Screen overlay warning: remove ability to query and remember allowed apps for API 30+

as we can't query all installed apps anymore when targeting API 30

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

@@ -198,7 +198,10 @@ public class AppModule {
 	ScreenFilterMonitor provideScreenFilterMonitor(
 			LifecycleManager lifecycleManager,
 			ScreenFilterMonitorImpl screenFilterMonitor) {
-		lifecycleManager.registerService(screenFilterMonitor);
+		if (SDK_INT <= 29) {
+			// this keeps track of installed apps and does not work on API 30+
+			lifecycleManager.registerService(screenFilterMonitor);
+		}
 		return screenFilterMonitor;
 	}
 

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

@@ -58,7 +58,7 @@ class ScreenFilterMonitorImpl implements ScreenFilterMonitor, Service {
 			Logger.getLogger(ScreenFilterMonitorImpl.class.getName());
 
 	/*
- 	 * Ignore Play Services if it uses this package name and public key - it's
+	 * Ignore Play Services if it uses this package name and public key - it's
 	 * effectively a system app, but not flagged as such on older systems
 	 */
 	private static final String PLAY_SERVICES_PACKAGE =
@@ -108,7 +108,7 @@ class ScreenFilterMonitorImpl implements ScreenFilterMonitor, Service {
 		Set<String> allowed = prefs.getStringSet(PREF_KEY_ALLOWED,
 				Collections.emptySet());
 		List<AppDetails> apps = new ArrayList<>();
-		List<PackageInfo> packageInfos =
+		@SuppressLint("QueryPermissionsNeeded") List<PackageInfo> packageInfos =
 				pm.getInstalledPackages(GET_PERMISSIONS);
 		for (PackageInfo packageInfo : packageInfos) {
 			if (!allowed.contains(packageInfo.packageName)

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

@@ -39,9 +39,11 @@ import androidx.appcompat.widget.Toolbar;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
 
+import static android.os.Build.VERSION.SDK_INT;
 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.Collections.emptyList;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.briar.android.TestingConstants.PREVENT_SCREENSHOTS;
@@ -201,9 +203,15 @@ public abstract class BaseActivity extends AppCompatActivity
 		// If the dialog is already visible, filter the tap
 		ScreenFilterDialogFragment f = findDialogFragment();
 		if (f != null && f.isVisible()) return false;
-		Collection<AppDetails> apps = screenFilterMonitor.getApps();
-		// If all overlay apps have been allowed, allow the tap
-		if (apps.isEmpty()) return true;
+		Collection<AppDetails> apps;
+		// querying all apps is only possible at API 29 and below
+		if (SDK_INT <= 29) {
+			apps = screenFilterMonitor.getApps();
+			// If all overlay apps have been allowed, allow the tap
+			if (apps.isEmpty()) return true;
+		} else {
+			apps = emptyList();
+		}
 		// Show dialog unless onSaveInstanceState() has been called, see #1112
 		FragmentManager fm = getSupportFragmentManager();
 		if (!fm.isStateSaved()) {
@@ -265,7 +273,12 @@ public abstract class BaseActivity extends AppCompatActivity
 	private void protectToolbar() {
 		findToolbar();
 		if (toolbar != null) {
-			boolean filter = !screenFilterMonitor.getApps().isEmpty();
+			boolean filter;
+			if (SDK_INT <= 29) {
+				filter = !screenFilterMonitor.getApps().isEmpty();
+			} else {
+				filter = true;
+			}
 			UiUtils.setFilterTouchesWhenObscured(toolbar, filter);
 		}
 	}

briar-android/src/main/java/org/briarproject/briar/android/fragment/ScreenFilterDialogFragment.java

