Ubuntu 12.04 with Unity 2D, for a general user it appears very difficult and for some users even impossible to resize the Ubuntu launcher. On other hand with Unity 3D, this can be done very easily from appearance settings simply by dragging the slider but this method is only available for Unity 3D not 2D. This tutorial explains you how you can easily reduce (or change) the launcher size in Ubuntu 2D.
For reducing launcher size you will have to edit three code files in sequence, you can very easily do that, it is not that difficult as it looks like. Follow the given steps:
Step-1 Open terminal and run the following command:
sudo gedit /usr/share/unity-2d/shell/Shell.qml
This will open Shell.qml file for editing
Lookup for LauncherLoader section and change its width to 50, as shown below:
Step-2 Open the IconTile.qml file by running the following command:
sudo gedit /usr/share/unity-2d/shell/common/IconTile.qml
Look up Image section and change sourceSize.width and sourceSize.height both to 32, see the following screenshot:
Step-3 (Final Setp): Run following command to open LauncherList.qm file:
sudo gedit /usr/share/unity-2d/shell/launcher/LauncherList.qml
Now change property int titlesize to 38 for property int selectionOutlineSize to 50:
That’s all. Restart your computer and see how your new launcher looks like.