Merge branch 'AndroidX' into 'master'

AndroidX Migration

See merge request briar/briar!1176

briar-android/src/androidTest/java/org/briarproject/briar/android/BriarTestComponentApplication.java

@@ -12,7 +12,7 @@ public class BriarTestComponentApplication extends BriarApplicationImpl {
 				.appModule(new AppModule(this)).build();
 		// We need to load the eager singletons directly after making the
 		// dependency graphs
-		BrambleCoreModule.initEagerSingletons(component);
+		BrambleCoreModule.initEagerSingletons(component);  // FIXME AbstractMethodError
 		BrambleAndroidModule.initEagerSingletons(component);
 		BriarCoreModule.initEagerSingletons(component);
 		AndroidEagerSingletons.initEagerSingletons(component);

briar-android/src/androidTest/java/org/briarproject/briar/android/BriarTestRunner.java

@@ -2,7 +2,8 @@ package org.briarproject.briar.android;
 
 import android.app.Application;
 import android.content.Context;
-import android.support.test.runner.AndroidJUnitRunner;
+
+import androidx.test.runner.AndroidJUnitRunner;
 
 public class BriarTestRunner extends AndroidJUnitRunner {
 

briar-android/src/androidTest/java/org/briarproject/briar/android/UiTest.java

@@ -2,7 +2,6 @@ package org.briarproject.briar.android;
 
 import android.app.Activity;
 import android.content.Intent;
-import android.support.test.espresso.intent.rule.IntentsTestRule;
 
 import org.briarproject.bramble.api.account.AccountManager;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
@@ -12,13 +11,16 @@ import org.briarproject.briar.R;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
-import static android.support.test.InstrumentationRegistry.getTargetContext;
+import androidx.test.espresso.intent.rule.IntentsTestRule;
+
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
+
 
 @SuppressWarnings("WeakerAccess")
 public abstract class UiTest {
 
 	protected final String USERNAME =
-			getTargetContext().getString(R.string.screenshot_alice);
+			getApplicationContext().getString(R.string.screenshot_alice);
 	protected static final String PASSWORD = "123456";
 
 	@Inject
@@ -27,9 +29,7 @@ public abstract class UiTest {
 	protected LifecycleManager lifecycleManager;
 
 	public UiTest() {
-		BriarTestComponentApplication app =
-				(BriarTestComponentApplication) getTargetContext()
-						.getApplicationContext();
+		BriarTestComponentApplication app = getApplicationContext();
 		inject((BriarUiTestComponent) app.getApplicationComponent());
 	}
 
@@ -64,8 +64,8 @@ public abstract class UiTest {
 			accountManager.createAccount(USERNAME, PASSWORD);
 			if (runnable != null) {
 				Intent serviceIntent =
-						new Intent(getTargetContext(), BriarService.class);
-				getTargetContext().startService(serviceIntent);
+						new Intent(getApplicationContext(), BriarService.class);
+				getApplicationContext().startService(serviceIntent);
 				try {
 					lifecycleManager.waitForStartup();
 				} catch (InterruptedException e) {

briar-android/src/androidTest/java/org/briarproject/briar/android/ViewActions.java

@@ -1,21 +1,22 @@
 package org.briarproject.briar.android;
 
 import android.app.Activity;
-import android.support.test.espresso.PerformException;
-import android.support.test.espresso.UiController;
-import android.support.test.espresso.ViewAction;
-import android.support.test.runner.lifecycle.ActivityLifecycleMonitor;
-import android.support.test.runner.lifecycle.ActivityLifecycleMonitorRegistry;
-import android.support.test.runner.lifecycle.Stage;
 import android.view.View;
 
 import org.hamcrest.Matcher;
 
 import java.util.concurrent.TimeoutException;
 
-import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
-import static android.support.test.espresso.util.HumanReadables.describe;
-import static android.support.test.espresso.util.TreeIterables.breadthFirstViewTraversal;
+import androidx.test.espresso.PerformException;
+import androidx.test.espresso.UiController;
+import androidx.test.espresso.ViewAction;
+import androidx.test.runner.lifecycle.ActivityLifecycleMonitor;
+import androidx.test.runner.lifecycle.ActivityLifecycleMonitorRegistry;
+import androidx.test.runner.lifecycle.Stage;
+
+import static androidx.test.espresso.matcher.ViewMatchers.isDisplayed;
+import static androidx.test.espresso.util.HumanReadables.describe;
+import static androidx.test.espresso.util.TreeIterables.breadthFirstViewTraversal;
 import static java.lang.System.currentTimeMillis;
 import static java.util.concurrent.TimeUnit.SECONDS;
 

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/AttachmentRetrieverIntegrationTest.java

@@ -1,8 +1,6 @@
 package org.briarproject.briar.android.attachment;
 
 import android.content.res.AssetManager;
-import android.support.test.InstrumentationRegistry;
-import android.support.test.runner.AndroidJUnit4;
 
 import org.briarproject.bramble.api.UniqueId;
 import org.briarproject.bramble.api.sync.MessageId;
@@ -16,6 +14,9 @@ import java.io.InputStream;
 import java.net.URL;
 import java.util.Random;
 
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
@@ -264,7 +265,7 @@ public class AttachmentRetrieverIntegrationTest {
 	}
 
 	private InputStream getAssetInputStream(String name) throws IOException {
-		AssetManager assets = InstrumentationRegistry.getContext().getAssets();
+		AssetManager assets = getApplicationContext().getAssets();
 		return assets.open(name);
 	}
 

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/conversation/ConversationActivityNotSignedInTest.java

@@ -2,18 +2,19 @@ package org.briarproject.briar.android.conversation;
 
 import android.content.Context;
 import android.content.Intent;
-import android.support.test.rule.ActivityTestRule;
-import android.support.test.runner.AndroidJUnit4;
 
 import org.briarproject.briar.R;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
-import static android.support.test.InstrumentationRegistry.getInstrumentation;
-import static android.support.test.espresso.Espresso.onView;
-import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
-import static android.support.test.espresso.matcher.ViewMatchers.withText;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.rule.ActivityTestRule;
+
+import static androidx.test.espresso.Espresso.onView;
+import static androidx.test.espresso.matcher.ViewMatchers.isDisplayed;
+import static androidx.test.espresso.matcher.ViewMatchers.withText;
+import static androidx.test.platform.app.InstrumentationRegistry.getInstrumentation;
 import static org.briarproject.briar.android.ViewActions.waitUntilMatches;
 import static org.briarproject.briar.android.conversation.ConversationActivity.CONTACT_ID;
 

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/navdrawer/NavDrawerActivityTest.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.navdrawer;
 
-import android.support.test.espresso.contrib.DrawerActions;
-import android.support.test.runner.AndroidJUnit4;
 import android.view.Gravity;
 
 import org.briarproject.briar.R;
@@ -12,15 +10,18 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
-import static android.support.test.espresso.Espresso.onView;
-import static android.support.test.espresso.action.ViewActions.click;
-import static android.support.test.espresso.assertion.ViewAssertions.matches;
-import static android.support.test.espresso.contrib.DrawerMatchers.isClosed;
-import static android.support.test.espresso.intent.Intents.intended;
-import static android.support.test.espresso.intent.matcher.IntentMatchers.hasComponent;
-import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
-import static android.support.test.espresso.matcher.ViewMatchers.withId;
-import static android.support.test.espresso.matcher.ViewMatchers.withText;
+import androidx.test.espresso.contrib.DrawerActions;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+
+import static androidx.test.espresso.Espresso.onView;
+import static androidx.test.espresso.action.ViewActions.click;
+import static androidx.test.espresso.assertion.ViewAssertions.matches;
+import static androidx.test.espresso.contrib.DrawerMatchers.isClosed;
+import static androidx.test.espresso.intent.Intents.intended;
+import static androidx.test.espresso.intent.matcher.IntentMatchers.hasComponent;
+import static androidx.test.espresso.matcher.ViewMatchers.isDisplayed;
+import static androidx.test.espresso.matcher.ViewMatchers.withId;
+import static androidx.test.espresso.matcher.ViewMatchers.withText;
 
 @RunWith(AndroidJUnit4.class)
 public class NavDrawerActivityTest extends UiTest {

briar-android/src/androidTestScreenshot/java/org/briarproject/briar/android/BriarUiTestComponent.java

@@ -4,7 +4,8 @@ import org.briarproject.bramble.BrambleAndroidModule;
 import org.briarproject.bramble.BrambleCoreModule;
 import org.briarproject.bramble.account.BriarAccountModule;
 import org.briarproject.briar.BriarCoreModule;
-import org.briarproject.briar.android.contact.ConversationActivityScreenshotTest;
+import org.briarproject.briar.android.attachment.AttachmentModule;
+import org.briarproject.briar.android.conversation.ConversationActivityScreenshotTest;
 import org.briarproject.briar.android.settings.SettingsActivityScreenshotTest;
 
 import javax.inject.Singleton;
@@ -14,6 +15,7 @@ import dagger.Component;
 @Singleton
 @Component(modules = {
 		AppModule.class,
+		AttachmentModule.class,
 		BriarCoreModule.class,
 		BrambleAndroidModule.class,
 		BriarAccountModule.class,

briar-android/src/androidTestScreenshot/java/org/briarproject/briar/android/ScreenshotTest.java

@@ -30,7 +30,8 @@ public abstract class ScreenshotTest extends UiTest {
 		try {
 			Screengrab.screenshot(name, new FalconScreenshotStrategy(activity));
 		} catch (RuntimeException e) {
-			if (!e.getMessage().equals("Unable to capture screenshot."))
+			if (e.getMessage() == null ||
+					!e.getMessage().equals("Unable to capture screenshot."))
 				throw e;
 			// The tests should still pass when run from AndroidStudio
 			// without manually granting permissions like fastlane does.

briar-android/src/androidTestScreenshot/java/org/briarproject/briar/android/SetupDataTest.java

@@ -1,36 +1,31 @@
 package org.briarproject.briar.android;
 
-import android.support.test.espresso.intent.rule.IntentsTestRule;
-import android.support.test.runner.AndroidJUnit4;
-import android.support.test.uiautomator.UiDevice;
-import android.support.test.uiautomator.UiObject;
-import android.support.test.uiautomator.UiSelector;
+import android.content.Context;
 