@@ -5,6 +5,7 @@ import android.app.Activity;
 import android.app.Dialog;
 import android.content.Context;
 import android.content.DialogInterface;
+import android.content.Intent;
 import android.os.Bundle;
 import android.text.TextUtils;
 import android.view.LayoutInflater;
@@ -28,6 +29,10 @@ import javax.inject.Inject;
 import androidx.appcompat.app.AlertDialog;
 import androidx.fragment.app.DialogFragment;
 
+import static android.os.Build.VERSION.SDK_INT;
+import static android.provider.Settings.ACTION_MANAGE_OVERLAY_PERMISSION;
+import static android.view.View.GONE;
+
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class ScreenFilterDialogFragment extends DialogFragment {
@@ -37,7 +42,7 @@ public class ScreenFilterDialogFragment extends DialogFragment {
 	@Inject
 	ScreenFilterMonitor screenFilterMonitor;
 
-	DismissListener dismissListener = null;
+	private DismissListener dismissListener = null;
 
 	public static ScreenFilterDialogFragment newInstance(
 			Collection<AppDetails> apps) {
@@ -83,10 +88,20 @@ public class ScreenFilterDialogFragment extends DialogFragment {
 		View dialogView = inflater.inflate(R.layout.dialog_screen_filter, null);
 		builder.setView(dialogView);
 		TextView message = dialogView.findViewById(R.id.screen_filter_message);
-		message.setText(getString(R.string.screen_filter_body,
-				TextUtils.join("\n", appNames)));
 		CheckBox allow = dialogView.findViewById(R.id.screen_filter_checkbox);
-		builder.setNeutralButton(R.string.continue_button, (dialog, which) -> {
+		if (SDK_INT <= 29) {
+			message.setText(getString(R.string.screen_filter_body,
+					TextUtils.join("\n", appNames)));
+		} else {
+			message.setText(R.string.screen_filter_body_api_30);
+			allow.setVisibility(GONE);
+			builder.setNeutralButton(R.string.screen_filter_review_apps,
+					(dialog, which) -> {
+						Intent i = new Intent(ACTION_MANAGE_OVERLAY_PERMISSION);
+						startActivity(i);
+					});
+		}
+		builder.setPositiveButton(R.string.continue_button, (dialog, which) -> {
 			if (allow.isChecked()) screenFilterMonitor.allowApps(packageNames);
 			dialog.dismiss();
 		});

briar-android/src/main/java/org/briarproject/briar/api/android/ScreenFilterMonitor.java

@@ -14,6 +14,8 @@ public interface ScreenFilterMonitor {
 	 * SYSTEM_ALERT_WINDOW permission, excluding system apps, Google Play
 	 * Services, and any apps that have been allowed by calling
 	 * {@link #allowApps(Collection)}.
+	 *
+	 * Only works on SDK_INT 29 and below.
 	 */
 	@UiThread
 	Collection<AppDetails> getApps();
@@ -21,6 +23,8 @@ public interface ScreenFilterMonitor {
 	/**
 	 * Allows the apps with the given package names to use overlay windows.
 	 * They will not be returned by future calls to {@link #getApps()}.
+	 *
+	 * Only works on SDK_INT 29 and below.
 	 */
 	@UiThread
 	void allowApps(Collection<String> packageNames);

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

@@ -590,7 +590,9 @@
 	<!-- Screen Filters & Tapjacking -->
 	<string name="screen_filter_title">Screen overlay detected</string>
 	<string name="screen_filter_body">Another app is drawing on top of Briar. To protect your security, Briar will not respond to touches when another app is drawing on top.\n\nThe following apps might be drawing on top:\n\n%1$s</string>
+	<string name="screen_filter_body_api_30">Another app is drawing on top of Briar. To protect your security, Briar will not respond to touches when another app is drawing on top.\n\nReview apps below to find the responsible app.</string>
 	<string name="screen_filter_allow">Allow these apps to draw on top</string>
+	<string name="screen_filter_review_apps">Review apps</string>
 
 	<!-- Permission Requests -->
 	<string name="permission_camera_title">Camera permission</string>