Show expiry warning when running on Android 4

After a set date a snackbar is shown, warning that Briar will stop
working at a later set date.

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

@@ -2,6 +2,7 @@ package org.briarproject.briar.android;
 
 import org.briarproject.briar.BuildConfig;
 
+import static android.os.Build.VERSION.SDK_INT;
 import static java.util.concurrent.TimeUnit.DAYS;
 
 public interface TestingConstants {
@@ -19,10 +20,15 @@ public interface TestingConstants {
 	 */
 	boolean PREVENT_SCREENSHOTS = !IS_DEBUG_BUILD;
 
+	boolean IS_OLD_ANDROID = SDK_INT <= 19;
+	long OLD_ANDROID_WARN_DATE = 1659225600_000L;   // 2022-07-31
+	long OLD_ANDROID_EXPIRY_DATE = 1675123200_000L; // 2023-01-31
+
 	/**
-	 * Debug builds expire after 90 days. Release builds expire after 292
-	 * million years.
+	 * Debug builds expire after 90 days. Release builds running on Android 4
+	 * expire at a set date, otherwise they expire after 292 million years.
 	 */
 	long EXPIRY_DATE = IS_DEBUG_BUILD ?
-			BuildConfig.BuildTimestamp + DAYS.toMillis(90) : Long.MAX_VALUE;
+			BuildConfig.BuildTimestamp + DAYS.toMillis(90)
+			: (IS_OLD_ANDROID ? OLD_ANDROID_EXPIRY_DATE : Long.MAX_VALUE);
 }

briar-android/src/main/java/org/briarproject/briar/android/navdrawer/NavDrawerActivity.java

@@ -75,12 +75,15 @@ import static org.briarproject.bramble.api.plugin.Plugin.State.ENABLING;
 import static org.briarproject.bramble.api.plugin.Plugin.State.STARTING_STOPPING;
 import static org.briarproject.briar.android.BriarService.EXTRA_STARTUP_FAILED;
 import static org.briarproject.briar.android.BriarService.EXTRA_START_RESULT;
+import static org.briarproject.briar.android.TestingConstants.EXPIRY_DATE;
 import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_PASSWORD;
 import static org.briarproject.briar.android.navdrawer.IntentRouter.handleExternalIntent;
+import static org.briarproject.briar.android.util.UiUtils.formatDateFull;
 import static org.briarproject.briar.android.util.UiUtils.getDaysUntilExpiry;
 import static org.briarproject.briar.android.util.UiUtils.observeOnce;
 import static org.briarproject.briar.android.util.UiUtils.resolveColorAttribute;
+import static org.briarproject.briar.android.util.UiUtils.shouldWarnOldAndroidExpiry;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -137,9 +140,11 @@ public class NavDrawerActivity extends BriarActivity implements
 		setContentView(R.layout.activity_nav_drawer);
 
 		BriarApplication app = (BriarApplication) getApplication();
-		if (IS_DEBUG_BUILD && !app.isInstrumentationTest()) {
-			navDrawerViewModel.showExpiryWarning()
-					.observe(this, this::showExpiryWarning);
+		if (!app.isInstrumentationTest()) {
+			if (IS_DEBUG_BUILD || shouldWarnOldAndroidExpiry()) {
+				navDrawerViewModel.showExpiryWarning()
+						.observe(this, this::showExpiryWarning);
+			}
 		}
 		navDrawerViewModel.shouldAskForDozeWhitelisting().observe(this, ask -> {
 			if (ask) showDozeDialog(getString(R.string.setup_doze_intro));
@@ -207,7 +212,9 @@ public class NavDrawerActivity extends BriarActivity implements
 	public void onStart() {
 		super.onStart();
 		lockManager.checkIfLockable();
-		if (IS_DEBUG_BUILD) navDrawerViewModel.checkExpiryWarning();
+		if (IS_DEBUG_BUILD || shouldWarnOldAndroidExpiry()) {
+			navDrawerViewModel.checkExpiryWarning();
+		}
 	}
 
 	@Override
@@ -377,14 +384,23 @@ public class NavDrawerActivity extends BriarActivity implements
 			return;
 		}
 
