Eclipse - Editor hidden - Fix!

I hit a weird error today where in Eclipse I couldn't seem to open any files - the editor seemed to be minimized somehow! Even restarting eclipse didn't fix it. After a bit of playing about - I've got a solution I thought I would share.

1. Go to Window -> New Window. This will open a second instance of Eclipse. 
2. Notice you can now open files again. But you aren't done - you need Eclipse to remember this setting.
3. Close the old window (the one you couldn't open files with) first.
4. Now close the new window (the one you can open files with). This will persist your new setting (where you want  to be able to open files!). 
5. Open Eclipse - you should be back in business. 

Hope this helps someone :-)

AVD Manager - Unable to find a 'userdata.img' file for ABI armeabi to copy into the AVD folder

When trying to create a new Android 4.0.3 virtual device I hit this problem for ages. When I clicked Create AVD it was just doing nothing:

On further investigation I noticed that eclipse was saying the following:

"Unable to find a 'userdata.img' file for ABI armeabi to copy into the AVD folder."

In order to fix this problem, in Eclipse choose Window -> Android SDK Manager

Once this loads, you need to ensure that you have installed ARM EABI v7a System Image under Android 4.0.3 (API15). 

Once this is installed, try to create the AVD again and it should just work. It would have been much better if the "Create AVD" button did something instead of just failing silently! Hope this helps you out.

Set JAVA_HOME in Windows 7

A common hassle whenever you get a new laptop or PC is setting up the java environment variables so that when you install Eclipse or Netbeans you are ready to go. For your, and my own future reference, this is how it is done (on Windows 7 at least).

1. Find out where you have installed the JDK, or install it from here:

e.g. C:\Program Files\Java\jdk1.7.0_04

2. Press the Windows button and type in "Environment Variables" and press enter.

This will open the following window:

3. Under System Variables, click "New..." and enter JAVA_HOME for the variable name, and the path to your jdk for your variable value:

4. Press OK.

5. Select the variable "Path" and choose to Edit this, and add the following at the end of the string:

%JAVA_HOME%\bin; 

6. Press OK, and then OK to the main dialog. You will now have your Java environment variables set up correctly.

That should be it - if I've missed anything out or you have any problems let me know!

Android - Could not find HelloWorld.apk! - fix

So my first experience of Android development left me frustrated after getting an error trying to launch the  simple Hello World example!

Simple fix - basically when I set up eclipse I forgot to set the JAVA_HOME path variable.

The symptoms are this in the console:

[2011-12-12 22:37:05 - RoryHelloWorld] Android Launch!

[2011-12-12 22:37:05 - RoryHelloWorld] adb is running normally.

[2011-12-12 22:37:05 - RoryHelloWorld] Could not find RoryHelloWorld.apk!

The fix is simple. Open up your machines environment variables (in Vista it's Control Panel -> System -> Advanced System Settings -> Environment Variables).

In System Variables add a new variable JAVA_HOME set to where your JDK is installed, e.g.

JAVA_HOME=C:\Program Files\Java\jdk1.6.0_12\

Then add JAVA_HOME to your Path variable. I added:

%JAVA_HOME%\bin;%PATH%; to the end of mine. 

Restart eclipse for the changes to take effect, then the next time you run your app it should work!

Paintable - Multi-touch table

As I have only recently become a project manager I have been thinking back over previous projects I have worked on and my only experience before of being a project manager was in my masters year at the University of Strathclyde. With a team of 7 people, a load of Java code, a budget of £2000 and 12-weeks to do it (along side our dissertations and other classes) we managed to pull together something quite remarkable - a multi-touch table.

Using the reacTIVision software toolkit (http://reactivision.sourceforge.net/), a Mac mini,a projector, a piece of perspex and a table from Ikea we produced an extensible framework from which the university could add new applications.

The following Youtube links show the table being used as a paint application , and also a simple checkers game.

Paintable - Multitouch interaction:

Paintable - Checkers game:

Not perfect but the concept is there! Oh and before anyone comments about it I do know that my .NET blog's first proper post contains Java and no .NET at all!