-import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.briar.R;
-import org.briarproject.briar.android.login.OpenDatabaseActivity;
-import org.briarproject.briar.android.login.SetupActivity;
+import org.briarproject.briar.android.account.SetupActivity;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
-import static android.support.test.InstrumentationRegistry.getInstrumentation;
-import static android.support.test.InstrumentationRegistry.getTargetContext;
-import static android.support.test.espresso.Espresso.onView;
-import static android.support.test.espresso.action.ViewActions.click;
-import static android.support.test.espresso.action.ViewActions.typeText;
-import static android.support.test.espresso.assertion.ViewAssertions.matches;
-import static android.support.test.espresso.intent.Intents.intended;
-import static android.support.test.espresso.intent.matcher.IntentMatchers.hasComponent;
-import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
-import static android.support.test.espresso.matcher.ViewMatchers.isRoot;
-import static android.support.test.espresso.matcher.ViewMatchers.withId;
-import static android.support.test.espresso.matcher.ViewMatchers.withText;
-import static android.support.test.runner.lifecycle.Stage.PAUSED;
+import androidx.test.espresso.intent.rule.IntentsTestRule;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.uiautomator.UiDevice;
+import androidx.test.uiautomator.UiObject;
+import androidx.test.uiautomator.UiSelector;
+
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
+import static androidx.test.espresso.Espresso.onView;
+import static androidx.test.espresso.action.ViewActions.click;
+import static androidx.test.espresso.action.ViewActions.typeText;
+import static androidx.test.espresso.assertion.ViewAssertions.matches;
+import static androidx.test.espresso.matcher.ViewMatchers.isDisplayed;
+import static androidx.test.espresso.matcher.ViewMatchers.withId;
+import static androidx.test.espresso.matcher.ViewMatchers.withText;
+import static androidx.test.platform.app.InstrumentationRegistry.getInstrumentation;
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.ID;
-import static org.briarproject.briar.android.ViewActions.waitForActivity;
 import static org.briarproject.briar.android.ViewActions.waitUntilMatches;
 import static org.briarproject.briar.android.util.UiUtils.needsDozeWhitelisting;
 import static org.junit.Assert.assertTrue;
@@ -82,7 +77,7 @@ public class SetupDataTest extends ScreenshotTest {
 				.perform(click());
 
 		// White-list Doze if needed
-		if (needsDozeWhitelisting(getTargetContext())) {
+		if (needsDozeWhitelisting(getApplicationContext())) {
 			onView(withText(R.string.setup_doze_button))
 					.check(matches(isDisplayed()))
 					.perform(click());
@@ -96,14 +91,8 @@ public class SetupDataTest extends ScreenshotTest {
 					.perform(click());
 		}
 
-		// wait for OpenDatabaseActivity to show up
-		onView(isRoot())
-				.perform(waitForActivity(testRule.getActivity(), PAUSED));
-		intended(hasComponent(OpenDatabaseActivity.class.getName()));
-
-		assertTrue(accountManager.hasDatabaseKey());
-
 		lifecycleManager.waitForStartup();
+		assertTrue(accountManager.hasDatabaseKey());
 		createTestData();
 
 		// close expiry warning
@@ -118,31 +107,18 @@ public class SetupDataTest extends ScreenshotTest {
 	private void createTestData() {
 		try {
 			createTestDataExceptions();
-		} catch (DbException | FormatException e) {
+		} catch (DbException e) {
 			throw new AssertionError(e);
 		}
 	}
 
 	private void createTestDataExceptions()
-			throws DbException, FormatException {
-		String bobName =
-				getTargetContext().getString(R.string.screenshot_bob);
+			throws DbException {
+		Context ctx = getApplicationContext();
+		String bobName = ctx.getString(R.string.screenshot_bob);
 		Contact bob = testDataCreator.addContact(bobName);
 
-		String bobHi = getTargetContext()
-				.getString(R.string.screenshot_message_1);
-		long bobTime = getMinutesAgo(2);
-		testDataCreator.addPrivateMessage(bob, bobHi, bobTime, true);
-
-		String aliceHi = getTargetContext()
-				.getString(R.string.screenshot_message_2);
-		long aliceTime = getMinutesAgo(1);
-		testDataCreator.addPrivateMessage(bob, aliceHi, aliceTime, false);
-
-		String bobHi2 = getTargetContext()
-				.getString(R.string.screenshot_message_3);
-		long bobTime2 = getMinutesAgo(0);
-		testDataCreator.addPrivateMessage(bob, bobHi2, bobTime2, true);
+		// TODO add messages
 
 		connectionRegistry.registerConnection(bob.getId(), ID, true);
 	}

briar-android/src/androidTestScreenshot/java/org/briarproject/briar/android/conversation/ConversationActivityScreenshotTest.java

@@ -1,25 +1,19 @@
-package org.briarproject.briar.android.contact;
+package org.briarproject.briar.android.conversation;
 
 import android.content.Context;
 import android.content.Intent;
-import android.support.test.rule.ActivityTestRule;
-import android.support.test.runner.AndroidJUnit4;
 
-import org.briarproject.briar.R;
 import org.briarproject.briar.android.BriarUiTestComponent;
 import org.briarproject.briar.android.ScreenshotTest;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
-import static android.support.test.InstrumentationRegistry.getInstrumentation;
-import static android.support.test.espresso.Espresso.onView;
-import static android.support.test.espresso.matcher.ViewMatchers.isCompletelyDisplayed;
-import static android.support.test.espresso.matcher.ViewMatchers.withId;
-import static android.support.test.espresso.matcher.ViewMatchers.withText;
-import static org.briarproject.briar.android.ViewActions.waitUntilMatches;
-import static org.briarproject.briar.android.contact.ConversationActivity.CONTACT_ID;
-import static org.hamcrest.Matchers.allOf;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.rule.ActivityTestRule;
+
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
+import static org.briarproject.briar.android.conversation.ConversationActivity.CONTACT_ID;
 
 @RunWith(AndroidJUnit4.class)
 public class ConversationActivityScreenshotTest extends ScreenshotTest {
@@ -34,17 +28,13 @@ public class ConversationActivityScreenshotTest extends ScreenshotTest {
 	}
 
 	@Test
-	public void messaging() throws Exception {
-		Context targetContext = getInstrumentation().getTargetContext();
+	public void messaging() {
+		Context targetContext = getApplicationContext();
 		Intent intent = new Intent(targetContext, ConversationActivity.class);
 		intent.putExtra(CONTACT_ID, 1);
 		testRule.launchActivity(intent);
 
-		onView(withId(R.id.conversationView))
-				.perform(waitUntilMatches(allOf(
-						withText(R.string.screenshot_message_3),
-						isCompletelyDisplayed())
-				));
+		// TODO add test data and wait for it do appear
 
 		screenshot("manual_messaging", testRule.getActivity());
 	}

briar-android/src/androidTestScreenshot/java/org/briarproject/briar/android/settings/SettingsActivityScreenshotTest.java

@@ -1,10 +1,6 @@
 package org.briarproject.briar.android.settings;
 
 import android.content.Intent;
-import android.support.test.espresso.contrib.DrawerActions;
-import android.support.test.rule.ActivityTestRule;
-import android.support.test.runner.AndroidJUnit4;
-import android.support.v7.widget.RecyclerView;
 import android.view.Gravity;
 
 import org.briarproject.briar.R;
@@ -15,18 +11,23 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
-import static android.support.test.espresso.Espresso.onView;
-import static android.support.test.espresso.action.ViewActions.click;
-import static android.support.test.espresso.assertion.ViewAssertions.matches;
-import static android.support.test.espresso.contrib.DrawerMatchers.isClosed;
-import static android.support.test.espresso.contrib.RecyclerViewActions.scrollTo;
-import static android.support.test.espresso.matcher.ViewMatchers.hasDescendant;
-import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
-import static android.support.test.espresso.matcher.ViewMatchers.isEnabled;
-import static android.support.test.espresso.matcher.ViewMatchers.withChild;
-import static android.support.test.espresso.matcher.ViewMatchers.withClassName;
-import static android.support.test.espresso.matcher.ViewMatchers.withId;
-import static android.support.test.espresso.matcher.ViewMatchers.withText;
+import androidx.recyclerview.widget.RecyclerView;
+import androidx.test.espresso.contrib.DrawerActions;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.rule.ActivityTestRule;
+
+import static androidx.test.espresso.Espresso.onView;
+import static androidx.test.espresso.action.ViewActions.click;
+import static androidx.test.espresso.assertion.ViewAssertions.matches;
+import static androidx.test.espresso.contrib.DrawerMatchers.isClosed;
+import static androidx.test.espresso.contrib.RecyclerViewActions.scrollTo;
+import static androidx.test.espresso.matcher.ViewMatchers.hasDescendant;
+import static androidx.test.espresso.matcher.ViewMatchers.isDisplayed;
+import static androidx.test.espresso.matcher.ViewMatchers.isEnabled;
+import static androidx.test.espresso.matcher.ViewMatchers.withChild;
+import static androidx.test.espresso.matcher.ViewMatchers.withClassName;
+import static androidx.test.espresso.matcher.ViewMatchers.withId;
+import static androidx.test.espresso.matcher.ViewMatchers.withText;
 import static org.briarproject.briar.android.ViewActions.waitUntilMatches;
 import static org.hamcrest.CoreMatchers.is;
 

briar-android/src/main/java/im/delight/android/identicons/Identicon.java

@@ -19,8 +19,9 @@ package im.delight.android.identicons;
 import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Paint;
-import android.support.annotation.NonNull;
-import android.support.annotation.UiThread;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.UiThread;
 
 import static android.graphics.Paint.Style.FILL;
 

briar-android/src/main/java/im/delight/android/identicons/IdenticonDrawable.java

@@ -20,8 +20,9 @@ import android.graphics.Canvas;
 import android.graphics.ColorFilter;
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
-import android.support.annotation.NonNull;
-import android.support.annotation.UiThread;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.UiThread;
 
 import static android.graphics.PixelFormat.OPAQUE;
 

briar-android/src/main/java/org/briarproject/briar/android/AndroidComponent.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android;
 
-import android.arch.lifecycle.ViewModelProvider;
-
 import org.briarproject.bramble.BrambleAndroidEagerSingletons;
 import org.briarproject.bramble.BrambleAndroidModule;
 import org.briarproject.bramble.BrambleCoreEagerSingletons;
@@ -61,6 +59,7 @@ import java.util.concurrent.Executor;
 
 import javax.inject.Singleton;
 
