Palindraw

Palindraw is the third game I created for Android and released on Google Play. Palindraw™ is a challenging new type of line puzzle game. Complete each puzzle by twisting colorful lines from colored dots through the empty squares. As you draw a line in one direction, a second line will flow from the colored dot in the exact opposite direction. Colorful lines wrap around each other in a symmetric pattern. Colliding with an existing line will break it so be careful to keep an eye on the opposite end!

Android Development – Sudoku Forever

Sudoku Forever™ is a free Sudoku puzzle game available on Google Play. Sudoku Forever features a random puzzle generator that creates each new game on the fly. This allows for a virtually limitless number of fun and challenging Sudoku puzzles.

'eregi' is deprecated errors

The other weekend I was setting up Plogger for my daughter to share her photos. She’s been really getting in to photography and I think she’s really getting good at it. If you’re interested (and she starts uploading stuff and takes down the pics I posted) you can check it out here: lexie.fourthwoods.com
Anyway, apparently I’m running a newer PHP than Plogger was originally written for because I got a bunch of errors along the lines of:

Deprecated: Function eregi() is deprecated in blah....

It seems the whole class of functions have been deprecated in PHP 5.3.0. Fortunately there is an easy fix. For instance:

eregi("NIKON", $make)

should be changed to:

preg_match('/NIKON/i',$make)

Note the regular expression is wrapped in ‘/’ characters which denote the pattern to search. after the last ‘/’ is the ‘i’ modifier flag which indicates case insensitive which is what eregi does.
Other functions that can be replaced similarly are:

ereg()          // replace with preg_match()
ereg_replace()  // replace with preg_replace()
eregi()         // replace with preg_match() with the 'i'
                // modifier
eregi_replace() // replace with preg_replace() with the
                // 'i' modifier

‘eregi’ is deprecated errors

The other weekend I was setting up Plogger for my daughter to share her photos. She’s been really getting in to photography and I think she’s really getting good at it. If you’re interested (and she starts uploading stuff and takes down the pics I posted) you can check it out here: lexie.fourthwoods.com.


Anyway, apparently I’m running a newer PHP than Plogger was originally written for because I got a bunch of errors along the lines of:

Deprecated: Function eregi() is deprecated in blah....

It seems thewhole class of functions have been deprecated in PHP 5.3.0. Fortunately there is an easy fix. For instance:

eregi("NIKON", $make)

should be changed to:

preg_match('/NIKON/i', $make)

Note the regular expression is wrapped in ‘/’ characters which denote the pattern to search. after the last ‘/’ is the ‘i’ modifier flag which indicates case insensitive which is what eregi does.


Other functions that can be replaced similarly are:

ereg()          // replace with preg_match()
ereg_replace()  // replace with preg_replace()
eregi()         // replace with preg_match() with the 'i'
                // modifier
eregi_replace() // replace with preg_replace() with the
                // 'i' modifier

Sudoku Forever

I’ve taken the Sudoku JavaScript game I created and ported it to an app for Android. Sudoku Forever is based on the same Sudoku solver described in my JavaScript article but with a few more improvements and optimizations. It is very fast consistently generating a new board between 200 and 500 milliseconds.


Here’s a screenshot: Sudoku Forever Screenshot

Sudoku Forever also features the ability to save the current game state whenever you close the app as well as Save Game slots so you can save the current game and come back to it later.


Here’s the Home Page for Sudoku Forever.
And of course the link to it on Google Play.

Let me know what you think and be sure to leave a rating and feedback on Google Play!

Poor-man's promo check for Android apps.

When I first created Baby’s First Game for Android I gave away a free promotional version. This promotional version was basically to get feedback from people before the real release. I wanted the app to only work for a limited time after which it would disable itself. I suppose I could have just released the full version without any limitations but I didn’t know how well (or poorly as it turns out) my app would do or how a free version floating around would affect it. Plus I wanted to see how one might create a time limited app anyway.


I created a single method called doPromoCheck() that stores the current install date in the app settings and checks them on every start up. I also added a check to alert the user once a day that the application was a promotional version and would expire in x number of days. This message I wanted shown only once a day as to not annoy the users. Here’s the method with some static class variables for configuration:

...
private static final String PROMO_DATE = "promoDate";
private static final String PROMO_DISPLAYED = "promoDisplayed";
private static final long DAYS_MILLIS = 24 * 60 * 60 * 1000;
private static final long PROMO_DURATION = DAYS_MILLIS * 30; // 30 days

private void doPromoCheck() {
  SharedPreferences prefs = getPreferences(Context.MODE_PRIVATE);
  SharedPreferences.Editor editor = prefs.edit();
  long now = System.currentTimeMillis();
  long exp = prefs.getLong(PROMO_DATE, now + PROMO_DURATION);
  editor.putLong(PROMO_DATE, exp);

