diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/private/Preview/MarkDown.php | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/lib/private/Preview/MarkDown.php b/lib/private/Preview/MarkDown.php index 91e276eb170..64e734acabe 100644 --- a/lib/private/Preview/MarkDown.php +++ b/lib/private/Preview/MarkDown.php @@ -24,6 +24,9 @@ namespace OC\Preview; +use OCP\Files\File; +use OCP\IImage; + class MarkDown extends TXT { /** * {@inheritDoc} @@ -31,4 +34,111 @@ class MarkDown extends TXT { public function getMimeType(): string { return '/text\/(x-)?markdown/'; } + + public function getThumbnail(File $file, int $maxX, int $maxY): ?IImage { + $content = $file->fopen('r'); + + if ($content === false) { + return null; + } + + $content = stream_get_contents($content,3000); + + //don't create previews of empty text files + if (trim($content) === '') { + return null; + } + + // Merge text paragraph lines that might belong together + $content = preg_replace('/^(\s*)\*\s/mU', '$1- ', $content); + + $content = preg_replace('/((?!^(\s*-|#)).*)(\w|\\|\.)(\r\n|\n|\r)(\w|\*)/mU', '$1 $3', $content); + + // Remove markdown symbols that we cannot easily represent in renered text in the preview + $content = preg_replace('/\*\*(.*)\*\*/U', '$1', $content); + $content = preg_replace('/\*(.*)\*/U', '$1', $content); + $content = preg_replace('/\_\_(.*)\_\_/U', '$1', $content); + $content = preg_replace('/\_(.*)\_/U', '$1', $content); + $content = preg_replace('/\~\~(.*)\~\~/U', '$1', $content); + + $content = preg_replace('/\!?\[((.|\n)*)\]\((.*)\)/mU', '$1 ($3)', $content); + $content = preg_replace('/\n\n+/', "\n", $content); + + $content = preg_replace('/[\x{10000}-\x{10FFFF}]/u', '', $content); + + $lines = preg_split("/\r\n|\n|\r/", $content); + + // Define text size of text file preview + $fontSize = $maxX ? (int) ((1 / ($maxX >= 512 ? 60 : 40) * $maxX)) : 10; + + $image = imagecreate($maxX, $maxY); + imagecolorallocate($image, 255, 255, 255); + $textColor = imagecolorallocate($image, 0, 0, 0); + + $fontFile = __DIR__ . '/../../../core/fonts/NotoSans-Regular.ttf'; + $fontFileBold = __DIR__ . '/../../../core/fonts/NotoSans-Bold.ttf'; + + $canUseTTF = function_exists('imagettftext'); + + $textOffset = (int)min($maxX * 0.05, $maxY * 0.05); + $nextLineStart = 0; + $y = $textOffset; + foreach ($lines as $line) { + $actualFontSize = $fontSize; + if (mb_strpos($line, '# ') === 0) { + $actualFontSize *= 2; + } + if (mb_strpos($line, '## ') === 0) { + $actualFontSize *= 1.8; + } + if (mb_strpos($line, '### ') === 0) { + $actualFontSize *= 1.6; + } + if (mb_strpos($line, '#### ') === 0) { + $actualFontSize *= 1.4; + } + if (mb_strpos($line, '##### ') === 0) { + $actualFontSize *= 1.2; + } + if (mb_strpos($line, '###### ') === 0) { + $actualFontSize *= 1.1; + } + + // Add spacing before headlines + if ($actualFontSize !== $fontSize && $y !== $textOffset) { + $y += (int)($actualFontSize * 2); + } + + $x = $textOffset; + $y += (int)($nextLineStart + $actualFontSize); + + if ($canUseTTF === true) { + $wordWrap = (int)((1 / $actualFontSize * 1.3) * $maxX); + + // Get rid of markdown symbols that we still needed for the font size + $line = preg_replace('/^#*\s/', '', $line); + + $wrappedText = wordwrap($line, $wordWrap,"\n"); + $linesWrapped = count(explode("\n", $wrappedText)); + imagettftext($image, $actualFontSize, 0, $x, $y, $textColor, $actualFontSize === $fontSize ? $fontFile : $fontFileBold, $wrappedText); + $nextLineStart = (int)($linesWrapped * ceil($actualFontSize * 2)); + if ($actualFontSize !== $fontSize && $y !== $textOffset) { + $nextLineStart -= $actualFontSize; + } + } else { + $y -= (int)$fontSize; + imagestring($image, 1, $x, $y, $line, $textColor); + $nextLineStart = $fontSize; + } + + if ($y >= $maxY) { + break; + } + } + + $imageObject = new \OC_Image(); + $imageObject->setResource($image); + + return $imageObject->valid() ? $imageObject : null; + } } |