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Smart Poster object for the NFC Reader Tutorial
/*
* Copyright (C) 2010 The Android Open Source Project
* Modified by Sylvain Saurel for a tutorial
*
* 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 com.ssaurel.nfcreader.record;
import android.app.Activity;
import android.nfc.FormatException;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.support.v4.content.ContextCompat;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.LinearLayout;
import com.google.common.base.Charsets;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import com.ssaurel.nfcreader.R;
import com.ssaurel.nfcreader.model.History;
import com.ssaurel.nfcreader.parser.NdefMessageParser;
import com.ssaurel.nfcreader.utils.Utils;
import java.util.Arrays;
import java.util.NoSuchElementException;
/**
* A representation of an NFC Forum "Smart Poster".
*/
public class SmartPoster implements ParsedNdefRecord {
/**
* NFC Forum Smart Poster Record Type Definition section 3.2.1.
*
* "The Title record for the service (there can be many of these in
* different languages, but a language MUST NOT be repeated). This record is
* optional."
*/
private final TextRecord mTitleRecord;
/**
* NFC Forum Smart Poster Record Type Definition section 3.2.1.
*
* "The URI record. This is the core of the Smart Poster, and all other
* records are just metadata about this record. There MUST be one URI record
* and there MUST NOT be more than one."
*/
private final UriRecord mUriRecord;
/**
* NFC Forum Smart Poster Record Type Definition section 3.2.1.
*
* "The Action record. This record describes how the service should be
* treated. For example, the action may indicate that the device should save
* the URI as a bookmark or open a browser. The Action record is optional.
* If it does not exist, the device may decide what to do with the service.
* If the action record exists, it should be treated as a strong suggestion;
* the UI designer may ignore it, but doing so will induce a different user
* experience from device to device."
*/
private final RecommendedAction mAction;
/**
* NFC Forum Smart Poster Record Type Definition section 3.2.1.
*
* "The Type record. If the URI references an external entity (e.g., via a
* URL), the Type record may be used to declare the MIME type of the entity.
* This can be used to tell the mobile device what kind of an object it can
* expect before it opens the connection. The Type record is optional."
*/
private final String mType;
public SmartPoster(UriRecord uri, TextRecord title, RecommendedAction action, String type) {
mUriRecord = Preconditions.checkNotNull(uri);
mTitleRecord = title;
mAction = Preconditions.checkNotNull(action);
mType = type;
}
public UriRecord getUriRecord() {
return mUriRecord;
}
/**
* Returns the title of the smart poster. This may be {@code null}.
*/
public TextRecord getTitle() {
return mTitleRecord;
}
public static SmartPoster parse(NdefRecord record) {
Preconditions.checkArgument(record.getTnf() == NdefRecord.TNF_WELL_KNOWN);
Preconditions.checkArgument(Arrays.equals(record.getType(), NdefRecord.RTD_SMART_POSTER));
try {
NdefMessage subRecords = new NdefMessage(record.getPayload());
return parse(subRecords.getRecords());
} catch (FormatException e) {
throw new IllegalArgumentException(e);
}
}
public static SmartPoster parse(NdefRecord[] recordsRaw) {
try {
Iterable<ParsedNdefRecord> records = NdefMessageParser.getRecords(recordsRaw);
UriRecord uri = Iterables.getOnlyElement(Iterables.filter(records, UriRecord.class));
TextRecord title = getFirstIfExists(records, TextRecord.class);
RecommendedAction action = parseRecommendedAction(recordsRaw);
String type = parseType(recordsRaw);
return new SmartPoster(uri, title, action, type);
} catch (NoSuchElementException e) {
throw new IllegalArgumentException(e);
}
}
public static boolean isPoster(NdefRecord record) {
try {
parse(record);
return true;
} catch (IllegalArgumentException e) {
return false;
}
}
public String str() {
if (mTitleRecord != null) {
return mTitleRecord.str() + "\n" + mUriRecord.str();
} else {
return mUriRecord.str();
}
}
/**
* Returns the first element of {@code elements} which is an instance of
* {@code type}, or {@code null} if no such element exists.
*/
private static <T> T getFirstIfExists(Iterable<?> elements, Class<T> type) {
Iterable<T> filtered = Iterables.filter(elements, type);
T instance = null;
if (!Iterables.isEmpty(filtered)) {
instance = Iterables.get(filtered, 0);
}
return instance;
}
public enum RecommendedAction {
UNKNOWN((byte) -1), DO_ACTION((byte) 0), SAVE_FOR_LATER((byte) 1), OPEN_FOR_EDITING(
(byte) 2);
private static final ImmutableMap<Byte, RecommendedAction> LOOKUP;
static {
ImmutableMap.Builder<Byte, RecommendedAction> builder = ImmutableMap.builder();
for (RecommendedAction action : RecommendedAction.values()) {
builder.put(action.getByte(), action);
}
LOOKUP = builder.build();
}
private final byte mAction;
private RecommendedAction(byte val) {
this.mAction = val;
}
private byte getByte() {
return mAction;
}
}
private static NdefRecord getByType(byte[] type, NdefRecord[] records) {
for (NdefRecord record : records) {
if (Arrays.equals(type, record.getType())) {
return record;
}
}
return null;
}
private static final byte[] ACTION_RECORD_TYPE = new byte[] {'a', 'c', 't'};
private static RecommendedAction parseRecommendedAction(NdefRecord[] records) {
NdefRecord record = getByType(ACTION_RECORD_TYPE, records);
if (record == null) {
return RecommendedAction.UNKNOWN;
}
byte action = record.getPayload()[0];
if (RecommendedAction.LOOKUP.containsKey(action)) {
return RecommendedAction.LOOKUP.get(action);
}
return RecommendedAction.UNKNOWN;
}
private static final byte[] TYPE_TYPE = new byte[] {'t'};
private static String parseType(NdefRecord[] records) {
NdefRecord type = getByType(TYPE_TYPE, records);
if (type == null) {
return null;
}
return new String(type.getPayload(), Charsets.UTF_8);
}
}
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