Exploring the Tap Hypothesis with libGDX

The Tap Hypothesis

Mobile platform users want simple easy to play games that do not require large amounts of time.

Testing The Tap Hypothesis with libGDX

Due to the viral nature of Android games like Flappy Bird and Don't Tap The White Tile I set out to see why they are so well received and attempt to replicate their success. I know that this is not an easy task, but I thought at best  Fish Fry would be a viral success, at worst I got to play with libGDX and learn a few new tricks.

I looked at the popular games and came up with 3 common elements.

1. They all have a simple user interface, the user either taps or swipes the screen. Nothing complicated, just tap or swipe. 
2. They are easy to play and as the player's score goes up the difficulty increases.
3. One "round" of play is usually under five minutes.

So I attempted to replicate these elements in my game. Here is a quick demo:

To play the player simply waits for the clouds to flash then taps the screen. (Element number 1 check!)

Every 5 points the time from the flash to when the lightening strikes decreases by 25 milliseconds. (Two down one to go)

And last but not least each round of play is usually pretty short. 1 to 2 minutes max, I have trouble getting higher than 31 as a score.

Results?

I will have to get back to you, I just posted the game last night (8/1/2015), but if you have any comments on the testing hypothesis I would love to hear them!!

Update

As of 9/1/2015 I have had 28 downloads, with more than 50% retention. Still hoping it goes viral, but not yet.

Xamarin.Android Ways to Customize Dialogs

From generic Android to Custom

On the left is Standard Android, on the right is customized. Now I am aware that it is nothing special, however I hope that readers will find the properties they need to modify in order to customize their dialogs by reading this. It is a very simple push in the right direction. I, unfortunately, am no UI designer.

Standard Android Dialog Code

First is the layout. 

Below is my layout. There are extra bits here in the EditTexts, Buttons, and Slider. You can use any layout you wish to design for dialogs, below is only an example and will not compile if you try to copy this xml right into your project. I will show you how to customize the dialog appearance and location not the controls in the dialog. That will come in a later post.

Now the Code

This code should appear in the overridden OnCreateDialog(int id) method in the activity in which you wish to show the dialog. In my case the code was found in the Details Activity. In the code below there is a const int NewGame=1 that has been previously declared. Also you will need to override the OnCreateDialog method in your class. This method override is important and if you don't override it properly your dialog won't show. So line by line. case NewGame which is equal to 1 because I previously defined it as 1. You could simply use the integer 1 and not define an integer constant this just makes it more readable as to which dialog you are working with because you may show more than one in any given activity.

This code tells the system how to build your dialog. To show it you simply call ShowDialog(NewGame) if you are on the UI Thread or RunOnUiThread(()=>ShowDialog(NewGame)) if on a background thread. An example of how you might call Show Dialog is below.

Custom Dialog

In the example if I change the root element or the first linear layout to the following. You will need to know about .9.png(9 patch).There are online tools to create them. Here is another explanation. I am no expert. I found one and edited it with paint. It is shown below.

The legbg.9.png

 

Custom Code

(Scroll to see comments)

After calling the show dialog code you will now see the customized dialog.

Xamarin.Android- Lock Activity Page Orientation

Lock Screen Orientation

To lock the Orientation of an activity you simply add the ScreenOrientation attribute to the [Activity()] block in your activity. Also you need to add- using Android.Content.PM; Thats all, set the attribute to ScreenOrientation.Portrait or ScreenOrientation.Landscape.

I am not to keen and trying to guess where things should go so I add a complete activity definition below which gives the same answer as this stack overflow post.

Xamarin Android - Application Overview- Using the application class for global variables

Here I just wanted to give a very basic tutorial on how to make a global memory space for an android application so you don't have to constantly read from sharedpreferences or pass things back and forth between activities with bundles.

Create the application class

To start add a blank class to your project and name it whatever you want. I named mine ExampleApp. Then make it inherit the Application class by simply adding : Application. Then add the two methods show below. The code in the OnCreate method will be called before any code in the activity marked as MainLauncher.

Update AndroidManifest.xml

Once you have done that you will need to go to your AndroidManifest.xml and add the android:name to your application tag. make sure that the value of name matches the name of your class that inherited form application. So notice that the value for my android:name is ExampleApp and that is the name of my class that inherits from Application.

Putting it all together

To access (get or set) the public property myString in any other activity use the code below. Since we can get and set variables in the application class we can use this as a mens of passing values back and forth between activities. I am not saying this is the best way, you should be careful about how you use this, just showing another way to handle global variables using Xamarin.Android.

Xamarin.Android Custom View

Here is a simple outline for a custom view. I needed to create one for my own app and I didn't find all the info in one place. Hopefully this will help

The class definition

You must have at minimum the following in your class file. Then in the OnDraw method, tell it how to draw your view.

Adding your view to a layout

For the class attribute make sure that it is the namespace of the custom view in all lowercase. Then it is the class name of the custom view exactly as it is written in the class file. Example: As you can see below the class is "mynamespace.CustomView"

Events

You can wire up touch event listeners in the activity that shows the view with

Xamarin.Android Loading Images From the web

I recently decided to write an app and release it to the play store. The game is called Connect the Game and is available at connectthegame.com or from the play store. I decided I was going to allow login with facebook and give the ability to invite facebook friends. However there was no facebook development kit that had a friend picker that I could just plug in. So I went to my friend google and found this post on Xamarin's website which points you to MonoDroid.UrlImageViewHelper. I attempted to use the Monodroid ViewHelper but it was too slow when trying to load up 500 facebook friend thumbnails. So I started pulling apart the code to find the bottleneck and I came up with a slimmed down version and it is fast. So without further ado the code.

If you wish to see how well this works you can try try the app. Login with your facebook account and then select new game. From the popup dialog touch Invite with facebook and watch the images load.

This is used to load thumbnails asynchronously. If you don't want to loose quality then change the call

bit.Compress(Bitmap.CompressFormat.Jpeg, 70, mstream);

to whatever fits your needs.

Image Helper Class

Facebook Friend Object

This is an object I created, you can create your own or modify this to make the class more generic. I only needed it for Facebook hence the non generic object

Putting them together in a List Adapter

How to Capture Unhandled Exceptions using Xamarin Android and C#

I looked and looked for a good way to catch unhandled exceptions in my android app that I wrote using Xamarin for Visual Studio. I am not interested in sending them to a webserver at this time, I just want to catch them and log them. I came across this post and became discouraged,

http://mono-for-android.1047100.n5.nabble.com/Catch-all-the-exceptions-td5165993.html

However, this is a solution I came up with to capture unhandled exceptions using Xamarin Android and C# that works for me so I thought I would share it.

Implementing the application class allowed for a global unhandled exception catcher.

The full source is available at
https://github.com/Xandroid4Net/MyExamples/tree/master/UnhandledExceptionExample