[platform-ui-dev] Code warnings that should be fixed

["Tod Creasey" <Tod_Creasey@xxxxxxx>]

Olivier from the jdt core team has pointed out some problems we have in the
ui and jdt components that should be addressed. I am going to deal with
those in the platform ui portions of the code but those of you covering
platform text, external tools and jdt should look at your code for these
issues. Both of them can be found by using the Java Compiler preference
page to set the priorities higher on these problems.

1) Unused local variables. The VM will allocate space for an Object that is
never used and the garbage collector will have to clean it up.

2) Static members accessed through a non static reference.

This is the following:

Say your plugin has a default instance and a static method myStatic(). It
is the difference between calling

MyPlugin.myStatic()

and

myPlugin.getDefault().myStatic().

The second (incorrect) scenario has a series of issues
1) The compiler cannot remove what preceeds the static message send, which
could potentially have a side-effect - especially if you are creating new
instances to get at the API.
2) This style reduces the readability and the maintability of the code..
This code is still a valid piece of code even with JDK 1.4.1. It is simply
a style that should be avoided (see point 10.2 of the Java conventions).
3) In the case of constants used in switch statements this is invalid code
in JDK1.2.2, (although it is fixed since 1.3).

Tod