ActivityFirstRunHelper.java

package com.atomicrobot.app;

import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;

public class ActivityFirstRunHelper {
    private static final String PREFERENCES_NAME_FIRST_RUN = "first_run";

    private static final String PREFERENCES_KEY_FIRST_RUN_BOOL = "first_run";

    private static final String PREFERENCES_NAME_VERSION = "version";

    private static final String PREFERENCES_KEY_LAST_VERSION_CODE_INT = "last_version_code";

    public static interface FirstRunBehavior {
        public void onFirstRun(Activity activity);

        public void onAfterFirstRun(Activity activity);
    }

    public static interface VersionChangedBehavior {
        public void onVersionChanged(int oldVersion, int newVersion);

        public void onVersionUnchanged();

        public void onNewInstall();
    }

    public static void handleFirstRunIfNeeded(Activity activity, FirstRunBehavior responder) {
        SharedPreferences preferences = activity.getSharedPreferences(PREFERENCES_NAME_FIRST_RUN, Context.MODE_PRIVATE);
        boolean isFirstRun = preferences.getBoolean(PREFERENCES_KEY_FIRST_RUN_BOOL, true);
        if (isFirstRun) {
            responder.onFirstRun(activity);
            preferences.edit().putBoolean(PREFERENCES_KEY_FIRST_RUN_BOOL, false).commit();
        } else {
            responder.onAfterFirstRun(activity);
        }
    }

    public static void handleVersionChanged(Activity activity, VersionChangedBehavior responder) {
        SharedPreferences preferences = activity.getSharedPreferences(PREFERENCES_NAME_VERSION, Context.MODE_PRIVATE);
        int lastVersionCode = preferences.getInt(PREFERENCES_KEY_LAST_VERSION_CODE_INT, -1);
        if (lastVersionCode == -1) {
            responder.onNewInstall();
        }

        String packageName = activity.getPackageName();
        PackageManager packageManager = activity.getPackageManager();
        int thisVersionCode = -1;
        try {
            PackageInfo packageInfo = packageManager.getPackageInfo(packageName, 0);
            thisVersionCode = packageInfo.versionCode;
        } catch (NameNotFoundException ex) {
            // This should never happen...
        }

        if (lastVersionCode != thisVersionCode) {
            responder.onVersionChanged(lastVersionCode, thisVersionCode);
            preferences.edit().putInt(PREFERENCES_KEY_LAST_VERSION_CODE_INT, thisVersionCode).commit();
        } else {
            responder.onVersionUnchanged();
        }
    }
}