+import androidx.lifecycle.ViewModelProvider;
 import dagger.Component;
 
 @Singleton

briar-android/src/main/java/org/briarproject/briar/android/AndroidNotificationManagerImpl.java

@@ -9,11 +9,6 @@ import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
-import android.support.annotation.Nullable;
-import android.support.annotation.StringRes;
-import android.support.annotation.UiThread;
-import android.support.v4.app.NotificationCompat;
-import android.support.v4.app.TaskStackBuilder;
 
 import org.briarproject.bramble.api.Multiset;
 import org.briarproject.bramble.api.contact.ContactId;
@@ -56,6 +51,12 @@ import java.util.concurrent.atomic.AtomicBoolean;
 import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
+import androidx.annotation.Nullable;
+import androidx.annotation.StringRes;
+import androidx.annotation.UiThread;
+import androidx.core.app.NotificationCompat;
+import androidx.core.app.TaskStackBuilder;
+
 import static android.app.Notification.DEFAULT_LIGHTS;
 import static android.app.Notification.DEFAULT_SOUND;
 import static android.app.Notification.DEFAULT_VIBRATE;
@@ -65,13 +66,13 @@ import static android.content.Context.NOTIFICATION_SERVICE;
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
 import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
 import static android.os.Build.VERSION.SDK_INT;
-import static android.support.v4.app.NotificationCompat.CATEGORY_MESSAGE;
-import static android.support.v4.app.NotificationCompat.CATEGORY_SERVICE;
-import static android.support.v4.app.NotificationCompat.CATEGORY_SOCIAL;
-import static android.support.v4.app.NotificationCompat.PRIORITY_LOW;
-import static android.support.v4.app.NotificationCompat.PRIORITY_MIN;
-import static android.support.v4.app.NotificationCompat.VISIBILITY_SECRET;
-import static android.support.v4.content.ContextCompat.getColor;
+import static androidx.core.app.NotificationCompat.CATEGORY_MESSAGE;
+import static androidx.core.app.NotificationCompat.CATEGORY_SERVICE;
+import static androidx.core.app.NotificationCompat.CATEGORY_SOCIAL;
+import static androidx.core.app.NotificationCompat.PRIORITY_LOW;
+import static androidx.core.app.NotificationCompat.PRIORITY_MIN;
+import static androidx.core.app.NotificationCompat.VISIBILITY_SECRET;
+import static androidx.core.content.ContextCompat.getColor;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
 import static org.briarproject.briar.android.conversation.ConversationActivity.CONTACT_ID;
 import static org.briarproject.briar.android.navdrawer.NavDrawerActivity.BLOG_URI;

briar-android/src/main/java/org/briarproject/briar/android/BriarService.java

@@ -13,7 +13,6 @@ import android.content.IntentFilter;
 import android.content.ServiceConnection;
 import android.os.Binder;
 import android.os.IBinder;
-import android.support.v4.app.NotificationCompat;
 
 import org.briarproject.bramble.api.account.AccountManager;
 import org.briarproject.bramble.api.crypto.SecretKey;
@@ -32,6 +31,8 @@ import java.util.logging.Logger;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import androidx.core.app.NotificationCompat;
+
 import static android.app.NotificationManager.IMPORTANCE_DEFAULT;
 import static android.app.NotificationManager.IMPORTANCE_NONE;
 import static android.app.PendingIntent.FLAG_UPDATE_CURRENT;
@@ -42,7 +43,7 @@ import static android.content.Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS;
 import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
 import static android.content.Intent.FLAG_ACTIVITY_NO_ANIMATION;
 import static android.os.Build.VERSION.SDK_INT;
-import static android.support.v4.app.NotificationCompat.VISIBILITY_SECRET;
+import static androidx.core.app.NotificationCompat.VISIBILITY_SECRET;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.ALREADY_RUNNING;

briar-android/src/main/java/org/briarproject/briar/android/NotificationCleanupService.java

@@ -3,12 +3,13 @@ package org.briarproject.briar.android;
 import android.app.IntentService;
 import android.content.Intent;
 import android.net.Uri;
-import android.support.annotation.Nullable;
 
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 
 import javax.inject.Inject;
 
+import androidx.annotation.Nullable;
+
 import static org.briarproject.briar.android.navdrawer.NavDrawerActivity.BLOG_URI;
 import static org.briarproject.briar.android.navdrawer.NavDrawerActivity.CONTACT_ADDED_URI;
 import static org.briarproject.briar.android.navdrawer.NavDrawerActivity.CONTACT_URI;

briar-android/src/main/java/org/briarproject/briar/android/ScreenFilterMonitorImpl.java

@@ -11,7 +11,6 @@ import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.content.pm.PackageManager.NameNotFoundException;
 import android.content.pm.Signature;
-import android.support.annotation.UiThread;
 
 import org.briarproject.bramble.api.lifecycle.Service;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -36,6 +35,8 @@ import java.util.logging.Logger;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import androidx.annotation.UiThread;
+
 import static android.Manifest.permission.SYSTEM_ALERT_WINDOW;
 import static android.content.Intent.ACTION_PACKAGE_ADDED;
 import static android.content.Intent.ACTION_PACKAGE_CHANGED;

briar-android/src/main/java/org/briarproject/briar/android/StartupFailureActivity.java

@@ -3,8 +3,6 @@ package org.briarproject.briar.android;
 import android.app.NotificationManager;
 import android.content.Intent;
 import android.os.Bundle;
-import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
 
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
@@ -14,6 +12,9 @@ import org.briarproject.briar.android.activity.BaseActivity;
 import org.briarproject.briar.android.fragment.BaseFragment.BaseFragmentListener;
 import org.briarproject.briar.android.fragment.ErrorFragment;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
 import static java.util.Objects.requireNonNull;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult;
 import static org.briarproject.briar.android.BriarService.EXTRA_NOTIFICATION_ID;

briar-android/src/main/java/org/briarproject/briar/android/account/AuthorNameFragment.java

@@ -1,14 +1,15 @@
 package org.briarproject.briar.android.account;
 
 import android.os.Bundle;
-import android.support.design.widget.TextInputEditText;
-import android.support.design.widget.TextInputLayout;
 import android.text.Editable;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.Button;
 
+import com.google.android.material.textfield.TextInputEditText;
+import com.google.android.material.textfield.TextInputLayout;
+
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;

briar-android/src/main/java/org/briarproject/briar/android/account/DozeFragment.java

@@ -3,7 +3,6 @@ package org.briarproject.briar.android.account;
 import android.annotation.SuppressLint;
 import android.content.Intent;
 import android.os.Bundle;
-import android.support.annotation.Nullable;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -17,6 +16,8 @@ import org.briarproject.briar.android.account.PowerView.OnCheckedChangedListener
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.util.UiUtils;
 
+import androidx.annotation.Nullable;
+
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
 import static java.util.Objects.requireNonNull;

briar-android/src/main/java/org/briarproject/briar/android/account/DozeView.java

@@ -2,13 +2,14 @@ package org.briarproject.briar.android.account;
 
 
 import android.content.Context;
-import android.support.annotation.Nullable;
-import android.support.annotation.UiThread;
 import android.util.AttributeSet;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
 
+import androidx.annotation.Nullable;
+import androidx.annotation.UiThread;
+
 import static org.briarproject.briar.android.util.UiUtils.needsDozeWhitelisting;
 
 @UiThread

briar-android/src/main/java/org/briarproject/briar/android/account/HuaweiView.java

@@ -5,8 +5,6 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
-import android.support.annotation.StringRes;
-import android.support.annotation.UiThread;
 import android.util.AttributeSet;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -16,6 +14,9 @@ import java.util.List;
 
 import javax.annotation.Nullable;
 
+import androidx.annotation.StringRes;
+import androidx.annotation.UiThread;
+
 import static android.os.Build.VERSION.SDK_INT;
 
 @UiThread

briar-android/src/main/java/org/briarproject/briar/android/account/LockManagerImpl.java

@@ -3,11 +3,8 @@ package org.briarproject.briar.android.account;
 import android.app.AlarmManager;
 import android.app.Application;
 import android.app.PendingIntent;
-import android.arch.lifecycle.LiveData;
-import android.arch.lifecycle.MutableLiveData;
 import android.content.Context;
 import android.content.Intent;
-import android.support.annotation.UiThread;
 
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
@@ -30,6 +27,10 @@ import java.util.logging.Logger;
 import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
+import androidx.annotation.UiThread;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+
 import static android.app.AlarmManager.ELAPSED_REALTIME;
 import static android.app.PendingIntent.getService;
 import static android.content.Context.ALARM_SERVICE;

briar-android/src/main/java/org/briarproject/briar/android/account/PowerView.java

@@ -3,10 +3,6 @@ package org.briarproject.briar.android.account;
 import android.content.Context;
 import android.os.Parcel;
 import android.os.Parcelable;
-import android.support.annotation.Nullable;
-import android.support.annotation.StringRes;
-import android.support.annotation.UiThread;
-import android.support.constraint.ConstraintLayout;
 import android.util.AttributeSet;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -18,6 +14,11 @@ import android.widget.TextView;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
 
+import androidx.annotation.Nullable;
+import androidx.annotation.StringRes;
+import androidx.annotation.UiThread;
+import androidx.constraintlayout.widget.ConstraintLayout;
+
 import static android.content.Context.LAYOUT_INFLATER_SERVICE;
 import static org.briarproject.briar.android.util.UiUtils.showOnboardingDialog;
 

briar-android/src/main/java/org/briarproject/briar/android/account/SetPasswordFragment.java

@@ -2,8 +2,6 @@ package org.briarproject.briar.android.account;
 
 import android.os.Bundle;
 import android.os.IBinder;
-import android.support.design.widget.TextInputEditText;
-import android.support.design.widget.TextInputLayout;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -11,6 +9,9 @@ import android.view.inputmethod.InputMethodManager;
 import android.widget.Button;
 import android.widget.ProgressBar;
 
+import com.google.android.material.textfield.TextInputEditText;
+import com.google.android.material.textfield.TextInputLayout;
+
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;

briar-android/src/main/java/org/briarproject/briar/android/account/SetupControllerImpl.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.account;
 
-import android.support.annotation.Nullable;
-
 import org.briarproject.bramble.api.account.AccountManager;
 import org.briarproject.bramble.api.crypto.PasswordStrengthEstimator;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
@@ -14,6 +12,8 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import androidx.annotation.Nullable;
+
 @NotNullByDefault
 public class SetupControllerImpl implements SetupController {
 

briar-android/src/main/java/org/briarproject/briar/android/account/SetupFragment.java

