应用源码之Tag.zip

/* * 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 com.android.apps.tag.record; import com.android.apps.tag.R; import com.android.apps.tag.message.NdefMessageParser; 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 android.app.Activity; import android.content.Context; import android.nfc.FormatException; import android.nfc.NdefMessage; import android.nfc.NdefRecord; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.ViewGroup.LayoutParams; import android.widget.LinearLayout; import java.util.Arrays; import java.util.Locale; import java.util.NoSuchElementException; import javax.annotation.Nullable; /** * A representation of an NFC Forum "Smart Poster". */ public class SmartPoster extends 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 Icon record. A Smart Poster may include an icon by including one * or many MIME-typed image records within the Smart Poster. If the * device supports images, it SHOULD select and display one of these, * depending on the device capabilities. The device SHOULD display only * one. The Icon record is optional." */ private final ImageRecord mImageRecord; /** * 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; private SmartPoster(UriRecord uri, @Nullable TextRecord title, @Nullable ImageRecord image, RecommendedAction action, @Nullable String type) { mUriRecord = Preconditions.checkNotNull(uri); mTitleRecord = title; mImageRecord = image; 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); ImageRecord image = getFirstIfExists(records, ImageRecord.class); RecommendedAction action = parseRecommendedAction(recordsRaw); String type = parseType(recordsRaw); return new SmartPoster(uri, title, image, 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; } } @Override public View getView(Activity activity, LayoutInflater inflater, ViewGroup parent, int offset) { if (mTitleRecord != null) { // Build a container to hold the title and the URI LinearLayout container = new LinearLayout(activity); container.setOrientation(LinearLayout.VERTICAL); container.setLayoutParams(new LayoutParams( LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT)); container.addView(mTitleRecord.getView(activity, inflater, container, offset)); inflater.inflate(R.layout.tag_divider, container); container.addView(mUriRecord.getView(activity, inflater, container, offset)); return container; } else { // Just a URI, return a view for it directly return mUriRecord.getView(activity, inflater, parent, offset); } } @Override public String getSnippet(Context context, Locale locale) { if (mTitleRecord != null) { return mTitleRecord.getText(); } return mUriRecord.getPrettyUriString(context); } /** * 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; } private 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; }