Nautilus - Expand/Collapse directory tree with keyboard

I use Ubuntu 9.04 and generally prefer to use the keyboard while navigating through directories in Nautilus.

Discovered a nice feature today.
Quite handy if you don't want to move away from the current view and just see the contents of current directory.

To open/expand a directory tree, use <Shift> + <Right key>
To close/collapse a directory tree, use <Shift> + <Left key>

This trick also works in the Tree pane/Side bar (F9)

Setting up the tools for J2ME app development

Aim: To setup tools and environment for J2ME application development
My OS: Ubuntu jaunty

JRE
1. Download and install JRE (Java Runtime Environment) using the Synaptic Package Manager. The JRE is required for Eclipse to run.

Eclipse
2. Download and install Eclipse. I use this Eclipse Ganymede package.
Make sure you are able to launch Eclipse after it has been downloaded and extracted.
If Eclipse won't start with messages like 'Widget disposed too early', try adding this line to eclipse.ini
-Dorg.eclipse.swt.browser.XULRunnerPath=/usr/lib/xulrunner
this worked for me! BTW, eclipse log is located at /.metadata/.log
.metadata is a hidden folder!

Sun WTK
3. Download and install the Wireless Tool Kit. Although, Sun now has a Java ME SDK 3.0, it is currently available only for Windows. I use the earlier Sun Java Wireless Toolkit 2.5.2. Extract the contents to a suitable directory.

EclipseME plugin
4. Next we proceed to download the plugin to help us develop the J2ME midlets. Although the EclipseME project has graduated and is now called Eclipse Mobile Tools for Java (MTJ), I did face some problems with it on my Ubuntu machine. Problems were especially related to Proguard not being able to find my inner classes and throwing NoClassDefFound errors during Obfuscation. Hence I decided to switch back to the tried and tested EclipseME 1.7.9 plugin.
To install, use Eclipse's Software Updates feature and add the site http://www.eclipseme.org/updates


Proceed with the installation. Restart Eclipse if asked to. After successful installation, you should be able to see a new 'J2ME' option under Eclipse -> Window -> Preferences

Proguard
5. This is a must if you wish to optimize the resulting jar and also make sure nobody copies your code (Obfuscate). I downloaded the latest Proguard4.4.tar.gz version. Extract it to a suitable directory.

Antenna Eclipse Plugin
6. Add the plugin update site http://antenna.sf.net/update via Eclipse's Software Updates feature and install it.


Proceed to install the plugin. Restart Eclipse if asked to.
Installation guide is here.

You can also download the Antenna Jar
This is required if you wish to build using Ant (build.xml) How to set it up and use it will be covered in another post.

Wiring it all!

Browse to Eclipse -> Window -> Preferences -> J2ME (Left side option)
Set the Antenna JAR and WTK Root properties
Antenna JAR (antenna.preprocessor.v2_1.7.7.jar) will be located under Eclipse/plugins directory
WTK Root is where you extracted the contents in Step 3 above.


Import the Sun WTK Emulation devices in Eclipse
Open Eclipse -> Window -> Preferences -> J2ME (Left side option) -> Device Management
Click Import
In the Import Devices dialog that pops up, browse for the WTK/bin directory.
Click Refresh. You should see this.

Click Finish

On Preferences screen, Click J2ME -> Packaging -> Obfuscation and set the Proguard Root Directory.
Set it to the path where you extracted Proguard contents in step 5 above. Mine is /media/sda5/Dev/proguard4.4

All Done!

Now import an existing project or create a dummy project.
Right click on the project and enable 'Antenna Preprocessor'.
Now if you see the Project Properties (Alt-Enter), you should see a new option 'Antenna preprocessor' under it.



JMUnit
If you wish to write Test cases, you should consider adding JMUnit jar to your project classpath.

A nice guide on using JMUnit is here

You are all set to start J2ME programming.
Next, I ll post on how to actually start using these tools and make the most out of it.

Reinstall Windows on existing Linux partition

What I wanted to do:

- Remove logical partitions

- Cleanly reinstall Windows XP

- Resize and merge existing logical partitions

- Make sure Ubuntu is unaffected (Grub)

Note #1. Partition magic will not help, if you attempt to resize/move an existing partition due to the presence of the linux partition.

Note #2. Grub is my boot loader. I did not note down the partition on which my linux is installed and kind of regretted later. Note down the partition information when you attempt to boot into Ubuntu ..something like 'Booting from hd (0,5)' etc

Here is what I did.