@@ -1,6 +1,5 @@
 package org.briarproject.briar.android.account;
 
-import android.support.annotation.Nullable;
 import android.text.Editable;
 import android.text.TextWatcher;
 import android.view.KeyEvent;
@@ -18,6 +17,8 @@ import org.briarproject.briar.android.fragment.BaseFragment;
 
 import javax.inject.Inject;
 
+import androidx.annotation.Nullable;
+
 import static android.view.inputmethod.EditorInfo.IME_ACTION_DONE;
 import static android.view.inputmethod.EditorInfo.IME_ACTION_NEXT;
 import static org.briarproject.briar.android.util.UiUtils.enterPressed;

briar-android/src/main/java/org/briarproject/briar/android/account/UnlockActivity.java

@@ -8,8 +8,6 @@ import android.hardware.biometrics.BiometricPrompt.AuthenticationResult;
 import android.hardware.biometrics.BiometricPrompt.Builder;
 import android.os.Bundle;
 import android.os.CancellationSignal;
-import android.support.annotation.Nullable;
-import android.support.annotation.RequiresApi;
 import android.widget.Toast;
 
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
@@ -23,6 +21,9 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
+
 import static android.hardware.biometrics.BiometricPrompt.BIOMETRIC_ERROR_CANCELED;
 import static android.hardware.biometrics.BiometricPrompt.BIOMETRIC_ERROR_USER_CANCELED;
 import static android.os.Build.VERSION.SDK_INT;

briar-android/src/main/java/org/briarproject/briar/android/activity/ActivityComponent.java

@@ -20,10 +20,10 @@ import org.briarproject.briar.android.blog.ReblogFragment;
 import org.briarproject.briar.android.blog.RssFeedImportActivity;
 import org.briarproject.briar.android.blog.RssFeedManageActivity;
 import org.briarproject.briar.android.blog.WriteBlogPostActivity;
-import org.briarproject.briar.android.contact.add.remote.AddContactActivity;
-import org.briarproject.briar.android.contact.add.remote.LinkExchangeFragment;
 import org.briarproject.briar.android.contact.ContactListFragment;
 import org.briarproject.briar.android.contact.ContactModule;
+import org.briarproject.briar.android.contact.add.remote.AddContactActivity;
+import org.briarproject.briar.android.contact.add.remote.LinkExchangeFragment;
 import org.briarproject.briar.android.contact.add.remote.NicknameFragment;
 import org.briarproject.briar.android.contact.add.remote.PendingContactListActivity;
 import org.briarproject.briar.android.conversation.AliasDialogFragment;

briar-android/src/main/java/org/briarproject/briar/android/activity/ActivityModule.java

@@ -2,14 +2,14 @@ package org.briarproject.briar.android.activity;
 
 import android.app.Activity;
 
+import org.briarproject.briar.android.account.SetupController;
+import org.briarproject.briar.android.account.SetupControllerImpl;
 import org.briarproject.briar.android.controller.BriarController;
 import org.briarproject.briar.android.controller.BriarControllerImpl;
 import org.briarproject.briar.android.controller.DbController;
 import org.briarproject.briar.android.controller.DbControllerImpl;
 import org.briarproject.briar.android.login.ChangePasswordController;
 import org.briarproject.briar.android.login.ChangePasswordControllerImpl;
-import org.briarproject.briar.android.account.SetupController;
-import org.briarproject.briar.android.account.SetupControllerImpl;
 import org.briarproject.briar.android.navdrawer.NavDrawerController;
 import org.briarproject.briar.android.navdrawer.NavDrawerControllerImpl;
 

briar-android/src/main/java/org/briarproject/briar/android/activity/BaseActivity.java

@@ -2,12 +2,6 @@ package org.briarproject.briar.android.activity;
 
 import android.content.Context;
 import android.os.Bundle;
-import android.support.annotation.LayoutRes;
-import android.support.annotation.UiThread;
-import android.support.v4.app.Fragment;
-import android.support.v4.app.FragmentManager;
-import android.support.v7.app.AppCompatActivity;
-import android.support.v7.widget.Toolbar;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewGroup.LayoutParams;
@@ -39,9 +33,16 @@ import java.util.logging.Logger;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
-import static android.arch.lifecycle.Lifecycle.State.STARTED;
+import androidx.annotation.LayoutRes;
+import androidx.annotation.UiThread;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.appcompat.widget.Toolbar;
+import androidx.fragment.app.Fragment;
+import androidx.fragment.app.FragmentManager;
+
 import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
 import static android.view.WindowManager.LayoutParams.FLAG_SECURE;
+import static androidx.lifecycle.Lifecycle.State.STARTED;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.briar.android.TestingConstants.PREVENT_SCREENSHOTS;

briar-android/src/main/java/org/briarproject/briar/android/activity/BriarActivity.java

@@ -1,10 +1,6 @@
 package org.briarproject.briar.android.activity;
 
 import android.content.Intent;
-import android.support.annotation.RequiresApi;
-import android.support.v7.app.ActionBar;
-import android.support.v7.app.AlertDialog;
-import android.support.v7.widget.Toolbar;
 import android.transition.Transition;
 import android.view.Window;
 import android.widget.CheckBox;
@@ -25,6 +21,11 @@ import java.util.logging.Logger;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import androidx.annotation.RequiresApi;
+import androidx.appcompat.app.ActionBar;
+import androidx.appcompat.app.AlertDialog;
+import androidx.appcompat.widget.Toolbar;
+
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TASK;
 import static android.content.Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS;
 import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentCreationTask.java

@@ -4,7 +4,6 @@ import android.content.ContentResolver;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory.Options;
 import android.net.Uri;
-import android.support.annotation.Nullable;
 
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
@@ -22,6 +21,8 @@ import java.io.InputStream;
 import java.util.Collection;
 import java.util.logging.Logger;
 
+import androidx.annotation.Nullable;
+
 import static android.graphics.Bitmap.CompressFormat.JPEG;
 import static android.graphics.BitmapFactory.decodeStream;
 import static java.util.logging.Level.INFO;

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentCreator.java

@@ -1,8 +1,6 @@
 package org.briarproject.briar.android.attachment;
 
-import android.arch.lifecycle.LiveData;
 import android.net.Uri;
-import android.support.annotation.UiThread;
 
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -13,6 +11,9 @@ import org.briarproject.briar.api.messaging.AttachmentHeader;
 import java.util.Collection;
 import java.util.List;
 
+import androidx.annotation.UiThread;
+import androidx.lifecycle.LiveData;
+
 @NotNullByDefault
 public interface AttachmentCreator {
 

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentCreatorImpl.java

@@ -2,11 +2,7 @@ package org.briarproject.briar.android.attachment;
 
 
 import android.app.Application;
-import android.arch.lifecycle.LiveData;
-import android.arch.lifecycle.MutableLiveData;
 import android.net.Uri;
-import android.support.annotation.Nullable;
-import android.support.annotation.UiThread;
 
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
@@ -30,6 +26,11 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import androidx.annotation.Nullable;
+import androidx.annotation.UiThread;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logException;

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentDimensions.java

@@ -1,13 +1,14 @@
 package org.briarproject.briar.android.attachment;
 
 import android.content.res.Resources;
-import android.support.annotation.VisibleForTesting;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
 
 import javax.annotation.concurrent.Immutable;
 
+import androidx.annotation.VisibleForTesting;
+
 @Immutable
 @NotNullByDefault
 class AttachmentDimensions {

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentItem.java

@@ -2,7 +2,6 @@ package org.briarproject.briar.android.attachment;
 
 import android.os.Parcel;
 import android.os.Parcelable;
-import android.support.annotation.Nullable;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.MessageId;
@@ -12,6 +11,8 @@ import java.util.concurrent.atomic.AtomicLong;
 
 import javax.annotation.concurrent.Immutable;
 
+import androidx.annotation.Nullable;
+
 import static java.util.Objects.requireNonNull;
 
 @Immutable

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentManager.java

@@ -1,8 +1,6 @@
 package org.briarproject.briar.android.attachment;
 
-import android.arch.lifecycle.LiveData;
 import android.net.Uri;
-import android.support.annotation.UiThread;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.api.messaging.AttachmentHeader;
@@ -10,6 +8,9 @@ import org.briarproject.briar.api.messaging.AttachmentHeader;
 import java.util.Collection;
 import java.util.List;
 
+import androidx.annotation.UiThread;
+import androidx.lifecycle.LiveData;
+
 @UiThread
 @NotNullByDefault
 public interface AttachmentManager {

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentRetriever.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.attachment;
 
-import android.support.annotation.Nullable;
-
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.MessageId;
@@ -11,6 +9,8 @@ import org.briarproject.briar.api.messaging.AttachmentHeader;
 import java.io.InputStream;
 import java.util.List;
 
+import androidx.annotation.Nullable;
+
 @NotNullByDefault
 public interface AttachmentRetriever {
 

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentRetrieverImpl.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.attachment;
 
-import android.support.annotation.Nullable;
-
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.MessageId;
@@ -18,6 +16,8 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import androidx.annotation.Nullable;
+
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 

briar-android/src/main/java/org/briarproject/briar/android/attachment/ImageHelper.java

@@ -1,11 +1,11 @@
 package org.briarproject.briar.android.attachment;
 
-import android.support.annotation.Nullable;
-
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.io.InputStream;
 
+import androidx.annotation.Nullable;
+
 @NotNullByDefault
 public interface ImageHelper {
 

briar-android/src/main/java/org/briarproject/briar/android/attachment/ImageHelperImpl.java

@@ -1,7 +1,6 @@
 package org.briarproject.briar.android.attachment;
 
 import android.graphics.BitmapFactory;
-import android.support.annotation.Nullable;
 import android.webkit.MimeTypeMap;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -11,6 +10,8 @@ import java.io.InputStream;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
+import androidx.annotation.Nullable;
+
 @Immutable
 @NotNullByDefault
 class ImageHelperImpl implements ImageHelper {

briar-android/src/main/java/org/briarproject/briar/android/attachment/ImageSizeCalculator.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.attachment;
 
-import android.support.media.ExifInterface;
-
 import com.bumptech.glide.util.MarkEnforcingInputStream;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -11,13 +9,15 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.util.logging.Logger;
 
