNull;
+import androidx.fragment.app.Fragment;
 import android.view.MenuItem;
 import android.view.Window;
 import android.view.WindowManager;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/ViewTaskFragment.java b/opentasks/src/main/java/org/dmfs/tasks/ViewTaskFragment.java
index 9b69ee108..8b3539c79 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/ViewTaskFragment.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/ViewTaskFragment.java
@@ -28,19 +28,19 @@
 import android.database.ContentObserver;
 import android.net.Uri;
 import android.os.Bundle;
-import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
-import android.support.design.widget.AppBarLayout;
-import android.support.design.widget.AppBarLayout.OnOffsetChangedListener;
-import android.support.design.widget.CoordinatorLayout;
-import android.support.design.widget.FloatingActionButton;
-import android.support.design.widget.Snackbar;
-import android.support.v4.app.ActivityCompat;
-import android.support.v4.view.MenuItemCompat;
-import android.support.v7.app.AppCompatActivity;
-import android.support.v7.widget.ShareActionProvider;
-import android.support.v7.widget.Toolbar;
-import android.support.v7.widget.Toolbar.OnMenuItemClickListener;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import com.google.android.material.appbar.AppBarLayout;
+import com.google.android.material.appbar.AppBarLayout.OnOffsetChangedListener;
+import androidx.coordinatorlayout.widget.CoordinatorLayout;
+import com.google.android.material.floatingactionbutton.FloatingActionButton;
+import com.google.android.material.snackbar.Snackbar;
+import androidx.core.app.ActivityCompat;
+import androidx.core.view.MenuItemCompat;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.appcompat.widget.ShareActionProvider;
+import androidx.appcompat.widget.Toolbar;
+import androidx.appcompat.widget.Toolbar.OnMenuItemClickListener;
 import android.text.TextUtils;
 import android.view.LayoutInflater;
 import android.view.Menu;
@@ -794,7 +794,7 @@ private void animate(View v, int duration, int visibility)
      * @param activty
      *         an {@link AppCompatActivity}.
      */
-    public void setupToolbarAsActionbar(android.support.v7.app.AppCompatActivity activty)
+    public void setupToolbarAsActionbar(androidx.appcompat.app.AppCompatActivity activty)
     {
         if (mToolBar == null)
         {
@@ -820,7 +820,7 @@ private void showFloatingActionButton(final boolean show)
         {
             p.setAnchorId(R.id.appbar);
             mFloatingActionButton.setLayoutParams(p);
-            mFloatingActionButton.setVisibility(View.VISIBLE);
+            mFloatingActionButton.show();
             // make sure the FAB has the right color
             updateColor();
         }
@@ -828,7 +828,7 @@ private void showFloatingActionButton(final boolean show)
         {
             p.setAnchorId(View.NO_ID);
             mFloatingActionButton.setLayoutParams(p);
-            mFloatingActionButton.setVisibility(View.GONE);
+            mFloatingActionButton.hide();
         }
     }
 }
diff --git a/opentasks/src/main/java/org/dmfs/tasks/actions/CancelNotificationAction.java b/opentasks/src/main/java/org/dmfs/tasks/actions/CancelNotificationAction.java
index 9f97efd09..ebb113f2d 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/actions/CancelNotificationAction.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/actions/CancelNotificationAction.java
@@ -20,7 +20,7 @@
 import android.content.ContentUris;
 import android.content.Context;
 import android.net.Uri;
-import android.support.v4.app.NotificationManagerCompat;
+import androidx.core.app.NotificationManagerCompat;
 
 import org.dmfs.android.contentpal.RowDataSnapshot;
 import org.dmfs.tasks.contract.TaskContract;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/actions/DelayedAction.java b/opentasks/src/main/java/org/dmfs/tasks/actions/DelayedAction.java
index 482846f9d..99b80e0ee 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/actions/DelayedAction.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/actions/DelayedAction.java
@@ -25,7 +25,7 @@
 import android.content.OperationApplicationException;
 import android.net.Uri;
 import android.os.RemoteException;
-import android.support.v4.app.AlarmManagerCompat;
+import androidx.core.app.AlarmManagerCompat;
 
 import org.dmfs.android.contentpal.RowDataSnapshot;
 import org.dmfs.tasks.contract.TaskContract;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/actions/NotifyAction.java b/opentasks/src/main/java/org/dmfs/tasks/actions/NotifyAction.java
index b416c3820..053b99f57 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/actions/NotifyAction.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/actions/NotifyAction.java
@@ -27,8 +27,8 @@
 import android.net.Uri;
 import android.os.Build;
 import android.os.RemoteException;
-import android.support.v4.app.NotificationCompat;
-import android.support.v4.app.NotificationManagerCompat;
+import androidx.core.app.NotificationCompat;
+import androidx.core.app.NotificationManagerCompat;
 import android.text.format.DateUtils;
 
 import org.dmfs.android.bolts.color.colors.ResourceColor;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/actions/OpenAction.java b/opentasks/src/main/java/org/dmfs/tasks/actions/OpenAction.java
index 53da32365..ffea58cf2 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/actions/OpenAction.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/actions/OpenAction.java
@@ -22,7 +22,7 @@
 import android.content.OperationApplicationException;
 import android.net.Uri;
 import android.os.RemoteException;
-import android.support.v4.app.TaskStackBuilder;
+import androidx.core.app.TaskStackBuilder;
 
 import org.dmfs.android.contentpal.RowDataSnapshot;
 import org.dmfs.tasks.contract.TaskContract;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/actions/PostUndoAction.java b/opentasks/src/main/java/org/dmfs/tasks/actions/PostUndoAction.java
index 04fd67406..8207f1595 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/actions/PostUndoAction.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/actions/PostUndoAction.java
@@ -25,8 +25,8 @@
 import android.net.Uri;
 import android.os.Build;
 import android.os.RemoteException;
-import android.support.v4.app.NotificationCompat;
-import android.support.v4.app.NotificationManagerCompat;
+import androidx.core.app.NotificationCompat;
+import androidx.core.app.NotificationManagerCompat;
 import android.widget.RemoteViews;
 
 import org.dmfs.android.contentpal.RowDataSnapshot;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/groupings/BaseTaskViewDescriptor.java b/opentasks/src/main/java/org/dmfs/tasks/groupings/BaseTaskViewDescriptor.java
index abc81b55d..b5f91de59 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/groupings/BaseTaskViewDescriptor.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/groupings/BaseTaskViewDescriptor.java
@@ -18,7 +18,7 @@
 
 import android.annotation.SuppressLint;
 import android.database.Cursor;
-import android.support.v4.util.SparseArrayCompat;
+import androidx.collection.SparseArrayCompat;
 import android.text.TextUtils;
 import android.text.format.Time;
 import android.view.View;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/groupings/ByList.java b/opentasks/src/main/java/org/dmfs/tasks/groupings/ByList.java
index a74e0fd81..abc06b011 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/groupings/ByList.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/groupings/ByList.java
@@ -20,7 +20,7 @@
 import android.content.res.Resources;
 import android.database.Cursor;
 import android.graphics.Paint;
-import android.support.v4.app.FragmentActivity;
+import androidx.fragment.app.FragmentActivity;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.BaseExpandableListAdapter;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/groupings/ByPriority.java b/opentasks/src/main/java/org/dmfs/tasks/groupings/ByPriority.java
index ed8e8bf3c..7f0d5fe32 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/groupings/ByPriority.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/groupings/ByPriority.java
@@ -20,7 +20,7 @@
 import android.content.res.Resources;
 import android.database.Cursor;
 import android.graphics.Paint;
-import android.support.v4.app.FragmentActivity;
+import androidx.fragment.app.FragmentActivity;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.BaseExpandableListAdapter;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/AbstractCursorLoaderFactory.java b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/AbstractCursorLoaderFactory.java
index 69c49cbde..7f10b1c7b 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/AbstractCursorLoaderFactory.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/AbstractCursorLoaderFactory.java
@@ -18,7 +18,7 @@
 
 import android.content.Context;
 import android.database.Cursor;
-import android.support.v4.content.Loader;
+import androidx.loader.content.Loader;
 
