Inspiration: 50 Android games in one video..

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- homerunbattle 3d
- speed forge 3d
- radiant
- flight director
- Zen Table Tennis
- tank ace 1944
- sky force
- Shoot U!
- Armageddon Squadron
- Light Racer 3D
- gang wars
- Wave Blazer
- death ride
- head to head racing
- avatar
- Farm Frenzy
- light racer
- Family Guy Uncensored
- super boom boom
- toonwarz
- air hockey
- meteor
- what the doodle!?
- Raging Thunder
- the settlers
- lightup
- the game of life
- military madness
- bebbled
- jump santa jump
- diner dash
- brain challenge
- assassins creed
- space physics
- million dollar poker
- derek jeter 2009
- armored strike
- robo defense
- guitar hero
- air attack
- wpt texas hold'em
- de Blob
- papastacker
- spades
- spore
- tennis slam
- Iron Sight
- TETRIS
- tower bloxx
- mechanics touch
- TightRope Hero
- flying aces

Game Developers Conference 2010 organizers have announced that they are working together with Google "to celebrate and inspire the mobile and independent game development communities" by offering free Nexus One and Verizon Droid by Motorola phones to select attendees.

The newly announced offer, part of Google's outreach into the mobile phone space as it expands use of its Android operating system, is open to qualifying developers who register to attend GDC 2010 by February 4th, 2010.

The Game Developers Conference, as the world’s largest professional-only game developer event, has been at the center of the industry’s discussions on these topics.

It serves as home to major Summits such as the GDC Mobile/Handheld Summit and the Independent Games Summit, as well as the IGF Mobile competition to award handheld game innovation.

In recent years, the smartphone has become one of the most widespread and widely-used game platforms, and has proven particularly suited to independent developers experimenting with new and unusual gameplay.

As an official statement on the tie-in notes: "This makes conference attendees great potential developers of new content for phones using the Android operating system." Alongside the announcement, Google's Eric Chu has posted about Android's GDC 2010 presence on the official Android Developers weblog.

"At the GDC, we are constantly looking for ways to help the game development community learn and thrive. The mobile and independent game spaces having been providing so many of those opportunities for years now," said Meggan Scavio, event director of the Game Developers Conference. "We are so appreciative that we can better reach those goals by actually putting a new opportunity – Android-powered devices – into the hands of our attendees."

Early Bird rates for GDC 2010 end February 4. For more information about the 2010 Game Developers Conference, including the eight summits and the Android phone promotion, please visit the official Game Developers Conference website.

Creating multiple sqlite database tables in Android

Most of the Android database examples you will find on the web will usually contain only one table to demonstrate the basic database concepts.

That's great, the only problem with this is that most non-trivial database implementations will contain more than one table.

The standard database creation string for a single table will probably look a lot like the below:


private static final String CREATE_TABLE_1 =
" create table " + table1 +
" (_id integer primary key autoincrement," +
" title text not null, body text not null);";

Which is called in your DB Adapter class like this:


@Override
public void onCreate(SQLiteDatabase db) {

db.execSQL(CREATE_TABLE_1);
}

So what to do if you want to create more than one table?
You may do the below.. but will it work?
Note that this is one big string containing three separate create statements...


private static final String DATABASE_CREATE_MULTIPLE_TABLES =
" create table " + ITEMS_TABLE +
" (_id integer primary key autoincrement," +
" title text not null)" +

" create table " + TAGS_TABLE +
" (_id integer primary key autoincrement," +
" tagName text not null)" +

" create table " + LOCATIONS_TABLE +
" (_id integer primary key autoincrement," +
" locationName text not null, gpsCoOrds text);"
;

And then you try calling them in your DB Adapter class like so:


@Override
public void onCreate(SQLiteDatabase db) {

db.execSQL(DATABASE_CREATE_MULTIPLE_TABLES);
}

So you're trying to create the three tables in one call to db.execSQL.


This appears to compile and run successfully, you can even read and write to the FIRST table that is created, but..

..when you try to read or write to any other table you will see the dreaded

'Sorry! The application Kdkddfblah (process test.Kdkddfblah) has stopped unexpectedly. Please try again'

..error message.

Uh-oh.

If you debug your application, you might see references to syntax errors 'near create', and possible a reference that the table doesn't exist.

Hmm... What went wrong?

The answer is that sqlite, and therefore the db.exec method, only lets you execute one sql command at a time. We were trying to run three sql statements in one go in db.execSQL(DATABASE_CREATE_MULTIPLE_TABLES);.

So what you need to do to fix this is move each of the above table create statements into their own strings, like this (Note that this now creates three seperate strings, unlike above):


private static final String CREATE_TABLE_1 =
" create table " + table1 +
" (_id integer primary key autoincrement," +
" title text not null, body text not null);";

private static final String CREATE_TABLE_2 =
" create table " + TAGS_TABLE +
" (_id integer primary key autoincrement," +
" tagName text not null)";

private static final String CREATE_TABLE_3 =
" create table " + LOCATIONS_TABLE +
" (_id integer primary key autoincrement," +
" locationName text not null, gpsCoOrds text);";

.. and then use these strings in your onCreate method like below, this then works.