-import static android.support.media.ExifInterface.ORIENTATION_ROTATE_270;
-import static android.support.media.ExifInterface.ORIENTATION_ROTATE_90;
-import static android.support.media.ExifInterface.ORIENTATION_TRANSPOSE;
-import static android.support.media.ExifInterface.ORIENTATION_TRANSVERSE;
-import static android.support.media.ExifInterface.TAG_IMAGE_LENGTH;
-import static android.support.media.ExifInterface.TAG_IMAGE_WIDTH;
-import static android.support.media.ExifInterface.TAG_ORIENTATION;
+import androidx.exifinterface.media.ExifInterface;
+
+import static androidx.exifinterface.media.ExifInterface.ORIENTATION_ROTATE_270;
+import static androidx.exifinterface.media.ExifInterface.ORIENTATION_ROTATE_90;
+import static androidx.exifinterface.media.ExifInterface.ORIENTATION_TRANSPOSE;
+import static androidx.exifinterface.media.ExifInterface.ORIENTATION_TRANSVERSE;
+import static androidx.exifinterface.media.ExifInterface.TAG_IMAGE_LENGTH;
+import static androidx.exifinterface.media.ExifInterface.TAG_IMAGE_WIDTH;
+import static androidx.exifinterface.media.ExifInterface.TAG_ORIENTATION;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logException;

briar-android/src/main/java/org/briarproject/briar/android/blog/BaseController.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.blog;
 
-import android.support.annotation.UiThread;
-
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
@@ -14,6 +12,8 @@ import java.util.Collection;
 
 import javax.annotation.Nullable;
 
+import androidx.annotation.UiThread;
+
 @NotNullByDefault
 interface BaseController {
 

briar-android/src/main/java/org/briarproject/briar/android/blog/BaseControllerImpl.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.blog;
 
-import android.support.annotation.CallSuper;
-
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.event.EventBus;
@@ -32,6 +30,8 @@ import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 
+import androidx.annotation.CallSuper;
+
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;

briar-android/src/main/java/org/briarproject/briar/android/blog/BasePostFragment.java

@@ -4,8 +4,6 @@ import android.content.Intent;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Looper;
-import android.support.annotation.CallSuper;
-import android.support.annotation.UiThread;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -21,6 +19,9 @@ import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 
+import androidx.annotation.CallSuper;
+import androidx.annotation.UiThread;
+
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;

briar-android/src/main/java/org/briarproject/briar/android/blog/BlogActivity.java

@@ -2,7 +2,6 @@ package org.briarproject.briar.android.blog;
 
 import android.content.Intent;
 import android.os.Bundle;
-import android.support.v7.widget.Toolbar;
 
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
@@ -16,6 +15,8 @@ import org.briarproject.briar.android.sharing.BlogSharingStatusActivity;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import androidx.appcompat.widget.Toolbar;
+
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class BlogActivity extends BriarActivity

briar-android/src/main/java/org/briarproject/briar/android/blog/BlogController.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.blog;
 
-import android.support.annotation.UiThread;
-
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -11,6 +9,8 @@ import org.briarproject.briar.android.controller.handler.ResultExceptionHandler;
 
 import java.util.Collection;
 
+import androidx.annotation.UiThread;
+
 @NotNullByDefault
 public interface BlogController extends BaseController {
 

briar-android/src/main/java/org/briarproject/briar/android/blog/BlogFragment.java

@@ -4,11 +4,6 @@ import android.content.DialogInterface;
 import android.content.Intent;
 import android.os.Bundle;
 import android.os.Parcelable;
-import android.support.annotation.UiThread;
-import android.support.v7.app.ActionBar;
-import android.support.v7.app.AlertDialog;
-import android.support.v7.widget.LinearLayoutManager;
-import android.support.v7.widget.RecyclerView.LayoutManager;
 import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuInflater;
@@ -41,10 +36,16 @@ import java.util.Collection;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import androidx.annotation.UiThread;
+import androidx.appcompat.app.ActionBar;
+import androidx.appcompat.app.AlertDialog;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView.LayoutManager;
+
 import static android.app.Activity.RESULT_OK;
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
-import static android.support.design.widget.Snackbar.LENGTH_LONG;
 import static android.widget.Toast.LENGTH_SHORT;
+import static com.google.android.material.snackbar.Snackbar.LENGTH_LONG;
 import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_SHARE_BLOG;

briar-android/src/main/java/org/briarproject/briar/android/blog/BlogPostAdapter.java

@@ -1,8 +1,6 @@
 package org.briarproject.briar.android.blog;
 
 import android.content.Context;
-import android.support.annotation.Nullable;
-import android.support.v4.app.FragmentManager;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -12,6 +10,9 @@ import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.util.BriarAdapter;
 
+import androidx.annotation.Nullable;
+import androidx.fragment.app.FragmentManager;
+
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 class BlogPostAdapter extends BriarAdapter<BlogPostItem, BlogPostViewHolder> {

briar-android/src/main/java/org/briarproject/briar/android/blog/BlogPostFragment.java

@@ -1,7 +1,6 @@
 package org.briarproject.briar.android.blog;
 
 import android.os.Bundle;
-import android.support.annotation.UiThread;
 
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
@@ -14,6 +13,8 @@ import org.briarproject.briar.api.blog.BlogPostHeader;
 
 import javax.inject.Inject;
 
+import androidx.annotation.UiThread;
+
 @UiThread
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault

briar-android/src/main/java/org/briarproject/briar/android/blog/BlogPostItem.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.blog;
 
-import android.support.annotation.NonNull;
-
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.sync.GroupId;
@@ -11,6 +9,8 @@ import org.briarproject.briar.api.blog.BlogPostHeader;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.NotThreadSafe;
 
+import androidx.annotation.NonNull;
+
 @NotThreadSafe
 public class BlogPostItem implements Comparable<BlogPostItem> {
 

briar-android/src/main/java/org/briarproject/briar/android/blog/BlogPostViewHolder.java

@@ -2,11 +2,6 @@ package org.briarproject.briar.android.blog;
 
 import android.content.Context;
 import android.content.Intent;
-import android.support.annotation.NonNull;
-import android.support.annotation.UiThread;
-import android.support.v4.app.FragmentManager;
-import android.support.v4.view.ViewCompat;
-import android.support.v7.widget.RecyclerView;
 import android.text.Spanned;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -22,6 +17,12 @@ import org.briarproject.briar.api.blog.BlogPostHeader;
 
 import javax.annotation.Nullable;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.UiThread;
+import androidx.core.view.ViewCompat;
+import androidx.fragment.app.FragmentManager;
+import androidx.recyclerview.widget.RecyclerView;
+
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;

briar-android/src/main/java/org/briarproject/briar/android/blog/FeedController.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.blog;
 
-import android.support.annotation.UiThread;
-
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.android.controller.handler.ResultExceptionHandler;
@@ -9,6 +7,8 @@ import org.briarproject.briar.api.blog.Blog;
 
 import java.util.Collection;
 
+import androidx.annotation.UiThread;
+
 @NotNullByDefault
 public interface FeedController extends BaseController {
 

briar-android/src/main/java/org/briarproject/briar/android/blog/FeedFragment.java

@@ -3,8 +3,6 @@ package org.briarproject.briar.android.blog;
 import android.content.Intent;
 import android.os.Bundle;
 import android.os.Parcelable;
-import android.support.annotation.UiThread;
-import android.support.v7.widget.LinearLayoutManager;
 import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuInflater;
@@ -31,9 +29,12 @@ import java.util.logging.Logger;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import androidx.annotation.UiThread;
+import androidx.recyclerview.widget.LinearLayoutManager;
+
 import static android.app.Activity.RESULT_OK;
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
-import static android.support.design.widget.Snackbar.LENGTH_LONG;
+import static com.google.android.material.snackbar.Snackbar.LENGTH_LONG;
 import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_WRITE_BLOG_POST;

briar-android/src/main/java/org/briarproject/briar/android/blog/FeedPostFragment.java

@@ -1,7 +1,6 @@
 package org.briarproject.briar.android.blog;
 
 import android.os.Bundle;
-import android.support.annotation.UiThread;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -17,6 +16,8 @@ import org.briarproject.briar.android.controller.handler.UiResultExceptionHandle
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import androidx.annotation.UiThread;
+
 import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
 

briar-android/src/main/java/org/briarproject/briar/android/blog/RssFeedAdapter.java

@@ -1,7 +1,6 @@
 package org.briarproject.briar.android.blog;
 
 import android.content.Context;
-import android.support.v7.widget.RecyclerView;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -13,6 +12,8 @@ import org.briarproject.briar.android.util.BriarAdapter;
 import org.briarproject.briar.android.util.UiUtils;
 import org.briarproject.briar.api.feed.Feed;
 
+import androidx.recyclerview.widget.RecyclerView;
+
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
 

briar-android/src/main/java/org/briarproject/briar/android/blog/RssFeedImportActivity.java

@@ -1,7 +1,6 @@
 package org.briarproject.briar.android.blog;
 
 import android.os.Bundle;
-import android.support.v7.app.AlertDialog;
 import android.text.Editable;
 import android.text.TextWatcher;
 import android.util.Patterns;
@@ -27,6 +26,8 @@ import java.util.logging.Logger;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import androidx.appcompat.app.AlertDialog;
+
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
 import static android.view.inputmethod.EditorInfo.IME_ACTION_DONE;

briar-android/src/main/java/org/briarproject/briar/android/blog/RssFeedManageActivity.java

@@ -3,13 +3,12 @@ package org.briarproject.briar.android.blog;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.os.Bundle;
-import android.support.design.widget.Snackbar;
-import android.support.v7.app.AlertDialog;
-import android.support.v7.widget.LinearLayoutManager;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
 
+import com.google.android.material.snackbar.Snackbar;
+
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
@@ -24,8 +23,11 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import androidx.appcompat.app.AlertDialog;
+import androidx.recyclerview.widget.LinearLayoutManager;
+
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
-import static android.support.design.widget.Snackbar.LENGTH_LONG;
+import static com.google.android.material.snackbar.Snackbar.LENGTH_LONG;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logException;
 

briar-android/src/main/java/org/briarproject/briar/android/blog/WriteBlogPostActivity.java

@@ -2,7 +2,6 @@ package org.briarproject.briar.android.blog;
 
 import android.content.Intent;
 import android.os.Bundle;
-import android.support.annotation.Nullable;
 import android.view.MenuItem;
 import android.widget.ProgressBar;
 