 
 /**
diff --git a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/CursorLoaderFactory.java b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/CursorLoaderFactory.java
index 0906a077c..6ba738c2f 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/CursorLoaderFactory.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/CursorLoaderFactory.java
@@ -19,8 +19,8 @@
 import android.content.Context;
 import android.database.Cursor;
 import android.net.Uri;
-import android.support.v4.content.CursorLoader;
-import android.support.v4.content.Loader;
+import androidx.loader.content.CursorLoader;
+import androidx.loader.content.Loader;
 
 
 /**
diff --git a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/CustomCursorLoader.java b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/CustomCursorLoader.java
index bfd51d527..6e1d72ea8 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/CustomCursorLoader.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/CustomCursorLoader.java
@@ -18,7 +18,7 @@
 
 import android.content.Context;
 import android.database.Cursor;
-import android.support.v4.content.Loader;
+import androidx.loader.content.Loader;
 
 
 /**
diff --git a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/EmptyCursorLoaderFactory.java b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/EmptyCursorLoaderFactory.java
index f7763be64..3475eb5ce 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/EmptyCursorLoaderFactory.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/EmptyCursorLoaderFactory.java
@@ -19,7 +19,7 @@
 import android.content.Context;
 import android.database.Cursor;
 import android.database.MatrixCursor;
-import android.support.v4.content.CursorLoader;
+import androidx.loader.content.CursorLoader;
 
 
 /**
diff --git a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/PriorityCursorLoaderFactory.java b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/PriorityCursorLoaderFactory.java
index c12b7c325..a7ede4be9 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/PriorityCursorLoaderFactory.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/PriorityCursorLoaderFactory.java
@@ -18,7 +18,7 @@
 
 import android.content.Context;
 import android.database.Cursor;
-import android.support.v4.content.Loader;
+import androidx.loader.content.Loader;
 
 
 /**
diff --git a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/ProgressCursorLoaderFactory.java b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/ProgressCursorLoaderFactory.java
index 4288e1e0c..77260111e 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/ProgressCursorLoaderFactory.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/ProgressCursorLoaderFactory.java
@@ -18,7 +18,7 @@
 
 import android.content.Context;
 import android.database.Cursor;
-import android.support.v4.content.Loader;
+import androidx.loader.content.Loader;
 
 
 /**
diff --git a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/SearchHistoryCursorLoaderFactory.java b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/SearchHistoryCursorLoaderFactory.java
index d0dba2406..ea6ac54e4 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/SearchHistoryCursorLoaderFactory.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/SearchHistoryCursorLoaderFactory.java
@@ -18,7 +18,7 @@
 
 import android.content.Context;
 import android.database.Cursor;
-import android.support.v4.content.Loader;
+import androidx.loader.content.Loader;
 
 import org.dmfs.tasks.utils.SearchHistoryHelper;
 
diff --git a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/TimeRangeCursorLoader.java b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/TimeRangeCursorLoader.java
index 5912caffd..d97ae9117 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/TimeRangeCursorLoader.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/TimeRangeCursorLoader.java
@@ -18,7 +18,7 @@
 
 import android.content.Context;
 import android.database.Cursor;
-import android.support.v4.content.Loader;
+import androidx.loader.content.Loader;
 import android.text.format.Time;
 
 import org.dmfs.tasks.utils.TimeChangeListener;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/TimeRangeCursorLoaderFactory.java b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/TimeRangeCursorLoaderFactory.java
index a947f8d99..53df42f17 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/TimeRangeCursorLoaderFactory.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/TimeRangeCursorLoaderFactory.java
@@ -18,7 +18,7 @@
 
 import android.content.Context;
 import android.database.Cursor;
-import android.support.v4.content.Loader;
+import androidx.loader.content.Loader;
 
 
 /**
diff --git a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/TimeRangeStartCursorLoader.java b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/TimeRangeStartCursorLoader.java
index 4f78af487..4fc766ec1 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/TimeRangeStartCursorLoader.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/TimeRangeStartCursorLoader.java
@@ -18,7 +18,7 @@
 
 import android.content.Context;
 import android.database.Cursor;
-import android.support.v4.content.Loader;
+import androidx.loader.content.Loader;
 import android.text.format.Time;
 
 import org.dmfs.tasks.utils.TimeChangeListener;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/TimeRangeStartCursorLoaderFactory.java b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/TimeRangeStartCursorLoaderFactory.java
index 0ca926ffd..d302d1a43 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/TimeRangeStartCursorLoaderFactory.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/groupings/cursorloaders/TimeRangeStartCursorLoaderFactory.java
@@ -18,7 +18,7 @@
 
 import android.content.Context;
 import android.database.Cursor;
-import android.support.v4.content.Loader;
+import androidx.loader.content.Loader;
 
 
 /**
diff --git a/opentasks/src/main/java/org/dmfs/tasks/homescreen/TaskListSelectionFragment.java b/opentasks/src/main/java/org/dmfs/tasks/homescreen/TaskListSelectionFragment.java
index 6dfdc0a18..680b7624b 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/homescreen/TaskListSelectionFragment.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/homescreen/TaskListSelectionFragment.java
@@ -18,13 +18,12 @@
 
 import android.app.Activity;
 import android.database.Cursor;
-import android.net.Uri;
 import android.os.Bundle;
-import android.support.annotation.Nullable;
-import android.support.v4.app.ListFragment;
-import android.support.v4.app.LoaderManager;
-import android.support.v4.content.CursorLoader;
-import android.support.v4.content.Loader;
+import androidx.annotation.Nullable;
+import androidx.fragment.app.ListFragment;
+import androidx.loader.app.LoaderManager;
+import androidx.loader.content.CursorLoader;
+import androidx.loader.content.Loader;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/homescreen/TaskListWidgetUpdaterService.java b/opentasks/src/main/java/org/dmfs/tasks/homescreen/TaskListWidgetUpdaterService.java
index 8c9060f4b..c8a162d9b 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/homescreen/TaskListWidgetUpdaterService.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/homescreen/TaskListWidgetUpdaterService.java
@@ -26,7 +26,7 @@
 import android.database.Cursor;
 import android.database.sqlite.SQLiteDatabase;
 import android.net.Uri;
-import android.support.v4.content.CursorLoader;
+import androidx.loader.content.CursorLoader;
 import android.text.format.Time;
 import android.widget.RemoteViews;
 import android.widget.RemoteViewsService;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/model/Model.java b/opentasks/src/main/java/org/dmfs/tasks/model/Model.java
index 326c9e345..2899c85c2 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/model/Model.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/model/Model.java
@@ -22,7 +22,7 @@
 import android.content.ContentUris;
 import android.content.Context;
 import android.content.Intent;
-import android.support.v4.util.SparseArrayCompat;
+import androidx.collection.SparseArrayCompat;
 import android.text.TextUtils;
 
