Maven module :un.api : api-display :
Class : un.api.layout.Layout
Extends/Implements : un.api.event.EventSource
Subclasses : -

Layouts are object in charge of placing Positionables in a defined space.
They can be used in widgets for user interfaces, to calculate graph node
positions or any system which require dynamic positioning based on constraints.
author Johann Sorel

Variables : PROPERTY_VIEW, PROPERTY_DIRTY
Functions : getLayoutConstraintClass, setView, getView, setPositionables, getExtents, getExtents, update, getPositionables

Property indicating when the layout view ractangle change.

public Chars PROPERTY_VIEW

Property indicating when the layout element placement have changed.

public Chars PROPERTY_DIRTY

Get this layout constraint class.
Every layout may require different types of informations.
return expected positionable layout constraint class, can be null.

Class getLayoutConstraintClass ()

Set layout working bbox.
The layout will try to place elements within this bbox.
param extent

void setView (BBox extent)

Working bbox of this layout.
return BBox never null

BBox getView ()

Set collection of Positionable managed by the layout
param positionables

void setPositionables (Sequence positionables)

Calculate layout min, best and max extents based on given constraint.

Under minimum size the layout won't have a proper rendering.
Best extent provide the most appropriate rendering.
Over maximum size the layout will look over-stretched or have wasted space.

param buffer
param constraint can be null
return

Extents getExtents (Extents buffer, Extent constraint)

Minimum,best and maximum extent the layout needs for the current view.
Under minimum size or over maximum the layout won't have a proper rendering.
return Extent, never null

Extents getExtents ()

Update positionables transforms and size.
The transforms will be relative to coordinate (0,0).

void update ()

Get an iterator of Pair (Positionable,AbsoluteConstraint) for elements which intersect the given extent
param searchArea
return

Iterator getPositionables (BBox searchArea)