@@ -31,6 +30,8 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import androidx.annotation.Nullable;
+
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
 import static java.util.logging.Level.WARNING;

briar-android/src/main/java/org/briarproject/briar/android/contact/BaseContactListAdapter.java

@@ -1,7 +1,6 @@
 package org.briarproject.briar.android.contact;
 
 import android.content.Context;
-import android.support.annotation.NonNull;
 import android.view.View;
 
 import org.briarproject.bramble.api.contact.ContactId;
@@ -9,7 +8,9 @@ import org.briarproject.briar.android.util.BriarAdapter;
 
 import javax.annotation.Nullable;
 
-import static android.support.v7.util.SortedList.INVALID_POSITION;
+import androidx.annotation.NonNull;
+
+import static androidx.recyclerview.widget.SortedList.INVALID_POSITION;
 import static org.briarproject.briar.android.util.UiUtils.getContactDisplayName;
 
 public abstract class BaseContactListAdapter<I extends ContactItem, VH extends ContactItemViewHolder<I>>

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactItemViewHolder.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.contact;
 
-import android.support.annotation.UiThread;
-import android.support.v7.widget.RecyclerView;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ImageView;
@@ -14,6 +12,8 @@ import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactCl
 
 import javax.annotation.Nullable;
 
+import androidx.annotation.UiThread;
+import androidx.recyclerview.widget.RecyclerView;
 import im.delight.android.identicons.IdenticonDrawable;
 
 import static org.briarproject.briar.android.util.UiUtils.getContactDisplayName;

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListFragment.java

@@ -2,18 +2,14 @@ package org.briarproject.briar.android.contact;
 
 import android.content.Intent;
 import android.os.Bundle;
-import android.support.annotation.UiThread;
-import android.support.design.widget.FloatingActionButton;
-import android.support.design.widget.Snackbar;
-import android.support.v4.app.ActivityCompat;
-import android.support.v4.app.ActivityOptionsCompat;
-import android.support.v4.util.Pair;
-import android.support.v7.widget.LinearLayoutManager;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.TextView;
 
+import com.google.android.material.floatingactionbutton.FloatingActionButton;
+import com.google.android.material.snackbar.Snackbar;
+
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
@@ -54,13 +50,18 @@ import java.util.logging.Logger;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import androidx.annotation.UiThread;
+import androidx.core.app.ActivityCompat;
+import androidx.core.app.ActivityOptionsCompat;
+import androidx.core.util.Pair;
+import androidx.recyclerview.widget.LinearLayoutManager;
 import io.github.kobakei.materialfabspeeddial.FabSpeedDial;
 import io.github.kobakei.materialfabspeeddial.FabSpeedDial.OnMenuItemClickListener;
 
 import static android.os.Build.VERSION.SDK_INT;
-import static android.support.design.widget.Snackbar.LENGTH_INDEFINITE;
-import static android.support.v4.app.ActivityOptionsCompat.makeSceneTransitionAnimation;
-import static android.support.v4.view.ViewCompat.getTransitionName;
+import static androidx.core.app.ActivityOptionsCompat.makeSceneTransitionAnimation;
+import static androidx.core.view.ViewCompat.getTransitionName;
+import static com.google.android.material.snackbar.Snackbar.LENGTH_INDEFINITE;
 import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logDuration;

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListItemViewHolder.java

@@ -1,6 +1,5 @@
 package org.briarproject.briar.android.contact;
 
-import android.support.annotation.UiThread;
 import android.view.View;
 import android.widget.TextView;
 
@@ -14,7 +13,9 @@ import java.util.Locale;
 
 import javax.annotation.Nullable;
 
-import static android.support.v4.view.ViewCompat.setTransitionName;
+import androidx.annotation.UiThread;
+
+import static androidx.core.view.ViewCompat.setTransitionName;
 import static org.briarproject.briar.android.util.UiUtils.formatDate;
 
 @UiThread

briar-android/src/main/java/org/briarproject/briar/android/contact/add/remote/AddContactActivity.java

@@ -1,10 +1,7 @@
 package org.briarproject.briar.android.contact.add.remote;
 
-import android.arch.lifecycle.ViewModelProvider;
-import android.arch.lifecycle.ViewModelProviders;
 import android.content.Intent;
 import android.os.Bundle;
-import android.support.v7.app.ActionBar;
 import android.view.MenuItem;
 import android.widget.Toast;
 
@@ -18,6 +15,10 @@ import org.briarproject.briar.android.fragment.BaseFragment.BaseFragmentListener
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import androidx.appcompat.app.ActionBar;
+import androidx.lifecycle.ViewModelProvider;
+import androidx.lifecycle.ViewModelProviders;
+
 import static android.content.Intent.ACTION_SEND;
 import static android.content.Intent.ACTION_VIEW;
 import static android.content.Intent.EXTRA_TEXT;

briar-android/src/main/java/org/briarproject/briar/android/contact/add/remote/AddContactViewModel.java

@@ -1,10 +1,6 @@
 package org.briarproject.briar.android.contact.add.remote;
 
 import android.app.Application;
-import android.arch.lifecycle.AndroidViewModel;
-import android.arch.lifecycle.LiveData;
-import android.arch.lifecycle.MutableLiveData;
-import android.support.annotation.Nullable;
 
 import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.UnsupportedVersionException;
@@ -24,6 +20,11 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import androidx.annotation.Nullable;
+import androidx.lifecycle.AndroidViewModel;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.contact.HandshakeLinkConstants.LINK_REGEX;

briar-android/src/main/java/org/briarproject/briar/android/contact/add/remote/LinkExchangeFragment.java

@@ -1,14 +1,9 @@
 package org.briarproject.briar.android.contact.add.remote;
 
 import android.animation.ObjectAnimator;
-import android.arch.lifecycle.ViewModelProvider;
-import android.arch.lifecycle.ViewModelProviders;
 import android.content.ClipData;
 import android.content.ClipboardManager;
 import android.os.Bundle;
-import android.support.design.widget.TextInputEditText;
-import android.support.design.widget.TextInputLayout;
-import android.support.v4.app.ShareCompat.IntentBuilder;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -18,6 +13,9 @@ import android.widget.ScrollView;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import com.google.android.material.textfield.TextInputEditText;
+import com.google.android.material.textfield.TextInputLayout;
+
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
@@ -29,6 +27,10 @@ import java.util.regex.Matcher;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import androidx.core.app.ShareCompat.IntentBuilder;
+import androidx.lifecycle.ViewModelProvider;
+import androidx.lifecycle.ViewModelProviders;
+
 import static android.content.Context.CLIPBOARD_SERVICE;
 import static android.widget.Toast.LENGTH_SHORT;
 import static java.util.Objects.requireNonNull;

briar-android/src/main/java/org/briarproject/briar/android/contact/add/remote/NicknameFragment.java

@@ -1,16 +1,10 @@
 package org.briarproject.briar.android.contact.add.remote;
 
-import android.arch.lifecycle.ViewModelProvider;
-import android.arch.lifecycle.ViewModelProviders;
 import android.content.Context;
 import android.content.DialogInterface.OnClickListener;
 import android.content.Intent;
 import android.graphics.drawable.Drawable;
 import android.os.Bundle;
-import android.support.annotation.StringRes;
-import android.support.design.widget.TextInputEditText;
-import android.support.design.widget.TextInputLayout;
-import android.support.v7.app.AlertDialog.Builder;
 import android.text.Editable;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -19,6 +13,9 @@ import android.widget.Button;
 import android.widget.ProgressBar;
 import android.widget.Toast;
 
+import com.google.android.material.textfield.TextInputEditText;
+import com.google.android.material.textfield.TextInputLayout;
+
 import org.briarproject.bramble.api.UnsupportedVersionException;
 import org.briarproject.bramble.api.contact.PendingContact;
 import org.briarproject.bramble.api.db.ContactExistsException;
@@ -33,12 +30,17 @@ import org.briarproject.briar.android.fragment.BaseFragment;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
-import static android.support.v4.content.ContextCompat.getColor;
-import static android.support.v4.content.ContextCompat.getDrawable;
-import static android.support.v4.graphics.drawable.DrawableCompat.setTint;
+import androidx.annotation.StringRes;
+import androidx.appcompat.app.AlertDialog.Builder;
+import androidx.lifecycle.ViewModelProvider;
+import androidx.lifecycle.ViewModelProviders;
+
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
 import static android.widget.Toast.LENGTH_LONG;
+import static androidx.core.content.ContextCompat.getColor;
+import static androidx.core.content.ContextCompat.getDrawable;
+import static androidx.core.graphics.drawable.DrawableCompat.setTint;
 import static java.util.Objects.requireNonNull;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 import static org.briarproject.bramble.util.StringUtils.utf8IsTooLong;

briar-android/src/main/java/org/briarproject/briar/android/contact/add/remote/PendingContactListActivity.java

@@ -1,15 +1,11 @@
 package org.briarproject.briar.android.contact.add.remote;
 
-import android.arch.lifecycle.ViewModelProvider;
-import android.arch.lifecycle.ViewModelProviders;
 import android.content.DialogInterface.OnClickListener;
 import android.os.Bundle;
-import android.support.design.widget.Snackbar;
-import android.support.v7.app.ActionBar;
-import android.support.v7.app.AlertDialog;
-import android.support.v7.widget.LinearLayoutManager;
 import android.view.MenuItem;
 
+import com.google.android.material.snackbar.Snackbar;
+
 import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
@@ -24,7 +20,13 @@ import java.util.Collection;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
-import static android.support.design.widget.Snackbar.LENGTH_INDEFINITE;
+import androidx.appcompat.app.ActionBar;
+import androidx.appcompat.app.AlertDialog;
+import androidx.lifecycle.ViewModelProvider;
+import androidx.lifecycle.ViewModelProviders;
+import androidx.recyclerview.widget.LinearLayoutManager;
+
+import static com.google.android.material.snackbar.Snackbar.LENGTH_INDEFINITE;
 import static org.briarproject.bramble.api.contact.PendingContactState.FAILED;
 import static org.briarproject.briar.android.contact.add.remote.PendingContactItem.POLL_DURATION_MS;
 

briar-android/src/main/java/org/briarproject/briar/android/contact/add/remote/PendingContactListViewModel.java

