AnatImageViewer/includes/AnnotationHandler.php

<?php
namespace MediaWiki\Extension\AnatImageViewer;

require_once __DIR__ . '/../vendor/autoload.php';

use Devium\Toml\Toml;
use Devium\Toml\TomlError;
use MediaWiki\MediaWikiServices;
use Content;
use Title;
use CodeContentHandler;
use MediaWiki\Content\Renderer\ContentParseParams;
use ParserOutput;
use Html;
use IContextSource;
use MediaWiki\Content\ValidationParams;
use Status;


class AnnotationHandler extends CodeContentHandler {
    private const ANNOT_VERSION = '0.1';

	public function __construct(
		$modelId = AnnotationContent::MODEL,
		$formats = [ CONTENT_FORMAT_TEXT ]
	) {
		parent::__construct( $modelId, $formats );
	}

	protected function getContentClass() {
		return AnnotationContent::class;
	}
    
	/**
	 * Only allow this content handler to be used in the Module namespace
	 * @param Title $title
	 * @return bool
	 */
	public function canBeUsedOn( Title $title ) {
		if ( $title->getNamespace() !== NS_AV_ANNOT ) {
			return false;
		}

		return parent::canBeUsedOn( $title );
	}

	public function supportsPreloadContent(): bool {
		return true;
	}

	public function serializeContent( Content $content, $format = null ) {
		return parent::serializeContent( $content, $format );
	}

    public function unserializeContent( $text, $format = null ) {
		return new AnnotationContent( $text );
	}

	public function makeEmptyContent() {
		return new AnnotationContent( '' );
	}

    protected function fillParserOutput( Content $content, ContentParseParams $cpoParams, ParserOutput &$output	) {
        self::console_log('Fill Parser Output', true);

        parent::fillParserOutput( $content, $cpoParams, $output );

        try {
            $metadata = toml_decode($content->getText(), true);
        } catch (TomlError $e) {
            $output->addWarningMsg( $e->getMessage() );
			$output->setText( 'No image available' );
            return;
        }

        if (isset($metadata['baseImage'])) {
            $imageTitle = Title::makeTitleSafe( NS_FILE, $metadata['baseImage'] );
            $baseImage = MediaWikiServices::getInstance()->getRepoGroup()->findFile($imageTitle);
        } else {
            $baseImage = false;
        }

        $output->setText( self::buildSvg($metadata,$baseImage) );
    }

    /**
     * Build annotated SVG from TOML metadata
     * 
     * This takes in the metadata text from the file page (or the current editor)
     * and produces the html string for the svg with base image and annotations.
     * 
     * @param string $metadata The metadata object parsed from the text
     * @param File $baseImage The full url pointing to the base image to annotate
     * @return string Html string of the complete svg
     */
    private function buildSvg($metadata, $baseImage) {
        //Gather basic data
        $elBaseImg = '';
        $vbHeight = 100;
        $vbWidth = 100;
        if ($baseImage) {
            $baseImageUrl = $baseImage->getFullUrl();
            $baseHeight = $baseImage->getHeight();
            $baseWidth = $baseImage->getWidth();
            $baseAspect = $baseHeight / $baseWidth;
            $vbWidth = 100 / sqrt($baseAspect);
            $vbHeight = $baseAspect * $vbWidth;
            $attrBase = array(
                'class' => 'annot-base',
                'preserveAspectRatio' => 'none',
                'width' => $vbWidth,
                'height' => $vbHeight,
                'href' => $baseImageUrl
            );
            $elBaseImg = Html::rawElement('image', $attrBase);
            }

        //Render and return svg
        $attrSvg = array(
            'class' => 'annot-svg',
            'version' => '1.1',
            'viewBox' => "0 0 {$vbWidth} {$vbHeight}",
            'xml:space' => 'preserve',
            'xmlns' => 'http://www.w3.org/2000/svg'
        );
        if ($this->parameters['width'] > 0) {
            $attrSvg['width'] = $this->parameters['width'];
        }
        elseif ($this->parameters['height'] > 0) {
            $attrSvg['height'] = $this->parameters['height'];
        }

        if (isset($metadata['annotation'])) {
            $markers = [];
            $maskCircles = [];
            foreach($metadata['annotation'] as $label => $annot) {
                if (isset($annot['position'])) {
                    $attrMask = array(
                        'cx' => $annot['position']['0'],
                        'cy' => $annot['position']['1'],
                        'r' => '3.75',
                        'fill' => 'black'
                    );
                    $maskCirc = Html::rawElement('circle',$attrMask);
                    array_push($maskCircles,$maskCirc);
                    $attrMarkerCirc = array(
                        'cx' => $annot['position']['0'],
                        'cy' => $annot['position']['1'],
                        'r' => '3.75',
                        'style' => 'fill-opacity: .35; stroke-linejoin: bevel; stroke-width: .3793; stroke: #ff0000;',
                        'fill' => (isset($annot['light']) && $annot['light']) ? 'white' : 'balck'
                    );
                    $markCirc = Html::rawElement('circle',$attrMarkerCirc);
                    array_push($markers,$markCirc);
                    $attrMarkerText = array(
                        'x' => $annot['position']['0'], 
                        'y' => $annot['position']['1'],
                        'style' => 'fill: #ff0000; font-size: 5px; stroke-linejoin: bevel; stroke-width: .6968; text-align: center; text-anchor: middle; transform: translateY(1.5px);'
                    );
                    $markText = Html::rawElement('text',$attrMarkerText, isset($annot['label']) ? $annot['label'] : $label );
                    array_push($markers,$markText);
                }
            }            
        }

        return Html::rawElement('svg', $attrSvg, $elBaseImg . implode($markers) );
    }

	public function validateSave( Content $content, ValidationParams $validationParams ) {
        self::console_log('Validate Save', true);
        $status = Status::newGood();

        try {
            $tomlCheck = toml_decode($content->getText(), true);
        } catch (TomlError $e) {
			$status->fatal( 'content-failed-to-parse', 'SVG', "", $e->getMessage() );
        }

		return $status;
	}

    /**
     * Small helper function to display information on the browser console
     * 
     * Usage:
     * echo '<script>';
     * self::console_log('logged string');
     * echo '</script>';
     * 
     * @param $data information to display
     * @param bool $add_script_tags true to put information is inside complete script tag
     */
    public static function console_log($data, $add_script_tags = false) {
        $command = 'console.log('. json_encode($data, JSON_HEX_TAG).');';
        if ($add_script_tags) {
            $command = '<script>'. $command . '</script>';
        }
        echo $command;
    }
}