Task #1: Remove logical partition

As I said earlier, Partition magic will not help in this regard due to the presence of the Linux partition.

I booted using the Windows XP setup CD and using the partition utility, removed the logical partitions that I did not want.

Task #2: Install Windows

After the partitions were removed, I proceeded to install Windows XP on my newly formatted partition. Note, my Linux partition was untouched all this while.

Now, once XP was installed, the XP boot manager takes over and I could not see my Linux boot options. Now the task was to restore Grub as the boot manager.

Task #3: Resize partitions

Now I restarted the PC and booted using the Live CD.

Ubuntu has a Partition manager that ships with the Live CD.

Using that, I was able to resize the partitions

Task #4: Restore Grub

Once inside, In a terminal window, I used the following commands:

a. sudo grub

b. root hd(0,5)

(you may have noticed where Grub loads from as mentioned in Note#2 above)

if not, here is what can be done to find where Grub was previously installed

b1. find /boot/grub/stage1

c. setup hd(0)

d. quit

All done!

I now restarted the PC without the Live CD and was able to see the Grub menu with Ubuntu and Windows XP OS choices.

Configure Eclipse and MySQL on Ubuntu Jaunty

I assume that Eclipse and MySQL has already been installed. I use Eclipse Ganymede (3.4.2) and MySQL 3.5.1. For installing MySQL on Ubuntu, see my previous post.

1. Download MySQL JDBC Connector (mysql-connector-java-5.1.7.zip/jar)

Choose a mirror and download from here

Extract the contents of the jar/zip to a folder.

2. In Eclipse, click Menu -> Window -> Show View -> Other. Expand the 'Data Management' option and select 'Data Source Explorer'.

Click OK. The Data Source Explorer tab will open.

3. In Data Source Explorer, right click 'Database Connections' folder and click New.

The 'New Connection Profile' dialog will open. Select 'MySQL' and click Next.

Most likely your Drivers drop down will be empty. If yes, then it is time to create a new Driver definition.

4. Click on the small 'New Driver Definition' icon next to the drop down.

5. In the dialog that opens, select MySQL JDBC Driver v5.1. 

6. Click Jar/List tab. You need to add the MySQL JDBC connector jar that you downloaded and extracted in step 1 above. Click Add JAR/Zip and select the mysql-connector-java-5.1.7.jar that you extracted. Click OK

7. Change the Database from 'database' to 'mysql' in both Database and URL fields.

8. Enter the password that you had provided during MySQL installation.

9. Click Test Connection and you should see a ping succeeded dialog.

10. Click Finish. Your database connection is successfully created. If you Expand the connection tree, you can see the database and tables etc.

Happy querying!

Install and setup MySQL on Ubuntu Jaunty

Here is how I installed MySQL 5.1 Community Edition on Ubuntu Jaunty:

1. Install MySQL

Goto Synaptic Package Manager and in quick search type 'mysql-server-5.1' (without quotes). From the list that will be provided, choose to install package with name mysql-server-5.1. It will show you all the dependencies and proceed to install.

Alternately you can use apt-get command.

sudo apt-get install mysql-server-5.1

1a. During the installation it will prompt for a password. Enter password of your choice.

1b. Confirm the password. Make sure installation completes successfully

2. Test the installation

To test the installation, type the following in Terminal.

mysql --user=root --password=yourpassword

"Welcome to the MySQL monitor. Commands end with ; or \ g.
Your MySQL connection id is 53
Server version: 5.1.31-1ubuntu2 (Ubuntu)

Type 'help;' or '\ h' for help. Type '\ c' to clear the buffer."

After this you should be able to see the prompt change to

mysql>

3. Use the mysql database.

mysql> use mysql;

"Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed"

4. Now see the tables present in the database

mysql> show tables;

This will display all the tables present in the database.

MySQL has been successfully installed.

In the next post I ll show how I configured Eclipse to talk to MySQL!

Ubuntu Update Manager - Check/Uncheck All!

By default, the Ubuntu Update manager (Jaunty in my case), always has all the available updates checked (selected). But sometimes if I wish to select only a few of them, then unselecting the others was a real pain.

Here are two nice options that I found to Check All or Uncheck All the updates.

These options are available if you right-click on the checkmark/checkbox in the Update manager.

Handy!

Customize Nautilus Shortcut Keys

Today, I had this itch to customize the shortcut keys in my Ubuntu Jaunty --> Nautilus.

