do not use Dialer UI for incoming calls if audio permission is not granted

We cannot always request new permissions when Dialer UI is shown. For
example, Dialer UI can be shown over keyguard, which doesn't allow other
dialogs (like the permission request dialog) to be displayed. However it
doesn't return the failed response either, making ConnectionService kind
of stuck.

If we just do not use the Dialer UI when the permission is not granted,
it is at most a minor annoyance for the first time. After the user has
accepted an incoming call even just once, the permission will be
granted, and the Dialer integration will start to work just fine.

src/cheogram/java/com/cheogram/android/ConnectionService.java

@@ -1,54 +1,51 @@
 package com.cheogram.android;
 
+import android.Manifest;
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.Intent;
+import android.content.ServiceConnection;
+import android.graphics.drawable.Icon;
+import android.net.Uri;
+import android.os.Build;
+import android.os.Bundle;
+import android.os.IBinder;
+import android.telecom.CallAudioState;
+import android.telecom.Connection;
+import android.telecom.ConnectionRequest;
+import android.telecom.DisconnectCause;
+import android.telecom.PhoneAccountHandle;
+import android.telecom.StatusHints;
+import android.telecom.TelecomManager;
+import android.telephony.PhoneNumberUtils;
+import android.util.Log;
+
+import com.google.common.base.Joiner;
+import com.google.common.collect.ImmutableSet;
+import com.intentfilter.androidpermissions.NotificationSettings;
+import com.intentfilter.androidpermissions.PermissionManager;
+import com.intentfilter.androidpermissions.models.DeniedPermissions;
+
 import java.lang.ref.WeakReference;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Set;
 import java.util.Stack;
-
-import com.google.common.collect.ImmutableSet;
-
-import android.telecom.CallAudioState;
-import android.telecom.Connection;
-import android.telecom.ConnectionRequest;
-import android.telecom.DisconnectCause;
-import android.telecom.PhoneAccount;
-import android.telecom.PhoneAccountHandle;
-import android.telecom.StatusHints;
-import android.telecom.TelecomManager;
-import android.telephony.PhoneNumberUtils;
-
-import android.Manifest;
-import androidx.core.content.ContextCompat;
-import android.content.ComponentName;
-import android.content.Context;
-import android.content.Intent;
-import android.content.pm.PackageManager;
-import android.content.ServiceConnection;
-import android.graphics.drawable.Icon;
-import android.net.Uri;
-import android.os.Bundle;
-import android.os.IBinder;
-import android.os.Parcel;
-import android.util.Log;
-
-import com.intentfilter.androidpermissions.PermissionManager;
-import com.intentfilter.androidpermissions.NotificationSettings;
-import com.intentfilter.androidpermissions.models.DeniedPermissions;
-import io.michaelrocks.libphonenumber.android.NumberParseException;
+import java.util.Vector;
 
 import eu.siacs.conversations.R;
 import eu.siacs.conversations.entities.Account;
 import eu.siacs.conversations.services.AppRTCAudioManager;
 import eu.siacs.conversations.services.AvatarService;
-import eu.siacs.conversations.services.XmppConnectionService.XmppConnectionBinder;
 import eu.siacs.conversations.services.XmppConnectionService;
+import eu.siacs.conversations.services.XmppConnectionService.XmppConnectionBinder;
 import eu.siacs.conversations.ui.RtpSessionActivity;
 import eu.siacs.conversations.utils.PhoneNumberUtilWrapper;
 import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.jingle.JingleRtpConnection;
 import eu.siacs.conversations.xmpp.jingle.Media;
 import eu.siacs.conversations.xmpp.jingle.RtpEndUserState;
+import io.michaelrocks.libphonenumber.android.NumberParseException;
 
 public class ConnectionService extends android.telecom.ConnectionService {
     public XmppConnectionService xmppConnectionService = null;
@@ -64,9 +61,17 @@ public class ConnectionService extends android.telecom.ConnectionService {
             xmppConnectionService = null;
         }
     };
+    private PermissionManager mPermissionManager;
 