 import org.dmfs.provider.tasks.AuthorityUtil;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/notification/ActionService.java b/opentasks/src/main/java/org/dmfs/tasks/notification/ActionService.java
index 47104f85c..62dea8a02 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/notification/ActionService.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/notification/ActionService.java
@@ -23,8 +23,8 @@
 import android.content.OperationApplicationException;
 import android.net.Uri;
 import android.os.RemoteException;
-import android.support.annotation.NonNull;
-import android.support.v4.app.JobIntentService;
+import androidx.annotation.NonNull;
+import androidx.core.app.JobIntentService;
 import android.util.Log;
 
 import org.dmfs.android.contentpal.Projection;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/notification/TaskNotificationService.java b/opentasks/src/main/java/org/dmfs/tasks/notification/TaskNotificationService.java
index 4aacb4690..8038752d3 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/notification/TaskNotificationService.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/notification/TaskNotificationService.java
@@ -17,18 +17,17 @@
 package org.dmfs.tasks.notification;
 
 import android.app.Notification;
-import android.app.PendingIntent;
 import android.app.Service;
 import android.content.ContentUris;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.net.Uri;
-import android.support.annotation.NonNull;
-import android.support.v4.app.JobIntentService;
-import android.support.v4.app.NotificationCompat;
-import android.support.v4.app.NotificationCompat.Builder;
-import android.support.v4.app.NotificationManagerCompat;
+import androidx.annotation.NonNull;
+import androidx.core.app.JobIntentService;
+import androidx.core.app.NotificationCompat;
+import androidx.core.app.NotificationCompat.Builder;
+import androidx.core.app.NotificationManagerCompat;
 
 import org.dmfs.android.contentpal.Projection;
 import org.dmfs.android.contentpal.predicates.AnyOf;
@@ -44,19 +43,15 @@
 import org.dmfs.opentaskspal.readdata.TaskVersion;
 import org.dmfs.opentaskspal.views.TasksView;
 import org.dmfs.optional.Optional;
-import org.dmfs.provider.tasks.AuthorityUtil;
 import org.dmfs.tasks.JobIds;
 import org.dmfs.tasks.R;
 import org.dmfs.tasks.actions.utils.NotificationPrefs;
 import org.dmfs.tasks.contract.TaskContract.Tasks;
-import org.dmfs.tasks.model.ContentSet;
 import org.dmfs.tasks.notification.state.PrefState;
 import org.dmfs.tasks.notification.state.RowState;
 import org.dmfs.tasks.notification.state.TaskNotificationState;
 import org.dmfs.tasks.utils.In;
 
-import java.util.ArrayList;
-
 
 /**
  * A {@link Service} that triggers and updates {@link Notification}s for Due and Start alarms as well as pinned tasks.
diff --git a/opentasks/src/main/java/org/dmfs/tasks/notification/signals/NotificationSignal.java b/opentasks/src/main/java/org/dmfs/tasks/notification/signals/NotificationSignal.java
index 76bb23c02..c2fd95fb5 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/notification/signals/NotificationSignal.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/notification/signals/NotificationSignal.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.tasks.notification.signals;
 
-import android.support.v4.app.NotificationCompat;
+import androidx.core.app.NotificationCompat;
 
 
 /**
diff --git a/opentasks/src/main/java/org/dmfs/tasks/quicksettings/TaskQuickSettingsTile.java b/opentasks/src/main/java/org/dmfs/tasks/quicksettings/TaskQuickSettingsTile.java
index 4743b4c36..e483ced3d 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/quicksettings/TaskQuickSettingsTile.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/quicksettings/TaskQuickSettingsTile.java
@@ -4,7 +4,7 @@
 import android.os.Build;
 import android.service.quicksettings.Tile;
 import android.service.quicksettings.TileService;
-import android.support.annotation.RequiresApi;
+import androidx.annotation.RequiresApi;
 
 import org.dmfs.tasks.EditTaskActivity;
 
diff --git a/opentasks/src/main/java/org/dmfs/tasks/share/TaskBindings.java b/opentasks/src/main/java/org/dmfs/tasks/share/TaskBindings.java
index c67c62e5a..7568f52f1 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/share/TaskBindings.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/share/TaskBindings.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.tasks.share;
 
-import android.support.annotation.Nullable;
+import androidx.annotation.Nullable;
 import android.text.format.Time;
 
 import org.dmfs.iterators.Function;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/share/TimeFormatter.java b/opentasks/src/main/java/org/dmfs/tasks/share/TimeFormatter.java
index e9d575860..005cb680b 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/share/TimeFormatter.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/share/TimeFormatter.java
@@ -17,8 +17,8 @@
 package org.dmfs.tasks.share;
 
 import android.content.Context;
-import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import android.text.format.Time;
 
 import org.dmfs.iterators.Function;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/BaseActivity.java b/opentasks/src/main/java/org/dmfs/tasks/utils/BaseActivity.java
index a2a0c35b9..ecabdbc78 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/BaseActivity.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/BaseActivity.java
@@ -20,7 +20,7 @@
 import android.content.SharedPreferences;
 import android.os.Build;
 import android.os.Bundle;
-import android.support.v7.app.AppCompatActivity;
+import androidx.appcompat.app.AppCompatActivity;
 
 import org.dmfs.android.retentionmagic.RetentionMagic;
 import org.dmfs.tasks.utils.permission.BasicAppPermissions;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/DateFormatter.java b/opentasks/src/main/java/org/dmfs/tasks/utils/DateFormatter.java
index c196b0612..dcbcb2a48 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/DateFormatter.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/DateFormatter.java
@@ -18,7 +18,7 @@
 
 import android.content.Context;
 import android.content.res.Resources;
-import android.support.annotation.VisibleForTesting;
+import androidx.annotation.VisibleForTesting;
 import android.text.format.DateUtils;
 import android.text.format.Time;
 
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/ExpandableChildDescriptor.java b/opentasks/src/main/java/org/dmfs/tasks/utils/ExpandableChildDescriptor.java
index abf17329d..f137550f2 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/ExpandableChildDescriptor.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/ExpandableChildDescriptor.java
@@ -19,7 +19,7 @@
 import android.content.Context;
 import android.database.Cursor;
 import android.net.Uri;
-import android.support.v4.content.CursorLoader;
+import androidx.loader.content.CursorLoader;
 
 import org.dmfs.tasks.groupings.filters.AbstractFilter;
 
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/ExpandableGroupDescriptor.java b/opentasks/src/main/java/org/dmfs/tasks/utils/ExpandableGroupDescriptor.java
index 5ad8bdf75..b196b3cd1 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/ExpandableGroupDescriptor.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/ExpandableGroupDescriptor.java
@@ -18,8 +18,8 @@
 
 import android.content.Context;
 import android.database.Cursor;
-import android.support.v4.content.CursorLoader;
-import android.support.v4.content.Loader;
+import androidx.loader.content.CursorLoader;
+import androidx.loader.content.Loader;
 
 import org.dmfs.tasks.groupings.cursorloaders.AbstractCursorLoaderFactory;
 import org.dmfs.tasks.groupings.filters.AbstractFilter;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/ExpandableGroupDescriptorAdapter.java b/opentasks/src/main/java/org/dmfs/tasks/utils/ExpandableGroupDescriptorAdapter.java
index 6e7cb00ac..0214f1d61 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/ExpandableGroupDescriptorAdapter.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/ExpandableGroupDescriptorAdapter.java
@@ -20,8 +20,8 @@
 import android.database.Cursor;
 import android.os.Bundle;
 import android.os.Handler;
-import android.support.v4.app.LoaderManager;
-import android.support.v4.content.Loader;
+import androidx.loader.app.LoaderManager;
+import androidx.loader.content.Loader;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/In.java b/opentasks/src/main/java/org/dmfs/tasks/utils/In.java
index 0eae91e60..704c82bae 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/In.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/In.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.tasks.utils;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Predicate;
 import org.dmfs.android.contentpal.TransactionContext;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/ObservableSparseArrayCompat.java b/opentasks/src/main/java/org/dmfs/tasks/utils/ObservableSparseArrayCompat.java
index 792863375..ee3db218c 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/ObservableSparseArrayCompat.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/ObservableSparseArrayCompat.java
@@ -16,7 +16,7 @@
 package org.dmfs.tasks.utils;
 
