Android example source code file (Eula.java)

This example Android source code file (Eula.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, app, application, bufferedreader, charsequence, content, inputstreamreader, io, ioexception, preference_eula_accepted, preferences_eula, sharedpreferences, string, stringbuilder

The Eula.java Android example source code

/*
 * Copyright (C) 2008 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.google.android.photostream;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.SharedPreferences;

import java.io.IOException;
import java.io.BufferedReader;
import java.io.Closeable;
import java.io.InputStreamReader;

/**
 * Displays an EULA ("End User License Agreement") that the user has to accept before
 * using the application. Your application should call {@link Eula#showEula(android.app.Activity)}
 * in the onCreate() method of the first activity. If the user accepts the EULA, it will never
 * be shown again. If the user refuses, {@link android.app.Activity#finish()} is invoked
 * on your activity.
 */
class Eula {
    private static final String PREFERENCE_EULA_ACCEPTED = "eula.accepted";
    private static final String PREFERENCES_EULA = "eula";

    /**
     * Displays the EULA if necessary. This method should be called from the onCreate()
     * method of your main Activity.
     *
     * @param activity The Activity to finish if the user rejects the EULA.
     */
    static void showEula(final Activity activity) {
        final SharedPreferences preferences = activity.getSharedPreferences(PREFERENCES_EULA,
                Activity.MODE_PRIVATE);
        if (!preferences.getBoolean(PREFERENCE_EULA_ACCEPTED, false)) {
            final AlertDialog.Builder builder = new AlertDialog.Builder(activity);
            builder.setTitle(R.string.eula_title);
            builder.setCancelable(true);
            builder.setPositiveButton(R.string.eula_accept, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    accept(preferences);
                }
            });
            builder.setNegativeButton(R.string.eula_refuse, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    refuse(activity);
                }
            });
            builder.setOnCancelListener(new DialogInterface.OnCancelListener() {
                public void onCancel(DialogInterface dialog) {
                    refuse(activity);
                }
            });
            // UNCOMMENT TO ENABLE EULA
            //builder.setMessage(readFile(activity, R.raw.eula));
            builder.create().show();
        }
    }

    private static void accept(SharedPreferences preferences) {
        preferences.edit().putBoolean(PREFERENCE_EULA_ACCEPTED, true).commit();
    }

    private static void refuse(Activity activity) {
        activity.finish();
    }

    static void showDisclaimer(Activity activity) {
        final AlertDialog.Builder builder = new AlertDialog.Builder(activity);
        builder.setMessage(readFile(activity, R.raw.disclaimer));
        builder.setCancelable(true);
        builder.setTitle(R.string.disclaimer_title);
        builder.setPositiveButton(R.string.disclaimer_accept, null);
        builder.create().show();
    }

    private static CharSequence readFile(Activity activity, int id) {
        BufferedReader in = null;
        try {
            in = new BufferedReader(new InputStreamReader(
                    activity.getResources().openRawResource(id)));
            String line;
            StringBuilder buffer = new StringBuilder();
            while ((line = in.readLine()) != null) buffer.append(line).append('\n');
            return buffer;
        } catch (IOException e) {
            return "";
        } finally {
            closeStream(in);
        }
    }

    /**
     * Closes the specified stream.
     *
     * @param stream The stream to close.
     */
    private static void closeStream(Closeable stream) {
        if (stream != null) {
            try {
                stream.close();
            } catch (IOException e) {
                // Ignore
            }
        }
    }
}