NAME

Graphics::Grid::Justifiable - Role for supporting positional justifications in Graphics::Grid

VERSION

version 0.0001

DESCRIPTION

This role describes something that has "justification" which defines how the object's exact position be determined and ajusted from its (x, y) attributes.

ATTRIBUTES

just

The justification of the object, which consumes this role, relative to its (x, y) location.

The value is an arrayref in the form of [$hjust, $vjust], where $hjust and $vjust are two numbers for horizontal and vertical justification respectively. Each number is usually from 0 to 1, but can also beyond hat range. 0 means left alignment and 1 means right alighment.

Default is [0.5, 0.5], which means the object's center is aligned to its (x, y) position.

For example, for a rectangle which has $width and $height, and positioned at ($x, $y), the position of its left-bottom corner can be calculated in this way,

    $left   = $x - $hjust * $width;
    $bottom = $y - $vjust * $height;

This attribute also supports some string values. They map to numeric values like below.

    string                          numeric
    ---------------------------     ------------
    left                            [ 0,   0.5 ]
    top                             [ 0.5, 1   ]
    right                           [ 1,   0.5 ]
    bottom                          [ 0.5, 0   ]
    center | centre                 [ 0.5, 0.5 ]
    bottom_left | left_bottom       [ 0,   0   ]
    top_left | left_top             [ 0,   1   ]
    bottom_right | right_bottom     [ 1,   0   ]
    top_right | right_top           [ 1,   1   ]

hjust

A reader accessor for the horizontal justification.

vjust

A reader accessor for vertical justification.

METHODS

calc_left_bottom($x, $y, $width, $height)

Calculate (left, bottom) position according to x, y, width and height.

SEE ALSO

Graphics::Grid

AUTHOR

Stephan Loyd <sloyd@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2018 by Stephan Loyd.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.