  // check if the promo period has ended
  if(now > exp) {
    AlertDialog alertDialog;
    String ok = getResources().getString(R.string.label_ok);
    alertDialog = new AlertDialog.Builder(this)
        .setCancelable(false)
        .setPositiveButton(ok, new DialogInterface.OnClickListener() {
          public void onClick(DialogInterface dialog, int id) {
            finish(); // stops the app as soon as the dialog is dismissed.
          }
        }).create();
    String title = "Promo Version";
    alertDialog.setTitle(title);
    String msg = "This promotional version has expired. Please purchase the official version from Google Play.";
    alertDialog.setMessage(msg);
    alertDialog.show();
  } else {
    long disp = prefs.getLong(PROMO_DISPLAYED, now);

    // only display the dialog if it's been one day since the last time it was displayed
    if(now >= disp) {
      // save the next display time for one day from now.
      editor.putLong(PROMO_DISPLAYED, now + DAYS_MILLIS);
      AlertDialog alertDialog;
      String ok = getResources().getString(R.string.label_ok);
      alertDialog = new AlertDialog.Builder(this)
          .setCancelable(false)
          .setPositiveButton(ok, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int id) {
              // do nothing
            }
      }).create();

      String title = "Promo Version";
      alertDialog.setTitle(title);
      long days = (exp - now) / DAYS_MILLIS;
      String msg = "This promotional version will expire in " + days + " days. Please consider purchasing the official version from Google Play.";
      alertDialog.setMessage(msg);
      alertDialog.show();
    }
  }

  editor.commit();
}


The first time this is run it calculates the expiration date and stores it in the private app settings. Each time it is run after, it pulls the expiration out of the app settings. To use this method in your app, put the call as the first thing in your main Activity onCreate() method:

   protected void onCreate(Bundle savedInstanceState) {
      doPromoCheck();
      ...
   }


That’s it. Your application will now only last for 30 days and will simply show the promotional period ended dialog after. Of course, the app can be uninstalled and reinstalled to reset the expiration but it’s annoying and probably not worth the hassle to most people.

undefined reference to IID_IPicture

I was writing a small test application to display some pictures and ran into a linker error complaining about an undefined reference to IID_IPicture. In COM, interfaces are identified by a globally unique identifier string. To get the linker to pick them up you need to link to uuid.lib.

Replace Non-Alphanumeric Characters in a C++ String

I needed to replace the non-alphanumeric characters in a std::string. While the Java String class has the replace() and replaceAll() methods for doing this, the std::string class has no such utility methods. Instead you can use the std::replace_if function from the Standard Template Library. Here’s some example code:

#include <iostream>
#include <string>
#include <algorithm>

int isNotAlphaNum(char c)
{
        return !std::isalnum(c);
}

int main(int argc, char* argv[])
{
        std::string s1 = "some/string/with*/nonalpha/characters+1";
        std::cout << s1 << " : ";
        std::replace_if(s1.begin(), s1.end(), isNotAlphaNum, ' ');
        std::cout << s1 << std::endl;
        return 0;
}

The third parameter of the replace_if() function is a pointer to a function that performs the desired check and returns either true or false if the input satisfies the condition. The last parameter is the character to replace the matched character, in this case a space. This program produces the following:

$ ./replace.exe
some/string/with*/nonalpha/characters+1
some string with  nonalpha characters 1

Convert C++ String to Lower Case (or Upper Case)

I don’t usually need to convert string case in C++ so when the need comes up I’ve usually forgotten how to do it and have to Google.

While the Java String class has toLowerCase() and toUpperCase(), C++ std::string does not have such a utility method. Instead, you need to use the std::transform() function. Here’s some example code:

#include <iostream>
#include <string>
#include <utility>

int main(int argc, char* argv[])
{
        std::string s1 = "lowertoupper";
        std::string s2 = "UPPERTOLOWER";
        std::cout << s1 << " : ";
        std::transform(s1.begin(), s1.end(), s1.begin(), ::toupper);
        std::cout << s1 << std::endl;
        std::cout << s2 << " : ";
        std::transform(s2.begin(), s2.end(), s2.begin(), ::tolower);
        std::cout << s2 << std::endl;
        return 0;
}

Produces the following:

$ ./case.exe
lowertoupper : LOWERTOUPPER
UPPERTOLOWER : uppertolower

Note that while the Java toUpperCase() and toLowerCase() methods do not modify the original string, the std::transform function does.

Baby’s First Game

I’ve just launched Baby’s First Game for Android on Google Play. This is a game designed specifically for infants, toddlers and preschool age children. They will have fun learning about colors, shapes, numbers and letters. The skill levels are very customizable and can grow with your child.

This game was inspired by Baby Smash by Scott Hanselman and watching the games my own kids were interested in. Three mini-games provide a fun way to get familiar with and learn to identify colors, shapes, numbers and letters.

Just for Baby is targeted specifically at infants and young toddlers. It teaches action/reaction while familiarizing baby with colors and shapes. When baby touches the screen, a happy shape appears.

Find It! tests your child’s ability to identify colors, shapes, letters and numbers by picking them out of a group.

Pop It! is a fun way to work on your child’s hand/eye coordination while “popping” shapes as they fly across the screen. Baby’s First Game is and always will be Ad free. Baby’s First Game for Android is available now on Google Play:

Get it on Google Play