Android example source code file (TagViewer.java)

This example Android source code file (TagViewer.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

activity, android, layoutinflater, linearlayout, list, ndefmessage, ndefrecord, os, override, parcelable, parsedndefrecord, string, tagviewer, textview, ui, unknown, util, view, viewtag, widget

The TagViewer.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;

import android.app.Activity;
import android.content.Intent;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.os.Bundle;
import android.os.Parcelable;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.WindowManager;
import android.widget.LinearLayout;
import android.widget.TextView;

import com.example.android.nfc.record.ParsedNdefRecord;

import java.util.List;

/**
 * An {@link Activity} which handles a broadcast of a new tag that the device
 * just discovered.
 */
public class TagViewer extends Activity {

    static final String TAG = "ViewTag";

    /**
     * This activity will finish itself in this amount of time if the user
     * doesn't do anything.
     */
    static final int ACTIVITY_TIMEOUT_MS = 1 * 1000;

    TextView mTitle;

    LinearLayout mTagContent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.tag_viewer);
        mTagContent = (LinearLayout) findViewById(R.id.list);
        mTitle = (TextView) findViewById(R.id.title);
        resolveIntent(getIntent());
    }

    void resolveIntent(Intent intent) {
        // Parse the intent
        String action = intent.getAction();
        if (NfcAdapter.ACTION_TAG_DISCOVERED.equals(action)) {
            // When a tag is discovered we send it to the service to be save. We
            // include a PendingIntent for the service to call back onto. This
            // will cause this activity to be restarted with onNewIntent(). At
            // that time we read it from the database and view it.
            Parcelable[] rawMsgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
            NdefMessage[] msgs;
            if (rawMsgs != null) {
                msgs = new NdefMessage[rawMsgs.length];
                for (int i = 0; i < rawMsgs.length; i++) {
                    msgs[i] = (NdefMessage) rawMsgs[i];
                }
            } else {
                // Unknown tag type
                byte[] empty = new byte[] {};
                NdefRecord record = new NdefRecord(NdefRecord.TNF_UNKNOWN, empty, empty, empty);
                NdefMessage msg = new NdefMessage(new NdefRecord[] {record});
                msgs = new NdefMessage[] {msg};
            }
            // Setup the views
            setTitle(R.string.title_scanned_tag);
            buildTagViews(msgs);
        } else {
            Log.e(TAG, "Unknown intent " + intent);
            finish();
            return;
        }
    }

    void buildTagViews(NdefMessage[] msgs) {
        if (msgs == null || msgs.length == 0) {
            return;
        }
        LayoutInflater inflater = LayoutInflater.from(this);
        LinearLayout content = mTagContent;
        // Clear out any old views in the content area, for example if you scan
        // two tags in a row.
        content.removeAllViews();
        // Parse the first message in the list
        // Build views for all of the sub records
        List<ParsedNdefRecord> records = NdefMessageParser.parse(msgs[0]);
        final int size = records.size();
        for (int i = 0; i < size; i++) {
            ParsedNdefRecord record = records.get(i);
            content.addView(record.getView(this, inflater, content, i));
            inflater.inflate(R.layout.tag_divider, content, true);
        }
    }

    @Override
    public void onNewIntent(Intent intent) {
        setIntent(intent);
        resolveIntent(intent);
    }

    @Override
    public void setTitle(CharSequence title) {
        mTitle.setText(title);
    }
}