@@ -1,9 +1,6 @@
 package org.briarproject.briar.android.contact.add.remote;
 
 import android.app.Application;
-import android.arch.lifecycle.AndroidViewModel;
-import android.arch.lifecycle.LiveData;
-import android.arch.lifecycle.MutableLiveData;
 
 import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.contact.ContactManager;
@@ -29,6 +26,10 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import androidx.lifecycle.AndroidViewModel;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.contact.PendingContactState.OFFLINE;

briar-android/src/main/java/org/briarproject/briar/android/contact/add/remote/PendingContactViewHolder.java

@@ -1,8 +1,5 @@
 package org.briarproject.briar.android.contact.add.remote;
 
-import android.support.v4.content.ContextCompat;
-import android.support.v7.widget.AppCompatImageButton;
-import android.support.v7.widget.RecyclerView.ViewHolder;
 import android.view.View;
 import android.widget.TextView;
 
@@ -11,6 +8,10 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.view.TextAvatarView;
 
+import androidx.appcompat.widget.AppCompatImageButton;
+import androidx.core.content.ContextCompat;
+import androidx.recyclerview.widget.RecyclerView.ViewHolder;
+
 import static org.briarproject.briar.android.util.UiUtils.formatDate;
 
 @NotNullByDefault

briar-android/src/main/java/org/briarproject/briar/android/contactselection/BaseContactSelectorFragment.java

@@ -2,8 +2,6 @@ package org.briarproject.briar.android.contactselection;
 
 import android.content.Context;
 import android.os.Bundle;
-import android.support.annotation.CallSuper;
-import android.support.v7.widget.LinearLayoutManager;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -25,6 +23,9 @@ import java.util.Collection;
 
 import javax.annotation.Nullable;
 
+import androidx.annotation.CallSuper;
+import androidx.recyclerview.widget.LinearLayoutManager;
+
 import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
 import static org.briarproject.briar.android.contactselection.ContactSelectorActivity.CONTACTS;

briar-android/src/main/java/org/briarproject/briar/android/contactselection/BaseSelectableContactHolder.java

@@ -1,6 +1,5 @@
 package org.briarproject.briar.android.contactselection;
 
-import android.support.annotation.UiThread;
 import android.view.View;
 import android.widget.CheckBox;
 import android.widget.TextView;
@@ -12,6 +11,8 @@ import org.briarproject.briar.android.contact.ContactItemViewHolder;
 
 import javax.annotation.Nullable;
 
+import androidx.annotation.UiThread;
+
 import static org.briarproject.briar.android.util.UiUtils.GREY_OUT;
 
 @UiThread

briar-android/src/main/java/org/briarproject/briar/android/contactselection/ContactSelectorActivity.java

@@ -1,9 +1,6 @@
 package org.briarproject.briar.android.contactselection;
 
 import android.os.Bundle;
-import android.support.annotation.CallSuper;
-import android.support.annotation.LayoutRes;
-import android.support.annotation.UiThread;
 
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
@@ -19,6 +16,10 @@ import java.util.List;
 
 import javax.annotation.Nullable;
 
+import androidx.annotation.CallSuper;
+import androidx.annotation.LayoutRes;
+import androidx.annotation.UiThread;
+
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public abstract class ContactSelectorActivity

briar-android/src/main/java/org/briarproject/briar/android/contactselection/ContactSelectorListener.java

@@ -1,12 +1,12 @@
 package org.briarproject.briar.android.contactselection;
 
-import android.support.annotation.UiThread;
-
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.util.Collection;
 
+import androidx.annotation.UiThread;
+
 @NotNullByDefault
 public interface ContactSelectorListener {
 

briar-android/src/main/java/org/briarproject/briar/android/contactselection/SelectableContactHolder.java

@@ -1,6 +1,5 @@
 package org.briarproject.briar.android.contactselection;
 
-import android.support.annotation.UiThread;
 import android.view.View;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -8,6 +7,8 @@ import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactCl
 
 import javax.annotation.Nullable;
 
+import androidx.annotation.UiThread;
+
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
 

briar-android/src/main/java/org/briarproject/briar/android/controller/BriarControllerImpl.java

@@ -3,7 +3,6 @@ package org.briarproject.briar.android.controller;
 import android.app.Activity;
 import android.content.Intent;
 import android.os.IBinder;
-import android.support.annotation.CallSuper;
 
 import org.briarproject.bramble.api.account.AccountManager;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
@@ -21,6 +20,8 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import androidx.annotation.CallSuper;
+
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STARTING_SERVICES;
 import static org.briarproject.bramble.util.LogUtils.logException;

briar-android/src/main/java/org/briarproject/briar/android/controller/SharingController.java

@@ -1,12 +1,12 @@
 package org.briarproject.briar.android.controller;
 
-import android.support.annotation.UiThread;
-
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.util.Collection;
 
+import androidx.annotation.UiThread;
+
 @NotNullByDefault
 public interface SharingController {
 

briar-android/src/main/java/org/briarproject/briar/android/controller/SharingControllerImpl.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.controller;
 
-import android.support.annotation.UiThread;
-
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventBus;
@@ -18,6 +16,8 @@ import java.util.Set;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import androidx.annotation.UiThread;
+
 @NotNullByDefault
 public class SharingControllerImpl implements SharingController, EventListener {
 

briar-android/src/main/java/org/briarproject/briar/android/controller/handler/UiExceptionHandler.java

@@ -1,12 +1,12 @@
 package org.briarproject.briar.android.controller.handler;
 
-import android.support.annotation.UiThread;
-
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.android.DestroyableContext;
 
 import javax.annotation.concurrent.Immutable;
 
+import androidx.annotation.UiThread;
+
 @Immutable
 @NotNullByDefault
 public abstract class UiExceptionHandler<E extends Exception>

briar-android/src/main/java/org/briarproject/briar/android/controller/handler/UiResultExceptionHandler.java

@@ -1,12 +1,12 @@
 package org.briarproject.briar.android.controller.handler;
 
-import android.support.annotation.UiThread;
-
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.android.DestroyableContext;
 
 import javax.annotation.concurrent.Immutable;
 
+import androidx.annotation.UiThread;
+
 @Immutable
 @NotNullByDefault
 public abstract class UiResultExceptionHandler<R, E extends Exception>

briar-android/src/main/java/org/briarproject/briar/android/controller/handler/UiResultHandler.java

@@ -1,9 +1,9 @@
 package org.briarproject.briar.android.controller.handler;
 
-import android.support.annotation.UiThread;
-
 import org.briarproject.briar.android.DestroyableContext;
 
+import androidx.annotation.UiThread;
+
 public abstract class UiResultHandler<R> implements ResultHandler<R> {
 
 	private final DestroyableContext listener;

briar-android/src/main/java/org/briarproject/briar/android/conversation/AliasDialogFragment.java

@@ -1,18 +1,15 @@
 package org.briarproject.briar.android.conversation;
 
-import android.arch.lifecycle.ViewModelProvider;
-import android.arch.lifecycle.ViewModelProviders;
 import android.content.Context;
 import android.os.Bundle;
-import android.support.annotation.Nullable;
-import android.support.design.widget.TextInputLayout;
-import android.support.v7.app.AppCompatDialogFragment;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.Button;
 import android.widget.EditText;
 
+import com.google.android.material.textfield.TextInputLayout;
+
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
@@ -21,6 +18,11 @@ import org.briarproject.briar.android.activity.BaseActivity;
 
 import javax.inject.Inject;
 
+import androidx.annotation.Nullable;
+import androidx.appcompat.app.AppCompatDialogFragment;
+import androidx.lifecycle.ViewModelProvider;
+import androidx.lifecycle.ViewModelProviders;
+
 import static android.view.WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE;
 import static java.util.Objects.requireNonNull;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationActivity.java

@@ -1,23 +1,10 @@
 package org.briarproject.briar.android.conversation;
 
 import android.annotation.SuppressLint;
-import android.arch.lifecycle.Observer;
-import android.arch.lifecycle.ViewModelProvider;
-import android.arch.lifecycle.ViewModelProviders;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.os.Bundle;
 import android.os.Parcelable;
-import android.support.annotation.Nullable;
-import android.support.annotation.UiThread;
-import android.support.design.widget.Snackbar;
-import android.support.v4.app.ActivityCompat;
-import android.support.v4.app.ActivityOptionsCompat;
-import android.support.v4.content.ContextCompat;
-import android.support.v7.app.AlertDialog;
-import android.support.v7.widget.ActionMenuView;
-import android.support.v7.widget.LinearLayoutManager;
-import android.support.v7.widget.Toolbar;
 import android.transition.Slide;
 import android.transition.Transition;
 import android.util.SparseArray;
@@ -29,6 +16,8 @@ import android.widget.ImageView;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import com.google.android.material.snackbar.Snackbar;
+
 import org.briarproject.bramble.api.FeatureFlags;
 import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.contact.ContactId;
@@ -98,17 +87,29 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import androidx.annotation.Nullable;
+import androidx.annotation.UiThread;
+import androidx.appcompat.app.AlertDialog;
+import androidx.appcompat.widget.ActionMenuView;
+import androidx.appcompat.widget.Toolbar;
+import androidx.core.app.ActivityCompat;
+import androidx.core.app.ActivityOptionsCompat;
+import androidx.core.content.ContextCompat;
+import androidx.lifecycle.Observer;
+import androidx.lifecycle.ViewModelProvider;
+import androidx.lifecycle.ViewModelProviders;
+import androidx.recyclerview.widget.LinearLayoutManager;
 import de.hdodenhof.circleimageview.CircleImageView;
 import im.delight.android.identicons.IdenticonDrawable;
 import uk.co.samuelwall.materialtaptargetprompt.MaterialTapTargetPrompt;
 
-import static android.arch.lifecycle.Lifecycle.State.STARTED;
 import static android.os.Build.VERSION.SDK_INT;
-import static android.support.v4.app.ActivityOptionsCompat.makeSceneTransitionAnimation;
-import static android.support.v4.view.ViewCompat.setTransitionName;
-import static android.support.v7.util.SortedList.INVALID_POSITION;
 import static android.view.Gravity.RIGHT;
 import static android.widget.Toast.LENGTH_SHORT;
+import static androidx.core.app.ActivityOptionsCompat.makeSceneTransitionAnimation;
+import static androidx.core.view.ViewCompat.setTransitionName;
+import static androidx.lifecycle.Lifecycle.State.STARTED;
+import static androidx.recyclerview.widget.SortedList.INVALID_POSITION;
 import static java.util.Collections.emptyList;
 import static java.util.Collections.singletonList;
 import static java.util.Collections.sort;