+		String text;
+		if (IS_DEBUG_BUILD) {
+			text = getResources().getQuantityString(
+					R.plurals.expiry_warning, (int) daysUntilExpiry,
+					(int) daysUntilExpiry);
+		} else {
+			text = getResources().getQuantityString(
+					R.plurals.old_android_expiry_warning, (int) daysUntilExpiry,
+					formatDateFull(this, EXPIRY_DATE),
+					(int) daysUntilExpiry);
+		}
+
 		ViewGroup expiryWarning = findViewById(R.id.expiryWarning);
 		if (show) {
 			// show expiry warning text
 			TextView expiryWarningText =
 					expiryWarning.findViewById(R.id.expiryWarningText);
-			String text = getResources().getQuantityString(
-					R.plurals.expiry_warning, (int) daysUntilExpiry,
-					(int) daysUntilExpiry);
 			expiryWarningText.setText(text);
 			// make close button functional
 			ImageView expiryWarningClose =

briar-android/src/main/java/org/briarproject/briar/android/splash/SplashScreenActivity.java

@@ -27,6 +27,7 @@ import static java.lang.System.currentTimeMillis;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.briar.android.BriarApplication.ENTRY_ACTIVITY;
 import static org.briarproject.briar.android.TestingConstants.EXPIRY_DATE;
+import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -64,7 +65,7 @@ public class SplashScreenActivity extends BaseActivity {
 			int duration =
 					getResources().getInteger(R.integer.splashScreenDuration);
 			new Handler().postDelayed(() -> {
-				if (currentTimeMillis() >= EXPIRY_DATE) {
+				if (IS_DEBUG_BUILD && currentTimeMillis() >= EXPIRY_DATE) {
 					LOG.info("Expired");
 					startNextActivity(ExpiredActivity.class);
 				} else {

briar-android/src/main/java/org/briarproject/briar/android/util/UiUtils.java

@@ -110,6 +110,8 @@ import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.briar.BuildConfig.APPLICATION_ID;
 import static org.briarproject.briar.android.TestingConstants.EXPIRY_DATE;
+import static org.briarproject.briar.android.TestingConstants.IS_OLD_ANDROID;
+import static org.briarproject.briar.android.TestingConstants.OLD_ANDROID_WARN_DATE;
 import static org.briarproject.briar.android.reporting.CrashReportActivity.EXTRA_APP_LOGCAT;
 import static org.briarproject.briar.android.reporting.CrashReportActivity.EXTRA_APP_START_TIME;
 import static org.briarproject.briar.android.reporting.CrashReportActivity.EXTRA_INITIAL_COMMENT;
@@ -197,6 +199,11 @@ public class UiUtils {
 		return DateUtils.formatDateTime(ctx, time, flags);
 	}
 
+	public static String formatDateFull(Context ctx, long time) {
+		return DateUtils.formatDateTime(ctx, time,
+				FORMAT_SHOW_DATE | FORMAT_SHOW_YEAR | FORMAT_ABBREV_ALL);
+	}
+
 	/**
 	 * Returns the given duration in a human-friendly format. For example,
 	 * "7 days" or "1 hour 3 minutes".
@@ -232,6 +239,11 @@ public class UiUtils {
 		return (EXPIRY_DATE - now) / DAYS.toMillis(1);
 	}
 
+	public static boolean shouldWarnOldAndroidExpiry() {
+		return IS_OLD_ANDROID &&
+				System.currentTimeMillis() >= OLD_ANDROID_WARN_DATE;
+	}
+
 	public static SpannableStringBuilder getTeaser(Context ctx, Spanned text) {
 		if (text.length() < TEASER_LENGTH)
 			throw new IllegalArgumentException(

briar-android/src/main/res/values/strings.xml

@@ -56,6 +56,10 @@
 		<item quantity="one">This is a test version of Briar. Your account will expire in %d day and cannot be renewed.</item>
 		<item quantity="other">This is a test version of Briar. Your account will expire in %d days and cannot be renewed.</item>
 	</plurals>
+	<plurals name="old_android_expiry_warning">
+		<item quantity="one">Android 4 is no longer supported. Briar will stop working on %s (in %d day). Please install Briar on a newer device and create a new account.</item>
+		<item quantity="other">Android 4 is no longer supported. Briar will stop working on %s (in %d days). Please install Briar on a newer device and create a new account.</item>
+	</plurals>
 	<string name="expiry_date_reached">This software has expired.\nThank you for testing!</string>
 	<string name="download_briar">To continue using Briar, please download the latest release.</string>
 	<string name="create_new_account">You will need to create a new account, but you can use the same nickname.</string>