media-libs/edje/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
<herd>enlightenment</herd>
<use>
 <flag name='cache'>Enable caching</flag>
</use>
<longdescription>
Edje is a complex graphical design and layout library.

It's purpose is to be a sequel to "Ebits" which to date has serviced the needs of 
Enlightenment development for version 0.17. The original design paramteres under 
which Ebits came about were a lot more restricted than the resulting use of them, 
thus Edje was born.

Edje is a more complex layout engine compared to Ebits. It doesn't pretend to do 
containering and regular layout like a widget set. It still inherits the more 
simplistic layout ideas behind Ebits, but it now does them a lot more cleanly, 
allowing for easy expansion, and the ability to cover much more ground than Ebits 
ever could. For the purposes of Enlightenment 0.17, Edje should serve all the 
purposes of creating visual elements (borders of windows, scrollbars, etc.) and 
allow the designer the ability to animate, layout and control the look and feel of 
any program using Edje as its basic GUI constructor. This library allows for 
multiple collections of Layouts in one file, sharing the same image database and 
thus allowing a whole theme to be conveneintly packaged into 1 file and shipped 
around.

Edje, unlike Ebits, separates the layout and behavior logic. Edje files ship with an 
image database, used by all the parts in all the collections to source graphical 
data. It has a directory of logical part names pointing to the part collection entry 
ID in the file (thus allowing for multiple logical names to point to the same part 
collection, allowing for the sharing of data betwene display elements). Each part 
collection consists of a list of visual parts, as well as a list of programs. A 
program is a conditionally run program that if a particular event occurs (a button 
is pressed, a mouse enters or leaves a part) will trigger an action that may affect 
other parts. In this way a part collection can be "programmed" via its file as to 
hilight buttons when the mouse passes over them or show hidden parts when a button 
is clicked somewhere etc. The actions performed in changing from one state to 
another ar also allowed to transition over a period of time, allowing animation.

This separation and simplistic event driven style of programming can produce almost 
any look and feel one could want for basic visual elements. Anything more complex is 
likely the domain of an application or widget set that may use Edje as a conveneient 
way of being able to configure parts of the display.
</longdescription>
</pkgmetadata>