Android example source code file (TextRecord.java)

This example Android source code file (TextRecord.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, app, application, illegalargumentexception, io, layoutinflater, parsedndefrecord, string, textrecord, textview, ui, unsupportedencodingexception, us-ascii, utf-16, utf-8, view, viewgroup

The TextRecord.java Android example source code

/*
 * 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.example.android.nfc.record;

import android.app.Activity;
import android.nfc.NdefRecord;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.google.common.base.Preconditions;

import com.example.android.nfc.R;

import java.io.UnsupportedEncodingException;
import java.util.Arrays;

/**
 * An NFC Text Record
 */
public class TextRecord implements ParsedNdefRecord {

    /** ISO/IANA language code */
    private final String mLanguageCode;

    private final String mText;

    private TextRecord(String languageCode, String text) {
        mLanguageCode = Preconditions.checkNotNull(languageCode);
        mText = Preconditions.checkNotNull(text);
    }

    public View getView(Activity activity, LayoutInflater inflater, ViewGroup parent, int offset) {
        TextView text = (TextView) inflater.inflate(R.layout.tag_text, parent, false);
        text.setText(mText);
        return text;
    }

    public String getText() {
        return mText;
    }

    /**
     * Returns the ISO/IANA language code associated with this text element.
     */
    public String getLanguageCode() {
        return mLanguageCode;
    }

    // TODO: deal with text fields which span multiple NdefRecords
    public static TextRecord parse(NdefRecord record) {
        Preconditions.checkArgument(record.getTnf() == NdefRecord.TNF_WELL_KNOWN);
        Preconditions.checkArgument(Arrays.equals(record.getType(), NdefRecord.RTD_TEXT));
        try {
            byte[] payload = record.getPayload();
            /*
             * payload[0] contains the "Status Byte Encodings" field, per the
             * NFC Forum "Text Record Type Definition" section 3.2.1.
             *
             * bit7 is the Text Encoding Field.
             *
             * if (Bit_7 == 0): The text is encoded in UTF-8 if (Bit_7 == 1):
             * The text is encoded in UTF16
             *
             * Bit_6 is reserved for future use and must be set to zero.
             *
             * Bits 5 to 0 are the length of the IANA language code.
             */
            String textEncoding = ((payload[0] & 0200) == 0) ? "UTF-8" : "UTF-16";
            int languageCodeLength = payload[0] & 0077;
            String languageCode = new String(payload, 1, languageCodeLength, "US-ASCII");
            String text =
                new String(payload, languageCodeLength + 1,
                    payload.length - languageCodeLength - 1, textEncoding);
            return new TextRecord(languageCode, text);
        } catch (UnsupportedEncodingException e) {
            // should never happen unless we get a malformed tag.
            throw new IllegalArgumentException(e);
        }
    }

    public static boolean isText(NdefRecord record) {
        try {
            parse(record);
            return true;
        } catch (IllegalArgumentException e) {
            return false;
        }
    }
}