I wanted to assign the Alt-D key to select the location bar. Ctrl-L is the default option, but I find Alt-D easier on the fingers, especially when all fingers are resting on the correct keys on the keyboard! I also use Alt-D in Opera/Firefox to highlight the address in the address bar.

Unfortunately, The 'Keyboard Shortcuts' in System --> Preferences does not have any option for Nautilus.

A quick search landed me here and Wolki had a nice suggestion. It worked like a charm.

So to change Ctrl-L option to Alt-D, here is what needs to be done:

1. In Ubuntu Jaunty, Go to System --> Preferences --> Appearance --> Interface.

2. Enable the option 'Editable menu shortcut keys'

This is what Ubuntu Help says about this option:

"Editable menu shortcut keys

  Selecting this option allows you to define new keyboard shortcuts for menu items.

  To change an application shortcut key, open the menu, and with the mouse pointer on the menu item you wish to change, press the new combination of keys. To remove a shortcut key, press Backspace or Delete.

  When using this feature, you will not be warned if assigning a new shortcut key to a command also removes it from another command.

  There is no way to restore the original, default keyboard shortcut for a command.

  This feature does not maintain shortcuts that are normally common to all applications, such as Ctrl+C for Copy. This may lead to inconsistencies in your GNOME applications."

3. Now open Nautilus, click 'Go' menu and highlight the 'Location...' option by moving mouse pointer over it.

4. At this point, press Alt-D on the keyboard. The Ctrl-L shortcut will be replaced by Alt-D!

5. As a precaution, turn off the 'Editable menu shortcut keys' option.

6. If the shortcut does not work immediately, log out and log back in. (need not restart)

Disclaimer: Read the warnings in the above help extract carefully. You should know what you are doing!

Amarok tip on Ubuntu

Ok, this is neat. I have been using Amarok 2.0.2 for sometime on Ubuntu, but just discovered this today.

If you drag a song from 'Collection' to either the 'Current Track Info' window or 'Lyrics' window (and hold it there for couple of seconds), it displays some good options to 'Queue Track' or 'More' options to 'Edit Track details'. 

Holding down the dragged song on the 'More' option (also hold it for couple of second) also gives some more options!

See snapshots:

Ubuntu and the LCD projector!

I had a presentation in office and thought of using Ubuntu for it. But I was not sure if Ubuntu will behave well if I connect to the LCD projector. Didn't wanna take a chance.

Beforehand, I had done some research on connecting Ubuntu based laptop to the LCD projector and the problems that may arise.

This tip worked and helped me connect the Laptop running Ubuntu to the LCD projector.

1. Start the LCD projector (obviously!)

2. Start Ubuntu and log in with your username

3. Connect the projector to your laptop. Now like me, chances are, you may not see anything on the projector screen.

4. Now, log out (using ctrl-bkspace, if it works). Need not restart the laptop.

5. Log back in and you should see your Ubuntu desktop on the big screen!

Ubuntu, Openoffice, AnyRemote!

So I had this presentation in office and I thought of 'showcasing' ubuntu!

Had some trouble getting anyRemote to work on Ubuntu with Nokia E51, but eventually met with success. Initially I tried to download the .gz files from sourceforge.net and compile them myself. After resolving a few compiler dependencies, i could, configure, make and install. But I was still clueless and thought 'nothing seem to happen'

Eventually this is what worked well for me. And darn pretty simple too.

Make sure your Open office Impress presentation is loaded.

1. I downloaded and installed the java client for mobiles. Link

2. Instead of using the .gz files from sourceforge, I installed anyremote from the ubuntu repositories.

So I searched the Synaptic Package manager for gAnyRemote and installed it.

3. Start ganyremote on Ubuntu

In a terminal, type ganyremote

I got a message, saying 'Bluetooth service is not active', I ignored it.

ganyremote starts and an icon is visible in the top right panel.

4.Click on the icon and it will display a window with a list of applications.

5. I clicked on Open Office Impress and clicked 'Start'. The status changed to 'Managed'

6. Then I launced anyremote on mobile (Nokia E51).

7. Then from the options menu, I clicked 'Enter BT address'.

8. You need to know your PC's bluetooth address. For this type hcitool dev  in any Ubuntu terminal. Note down the 12 char address. Enter this address in your mobile (option 7 above). The format will be something like this btspp://0008F4163049:19 (the address in bold will be your PC's bluetooth address. Rest remains the same)

9. Now I switched to the impress presentation and using the keypad on mobile, I was able to control the presentation!