Comparing, QuickDiff and Restoring
Often, you want to see what actual changes you have done. To do this, you
can use the "Compare With" and QuickDiff functions.
Setting the QuickDiff provider
It's as easy as right-clicking in the QuickDiff marker line to the immediate left of Eclipse's
text editor(s).

Now, you can just hover the mouse over the QuickDiff marker line to see what was changed
locally.