     @Override
     public void onCreate() {
+        mPermissionManager = PermissionManager.getInstance(this);
+        mPermissionManager.setNotificationSettings(
+                new NotificationSettings.Builder()
+                        .withMessage(R.string.microphone_permission_for_call)
+                        .withSmallIcon(R.drawable.ic_notification).build()
+        );
+
         // From XmppActivity.connectToBackend
         Intent intent = new Intent(this, XmppConnectionService.class);
         intent.setAction("ui");
@@ -112,16 +117,9 @@ public class ConnectionService extends android.telecom.ConnectionService {
         Jid with = Jid.ofLocalAndDomain(tel, gateway[1]);
         CheogramConnection connection = new CheogramConnection(account, with, postDial);
 
-		PermissionManager permissionManager = PermissionManager.getInstance(this);
-		permissionManager.setNotificationSettings(
-			new NotificationSettings.Builder()
-				.withMessage(R.string.microphone_permission_for_call)
-				.withSmallIcon(R.drawable.ic_notification).build()
-		);
-
-		Set<String> permissions = new HashSet();
+        Set<String> permissions = new HashSet<>();
         permissions.add(Manifest.permission.RECORD_AUDIO);
-		permissionManager.checkPermissions(permissions, new PermissionManager.PermissionRequestListener() {
+        mPermissionManager.checkPermissions(permissions, new PermissionManager.PermissionRequestListener() {
             @Override
             public void onPermissionGranted() {
                 connection.setSessionId(xmppConnectionService.getJingleConnectionManager().proposeJingleRtpSession(
@@ -150,11 +148,34 @@ public class ConnectionService extends android.telecom.ConnectionService {
         return connection;
     }
 
+    @Override
+    public Connection onCreateIncomingConnection(PhoneAccountHandle handle, ConnectionRequest request) {
+        Bundle extras = request.getExtras();
+        String accountJid = extras.getString("account");
+        String withJid = extras.getString("with");
+        String sessionId = extras.getString("sessionId");
+
+        Account account = xmppConnectionService.findAccountByJid(Jid.of(accountJid));
+        Jid with = Jid.of(withJid);
+
+        CheogramConnection connection = new CheogramConnection(account, with, null);
+        connection.setSessionId(sessionId);
+        connection.setAddress(
+                Uri.fromParts("tel", with.getLocal(), null),
+                TelecomManager.PRESENTATION_ALLOWED
+        );
+        connection.setRinging();
+
+        xmppConnectionService.setOnRtpConnectionUpdateListener(connection);
+
+        return connection;
+    }
+
     public class CheogramConnection extends Connection implements XmppConnectionService.OnJingleRtpConnectionUpdate {
         protected Account account;
         protected Jid with;
         protected String sessionId = null;
-		protected Stack<String> postDial = new Stack();
+        protected Stack<String> postDial = new Stack<>();
         protected Icon gatewayIcon;
         protected WeakReference<JingleRtpConnection> rtpConnection = null;
 
@@ -203,6 +224,8 @@ public class ConnectionService extends android.telecom.ConnectionService {
                 setInitialized();
             } else if (state == RtpEndUserState.RINGING) {
                 setDialing();
+            } else if (state == RtpEndUserState.INCOMING_CALL) {
+                setRinging();
             } else if (state == RtpEndUserState.CONNECTED) {
                 xmppConnectionService.setDiallerIntegrationActive(true);
                 setActive();
@@ -221,7 +244,9 @@ public class ConnectionService extends android.telecom.ConnectionService {
 
         @Override
         public void onAudioDeviceChanged(AppRTCAudioManager.AudioDevice selectedAudioDevice, Set<AppRTCAudioManager.AudioDevice> availableAudioDevices) {
-			switch(selectedAudioDevice) {
+            if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.O) return;
+
+            switch (selectedAudioDevice) {
                 case SPEAKER_PHONE:
                     setAudioRoute(CallAudioState.ROUTE_SPEAKER);
                 case WIRED_HEADSET:
@@ -235,6 +260,17 @@ public class ConnectionService extends android.telecom.ConnectionService {
             }
         }
 
