Comments are added to improve readability of the item drawing code as
it is not always self-explanatory.

Furthermore, some lines are moved or deleted for various reasons:
 * Some lines were repeated or not doing any operations.
 * Objects/structures were initialised at one place but used much
   later in code which lead to poor legibility.
 * Dead code, variables and constants were present.

Change-Id: I833769cc594033d88a70ce192ae002ac091a37a5
Reviewed-by: Olivier Soldano <olivier.soldano@savoirfairelinux.com>