 import android.database.DataSetObservable;
-import android.support.v4.util.SparseArrayCompat;
+import androidx.collection.SparseArrayCompat;
 
 
 public class ObservableSparseArrayCompat<E> extends SparseArrayCompat<E>
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/SafeFragmentUiRunnable.java b/opentasks/src/main/java/org/dmfs/tasks/utils/SafeFragmentUiRunnable.java
index 21815fa70..4f4c1dc36 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/SafeFragmentUiRunnable.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/SafeFragmentUiRunnable.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.tasks.utils;
 
-import android.support.v4.app.Fragment;
+import androidx.fragment.app.Fragment;
 
 
 /**
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/SearchChildDescriptor.java b/opentasks/src/main/java/org/dmfs/tasks/utils/SearchChildDescriptor.java
index 85facdfc9..7c3a4bcdd 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/SearchChildDescriptor.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/SearchChildDescriptor.java
@@ -18,8 +18,8 @@
 
 import android.content.Context;
 import android.database.Cursor;
-import android.net.Uri;
-import android.support.v4.content.CursorLoader;
+
+import androidx.loader.content.CursorLoader;
 
 import org.dmfs.tasks.contract.TaskContract.Tasks;
 import org.dmfs.tasks.groupings.filters.AbstractFilter;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/TasksListCursorAdapter.java b/opentasks/src/main/java/org/dmfs/tasks/utils/TasksListCursorAdapter.java
index 7ab645298..34d4a3e21 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/TasksListCursorAdapter.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/TasksListCursorAdapter.java
@@ -31,13 +31,15 @@
 
 import java.util.ArrayList;
 
+import androidx.cursoradapter.widget.CursorAdapter;
+
 
 /**
  * An adapter to adapt a cursor containing task lists to a {@link Spinner}.
  *
  * @author Tobias Reinsch <tobias@dmfs.org>
  */
-public class TasksListCursorAdapter extends android.support.v4.widget.CursorAdapter
+public class TasksListCursorAdapter extends CursorAdapter
 {
     LayoutInflater mInflater;
 
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/TasksListCursorSpinnerAdapter.java b/opentasks/src/main/java/org/dmfs/tasks/utils/TasksListCursorSpinnerAdapter.java
index fc4ac41b2..da64335f7 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/TasksListCursorSpinnerAdapter.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/TasksListCursorSpinnerAdapter.java
@@ -29,13 +29,15 @@
 import org.dmfs.tasks.contract.TaskContract;
 import org.dmfs.tasks.model.TaskFieldAdapters;
 
+import androidx.cursoradapter.widget.CursorAdapter;
+
 
 /**
  * An adapter to adapt a cursor containing task lists to a {@link Spinner}.
  *
  * @author Arjun Naik<arjun@arjunnaik.in>
  */
-public class TasksListCursorSpinnerAdapter extends android.support.v4.widget.CursorAdapter implements SpinnerAdapter
+public class TasksListCursorSpinnerAdapter extends CursorAdapter implements SpinnerAdapter
 {
     LayoutInflater mInflater;
 
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/Update.java b/opentasks/src/main/java/org/dmfs/tasks/utils/Update.java
index 369d602bb..43e43457c 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/Update.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/Update.java
@@ -17,7 +17,7 @@
 package org.dmfs.tasks.utils;
 
 import android.content.ContentProviderOperation;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Operation;
 import org.dmfs.android.contentpal.RowData;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/ValidatingUri.java b/opentasks/src/main/java/org/dmfs/tasks/utils/ValidatingUri.java
index 25f801c24..ba001ae3a 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/ValidatingUri.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/ValidatingUri.java
@@ -17,7 +17,7 @@
 package org.dmfs.tasks.utils;
 
 import android.net.Uri;
-import android.support.annotation.Nullable;
+import androidx.annotation.Nullable;
 
 import org.dmfs.jems.fragile.Fragile;
 
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/colors/AdjustedForFab.java b/opentasks/src/main/java/org/dmfs/tasks/utils/colors/AdjustedForFab.java
index 24c796257..f5e5bba0f 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/colors/AdjustedForFab.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/colors/AdjustedForFab.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.tasks.utils.colors;
 
-import android.support.annotation.ColorInt;
+import androidx.annotation.ColorInt;
 
 import org.dmfs.android.bolts.color.Color;
 import org.dmfs.android.bolts.color.elementary.ValueColor;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/colors/DarkenedForStatusBar.java b/opentasks/src/main/java/org/dmfs/tasks/utils/colors/DarkenedForStatusBar.java
index 128c62bec..520fd2a20 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/colors/DarkenedForStatusBar.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/colors/DarkenedForStatusBar.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.tasks.utils.colors;
 
-import android.support.annotation.ColorInt;
+import androidx.annotation.ColorInt;
 
 import org.dmfs.android.bolts.color.Color;
 import org.dmfs.android.bolts.color.dynamic.lightness.HsvToned;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/colors/Mixed.java b/opentasks/src/main/java/org/dmfs/tasks/utils/colors/Mixed.java
index a4c1e7fec..0311db6d1 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/colors/Mixed.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/colors/Mixed.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.tasks.utils.colors;
 
-import android.support.annotation.ColorInt;
+import androidx.annotation.ColorInt;
 
 import org.dmfs.android.bolts.color.Color;
 import org.dmfs.android.bolts.color.elementary.ValueColor;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/colors/SmoothLightnessCapped.java b/opentasks/src/main/java/org/dmfs/tasks/utils/colors/SmoothLightnessCapped.java
index 9c0003229..29c601ee1 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/colors/SmoothLightnessCapped.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/colors/SmoothLightnessCapped.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.tasks.utils.colors;
 
-import android.support.annotation.ColorInt;
+import androidx.annotation.ColorInt;
 
 import org.dmfs.android.bolts.color.Color;
 import org.dmfs.android.bolts.color.dynamic.lightness.HsvToned;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/permission/LegacyAppPermissions.java b/opentasks/src/main/java/org/dmfs/tasks/utils/permission/LegacyAppPermissions.java
index 9069bf422..fc0a6b3d5 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/permission/LegacyAppPermissions.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/permission/LegacyAppPermissions.java
@@ -18,7 +18,7 @@
 
 import android.app.Activity;
 import android.content.Context;
-import android.support.v4.content.ContextCompat;
+import androidx.core.content.ContextCompat;
 
 import static android.content.pm.PackageManager.PERMISSION_GRANTED;
 
