icingaweb2/library/Icinga/Chart/Chart.php

163 lines
4.1 KiB
PHP

<?php
/* Icinga Web 2 | (c) 2013 Icinga Development Team | GPLv2+ */
namespace Icinga\Chart;
use Imagick;
use Icinga\Chart\Legend;
use Icinga\Chart\Palette;
use Icinga\Chart\Primitive\Drawable;
use Icinga\Chart\SVGRenderer;
use Icinga\Exception\IcingaException;
/**
* Base class for charts, extended by all other Chart classes.
*/
abstract class Chart implements Drawable
{
protected $align = false;
/**
* SVG renderer that handles
*
* @var SVGRenderer
*/
protected $renderer;
/**
* Legend to use for this chart
*
* @var Legend
*/
protected $legend;
/**
* The style-palette for this chart
*
* @var Palette
*/
protected $palette;
/**
* The title of this chart, used for providing accessibility features
*
* @var string
*/
public $title;
/**
* The description for this chart, mandatory for providing accessibility features
*
* @var string
*/
public $description;
/**
* Create a new chart object and create internal objects
*
* If you want to extend this class use the init() method as an extension point,
* as this will be called at the end of the construct call
*/
public function __construct()
{
$this->legend = new Legend();
$this->palette = new Palette();
$this->init();
}
/**
* Extension point for subclasses, called on __construct
*/
protected function init()
{
}
/**
* Extension point for implementing rendering logic
*
* This method is called after data validation, but before toSvg is called
*/
protected function build()
{
}
/**
* Check if the current dataset has the proper structure for this chart.
*
* Needs to be overwritten by extending classes. The default implementation returns false.
*
* @return bool True when the dataset is valid, otherwise false
*/
abstract public function isValidDataFormat();
/**
* Disable the legend for this chart
*/
public function disableLegend()
{
$this->legend = null;
}
/**
* Render this graph and return the created SVG
*
* @return string The SVG created by the SvgRenderer
*
* @throws IcingaException Thrown wen the dataset is not valid for this graph
* @see SVGRenderer::render
*/
public function render()
{
if (!$this->isValidDataFormat()) {
throw new IcingaException('Dataset for graph doesn\'t have the proper structure');
}
$this->build();
if ($this->align) {
$this->renderer->preserveAspectRatio();
$this->renderer->setXAspectRatioAlignment(SVGRenderer::X_ASPECT_RATIO_MIN);
$this->renderer->setYAspectRatioAlignment(SVGRenderer::Y_ASPECT_RATIO_MIN);
}
$this->renderer->setAriaDescription($this->description);
$this->renderer->setAriaTitle($this->title);
$this->renderer->getCanvas()->setAriaRole('presentation');
$this->renderer->getCanvas()->addElement($this);
return $this->renderer->render();
}
/**
* Return this graph rendered as PNG
*
* @param int $width The width of the PNG in pixel
* @param int $height The height of the PNG in pixel
*
* @return string A PNG binary string
*
* @throws IcingaException In case ImageMagick is not available
*/
public function toPng($width, $height)
{
if (! class_exists('Imagick')) {
throw new IcingaException('Cannot render PNGs without ImageMagick');
}
$image = new Imagick();
$image->readImageBlob($this->render());
$image->setImageFormat('png24');
$image->resizeImage($width, $height, imagick::FILTER_LANCZOS, 1);
return $image;
}
/**
* Align the chart to the top left corner instead of centering it
*
* @param bool $align
*/
public function alignTopLeft($align = true)
{
$this->align = $align;
}
}