Signing and publishing your app on Google play

In this post I will explain how to self sign your application and how to publish it on Google Play store.

First you must signup for a developers account here .It is a fee of $25 that you pay only once and your account will exist as long as it is not closed i.e for a lifetime. After you finish registration, you will be redirected to a screen for uploading new application. But before you upload your app you must be sure that it is signed and zip aligned apk package.

Using Eclipse it is very easy to sign and zip align your application. There are two types of signing: debug and release.

Debug signing:

When installing Android plugin for eclipse, one debug keystore (debug.keystore) is generated for you and it is located in Users/username/.android folder on Windows. You cannot run your apps even on AVD unless they are signed. But since there is debug keystore trough eclipse, you can test your apps without problems. Note that you can use keytool in java sdk bin folder to generate key for you manually.

Release signing:

About release signing you can again use Eclipse to generate new keystore and your key with your password and therefore sign you application for publishing. Just follow the instructions in Eclipse after clicking right click on the app project node in Package explorer and then selectiong Export menu item. In the next window select Android -> Export Android application.
Once you have signed your app it is ready for publishing.

Publishing your application

Go to this page for publishing. Click add new application to create your Google play application. Choose language and call it MyTestApp. Press upload APK. Give the new app a description, add two bigger images for the specific device that you plan your app to work on and also don't forget app icon 512x512 size. Choose App type, Category and Content rating. Add your website and email and click save. You are one step closer to publishing. Now on the left menu click Pricing and Distribution.

Select all countries and choose below options as you like. I choosed only the last two. Click save.

Now go up and on the right click publish button. You are done, now several hours are necesary before your app becomes available on Google Play.

Cheers :)))

First Android Application

In this short tutorial I will show you how to convert the screen of your Nexus 7 into checker board.

I assume you have installed java 1.6 or 1.7, Eclipse classic (Juno) with plugin for Android and these Android packages: Android 4.2.2, 4.0.3 and 2.3.3 with SDK, Documentation, Google APIs, ARM EABI, Samples for SDK and Tools all 3 packages.

First create Android application in Eclipse and call it CheckerBoardApp. Leave everything default except when creating the project set Theme to none. You can also rename the java package from example to... lets say CheckerBoardPkg or you can leave it default.For publishing your app on Google Play you must change the package name to something different than example because it will not be accepted

Once you have the new application generated add new java class in the main src folder and call it CheckerBoard.

Add this code in it and save:

package com.checkerboardpkg.checkerboardapp;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.View;

public class CheckerBoard extends View {

    private final int TILE_WIDTH_HEIGHT = 160;
    private Paint currentPaint = null;
   
    public CheckerBoard(Context context) {
        super(context);
        currentPaint = new Paint();
        setFocusable(true);

    }

    @Override
    protected void onDraw(Canvas canvas) {

        canvas.drawColor(Color.BLACK);

        int currentColor = 0;
       
        for (int i = 0; i < 8; i += 1) {
            for (int j = 0; j < 5; j += 1) {
               
                // set up color and Paint object
                if ((i + j) % 2 == 0) {
                    currentColor = Color.WHITE;
                } else {
                    currentColor = Color.BLACK;
                }
                currentPaint.setAntiAlias(true);
                currentPaint.setColor(currentColor);
               
                // draw rectangles to form checker board
                canvas.drawRect(j * this.TILE_WIDTH_HEIGHT, i
                        * this.TILE_WIDTH_HEIGHT, (j + 1)
                        * this.TILE_WIDTH_HEIGHT, (i + 1)
                        * this.TILE_WIDTH_HEIGHT, currentPaint);
            }
        }
    }
}


Basically what we do here is we create 8 rows and 5 columns of rectangles into the Canvas. We check the counters i and j if their sum is even or odd number and we change the color to white and than black appropriatelly. Each rectangle is 160x160 pixels so we get exactly 800x1280 screen which is the exact size of Nexus 7 screen resolution.


Now you must set the content of main acitivity to be the CheckerBoard view. We do that by adding this line

setContentView(new CheckerBoard(this));

as last statement in

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setContentView(new CheckerBoard(this));
    }

function in MainActivity.java class.

Now the code is ready but to see it in action you must create Android Virtual Machine to run it on.
In Eclipse press Window -> Android Virtual Device Manager and that click New. Name it Nexus7AVD, Device: Nexus 7, target: Android 4.2.2, and set RAM to 512. It is 1024 by default but it may not start up if on Windows with low memory. Set SD card to 100 MB. Click OK.

Then press start and then launch. Wait some time while the AVD is not started. After you see the batery icon on top, your AVD is ready to run so go to Eclipse and right click on the project node in package explorer and click Run as -> Android Application.

Here is what you should see:

 

Mine app was called TileGame, but you should see CheckerBoardApp instead