icingaweb2/library/Icinga/Chart/Graph/StackedGraph.php

90 lines
2.1 KiB
PHP

<?php
// {{{ICINGA_LICENSE_HEADER}}}
// {{{ICINGA_LICENSE_HEADER}}}
namespace Icinga\Chart\Graph;
use DOMElement;
use Icinga\Chart\Primitive\Drawable;
use Icinga\Chart\Render\RenderContext;
/**
* Graph implementation that stacks several graphs and displays them in a cumulative way
*/
class StackedGraph implements Drawable
{
/**
* All graphs displayed in this stackedgraph
*
* @var array
*/
private $stack = array();
/**
* An associative array containing x points as the key and an array of y values as the value
*
* @var array
*/
private $points = array();
/**
* Add a graph to this stack and aggregate the values on the fly
*
* This modifies the dataset as a side effect
*
* @param array $subGraph
*/
public function addGraph(array &$subGraph)
{
foreach ($subGraph['data'] as &$point) {
$x = $point[0];
if (!isset($this->points[$x])) {
$this->points[$x] = 0;
}
// store old y-value for displaying the actual (non-aggregated)
// value in the tooltip
$point[2] = $point[1];
$this->points[$x] += $point[1];
$point[1] = $this->points[$x];
}
}
/**
* Add a graph to the stack
*
* @param $graph
*/
public function addToStack($graph)
{
$this->stack[] = $graph;
}
/**
* Empty the stack
*
* @return bool
*/
public function stackEmpty()
{
return empty($this->stack);
}
/**
* Render this stack in the correct order
*
* @param RenderContext $ctx The context to use for rendering
*
* @return DOMElement The SVG representation of this graph
*/
public function toSvg(RenderContext $ctx)
{
$group = $ctx->getDocument()->createElement('g');
$renderOrder = array_reverse($this->stack);
foreach ($renderOrder as $stackElem) {
$group->appendChild($stackElem->toSvg($ctx));
}
return $group;
}
}