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/permission/MarshmallowPermissions.java b/opentasks/src/main/java/org/dmfs/tasks/utils/permission/MarshmallowPermissions.java
index 0edc42008..7464bc390 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/permission/MarshmallowPermissions.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/permission/MarshmallowPermissions.java
@@ -19,8 +19,8 @@
 import android.app.Activity;
 import android.content.Context;
 import android.content.SharedPreferences;
-import android.support.v4.app.ActivityCompat;
-import android.support.v4.content.ContextCompat;
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
 
 import org.dmfs.iterators.decorators.Filtered;
 import org.dmfs.iterators.filters.AnyOf;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/utils/permission/dialog/PermissionRequestDialogFragment.java b/opentasks/src/main/java/org/dmfs/tasks/utils/permission/dialog/PermissionRequestDialogFragment.java
index 7ee413eb5..313062fde 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/utils/permission/dialog/PermissionRequestDialogFragment.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/utils/permission/dialog/PermissionRequestDialogFragment.java
@@ -22,8 +22,8 @@
 import android.app.Dialog;
 import android.content.DialogInterface;
 import android.os.Bundle;
-import android.support.annotation.NonNull;
-import android.support.v4.app.DialogFragment;
+import androidx.annotation.NonNull;
+import androidx.fragment.app.DialogFragment;
 import android.text.Html;
 import android.text.method.LinkMovementMethod;
 import android.view.LayoutInflater;
diff --git a/opentasks/src/main/java/org/dmfs/tasks/widget/ListenableScrollView.java b/opentasks/src/main/java/org/dmfs/tasks/widget/ListenableScrollView.java
index dafd2c10d..0f5363203 100644
--- a/opentasks/src/main/java/org/dmfs/tasks/widget/ListenableScrollView.java
+++ b/opentasks/src/main/java/org/dmfs/tasks/widget/ListenableScrollView.java
@@ -17,7 +17,7 @@
 package org.dmfs.tasks.widget;
 
 import android.content.Context;
-import android.support.v4.widget.NestedScrollView;
+import androidx.core.widget.NestedScrollView;
 import android.util.AttributeSet;
 import android.widget.ScrollView;
 
diff --git a/opentasks/src/main/res/layout-v24/undo_notification.xml b/opentasks/src/main/res/layout-v24/undo_notification.xml
index bfc88ba1e..28dc99302 100644
--- a/opentasks/src/main/res/layout-v24/undo_notification.xml
+++ b/opentasks/src/main/res/layout-v24/undo_notification.xml
@@ -16,7 +16,7 @@
             android:ellipsize="marquee"
             android:fadingEdge="horizontal"
             android:gravity="center_vertical"
-            android:textAppearance="@style/TextAppearance.AppCompat.Notification.Title.colorFix"/>
+            android:textAppearance="@style/TextAppearance.Compat.Notification.Title.colorFix"/>
 
     <ImageView
             style="@style/ot_notification_icon_undo"
@@ -34,6 +34,6 @@
             android:paddingRight="16dip"
             android:text="@string/notification_undo"
             android:textAllCaps="true"
-            android:textAppearance="@style/TextAppearance.AppCompat.Notification.Action"/>
+            android:textAppearance="@style/TextAppearance.Compat.Notification.Action"/>
 
 </LinearLayout>
\ No newline at end of file
diff --git a/opentasks/src/main/res/layout/activity_task_list.xml b/opentasks/src/main/res/layout/activity_task_list.xml
index 04651c92b..afba29584 100644
--- a/opentasks/src/main/res/layout/activity_task_list.xml
+++ b/opentasks/src/main/res/layout/activity_task_list.xml
@@ -1,22 +1,22 @@
-<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
         xmlns:app="http://schemas.android.com/apk/res-auto"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:fitsSystemWindows="true">
 
-    <android.support.design.widget.AppBarLayout
+    <com.google.android.material.appbar.AppBarLayout
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
 
-        <android.support.v7.widget.Toolbar
+        <androidx.appcompat.widget.Toolbar
                 android:id="@+id/toolbar"
                 android:layout_width="match_parent"
                 android:layout_height="?attr/actionBarSize"
                 android:background="?attr/colorPrimary"
                 app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>
 
-        <android.support.design.widget.TabLayout
+        <com.google.android.material.tabs.TabLayout
                 android:id="@+id/tabs"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
@@ -24,16 +24,16 @@
                 app:tabIndicatorColor="@android:color/white"
                 app:tabIndicatorHeight="8dp"
                 app:tabMode="fixed"/>
-    </android.support.design.widget.AppBarLayout>
+    </com.google.android.material.appbar.AppBarLayout>
 
-    <android.support.v4.view.ViewPager xmlns:tools="http://schemas.android.com/tools"
+    <androidx.viewpager.widget.ViewPager xmlns:tools="http://schemas.android.com/tools"
             android:id="@+id/pager"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             app:layout_behavior="@string/appbar_scrolling_view_behavior"
             tools:context=".MainActivity"/>
 
-    <android.support.design.widget.FloatingActionButton
+    <com.google.android.material.floatingactionbutton.FloatingActionButton
             android:id="@+id/floating_action_button"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
@@ -43,4 +43,4 @@
             app:layout_anchorGravity="bottom|right|end"
             android:src="@drawable/ic_action_add"/>
 
-</android.support.design.widget.CoordinatorLayout>
\ No newline at end of file
+</androidx.coordinatorlayout.widget.CoordinatorLayout>
\ No newline at end of file
diff --git a/opentasks/src/main/res/layout/activity_task_twopane.xml b/opentasks/src/main/res/layout/activity_task_twopane.xml
index 7e3798a85..d9fe8a156 100644
--- a/opentasks/src/main/res/layout/activity_task_twopane.xml
+++ b/opentasks/src/main/res/layout/activity_task_twopane.xml
@@ -1,24 +1,24 @@
-<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
         xmlns:app="http://schemas.android.com/apk/res-auto"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:fitsSystemWindows="true">
 
-    <android.support.design.widget.AppBarLayout
+    <com.google.android.material.appbar.AppBarLayout
             android:id="@+id/appbar"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
             app:elevation="0dp">
 
-        <android.support.v7.widget.Toolbar
+        <androidx.appcompat.widget.Toolbar
                 android:id="@+id/toolbar"
                 android:layout_width="432dp"
                 android:layout_height="?attr/actionBarSize"
                 android:background="?attr/colorPrimary"
                 app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>
 
-        <android.support.design.widget.TabLayout
+        <com.google.android.material.tabs.TabLayout
                 android:id="@+id/tabs"
                 android:layout_width="432dp"
                 android:layout_height="wrap_content"
@@ -26,7 +26,7 @@
                 app:tabIndicatorColor="@android:color/white"
                 app:tabIndicatorHeight="8dp"
                 app:tabMode="fixed"/>
-    </android.support.design.widget.AppBarLayout>
+    </com.google.android.material.appbar.AppBarLayout>
 
     <FrameLayout
             android:id="@+id/task_detail_container"
@@ -41,14 +41,14 @@
             android:layout_marginStart="432dp"
             android:background="@drawable/opentasks_popup_background_mtrl_mult"/>
 
-    <android.support.v4.view.ViewPager xmlns:tools="http://schemas.android.com/tools"
+    <androidx.viewpager.widget.ViewPager xmlns:tools="http://schemas.android.com/tools"
             android:id="@+id/pager"
             android:layout_width="432dp"
             android:layout_height="match_parent"
             app:layout_behavior="@string/appbar_scrolling_view_behavior"
             tools:context=".MainActivity"/>
 
-    <android.support.design.widget.FloatingActionButton
+    <com.google.android.material.floatingactionbutton.FloatingActionButton
             android:id="@+id/floating_action_button"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
@@ -58,4 +58,4 @@
             app:layout_anchorGravity="bottom|right|end"
             android:src="@drawable/ic_action_add"/>
 
