oracular (3) Graphics::Primitive::Component.3pm.gz
NAME
Graphics::Primitive::Component - Base graphical unit
DESCRIPTION
A Component is an entity with a graphical representation.
SYNOPSIS
my $c = Graphics::Primitive::Component->new({
origin => Geometry::Primitive::Point->new({
x => $x, y => $y
}),
width => 500, height => 350
});
LIFECYCLE
prepare
Most components do the majority of their setup in the prepare. The goal of prepare is to establish
it's minimum height and width so that it can be properly positioned by a layout manager.
$driver->prepare($comp);
layout
This is not a method of Component, but a phase introduced by the use of Layout::Manager. If the
component is a container then each of it's child components (even the containers) will be positioned
according to the minimum height and width determined during prepare. Different layout manager
implementations have different rules, so consult the documentation for each for details. After this
phase has completed the origin, height and width should be set for all components.
$lm->do_layout($comp);
finalize
This final phase provides and opportunity for the component to do any final changes to it's internals
before being passed to a driver for drawing. An example might be a component that draws a fleuron at
it's extremities. Since the final height and width isn't known until this phase, it was impossible
for it to position these internal components until now. It may even defer creation of this
components until now.
It is not ok to defer all action to the finalize phase. If you do not establish a minimum hieght and
width during prepare then the layout manager may not provide you with enough space to draw.
$driver->finalize($comp);
draw
Handled by Graphics::Primitive::Driver.
$driver->draw($comp);
METHODS
Constructor
new Creates a new Component.
Instance Methods
background_color
Set this component's background color.
border
Set this component's border, which should be an instance of Border.
callback
Optional callback that is fired at the beginning of the "finalize" phase. This allows you to add
some sort of custom code that can modify the component just before it is rendered. The only argument
is the component itself.
Note that changing the position or the dimensions of the component will not re-layout the scene. You
may have weird results of you manipulate the component's dimensions here.
class
Set/Get this component's class, which is an abitrary string. Graphics::Primitive has no internal use
for this attribute but provides it for outside use.
color
Set this component's foreground color.
fire_callback
Method to execute this component's "callback".
get_tree
Get a tree for this component. Since components are -- by definiton -- leaf nodes, this tree will
only have the one member at it's root.
has_callback
Predicate that tells if this component has a "callback".
height
Set this component's height.
inside_bounding_box
Returns a Rectangle that defines the edges of the 'inside' box for this component. This box is
relative to the origin of the component.
inside_height
Get the height available in this container after taking away space for padding, margin and borders.
inside_width
Get the width available in this container after taking away space for padding, margin and borders.
margins
Set this component's margins, which should be an instance of Insets. Margins are the space outside
the component's bounding box, as in CSS. The margins should be outside the border.
maximum_height
Set/Get this component's maximum height. Used to inform a layout manager.
maximum_width
Set/Get this component's maximum width. Used to inform a layout manager.
minimum_height
Set/Get this component's minimum height. Used to inform a layout manager.
minimum_inside_height
Get the minimum height available in this container after taking away space for padding, margin and
borders.
minimum_inside_width
Get the minimum width available in this container after taking away space for padding, margin and
borders.
minimum_width
Set/Get this component's minimum width. Used to inform a layout manager.
name
Set this component's name. This is not required, but may inform consumers of a component. Pay
attention to that library's documentation.
origin
Set/Get the origin point for this component.
outside_height
Get the height consumed by padding, margin and borders.
outside_width
Get the width consumed by padding, margin and borders.
finalize
Method provided to give component one last opportunity to put it's contents into the provided space.
Called after prepare.
padding
Set this component's padding, which should be an instance of Insets. Padding is the space inside the
component's bounding box, as in CSS. This padding should be between the border and the component's
content.
page
If true then this component represents stand-alone page. This informs the driver that this component
(and any children) are to be renderered on a single surface. This only really makes sense in formats
that have pages such as PDF of PostScript.
prepare
Method to prepare this component for drawing. This is an empty sub and is meant to be overridden by
a specific implementation.
preferred_height
Set/Get this component's preferred height. Used to inform a layout manager.
preferred_width
Set/Get this component's preferred width. Used to inform a layout manager.
to_string
Get a string representation of this component in the form of:
$name $x,$y ($widthx$height)
visible
Set/Get this component's visible flag.
width
Set/Get this component's width.
AUTHOR
Cory Watson, "<gphat@cpan.org>"
BUGS
Please report any bugs or feature requests to "bug-geometry-primitive at rt.cpan.org", or through the web
interface at <http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Geometry-Primitive>. I will be notified,
and then you'll automatically be notified of progress on your bug as I make changes.
COPYRIGHT & LICENSE
Copyright 2008-2009 by Cory G Watson.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl
itself.