[kde-guidelines] Breadcrumbs

[Heiko Tietze]

There was no objection after presentation on the forums. So I will add this 
page to the HIG if nobody complains.

== Purpose ==
The breadcrumb pattern is a navigation aid that helps to keep track of the 
locations within programs or documents by a) providing information about the 
current position within the hierarchy, and b) offering shortcut links to jump 
to previously positions without using the Back button (e.g. home > documents > 
business). The breadcrumb extends the address bar with (clear) access to 
subsections. It has the advantage of distinctness in usage. As a drawback the 
breadcrumb usually needs more space.

== Guidelines ==
== Is this the right control ==
* Use a breadcrumb for orientation and navigation in strictly hierarchical 
data.
* Make sure the breadcrumb has only supportive functions. Do not use it as 
primary and exclusive navigation pattern.
* Do not use a breadcrumb to just identify or label of the position.
* Consider to use other controls like tags for flat or less organized content.
* Do not make the breadcrumb navigation dynamic by adopting the last users 
interactions (known as 'path breadcrumb'). Breadcrumbs should show the 
hierarchy, not the user's history.

=== Behavior ===
* Link all breadcrumb steps to the appropriate page or position respectively, 
except the current.
* Add the current position to the breadcrumbs.
* Consider to provide a dropdown list for alternate options on the same level. 
But always offer one-click access by default.

=== Appearance ===
* Keep the breadcrumb plain; do not use icons or other controls.
* Place the breadcrumb above the content control (e.g. file list).

* Do not place it above the navigation control (e.g. directory structure)
* Do not integrate it into the tool bar
* Do not place it in an extra tool bar.
* Do not integrate it into the title bar.

== Implementation ==
^design example to be done