[news.eclipse.platform.rcp] How to disable items on the Toolbar?

[sushma.shekar@xxxxxxx (Sushma s)]

Hi, 
  I have added items on the toolbar. i would like to disable a few items 
on the toolbar. 
I did have a look at Menu Contributions - Eclipsepedia which talks about 
visible-when, enable-when, active-when etc. But could not implement it. 

In extension to this, I have a dynamic pulldown (the items on the pulldown 
gets added dynamically) on the toolbar. I used AbstractContributionFactory 
for this and works fine.
  Now i would like to disable the items on the pulldown.How can i 
implement this?


Could u please post a few code snippets.

Thanks in advance