== History View
In this exercise you will learn how to use the History View to inspect
the revision history in a repository.

=== Preparation
Open the History View on your project by right-clicking on your
project and selecting 'Show In > History'. You should see the revision
graph of your repository.

=== How to configure History View to your needs
This history view displays Author, Date, Commit Message and modified
files of commits. The History View has quite some options to configure
which commits are displayed.

image:history-view-6.png[History View]

image:history-view-buttons.png[History View Buttons]

Depending on the use case you may want to ...

a. ... show only those commits which are reachable from the current
   branch. Hide all commits on other topic branches.
b. ... see only those commits which changed the selected resource
   (file, project, subfolder) or it’s children. E.g. display only
   those commits which touched the selected java file. The current
   selection is shown in the top right corner of the History view.
c. ... see only those commits which changed anything in the parent
   folder of the selected resource (file, project, subfolder) or it’s
   children. E.g. display only those commits which changed the same
   package as the selected java source.
d. ... see only those commits which changed anything in the same
   project as the selected resource or it’s children. Used when you
   are working in a repository which contains multiple projects.
e. ... don’t filter at all. Show all commits of the current repository

The ptions b., c. and d. are tied to the currently selected resource.
Button g. allows that the history view automatically updates when you
change the selection.

TIP: If you got lost with the different filters and the history
doesn’t show what you expect, set it back to show everything.
Therefore make sure that 'Show all branches and tags' (a) is turned on
and 'Show all changes in repository' (e) is selected.

=== Searching for Commits
Turn on 'Show Find toolbar' (f) and type in a search string in the
'Find' field. You can select where to search this string (in author or
committer name, commit message, ID of the change. The found commits
are highlighted. You can combine this search with the filters
explained above.

=== Exercises
With the help of filters and search find out ...
* ... which commits have been done to package
  'org.eclipse.example.calc.internal'
* ... who has done commit '92f83b4af8ef307e...' and which files have
  been touched in this commit
* ... how many branches are known which have commits changing
  'Calculator.java'

=== Actions on Commits
If you double-click on a file touched by a commit in the History View
you will get an editor with the content of that file in that commit.
If you turn on 'Compare Mode' (h) then a compare view opens which
compares the state of the file during that commit to the state in the
previous commit. This tells which lines have been changed by a certain
commit.

Once you have selected a commit in the History View the context menu
offers a lot of operations you can do on a commit.

* Create a new branch starting from the commit with id '27792504fad8...'
* Compare commit '92f83b4af8e...' with the second last commit on your
  branch. Which files are different in these two commits?
* Inspect commit 'a8c0e743721d81072de...' in the Commit Viewer. Get a
  single list of all modifications done by this commit by switching to
  the Diff pane in Commit Viewer.

link:index.html[Git Exercises]