icingaweb2/library/Icinga/Chart/Legend.php

103 lines
2.7 KiB
PHP

<?php
/* Icinga Web 2 | (c) 2013-2015 Icinga Development Team | GPLv2+ */
namespace Icinga\Chart;
use DOMElement;
use Icinga\Chart\Palette;
use Icinga\Chart\Primitive\Canvas;
use Icinga\Chart\Primitive\Drawable;
use Icinga\Chart\Primitive\Rect;
use Icinga\Chart\Primitive\Text;
use Icinga\Chart\Render\LayoutBox;
use Icinga\Chart\Render\RenderContext;
/**
* Drawable for creating a Graph Legend on the bottom of a graph.
*
* Usually used by the GridChart class internally.
*/
class Legend implements Drawable
{
/**
* Internal counter for unnamed label identifiers
*
* @var int
*/
private $internalCtr = 0;
/**
*
* Content of this legend
*
* @var array
*/
private $dataset = array();
/**
* Set the content to be displayed by this legend
*
* @param array $dataset An array of datasets in the form they are provided to the graphing implementation
*/
public function addDataset(array $dataset)
{
if (!isset($dataset['label'])) {
$dataset['label'] = 'Dataset ' . (++$this->internalCtr);
}
if (!isset($dataset['color'])) {
return;
}
$this->dataset[$dataset['color']] = $dataset['label'];
}
/**
* Render the legend to an SVG object
*
* @param RenderContext $ctx The context to use for rendering this legend
*
* @return DOMElement The SVG representation of this legend
*/
public function toSvg(RenderContext $ctx)
{
$outer = new Canvas('legend', new LayoutBox(0, 0, 100, 100));
$outer->getLayout()->setPadding(2, 2, 2, 2);
$nrOfColumns = 4;
$topstep = 10 / $nrOfColumns + 2;
$top = 0;
$left = 0;
$lastLabelEndPos = -1;
foreach ($this->dataset as $color => $text) {
$leftstep = 100 / $nrOfColumns + strlen($text);
// Make sure labels don't overlap each other
while ($lastLabelEndPos >= $left) {
$left += $leftstep;
}
// When a label is longer than the available space, use the next line
if ($left + strlen($text) > 100) {
$top += $topstep;
$left = 0;
}
$colorBox = new Rect($left, $top, 2, 2);
$colorBox->setFill($color)->setStrokeWidth(2);
$colorBox->keepRatio();
$outer->addElement($colorBox);
$textBox = new Text($left+5, $top+2, $text);
$textBox->setFontSize('2em');
$outer->addElement($textBox);
// readjust layout
$lastLabelEndPos = $left + strlen($text);
$left += $leftstep;
}
$svg = $outer->toSvg($ctx);
return $svg;
}
}