@Override
public void onCreate(SQLiteDatabase db) {

db.execSQL(CREATE_TABLE_1);
db.execSQL(CREATE_TABLE_2);
db.execSQL(CREATE_TABLE_3);
}

If you find this doesn't work for you, try dropping all the tables in your database and try again, or give the database a different name, or different version number. The SQLiteOpenHelper seems to have some troubles registering that the database is to be changed. It finds a db with the same name and version number, goes 'meh' and doesn't look to see if the structure is different at all.

You can also pull the sqlite db file right off your device (or emulator) by going into the DDMS perspective in Eclipse (Window menu\ Open perspective \ Other \ DDMS), navigating to the database file which will probably be at \data\data\*Your Application Name*\databases.

There's a 'pull file' button on the top left as seen highlighted below:



.. You can then open the DB in your favourite sqlite manager (I like Sqliteman) and play around. Can can also of course, push the file back to the device if you wish.

Psst..Remember that your layout files must have lowercase names..

Remember that your layout files must have lowercase names, or they won't show up in your autoComplete list of options after 'R.layout' in Eclipse when you try this :

setContentView(R.layout.test_db);


The file won't actually show up as having any errors in your package explorer (on the right by default in the IDE), but if you look down in the console (by default down the bottom), you'll see this:

Invalid file name: must contain only [a-z0-9_.]


You might see an error on your project name, but with all the folders and files it can be hard to track down the cause.

When you try to run your application you will see:

'Your project contains error(s) please fix them before running your application'


.. and it won't be happy until you delete the offending file, even if you're not actively referencing it in your code.



Hope that helps.. Happy coding!

Errors trying to run ADB (Android Debug Bridge)?

The Android Debug Bridge (adb) is a tool lets you manage the state of an emulator instance or Android-powered device.

I was trying to run it for the first time on my ubuntu 9.10 box and I kept getting this error:


desktop:~/dev/Android/android-sdk-linux/tools$ adb
No command 'adb' found, did you mean:
Command 'cdb' from package 'tinycdb' (main)
Command 'gdb' from package 'gdb' (main)
Command 'aub' from package 'aub' (universe)
Command 'dab' from package 'bsdgames' (universe)
Command 'mdb' from package 'mono-debugger' (universe)
Command 'arb' from package 'arb' (multiverse)
Command 'tdb' from package 'tads2-dev' (multiverse)
Command 'pdb' from package 'python' (main)
Command 'jdb' from package 'openjdk-6-jdk' (main)
Command 'jdb' from package 'sun-java6-jdk' (multiverse)
Command 'ab' from package 'apache2-utils' (main)
adb: command not found

What was I doing wrong?

A quick google search shows me the error of my ways.. I haven't added my Android SDK tools directory to my system path!


It should go something like this...

open a terminal window and type:

$ echo $PATH
---(should return the directories associated with $PATH)

$ export PATH=$PATH:/home/YOUR-USERNAME/sdk/tools
---(replace with path to your tools directory, you may need to add 'sudo' to the beginning of this cmd)
Update: later versions of the SDK have ADB moved to the platform-tools directory, so adjust the above accordingly.


$ echo $PATH
---(you should now see your tools directory added to the end of the $PATH variable)

$ adb devices
---(now adb should do something, if nothing else at least error, no devices)


And now I get:

List of devices attached
emulator-5554 device

Sweet Success!

p.s. Adding to the system path in Windows is along the lines of :

1. right-click '(My) Computer'
2. Select 'Properties'
3. Go to 'Advanced' or whatever tab you find 'Environment Variables'
4. Select 'Path' then 'Edit' and add your new path in.

Update: if you are using 64-bit linux you may need to also install the ia32-libs package like so:

sudo apt-get install ia32-libs





Including layouts: a working example

Here's a working example of including one layout inside another.

Let me know if you have any issues or questions.
This works with, and probably requires, a AVD version of 2.1 or thereabouts.



contents of droidTest1.java:

package androidforbeginners.droidTest1;

import android.app.Activity;
import android.os.Bundle;

public class droidTest1 extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}


contents of main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="combining layouts"
/>

<include android:id="@+id/cell1" layout="@layout/layout2" />
<include android:id="@+id/cell2" layout="@layout/layout3" />


</LinearLayout>



Contents of layout2.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="100px"
android:background="#0033cc"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="40px"
android:text="layout2"
/>
<CheckBox
android:layout_width="fill_parent"
android:layout_height="40px"
/>
</LinearLayout>


Contents of layout3.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="100px"
android:background="#0066cc"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="layout3"
/>
<CheckBox
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
</LinearLayout>


Output:



You could also include multiple occurrences of the one layout in your main.xml like this if you wanted:

contents of main.xml (revised):

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="combining layouts"
/>

<include android:id="@+id/cell1" layout="@layout/layout2" />
<include android:id="@+id/cell2" layout="@layout/layout2" />
<include android:id="@+id/cell3" layout="@layout/layout2" />
<include android:id="@+id/cell4" layout="@layout/layout2" />


</LinearLayout>


Although if you do this, I can't see a way to reference individual repeating items.

I think include is more including a single layout across multiple Activities.

Let me know in the comments if you know a way.

Till next time: Enjoy!