android/bluetooth/BluetoothGattService.java

/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package android.bluetooth;

import android.annotation.NonNull;
import android.bluetooth.annotations.RequiresLegacyBluetoothPermission;
import android.compat.annotation.UnsupportedAppUsage;
import android.os.Build;
import android.os.Parcel;
import android.os.ParcelUuid;
import android.os.Parcelable;

import java.util.ArrayList;
import java.util.List;
import java.util.UUID;

/**
 * Represents a Bluetooth GATT Service
 *
 * <p>Gatt Service contains a collection of {@link BluetoothGattCharacteristic}, as well as
 * referenced services.
 */
public class BluetoothGattService implements Parcelable {

    /** Primary service */
    public static final int SERVICE_TYPE_PRIMARY = 0;

    /** Secondary service (included by primary services) */
    public static final int SERVICE_TYPE_SECONDARY = 1;

    /**
     * The remote device this service is associated with. This applies to client applications only.
     *
     * @hide
     */
    @UnsupportedAppUsage protected BluetoothDevice mDevice;

    /**
     * The UUID of this service.
     *
     * @hide
     */
    protected UUID mUuid;

    /**
     * Instance ID for this service.
     *
     * @hide
     */
    protected int mInstanceId;

    /**
     * Handle counter override (for conformance testing).
     *
     * @hide
     */
    protected int mHandles = 0;

    /**
     * Service type (Primary/Secondary).
     *
     * @hide
     */
    protected int mServiceType;

    /** List of characteristics included in this service. */
    protected List<BluetoothGattCharacteristic> mCharacteristics;

    /** List of included services for this service. */
    protected List<BluetoothGattService> mIncludedServices;

    /** Whether the service uuid should be advertised. */
    private boolean mAdvertisePreferred;

    /**
     * Create a new BluetoothGattService.
     *
     * @param uuid The UUID for this service
     * @param serviceType The type of this service, {@link
     *     BluetoothGattService#SERVICE_TYPE_PRIMARY} or {@link
     *     BluetoothGattService#SERVICE_TYPE_SECONDARY}
     */
    public BluetoothGattService(UUID uuid, int serviceType) {
        mDevice = null;
        mUuid = uuid;
        mInstanceId = 0;
        mServiceType = serviceType;
        mCharacteristics = new ArrayList<BluetoothGattCharacteristic>();
        mIncludedServices = new ArrayList<BluetoothGattService>();
    }

    /**
     * Create a new BluetoothGattService
     *
     * @hide
     */
    /*package*/ BluetoothGattService(
            BluetoothDevice device, UUID uuid, int instanceId, int serviceType) {
        mDevice = device;
        mUuid = uuid;
        mInstanceId = instanceId;
        mServiceType = serviceType;
        mCharacteristics = new ArrayList<BluetoothGattCharacteristic>();
        mIncludedServices = new ArrayList<BluetoothGattService>();
    }

    /**
     * Create a new BluetoothGattService
     *
     * @hide
     */
    public BluetoothGattService(UUID uuid, int instanceId, int serviceType) {
        mDevice = null;
        mUuid = uuid;
        mInstanceId = instanceId;
        mServiceType = serviceType;
        mCharacteristics = new ArrayList<BluetoothGattCharacteristic>();
        mIncludedServices = new ArrayList<BluetoothGattService>();
    }

    /** @hide */
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel out, int flags) {
        out.writeParcelable(new ParcelUuid(mUuid), 0);
        out.writeInt(mInstanceId);
        out.writeInt(mServiceType);
        out.writeTypedList(mCharacteristics);

        ArrayList<BluetoothGattIncludedService> includedServices =
                new ArrayList<BluetoothGattIncludedService>(mIncludedServices.size());
        for (BluetoothGattService s : mIncludedServices) {
            includedServices.add(
                    new BluetoothGattIncludedService(s.getUuid(), s.getInstanceId(), s.getType()));
        }
        out.writeTypedList(includedServices);
    }

    public static final @NonNull Creator<BluetoothGattService> CREATOR =
            new Creator<>() {
                public BluetoothGattService createFromParcel(Parcel in) {
                    return new BluetoothGattService(in);
                }

                public BluetoothGattService[] newArray(int size) {
                    return new BluetoothGattService[size];
                }
            };

    private BluetoothGattService(Parcel in) {
        mUuid = ((ParcelUuid) in.readParcelable(null)).getUuid();
        mInstanceId = in.readInt();
        mServiceType = in.readInt();

        mCharacteristics = new ArrayList<BluetoothGattCharacteristic>();

        ArrayList<BluetoothGattCharacteristic> chrcs =
                in.createTypedArrayList(BluetoothGattCharacteristic.CREATOR);
        if (chrcs != null) {
            for (BluetoothGattCharacteristic chrc : chrcs) {
                chrc.setService(this);
                mCharacteristics.add(chrc);
            }
        }

        mIncludedServices = new ArrayList<BluetoothGattService>();