-</android.support.design.widget.CoordinatorLayout>
\ No newline at end of file
+</androidx.coordinatorlayout.widget.CoordinatorLayout>
\ No newline at end of file
diff --git a/opentasks/src/main/res/layout/activity_task_twopane_small.xml b/opentasks/src/main/res/layout/activity_task_twopane_small.xml
index 0fb33179c..837d1aadb 100644
--- a/opentasks/src/main/res/layout/activity_task_twopane_small.xml
+++ b/opentasks/src/main/res/layout/activity_task_twopane_small.xml
@@ -1,24 +1,24 @@
-<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
         xmlns:app="http://schemas.android.com/apk/res-auto"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:fitsSystemWindows="true">
 
-    <android.support.design.widget.AppBarLayout
+    <com.google.android.material.appbar.AppBarLayout
             android:id="@+id/appbar"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
             app:elevation="0dp">
 
-        <android.support.v7.widget.Toolbar
+        <androidx.appcompat.widget.Toolbar
                 android:id="@+id/toolbar"
                 android:layout_width="@dimen/opentasks_two_pane_list_width"
                 android:layout_height="?attr/actionBarSize"
                 android:background="?attr/colorPrimary"
                 app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>
 
-        <android.support.design.widget.TabLayout
+        <com.google.android.material.tabs.TabLayout
                 android:id="@+id/tabs"
                 android:layout_width="@dimen/opentasks_two_pane_list_width"
                 android:layout_height="wrap_content"
@@ -26,7 +26,7 @@
                 app:tabIndicatorColor="@android:color/white"
                 app:tabIndicatorHeight="8dp"
                 app:tabMode="fixed"/>
-    </android.support.design.widget.AppBarLayout>
+    </com.google.android.material.appbar.AppBarLayout>
 
 
     <FrameLayout
@@ -41,11 +41,11 @@
             android:background="@drawable/opentasks_popup_background_mtrl_mult"/>
 
 
-    <android.support.v4.view.ViewPager xmlns:tools="http://schemas.android.com/tools"
+    <androidx.viewpager.widget.ViewPager xmlns:tools="http://schemas.android.com/tools"
             android:id="@+id/pager"
             android:layout_width="@dimen/opentasks_two_pane_list_width"
             android:layout_height="match_parent"
             app:layout_behavior="@string/appbar_scrolling_view_behavior"
             tools:context=".MainActivity"/>
 
-</android.support.design.widget.CoordinatorLayout>
\ No newline at end of file
+</androidx.coordinatorlayout.widget.CoordinatorLayout>
\ No newline at end of file
diff --git a/opentasks/src/main/res/layout/fragment_task_view_detail.xml b/opentasks/src/main/res/layout/fragment_task_view_detail.xml
index 000c31854..0172b8870 100644
--- a/opentasks/src/main/res/layout/fragment_task_view_detail.xml
+++ b/opentasks/src/main/res/layout/fragment_task_view_detail.xml
@@ -1,13 +1,13 @@
-<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
         xmlns:app="http://schemas.android.com/apk/res-auto"
         android:layout_width="match_parent"
         android:layout_height="match_parent">
 
-    <android.support.design.widget.AppBarLayout
+    <com.google.android.material.appbar.AppBarLayout
             android:id="@+id/appbar"
             style="@style/opentasks_details_appbar">
 
-        <android.support.design.widget.CollapsingToolbarLayout
+        <com.google.android.material.appbar.CollapsingToolbarLayout
                 android:id="@+id/main.collapsing"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
@@ -115,10 +115,10 @@
                     </LinearLayout>
                 </org.dmfs.tasks.widget.TimeFieldView>
             </org.dmfs.tasks.widget.TaskView>
-        </android.support.design.widget.CollapsingToolbarLayout>
-    </android.support.design.widget.AppBarLayout>
+        </com.google.android.material.appbar.CollapsingToolbarLayout>
+    </com.google.android.material.appbar.AppBarLayout>
 
-    <android.support.v4.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
+    <androidx.core.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
             android:id="@+id/scrollView"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
@@ -130,9 +130,9 @@
                 android:background="@android:color/white"
                 android:layout_height="wrap_content"
                 android:orientation="vertical"/>
-    </android.support.v4.widget.NestedScrollView>
+    </androidx.core.widget.NestedScrollView>
 
-    <android.support.design.widget.FloatingActionButton
+    <com.google.android.material.floatingactionbutton.FloatingActionButton
             android:id="@+id/floating_action_button"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
@@ -142,7 +142,7 @@
             app:layout_anchor="@id/appbar"
             app:layout_anchorGravity="bottom|right|end"/>
 
-    <android.support.v7.widget.Toolbar
+    <androidx.appcompat.widget.Toolbar
             android:id="@+id/toolbar"
             android:layout_width="match_parent"
             android:layout_height="?attr/actionBarSize"
@@ -161,6 +161,6 @@
                 android:text=""
                 android:textColor="@android:color/white"
                 android:textSize="24sp"/>
-    </android.support.v7.widget.Toolbar>
+    </androidx.appcompat.widget.Toolbar>
 
-</android.support.design.widget.CoordinatorLayout>
\ No newline at end of file
+</androidx.coordinatorlayout.widget.CoordinatorLayout>
\ No newline at end of file
diff --git a/opentasks/src/main/res/layout/opentasks_fragment_empty_task.xml b/opentasks/src/main/res/layout/opentasks_fragment_empty_task.xml
index 5b9a72797..d22ecb7db 100644
--- a/opentasks/src/main/res/layout/opentasks_fragment_empty_task.xml
+++ b/opentasks/src/main/res/layout/opentasks_fragment_empty_task.xml
@@ -1,8 +1,8 @@
-<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
         android:layout_width="match_parent"
         android:layout_height="match_parent">
 
-    <android.support.design.widget.AppBarLayout
+    <com.google.android.material.appbar.AppBarLayout
             android:id="@+id/empty_task_fragment_appbar"
             style="@style/opentasks_details_appbar"
             android:layout_height="?attr/actionBarSize"/>
@@ -15,4 +15,4 @@
             android:textColor="@color/light_gray"
             android:text="@string/opentasks_details_no_task_selected"/>
 
-</android.support.design.widget.CoordinatorLayout>
\ No newline at end of file
+</androidx.coordinatorlayout.widget.CoordinatorLayout>
\ No newline at end of file
diff --git a/opentasks/src/main/res/layout/undo_notification.xml b/opentasks/src/main/res/layout/undo_notification.xml
index c0a85e0c1..a61a34086 100644
--- a/opentasks/src/main/res/layout/undo_notification.xml
+++ b/opentasks/src/main/res/layout/undo_notification.xml
@@ -27,7 +27,7 @@
             android:ellipsize="marquee"
             android:fadingEdge="horizontal"
             android:gravity="center_vertical"
-            android:textAppearance="@style/TextAppearance.AppCompat.Notification.Title.colorFix"/>
+            android:textAppearance="@style/TextAppearance.Compat.Notification.Title.colorFix"/>
 
     <ImageView
             android:layout_width="1dip"
@@ -53,6 +53,6 @@
             android:paddingRight="16dip"
             android:text="@string/notification_undo"
             android:textAllCaps="true"
-            android:textAppearance="@style/TextAppearance.AppCompat.Notification.Action"/>
+            android:textAppearance="@style/TextAppearance.Compat.Notification.Action"/>
 