+        @Override
+        public void onAnswer() {
+            // For incoming calls, a connection update may not have been triggered before answering
+            // so we have to acquire the rtp connection object here
+            this.rtpConnection =
+                    xmppConnectionService.getJingleConnectionManager()
+                            .findJingleRtpConnection(account, with, sessionId);
+
+            rtpConnection.get().acceptCall();
+        }
+
         @Override
         public void onDisconnect() {
             if (rtpConnection == null || rtpConnection.get() == null) {
@@ -276,9 +312,9 @@ public class ConnectionService extends android.telecom.ConnectionService {
             while (!postDial.empty()) {
                 String next = postDial.pop();
                 if (next.equals(";")) {
-					Stack v = (Stack) postDial.clone();
+                    Vector<String> v = new Vector<>(postDial);
                     Collections.reverse(v);
-					setPostDialWait(String.join("", v));
+                    setPostDialWait(Joiner.on("").skipNulls().join(v));
                     return;
                 } else if (next.equals(",")) {
                     sleep(2000);

src/main/java/eu/siacs/conversations/entities/Contact.java

@@ -599,7 +599,7 @@ public class Contact implements ListItem, Blockable {
             "/" + getJid().asBareJid().toString();
     }
 
-    protected PhoneAccountHandle phoneAccountHandle() {
+    public PhoneAccountHandle phoneAccountHandle() {
         ComponentName componentName = new ComponentName(
             "com.cheogram.android",
             "com.cheogram.android.ConnectionService"

src/main/java/eu/siacs/conversations/services/NotificationService.java

@@ -1,5 +1,6 @@
 package eu.siacs.conversations.services;
 
+import android.Manifest;
 import android.app.Notification;
 import android.app.NotificationChannel;
 import android.app.NotificationChannelGroup;
@@ -8,6 +9,7 @@ import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
+import android.content.pm.PackageManager;
 import android.content.res.Resources;
 import android.graphics.Bitmap;
 import android.graphics.Typeface;
@@ -16,9 +18,12 @@ import android.media.Ringtone;
 import android.media.RingtoneManager;
 import android.net.Uri;
 import android.os.Build;
+import android.os.Bundle;
 import android.os.SystemClock;
 import android.os.Vibrator;
 import android.preference.PreferenceManager;
+import android.telecom.PhoneAccountHandle;
+import android.telecom.TelecomManager;
 import android.text.SpannableString;
 import android.text.style.StyleSpan;
 import android.util.DisplayMetrics;
@@ -423,7 +428,58 @@ public class NotificationService {
         notify(DELIVERY_FAILED_NOTIFICATION_ID, summaryNotification);
     }
 
+    private synchronized boolean tryRingingWithDialerUI(final AbstractJingleConnection.Id id, final Set<Media> media) {
+        if (mXmppConnectionService.checkSelfPermission(Manifest.permission.RECORD_AUDIO) != PackageManager.PERMISSION_GRANTED) {
+            // We cannot always request audio permission in Dialer UI
+            // e.g. when Dialer is shown over keyguard
+            return false;
+        }
+
+        if (media.size() != 1 || !media.contains(Media.AUDIO)) {
+            // Currently our ConnectionService only handles single audio calls
+            Log.w(Config.LOGTAG, "only audio calls can be handled by cheogram connection service");
+            return false;
+        }
+
+        PhoneAccountHandle handle = null;
+        for (Contact contact : id.account.getRoster().getContacts()) {
+            if (!contact.getJid().getDomain().equals(id.with.getDomain()))
+                continue;
+            if (!contact.getPresences().anyIdentity("gateway", "pstn"))
+                continue;
+            handle = contact.phoneAccountHandle();
+            break;
+        }
+
+        if (handle == null) {
+            Log.w(Config.LOGTAG, "Could not find phone account handle for " + id.account.getJid().toString());
+            return false;
+        }
+
+        Bundle callInfo = new Bundle();
+        callInfo.putString("account", id.account.getJid().toString());
+        callInfo.putString("with", id.with.toString());
+        callInfo.putString("sessionId", id.sessionId);
+
+        TelecomManager telecomManager = mXmppConnectionService.getSystemService(TelecomManager.class);
+
+        try {
+            telecomManager.addNewIncomingCall(handle, callInfo);
+        } catch (SecurityException e) {
+            // There *could* be race conditions where the account is not registered yet
+            // when an incoming call is already received
+            Log.w(Config.LOGTAG, e);
+            return false;
+        }
+
+        return true;
+    }
+
     public synchronized void startRinging(final AbstractJingleConnection.Id id, final Set<Media> media) {
+        if (tryRingingWithDialerUI(id, media)) {
+            return;
+        }
+
         showIncomingCallNotification(id, media);
         final NotificationManager notificationManager = (NotificationManager) mXmppConnectionService.getSystemService(Context.NOTIFICATION_SERVICE);
         final int currentInterruptionFilter;