Eclipse Local History & Quick Diff

i worked long hours on my project, and it was working well. but after a series of edits, somehow the application was not working the way it should. what did i change to break my code? usually i smile, because i have things in a version control system. but: not this time (i should know better!). luckily there are some ways to find out what has been changed: with the local history and quick diff .

local history

even if not using a version control system, eclipse has a local history built-in. to compare and diff with the history, i use the menu

compare with local history

this opens the history view which offers compare and merge (see compare and merge in eclipse ):

history view

the number of entries (and size) of the local history is configured in the following workspace setting (menu window > preferences > general > workspace > local history ):

local history preferences

note: keeping a long history might slow down eclipse, especially at workspace closure time (see codewarrior tool tip #3 ). so better not to keep too much of history.

quick diff

the local history is nice, but there is even a faster way: quick diff !

quick diff can be enabled (if not already done) in the workspace settings (menu window > preferences > general > editors > text editors > quick diff ):

quick diff preferences

in the settings i can change the colors, and as well what to use as reference ((version on disk, latest cvs version  or pristine svn copy).

note: there seems to be a problem (oversight?) in eclipse (at least 3.6) with using ‘version on disk’: with saving a file the quick diff markers are gone too . but it works as expected with the svn settings. another good reason to use svn .

there is a general option to enable quick diff, and i have enabled as well the ‘show differences in overview ruler’.

what it does: it shows the differences in the left editor area (where usually the line numbers are):

quick diff color marker

the colors are as configured in the quick diff preferences shown earlier.

if i move the mouse over the marker, a pop-up window shows up:

quick diff mouse over

the first character in the pop up indicates what has changed:

• >: changed line
• +: inserted line
• -: deleted line

note the ‘press ‘f2′ for focus’ : that way i copy and restore my earlier version. quick is simple and fast  and gives me an immediate access to the earlier version.

happy quick diffing