 </LinearLayout>
\ No newline at end of file
diff --git a/opentasks/src/main/res/menu/task_list_activity_menu.xml b/opentasks/src/main/res/menu/task_list_activity_menu.xml
index 74bf614b5..7e2d40bf2 100644
--- a/opentasks/src/main/res/menu/task_list_activity_menu.xml
+++ b/opentasks/src/main/res/menu/task_list_activity_menu.xml
@@ -12,7 +12,7 @@
             android:id="@+id/search"
             android:title="@string/task_group_search_title"
             android:visible="false"
-            app:actionViewClass="android.support.v7.widget.SearchView"
+            app:actionViewClass="androidx.appcompat.widget.SearchView"
             app:showAsAction="collapseActionView"/>
     <item
             android:id="@+id/menu_visible_list"
diff --git a/opentasks/src/main/res/menu/view_task_fragment_menu.xml b/opentasks/src/main/res/menu/view_task_fragment_menu.xml
index b2f02aed7..b20a752d4 100644
--- a/opentasks/src/main/res/menu/view_task_fragment_menu.xml
+++ b/opentasks/src/main/res/menu/view_task_fragment_menu.xml
@@ -20,7 +20,7 @@
             android:title="@string/opentasks_task_details_menu_send"
             android:titleCondensed="@string/opentasks_task_details_menu_send_short"
             app:showAsAction="never"
-            app:actionProviderClass="android.support.v7.widget.ShareActionProvider"/>
+            app:actionProviderClass="androidx.appcompat.widget.ShareActionProvider"/>
     <item
             android:id="@+id/delete_task"
             android:icon="@drawable/content_discard"
diff --git a/opentasks/src/main/res/values-v21/styles.xml b/opentasks/src/main/res/values-v21/styles.xml
index 71fb88770..329602de4 100644
--- a/opentasks/src/main/res/values-v21/styles.xml
+++ b/opentasks/src/main/res/values-v21/styles.xml
@@ -11,13 +11,13 @@
         <item name="actionBarItemBackground">@drawable/selectable_background_white</item>
     </style>
 
-    <style name="TextAppearance.AppCompat.Notification.Title.colorFix">
+    <style name="TextAppearance.Compat.Notification.Title.colorFix">
         <item name="android:textColor">@color/abc_primary_text_material_light</item>
         <item name="android:fontFamily">sans-serif</item>
         <item name="android:textStyle">normal</item>
     </style>
 
-    <style name="TextAppearance.AppCompat.Notification.Action">
+    <style name="TextAppearance.Compat.Notification.Action">
         <item name="android:textColor">@color/abc_secondary_text_material_light</item>
         <item name="android:fontFamily">sans-serif-light</item>
         <item name="android:textStyle">bold</item>
diff --git a/opentasks/src/main/res/values/styles.xml b/opentasks/src/main/res/values/styles.xml
index 0673b2f1f..8d477619d 100644
--- a/opentasks/src/main/res/values/styles.xml
+++ b/opentasks/src/main/res/values/styles.xml
@@ -348,9 +348,9 @@
 
     <!-- styles for actionbar / toolbar -->
 
-    <style name="TextAppearance.AppCompat.Notification.Title.colorFix"/>
+    <style name="TextAppearance.Compat.Notification.Title.colorFix"/>
 
-    <style name="TextAppearance.AppCompat.Notification.Action"/>
+    <style name="TextAppearance.Compat.Notification.Action"/>
 
     <style name="ot_notification_icon_undo">
         <item name="android:src">@drawable/ic_24_undo_white</item>
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/operations/SubtaskRelation.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/operations/SubtaskRelation.java
index b149a5978..8df920a74 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/operations/SubtaskRelation.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/operations/SubtaskRelation.java
@@ -17,7 +17,7 @@
 package org.dmfs.opentaskspal.operations;
 
 import android.content.ContentProviderOperation;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.InsertOperation;
 import org.dmfs.android.contentpal.Operation;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/operations/TaskListTask.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/operations/TaskListTask.java
index 27193b9a4..9bb419d9c 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/operations/TaskListTask.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/operations/TaskListTask.java
@@ -17,7 +17,7 @@
 package org.dmfs.opentaskspal.operations;
 
 import android.content.ContentProviderOperation;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.InsertOperation;
 import org.dmfs.android.contentpal.Operation;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/predicates/AnyOf.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/predicates/AnyOf.java
index b14ed3d0f..de65d89cb 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/predicates/AnyOf.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/predicates/AnyOf.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.predicates;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Predicate;
 import org.dmfs.android.contentpal.predicates.DelegatingPredicate;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/predicates/BinaryPredicate.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/predicates/BinaryPredicate.java
index d2f06c6fc..ae6e559da 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/predicates/BinaryPredicate.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/predicates/BinaryPredicate.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.predicates;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Predicate;
 import org.dmfs.android.contentpal.TransactionContext;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/EffectiveDueDate.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/EffectiveDueDate.java
index 5c184266d..e288175db 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/EffectiveDueDate.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/EffectiveDueDate.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.readdata;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Projection;
 import org.dmfs.android.contentpal.RowDataSnapshot;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/EffectiveTaskColor.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/EffectiveTaskColor.java
index 47071cce7..9a3b5dff1 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/EffectiveTaskColor.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/EffectiveTaskColor.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.readdata;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.bolts.color.Color;
 import org.dmfs.android.bolts.color.colors.DelegatingColor;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/EffectiveTimezone.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/EffectiveTimezone.java
index 502a50a1f..11c454aec 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/EffectiveTimezone.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/EffectiveTimezone.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.readdata;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Projection;
 import org.dmfs.android.contentpal.RowDataSnapshot;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/Id.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/Id.java
index 60cf6641b..91e70f1c6 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/Id.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/Id.java
@@ -17,7 +17,7 @@
 package org.dmfs.opentaskspal.readdata;
 
 import android.provider.BaseColumns;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Projection;
 import org.dmfs.android.contentpal.RowDataSnapshot;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/PercentComplete.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/PercentComplete.java
index 6b00d1a21..8819bceda 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/PercentComplete.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/PercentComplete.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.readdata;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Projection;
 import org.dmfs.android.contentpal.RowDataSnapshot;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskCompletionTime.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskCompletionTime.java
index cfdfedd3f..c364fa08f 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskCompletionTime.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskCompletionTime.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.readdata;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Projection;
 import org.dmfs.android.contentpal.RowDataSnapshot;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskDateTime.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskDateTime.java
index f3ce16542..50fe7dafc 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskDateTime.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskDateTime.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.readdata;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Projection;
 import org.dmfs.android.contentpal.RowDataSnapshot;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskDuration.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskDuration.java
index 742c4f80a..6be74df9a 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskDuration.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskDuration.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.readdata;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Projection;
 import org.dmfs.android.contentpal.RowDataSnapshot;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskIsClosed.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskIsClosed.java
index d66e2f39b..a2f95e949 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskIsClosed.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskIsClosed.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.readdata;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Projection;
 import org.dmfs.android.contentpal.RowDataSnapshot;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskPin.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskPin.java
index f572cfded..c59d4fe28 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskPin.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskPin.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.readdata;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Projection;
 import org.dmfs.android.contentpal.RowDataSnapshot;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskStart.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskStart.java
index b3ce5b832..164194b61 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskStart.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskStart.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.readdata;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Projection;
 import org.dmfs.android.contentpal.RowDataSnapshot;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskStatus.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskStatus.java
index 53346a51d..83b3a4218 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskStatus.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskStatus.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.readdata;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Projection;
 import org.dmfs.android.contentpal.RowDataSnapshot;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskTitle.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskTitle.java
index 718231a36..3aafbc8a0 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskTitle.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskTitle.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.readdata;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Projection;
 import org.dmfs.android.contentpal.RowDataSnapshot;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskUri.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskUri.java
index 0e3e0310b..c8c551913 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskUri.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskUri.java
@@ -18,7 +18,7 @@
 