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationAdapter.java

@@ -1,9 +1,6 @@
 package org.briarproject.briar.android.conversation;
 
 import android.content.Context;
-import android.support.annotation.LayoutRes;
-import android.support.v7.widget.LinearLayoutManager;
-import android.support.v7.widget.RecyclerView.RecycledViewPool;
 import android.util.SparseArray;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -18,6 +15,10 @@ import org.briarproject.briar.android.util.ItemReturningAdapter;
 
 import javax.annotation.Nullable;
 
+import androidx.annotation.LayoutRes;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView.RecycledViewPool;
+
 @NotNullByDefault
 class ConversationAdapter
 		extends BriarAdapter<ConversationItem, ConversationItemViewHolder>

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationItem.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.conversation;
 
-import android.support.annotation.LayoutRes;
-
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
@@ -10,6 +8,8 @@ import org.briarproject.briar.api.conversation.ConversationMessageHeader;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.NotThreadSafe;
 
+import androidx.annotation.LayoutRes;
+
 @NotThreadSafe
 @NotNullByDefault
 abstract class ConversationItem {

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationItemViewHolder.java

@@ -1,16 +1,17 @@
 package org.briarproject.briar.android.conversation;
 
-import android.support.annotation.CallSuper;
-import android.support.annotation.Nullable;
-import android.support.annotation.UiThread;
-import android.support.constraint.ConstraintLayout;
-import android.support.v7.widget.RecyclerView.ViewHolder;
 import android.view.View;
 import android.widget.TextView;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
 
+import androidx.annotation.CallSuper;
+import androidx.annotation.Nullable;
+import androidx.annotation.UiThread;
+import androidx.constraintlayout.widget.ConstraintLayout;
+import androidx.recyclerview.widget.RecyclerView.ViewHolder;
+
 import static org.briarproject.bramble.util.StringUtils.trim;
 import static org.briarproject.briar.android.util.UiUtils.formatDate;
 

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationListener.java

@@ -1,11 +1,12 @@
 package org.briarproject.briar.android.conversation;
 
-import android.support.annotation.UiThread;
 import android.view.View;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.android.attachment.AttachmentItem;
 
+import androidx.annotation.UiThread;
+
 @UiThread
 @NotNullByDefault
 interface ConversationListener {

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationMessageItem.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.conversation;
 
-import android.support.annotation.LayoutRes;
-
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.android.attachment.AttachmentItem;
 import org.briarproject.briar.api.messaging.PrivateMessageHeader;
@@ -10,6 +8,8 @@ import java.util.List;
 
 import javax.annotation.concurrent.NotThreadSafe;
 
+import androidx.annotation.LayoutRes;
+
 @NotThreadSafe
 @NotNullByDefault
 class ConversationMessageItem extends ConversationItem {

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationMessageViewHolder.java

@@ -1,9 +1,5 @@
 package org.briarproject.briar.android.conversation;
 
-import android.support.annotation.UiThread;
-import android.support.constraint.ConstraintSet;
-import android.support.v7.widget.RecyclerView;
-import android.support.v7.widget.RecyclerView.RecycledViewPool;
 import android.view.View;
 import android.view.ViewGroup;
 
@@ -11,8 +7,13 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.attachment.AttachmentItem;
 
-import static android.support.constraint.ConstraintSet.WRAP_CONTENT;
-import static android.support.v4.content.ContextCompat.getColor;
+import androidx.annotation.UiThread;
+import androidx.constraintlayout.widget.ConstraintSet;
+import androidx.recyclerview.widget.RecyclerView;
+import androidx.recyclerview.widget.RecyclerView.RecycledViewPool;
+
+import static androidx.constraintlayout.widget.ConstraintSet.WRAP_CONTENT;
+import static androidx.core.content.ContextCompat.getColor;
 
 @UiThread
 @NotNullByDefault

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationNoticeItem.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.conversation;
 
-import android.support.annotation.LayoutRes;
-
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.api.conversation.ConversationRequest;
 import org.briarproject.briar.api.conversation.ConversationResponse;
@@ -9,6 +7,8 @@ import org.briarproject.briar.api.conversation.ConversationResponse;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.NotThreadSafe;
 
+import androidx.annotation.LayoutRes;
+
 @NotThreadSafe
 @NotNullByDefault
 class ConversationNoticeItem extends ConversationItem {

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationNoticeViewHolder.java

@@ -1,13 +1,14 @@
 package org.briarproject.briar.android.conversation;
 
-import android.support.annotation.CallSuper;
-import android.support.annotation.UiThread;
 import android.view.View;
 import android.widget.TextView;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
 
+import androidx.annotation.CallSuper;
+import androidx.annotation.UiThread;
+
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
 import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationRequestItem.java

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.conversation;
 
-import android.support.annotation.LayoutRes;
-
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.briar.api.client.SessionId;
@@ -12,6 +10,8 @@ import org.briarproject.briar.api.sharing.Shareable;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.NotThreadSafe;
 
+import androidx.annotation.LayoutRes;
+
 @NotThreadSafe
 @NotNullByDefault
 class ConversationRequestItem extends ConversationNoticeItem {

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationRequestViewHolder.java

@@ -1,12 +1,13 @@
 package org.briarproject.briar.android.conversation;
 
-import android.support.annotation.UiThread;
 import android.view.View;
 import android.widget.Button;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
 
+import androidx.annotation.UiThread;
+
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
 

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationViewModel.java

@@ -1,13 +1,7 @@
 package org.briarproject.briar.android.conversation;
 
 import android.app.Application;
-import android.arch.lifecycle.AndroidViewModel;
-import android.arch.lifecycle.LiveData;
-import android.arch.lifecycle.MutableLiveData;
-import android.arch.lifecycle.Transformations;
 import android.net.Uri;
-import android.support.annotation.Nullable;
-import android.support.annotation.UiThread;
 
 import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.contact.Contact;
@@ -44,6 +38,13 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import androidx.annotation.Nullable;
+import androidx.annotation.UiThread;
+import androidx.lifecycle.AndroidViewModel;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+import androidx.lifecycle.Transformations;
+
 import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationVisitor.java

@@ -1,8 +1,6 @@
 package org.briarproject.briar.android.conversation;
 
-import android.arch.lifecycle.LiveData;
 import android.content.Context;
-import android.support.annotation.UiThread;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.MessageId;
@@ -23,6 +21,9 @@ import java.util.List;
 
 import javax.annotation.Nullable;
 
+import androidx.annotation.UiThread;
+import androidx.lifecycle.LiveData;
+
 import static java.util.Collections.emptyList;
 import static org.briarproject.briar.android.conversation.ConversationRequestItem.RequestType.BLOG;
 import static org.briarproject.briar.android.conversation.ConversationRequestItem.RequestType.FORUM;

briar-android/src/main/java/org/briarproject/briar/android/conversation/ImageActivity.java

@@ -1,22 +1,9 @@
 package org.briarproject.briar.android.conversation;
 
-import android.arch.lifecycle.ViewModelProvider;
-import android.arch.lifecycle.ViewModelProviders;
 import android.content.DialogInterface.OnClickListener;
 import android.content.Intent;
 import android.graphics.drawable.Drawable;
 import android.os.Bundle;
-import android.support.annotation.Nullable;
-import android.support.annotation.RequiresApi;
-import android.support.design.widget.AppBarLayout;
-import android.support.v4.app.Fragment;
-import android.support.v4.app.FragmentManager;
-import android.support.v4.app.FragmentStatePagerAdapter;
-import android.support.v4.content.ContextCompat;
-import android.support.v4.graphics.drawable.DrawableCompat;
-import android.support.v4.view.ViewPager;
-import android.support.v7.app.AlertDialog.Builder;
-import android.support.v7.widget.Toolbar;
 import android.transition.Fade;
 import android.transition.Transition;
 import android.view.Menu;
@@ -26,6 +13,8 @@ import android.view.ViewTreeObserver.OnGlobalLayoutListener;
 import android.view.Window;
 import android.widget.TextView;
 
+import com.google.android.material.appbar.AppBarLayout;
+
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
@@ -42,18 +31,31 @@ import java.util.Locale;
 
 import javax.inject.Inject;
 
+import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
+import androidx.appcompat.app.AlertDialog.Builder;
+import androidx.appcompat.widget.Toolbar;
+import androidx.core.content.ContextCompat;
+import androidx.core.graphics.drawable.DrawableCompat;
+import androidx.fragment.app.Fragment;
+import androidx.fragment.app.FragmentManager;
+import androidx.fragment.app.FragmentStatePagerAdapter;
+import androidx.lifecycle.ViewModelProvider;
+import androidx.lifecycle.ViewModelProviders;
+import androidx.viewpager.widget.ViewPager;
+
 import static android.content.Intent.ACTION_CREATE_DOCUMENT;
 import static android.content.Intent.CATEGORY_OPENABLE;
 import static android.content.Intent.EXTRA_TITLE;
 import static android.graphics.Color.TRANSPARENT;
 import static android.os.Build.VERSION.SDK_INT;
-import static android.support.design.widget.Snackbar.LENGTH_LONG;
 import static android.view.View.GONE;
 import static android.view.View.SYSTEM_UI_FLAG_FULLSCREEN;
 import static android.view.View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN;
 import static android.view.View.SYSTEM_UI_FLAG_LAYOUT_STABLE;
 import static android.view.View.VISIBLE;
 import static android.view.WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS;
+import static com.google.android.material.snackbar.Snackbar.LENGTH_LONG;
 import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_SAVE_ATTACHMENT;
 import static org.briarproject.briar.android.util.UiUtils.formatDateAbsolute;

briar-android/src/main/java/org/briarproject/briar/android/conversation/ImageAdapter.java

@@ -2,8 +2,6 @@ package org.briarproject.briar.android.conversation;
 
 import android.content.Context;
 import android.content.res.Resources;
-import android.support.annotation.Nullable;
-import android.support.v7.widget.RecyclerView.Adapter;
 import android.util.DisplayMetrics;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -18,6 +16,9 @@ import org.briarproject.briar.android.conversation.glide.Radii;
 import java.util.ArrayList;
 import java.util.List;
 
+import androidx.annotation.Nullable;
+import androidx.recyclerview.widget.RecyclerView.Adapter;
+
 import static android.content.Context.WINDOW_SERVICE;
 import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.util.UiUtils.isRtl;