        ArrayList<BluetoothGattIncludedService> inclSvcs =
                in.createTypedArrayList(BluetoothGattIncludedService.CREATOR);
        if (chrcs != null) {
            for (BluetoothGattIncludedService isvc : inclSvcs) {
                mIncludedServices.add(
                        new BluetoothGattService(
                                null, isvc.getUuid(), isvc.getInstanceId(), isvc.getType()));
            }
        }
    }

    /**
     * Returns the device associated with this service.
     *
     * @hide
     */
    /*package*/ BluetoothDevice getDevice() {
        return mDevice;
    }

    /**
     * Returns the device associated with this service.
     *
     * @hide
     */
    /*package*/ void setDevice(BluetoothDevice device) {
        mDevice = device;
    }

    /**
     * Add an included service to this service.
     *
     * @param service The service to be added
     * @return true, if the included service was added to the service
     */
    @RequiresLegacyBluetoothPermission
    public boolean addService(BluetoothGattService service) {
        mIncludedServices.add(service);
        return true;
    }

    /**
     * Add a characteristic to this service.
     *
     * @param characteristic The characteristics to be added
     * @return true, if the characteristic was added to the service
     */
    @RequiresLegacyBluetoothPermission
    public boolean addCharacteristic(BluetoothGattCharacteristic characteristic) {
        mCharacteristics.add(characteristic);
        characteristic.setService(this);
        return true;
    }

    /**
     * Get characteristic by UUID and instanceId.
     *
     * @hide
     */
    /*package*/ BluetoothGattCharacteristic getCharacteristic(UUID uuid, int instanceId) {
        for (BluetoothGattCharacteristic characteristic : mCharacteristics) {
            if (uuid.equals(characteristic.getUuid())
                    && characteristic.getInstanceId() == instanceId) {
                return characteristic;
            }
        }
        return null;
    }

    /**
     * Force the instance ID.
     *
     * @hide
     */
    @UnsupportedAppUsage
    public void setInstanceId(int instanceId) {
        mInstanceId = instanceId;
    }

    /**
     * Get the handle count override (conformance testing.
     *
     * @hide
     */
    /*package*/ int getHandles() {
        return mHandles;
    }

    /**
     * Force the number of handles to reserve for this service. This is needed for conformance
     * testing only.
     *
     * @hide
     */
    public void setHandles(int handles) {
        mHandles = handles;
    }

    /**
     * Add an included service to the internal map.
     *
     * @hide
     */
    public void addIncludedService(BluetoothGattService includedService) {
        mIncludedServices.add(includedService);
    }

    /**
     * Returns the UUID of this service
     *
     * @return UUID of this service
     */
    public UUID getUuid() {
        return mUuid;
    }

    /**
     * Returns the instance ID for this service
     *
     * <p>If a remote device offers multiple services with the same UUID (ex. multiple battery
     * services for different batteries), the instance ID is used to distuinguish services.
     *
     * @return Instance ID of this service
     */
    public int getInstanceId() {
        return mInstanceId;
    }

    /** Get the type of this service (primary/secondary) */
    public int getType() {
        return mServiceType;
    }

    /**
     * Get the list of included GATT services for this service.
     *
     * @return List of included services or empty list if no included services were discovered.
     */
    public List<BluetoothGattService> getIncludedServices() {
        return mIncludedServices;
    }

    /**
     * Returns a list of characteristics included in this service.
     *
     * @return Characteristics included in this service
     */
    public List<BluetoothGattCharacteristic> getCharacteristics() {
        return mCharacteristics;
    }

    /**
     * Returns a characteristic with a given UUID out of the list of characteristics offered by this
     * service.
     *
     * <p>This is a convenience function to allow access to a given characteristic without
     * enumerating over the list returned by {@link #getCharacteristics} manually.
     *
     * <p>If a remote service offers multiple characteristics with the same UUID, the first instance
     * of a characteristic with the given UUID is returned.
     *
     * @return GATT characteristic object or null if no characteristic with the given UUID was
     *     found.
     */
    public BluetoothGattCharacteristic getCharacteristic(UUID uuid) {
        for (BluetoothGattCharacteristic characteristic : mCharacteristics) {
            if (uuid.equals(characteristic.getUuid())) {
                return characteristic;
            }
        }
        return null;
    }

    /**
     * Returns whether the uuid of the service should be advertised.
     *
     * @hide
     */
    public boolean isAdvertisePreferred() {
        return mAdvertisePreferred;
    }

    /**
     * Set whether the service uuid should be advertised.
     *
     * @hide
     */
    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
    public void setAdvertisePreferred(boolean advertisePreferred) {
        mAdvertisePreferred = advertisePreferred;
    }
}