feat: add png Exporter class

Author: adhocore

src/Exporter.php

@@ -0,0 +1,98 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the CLI-SYNTAX package.
+ *
+ * (c) Jitendra Adhikari <[email protected]>
+ *     <https://github.com/adhocore>
+ *
+ * Licensed under MIT license.
+ */
+
+namespace Ahc\CliSyntax;
+
+class Exporter extends Pretty
+{
+    /** @var integer Font size */
+    protected $size = 16;
+
+    /** @var string Font path */
+    protected $font = __DIR__ . '/../font/dejavu.ttf';
+
+    /** @var resource The image */
+    protected $image;
+
+    /** @var array */
+    protected $imgSize = [];
+
+    /** @var array Colors cached for each types. */
+    protected static $colors = [];
+
+    /** @var array Lengths of each line */
+    protected static $lengths = [];
+
+    public function __destruct()
+    {
+        if (\is_resource($this->image)) {
+            \imagedestroy($this->image);
+        }
+    }
+
+    public function export(string $output)
+    {
+        $this->imgSize = $this->estimateSize($this->code, 25);
+        $this->image   = \imagecreate($this->imgSize['x'], $this->imgSize['y']);
+
+        \imagecolorallocate($this->image, 0, 0, 0);
+
+        $this->parse();
+
+        \imagepng($this->image, $output);
+    }
+
+    protected function estimateSize(string $for, int $pad = 0): array
+    {
+        $eol = \substr_count($for, "\n") ?: 1;
+        $box = \imagettfbbox($this->size, 0, $this->font, $for);
+
+        return ['x' => $box[2] + $pad, 'y' => $box[1] + $pad, 'y1' => \intval($box[1] / $eol)];
+    }
+
+    protected function visit(\DOMElement $el)
+    {
+        $lineNo = $el->getLineNo() - 1;
+        $type   = $el->getAttribute('data-type');
+        $color  = $this->colorCode($type);
+        $text   = \str_replace(['&nbsp;', '&lt;', '&gt;'], [' ', '<', '>'], $el->textContent);
+
+        foreach (\explode("\n", \rtrim($text, "\r\n")) as $line) {
+            ++$lineNo;
+
+            $xlen = static::$lengths[$lineNo] ?? 0;
+            $xpos = 12 + $xlen;
+            $ypos = $this->imgSize['y1'] * $lineNo;
+
+            \imagefttext($this->image, $this->size, 0, $xpos, $ypos, $color, $this->font, $line);
+
+            static::$lengths[$lineNo] = $xlen + $this->estimateSize($line)['x'];
+        }
+    }
+
+    protected function colorCode(string $type): int
+    {
+        if (isset(static::$colors[$type])) {
+            return static::$colors[$type];
+        }
+
+        $palette = [
+            'comment' => [0, 96, 192],
+            'default' => [0, 192, 0],
+            'keyword' => [192, 0, 0],
+            'string'  => [192, 192, 0],
+        ];
+
+        return static::$colors[$type] = \imagecolorallocate($this->image, ...$palette[$type]);
+    }
+}