 import android.content.ContentUris;
 import android.net.Uri;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Projection;
 import org.dmfs.android.contentpal.RowDataSnapshot;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskVersion.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskVersion.java
index bfa9e9bfc..b96166f76 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskVersion.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/readdata/TaskVersion.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.readdata;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Projection;
 import org.dmfs.android.contentpal.RowDataSnapshot;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/rowdata/DateTimeListData.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/rowdata/DateTimeListData.java
index 59286e9e3..851fb1869 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/rowdata/DateTimeListData.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/rowdata/DateTimeListData.java
@@ -17,7 +17,7 @@
 package org.dmfs.opentaskspal.rowdata;
 
 import android.content.ContentProviderOperation;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 import android.text.TextUtils;
 
 import org.dmfs.android.contentpal.RowData;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/rowsets/Subtasks.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/rowsets/Subtasks.java
index 7bf864f09..943b44740 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/rowsets/Subtasks.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/rowsets/Subtasks.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.rowsets;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Projection;
 import org.dmfs.android.contentpal.RowReference;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tables/LocalTaskListsTable.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tables/LocalTaskListsTable.java
index 0e107353d..8c8b50f49 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tables/LocalTaskListsTable.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tables/LocalTaskListsTable.java
@@ -17,7 +17,7 @@
 package org.dmfs.opentaskspal.tables;
 
 import android.accounts.Account;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Table;
 import org.dmfs.android.contentpal.tables.AccountScoped;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tables/TaskListScoped.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tables/TaskListScoped.java
index 0493c36f0..16f362509 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tables/TaskListScoped.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tables/TaskListScoped.java
@@ -17,7 +17,7 @@
 package org.dmfs.opentaskspal.tables;
 
 import android.content.ContentProviderClient;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.InsertOperation;
 import org.dmfs.android.contentpal.Operation;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tables/TasksTable.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tables/TasksTable.java
index 1f0c92da0..693a2905b 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tables/TasksTable.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tables/TasksTable.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.tables;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.Table;
 import org.dmfs.android.contentpal.tables.BaseTable;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasklists/NameData.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasklists/NameData.java
index 28afc241b..f95bf896d 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasklists/NameData.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasklists/NameData.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.tasklists;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.RowData;
 import org.dmfs.android.contentpal.rowdata.CharSequenceRowData;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/DueData.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/DueData.java
index 5da31d045..d69558668 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/DueData.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/DueData.java
@@ -17,7 +17,7 @@
 package org.dmfs.opentaskspal.tasks;
 
 import android.content.ContentProviderOperation;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.RowData;
 import org.dmfs.android.contentpal.TransactionContext;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/ExDatesTaskData.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/ExDatesTaskData.java
index 9c86a4323..ae02fd6c0 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/ExDatesTaskData.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/ExDatesTaskData.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.tasks;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.RowData;
 import org.dmfs.android.contentpal.rowdata.DelegatingRowData;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/NoTimeData.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/NoTimeData.java
index 577569638..161284929 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/NoTimeData.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/NoTimeData.java
@@ -17,7 +17,7 @@
 package org.dmfs.opentaskspal.tasks;
 
 import android.content.ContentProviderOperation;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.RowData;
 import org.dmfs.android.contentpal.TransactionContext;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/OriginalInstanceSyncIdData.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/OriginalInstanceSyncIdData.java
index 1623217a6..06d062097 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/OriginalInstanceSyncIdData.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/OriginalInstanceSyncIdData.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.tasks;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.RowData;
 import org.dmfs.android.contentpal.rowdata.CharSequenceRowData;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/PinnedData.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/PinnedData.java
index 5b43cda56..7f5b1e7a9 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/PinnedData.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/PinnedData.java
@@ -17,7 +17,7 @@
 package org.dmfs.opentaskspal.tasks;
 
 import android.content.ContentProviderOperation;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.RowData;
 import org.dmfs.android.contentpal.TransactionContext;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/RDatesTaskData.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/RDatesTaskData.java
index 6189ddea8..cb25acaf1 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/RDatesTaskData.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/RDatesTaskData.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.tasks;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.RowData;
 import org.dmfs.android.contentpal.rowdata.DelegatingRowData;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/RRuleTaskData.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/RRuleTaskData.java
index 836807c88..4e570023a 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/RRuleTaskData.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/RRuleTaskData.java
@@ -17,7 +17,7 @@
 package org.dmfs.opentaskspal.tasks;
 
 import android.content.ContentProviderOperation;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.RowData;
 import org.dmfs.android.contentpal.TransactionContext;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/RelationData.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/RelationData.java
index 593e1e40d..957195bc2 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/RelationData.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/RelationData.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.tasks;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.RowData;
 import org.dmfs.android.contentpal.RowSnapshot;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/StatusData.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/StatusData.java
index 561de1cd6..54ee4da23 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/StatusData.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/StatusData.java
@@ -17,7 +17,7 @@
 package org.dmfs.opentaskspal.tasks;
 
 import android.content.ContentProviderOperation;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.RowData;
 import org.dmfs.android.contentpal.TransactionContext;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/SyncIdData.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/SyncIdData.java
index dfa627979..cb0170fe3 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/SyncIdData.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/SyncIdData.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.tasks;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.RowData;
 import org.dmfs.android.contentpal.rowdata.CharSequenceRowData;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/TimeData.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/TimeData.java
index 2e368d475..0ed40a6c0 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/TimeData.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/TimeData.java
@@ -17,7 +17,7 @@
 package org.dmfs.opentaskspal.tasks;
 
 import android.content.ContentProviderOperation;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.RowData;
 import org.dmfs.android.contentpal.TransactionContext;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/TitleData.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/TitleData.java
index 44c7bffe1..0bab9954d 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/TitleData.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/TitleData.java
@@ -16,7 +16,7 @@
 
 package org.dmfs.opentaskspal.tasks;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.RowData;
 import org.dmfs.android.contentpal.rowdata.CharSequenceRowData;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/VersionData.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/VersionData.java
index ff72da15f..3ef2dfd37 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/VersionData.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/tasks/VersionData.java
@@ -17,7 +17,7 @@
 package org.dmfs.opentaskspal.tasks;
 
 import android.content.ContentProviderOperation;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.RowData;
 import org.dmfs.android.contentpal.TransactionContext;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskspal/views/TaskListScoped.java b/opentaskspal/src/main/java/org/dmfs/opentaskspal/views/TaskListScoped.java
index 5dc934c02..df5846140 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskspal/views/TaskListScoped.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskspal/views/TaskListScoped.java
@@ -18,7 +18,7 @@
 
 import android.database.Cursor;
 import android.os.RemoteException;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.InsertOperation;
 import org.dmfs.android.contentpal.Predicate;
diff --git a/opentaskspal/src/main/java/org/dmfs/opentaskstestpal/InstanceTestData.java b/opentaskspal/src/main/java/org/dmfs/opentaskstestpal/InstanceTestData.java
index aba67495d..3a2c51c02 100644
--- a/opentaskspal/src/main/java/org/dmfs/opentaskstestpal/InstanceTestData.java
+++ b/opentaskspal/src/main/java/org/dmfs/opentaskstestpal/InstanceTestData.java
@@ -17,7 +17,7 @@
 package org.dmfs.opentaskstestpal;
 
 import android.content.ContentProviderOperation;
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import org.dmfs.android.contentpal.RowData;
 import org.dmfs.android.contentpal.TransactionContext;