android-35/android/nfc/NfcManager.java

/*
 * Copyright (C) 2010 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.nfc;

import android.annotation.SystemService;
import android.compat.annotation.UnsupportedAppUsage;
import android.content.Context;
import android.os.Build;

/**
 * High level manager used to obtain an instance of an {@link NfcAdapter}.
 * <p>
 * Use {@link android.content.Context#getSystemService(java.lang.String)}
 * with {@link Context#NFC_SERVICE} to create an {@link NfcManager},
 * then call {@link #getDefaultAdapter} to obtain the {@link NfcAdapter}.
 * <p>
 * Alternately, you can just call the static helper
 * {@link NfcAdapter#getDefaultAdapter(android.content.Context)}.
 *
 * <div class="special reference">
 * <h3>Developer Guides</h3>
 * <p>For more information about using NFC, read the
 * <a href="{@docRoot}guide/topics/nfc/index.html">Near Field Communication</a> developer guide.</p>
 * </div>
 *
 * @see NfcAdapter#getDefaultAdapter(android.content.Context)
 */
@SystemService(Context.NFC_SERVICE)
public final class NfcManager {
    private final NfcAdapter mAdapter;

    /**
     * @hide
     */
    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
    public NfcManager(Context context) {
        NfcAdapter adapter;
        context = context.getApplicationContext();
        if (context == null) {
            throw new IllegalArgumentException(
                    "context not associated with any application (using a mock context?)");
        }
        try {
            adapter = NfcAdapter.getNfcAdapter(context);
        } catch (UnsupportedOperationException e) {
            adapter = null;
        }
        mAdapter = adapter;
    }

    /**
     * Get the default NFC Adapter for this device.
     *
     * @return the default NFC Adapter
     */
    public NfcAdapter getDefaultAdapter() {
        return mAdapter;
    }
}