Android adding EULA(END USER LICENSE AGREMENT)

Adding an EULA

it is often useful to have an End User License Agreement (EULA) display when a user first installs and runs an app. If the user does not accept it, the downloaded application does not run.After a user does accept it, the EULA is never shown again.

It uses SharedPreferences with the boolean PREFERENCE_EULA_ACCEPTED to determine whether the EULA was previously accepted or not accepted.

src/com/jitesh/eula/Eula.java


package com.jitesh.eula;





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.InputStreamReader;
import java.io.Closeable;


class Eula {
    private static final String ASSET_EULA = "EULA";
    private static final String PREFERENCE_EULA_ACCEPTED = "eula.accepted";
    private static final String PREFERENCES_EULA = "eula";

    /**
     * callback to let the activity know when the user has accepted the EULA.
     */
    static interface OnEulaAgreedTo {

        /**
         * Called when the user has accepted the eula and the dialog closes.
         */
        void onEulaAgreedTo();
    }

    /**
     * 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.
     * @return Whether the user has agreed already.
     */
    static boolean show(final Activity activity) {
   
        final SharedPreferences preferences = activity.getSharedPreferences(PREFERENCES_EULA,
                Activity.MODE_PRIVATE);
        //to test:  preferences.edit().putBoolean(PREFERENCE_EULA_ACCEPTED, false).commit();
        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);
                    if (activity instanceof OnEulaAgreedTo) {
                        ((OnEulaAgreedTo) activity).onEulaAgreedTo();
                    }
                }
            });
            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);
                }
            });
            builder.setMessage(readEula(activity));
            builder.create().show();
            return false;
        }
        return true;
    }

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

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

    private static CharSequence readEula(Activity activity) {
        BufferedReader in = null;
        try {
            in = new BufferedReader(new InputStreamReader(activity.getAssets().open(ASSET_EULA)));
            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
            }
        }
    }
}

The Eula class needs to be customized as follows:

1. The actual text of the EULA needs to be put in a text file called EULA (as specified by the ASSET_EULA variable ) and placed in the assets/ directory of the Android project.This is loaded by the readEula() method of the Eula class.

2. There are few strings that need to be specified for the Acceptance dialog box.These

can be collected in the string’s resource file.

the strings.xml res/values/strings.xml

<resources>

    <string name="app_name">EULA</string>

    <string name="hello_world">Hello world!</string>

    <string name="menu_settings">Settings</string>

    <string name="title_activity_my_app">MyApp</string>

    

    

    <string name="hello">Welcome to MyApp</string>

    

    <string name="eula_title">License Agreement</string>

    <string name="eula_accept">Accept</string> 

    <string name="eula_refuse">Don\'t Accept</string> 

    

</resources>

the main activity class is as follows 

package com.jitesh.eula;

import android.app.Activity;

import android.os.Bundle;

public class MyApp extends Activity {

    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        

        Eula.show(this);

    }

}