Android N 高通平台飞行模式下拨打紧急拨号112流程

             简单说下这个流程：

            飞行模式下拨打112，首先是会打开radio，然后才拨出紧急号码的。

      1）在TelephonyConnectionService.java中，执行onCreateOutgoingConnection方法，如下：

             public Connection onCreateOutgoingConnection(
            PhoneAccountHandle connectionManagerPhoneAccount,
            final ConnectionRequest request) {
        Log.i(this, "onCreateOutgoingConnection, request: " + request);

       。。。。。。

        if (isEmergencyNumber) {
            mRequest = request;
            if (!phone.isRadioOn() || isAirplaneModeOn) {
                mUseEmergencyCallHelper = true;          //这里判断这个mUseEmergencyCallHelper = true
            }
        } else {
            switch (state) {
                case ServiceState.STATE_IN_SERVICE:
                case ServiceState.STATE_EMERGENCY_ONLY:
                    break;
                case ServiceState.STATE_OUT_OF_SERVICE:
                    if (phone.isUtEnabled() && number.endsWith("#")) {
                        Log.d(this, "onCreateOutgoingConnection dial for UT");
                        break;
                    } else {
                        return Connection.createFailedConnection(
                                DisconnectCauseUtil.toTelecomDisconnectCause(
                                        android.telephony.DisconnectCause.OUT_OF_SERVICE,
                                        "ServiceState.STATE_OUT_OF_SERVICE"));
                    }
                case ServiceState.STATE_POWER_OFF:
                    return Connection.createFailedConnection(
                            DisconnectCauseUtil.toTelecomDisconnectCause(
                                    android.telephony.DisconnectCause.POWER_OFF,
                                    "ServiceState.STATE_POWER_OFF"));
                default:
                    Log.d(this, "onCreateOutgoingConnection, unknown service state: %d", state);
                    return Connection.createFailedConnection(
                            DisconnectCauseUtil.toTelecomDisconnectCause(
                                    android.telephony.DisconnectCause.OUTGOING_FAILURE,
                                    "Unknown service state " + state));
            }
        }

        final Context context = getApplicationContext();
        if (VideoProfile.isVideo(request.getVideoState()) && isTtyModeEnabled(context) &&
                !isEmergencyNumber) {
            return Connection.createFailedConnection(DisconnectCauseUtil.toTelecomDisconnectCause(
                    android.telephony.DisconnectCause.VIDEO_CALL_NOT_ALLOWED_WHILE_TTY_ENABLED));
        }

        // Check for additional limits on CDMA phones.
        final Connection failedConnection = checkAdditionalOutgoingCallLimits(phone);
        if (failedConnection != null) {
            return failedConnection;
        }

        final TelephonyConnection connection =
                createConnectionFor(phone, null, true /* isOutgoing */, request.getAccountHandle(),
                        request.getTelecomCallId(), request.getAddress());
        if (connection == null) {
            return Connection.createFailedConnection(
                    DisconnectCauseUtil.toTelecomDisconnectCause(
                            android.telephony.DisconnectCause.OUTGOING_FAILURE,
                            "Invalid phone type"));
        }
        connection.setAddress(handle, PhoneConstants.PRESENTATION_ALLOWED);
        connection.setInitializing();
        connection.setVideoState(request.getVideoState());

        if (mUseEmergencyCallHelper) {
            if (mEmergencyCallHelper == null) {
                mEmergencyCallHelper = new EmergencyCallHelper(this);
            }
            mEmergencyCallHelper.startTurnOnRadioSequence(number,   //下面就走到这里了，代码跟进去，会发现有打开radio的操作
                    new EmergencyCallHelper.Callback() {
                        @Override
                        public void onComplete(Phone phone, boolean isRadioReady) {
                            if (connection.getState() == Connection.STATE_DISCONNECTED) {
                                // If the connection has already been disconnected, do nothing.
                            } else if (isRadioReady) {
                                connection.setInitialized();
                                placeOutgoingConnection(connection, phone, request);
                            } else {
                                Log.d(this, "onCreateOutgoingConnection, failed to turn on radio");
                                connection.setDisconnected(
                                        DisconnectCauseUtil.toTelecomDisconnectCause(
                                                android.telephony.DisconnectCause.POWER_OFF,
                                                "Failed to turn on radio."));
                                connection.destroy();
                            }
                        }
                    });

        } else {
            placeOutgoingConnection(connection, phone, request);
        }

        return connection;
    }


    }