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

We cannot request new permissions when Dialer UI is shown. For incoming
calls, if the Dialer UI is displayed over keyguard, then the user may
not even be able to see the permission notifications that we use for
outgoing calls.

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

@@ -1,31 +1,5 @@
 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;
@@ -33,19 +7,51 @@ import java.util.Set;
 import java.util.Stack;
 import java.util.Vector;
 
+import com.google.common.base.Joiner;
+import com.google.common.collect.ImmutableSet;
+
+import android.os.Build;
+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 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;
 import eu.siacs.conversations.services.XmppConnectionService.XmppConnectionBinder;
+import eu.siacs.conversations.services.XmppConnectionService;
 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;
@@ -61,17 +67,9 @@ 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");
@@ -117,9 +115,16 @@ 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<>();
 		permissions.add(Manifest.permission.RECORD_AUDIO);
-        mPermissionManager.checkPermissions(permissions, new PermissionManager.PermissionRequestListener() {
+		permissionManager.checkPermissions(permissions, new PermissionManager.PermissionRequestListener() {
 			@Override
 			public void onPermissionGranted() {
 				connection.setSessionId(xmppConnectionService.getJingleConnectionManager().proposeJingleRtpSession(
@@ -246,7 +251,7 @@ public class ConnectionService extends android.telecom.ConnectionService {
 		public void onAudioDeviceChanged(AppRTCAudioManager.AudioDevice selectedAudioDevice, Set<AppRTCAudioManager.AudioDevice> availableAudioDevices) {
 			if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.O) return;
 
-            switch (selectedAudioDevice) {
+			switch(selectedAudioDevice) {
 				case SPEAKER_PHONE:
 					setAudioRoute(CallAudioState.ROUTE_SPEAKER);
 				case WIRED_HEADSET:
@@ -314,7 +319,7 @@ public class ConnectionService extends android.telecom.ConnectionService {
 				if (next.equals(";")) {
 					Vector<String> v = new Vector<>(postDial);
 					Collections.reverse(v);
-                    setPostDialWait(Joiner.on("").skipNulls().join(v));
+					setPostDialWait(Joiner.on("").join(v));
 					return;
 				} else if (next.equals(",")) {
 					sleep(2000);

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

@@ -430,8 +430,9 @@ public class NotificationService {
 
     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
+            // We cannot request audio permission in Dialer UI
-            // e.g. when Dialer is shown over keyguard
+            // when Dialer is shown over keyguard, the user cannot even necessarily
+            // see notifications.
             return false;
         }
 
@@ -466,8 +467,8 @@ public class NotificationService {
         try {
             telecomManager.addNewIncomingCall(handle, callInfo);
         } catch (SecurityException e) {
-            // There *could* be race conditions where the account is not registered yet
+            // If the account is not registered or enabled, it could result in a security exception
-            // when an incoming call is already received
+            // Just fall back to the built-in UI in this case.
             Log.w(Config.LOGTAG, e);
             return false;
         }