nextcloud /
server
| Total Complexity | 47 |
| Total Lines | 384 |
| Duplicated Lines | 0 % |
| Changes | 2 | ||
| Bugs | 0 | Features | 0 |
Complex classes like PreviewManager often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use PreviewManager, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 44 | class PreviewManager implements IPreview { |
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| 45 | /** @var IConfig */ |
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| 46 | protected $config; |
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| 47 | |||
| 48 | /** @var IRootFolder */ |
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| 49 | protected $rootFolder; |
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| 50 | |||
| 51 | /** @var IAppData */ |
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| 52 | protected $appData; |
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| 53 | |||
| 54 | /** @var EventDispatcherInterface */ |
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| 55 | protected $eventDispatcher; |
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| 56 | |||
| 57 | /** @var Generator */ |
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| 58 | private $generator; |
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| 59 | |||
| 60 | /** @var GeneratorHelper */ |
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| 61 | private $helper; |
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| 62 | |||
| 63 | /** @var bool */ |
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| 64 | protected $providerListDirty = false; |
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| 65 | |||
| 66 | /** @var bool */ |
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| 67 | protected $registeredCoreProviders = false; |
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| 68 | |||
| 69 | /** @var array */ |
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| 70 | protected $providers = []; |
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| 71 | |||
| 72 | /** @var array mime type => support status */ |
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| 73 | protected $mimeTypeSupportMap = []; |
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| 74 | |||
| 75 | /** @var array */ |
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| 76 | protected $defaultProviders; |
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| 77 | |||
| 78 | /** @var string */ |
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| 79 | protected $userId; |
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| 80 | |||
| 81 | /** |
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| 82 | * PreviewManager constructor. |
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| 83 | * |
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| 84 | * @param IConfig $config |
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| 85 | * @param IRootFolder $rootFolder |
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| 86 | * @param IAppData $appData |
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| 87 | * @param EventDispatcherInterface $eventDispatcher |
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| 88 | * @param string $userId |
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| 89 | */ |
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| 90 | public function __construct(IConfig $config, |
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| 91 | IRootFolder $rootFolder, |
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| 92 | IAppData $appData, |
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| 93 | EventDispatcherInterface $eventDispatcher, |
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| 94 | GeneratorHelper $helper, |
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| 95 | $userId) { |
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| 96 | $this->config = $config; |
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| 97 | $this->rootFolder = $rootFolder; |
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| 98 | $this->appData = $appData; |
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| 99 | $this->eventDispatcher = $eventDispatcher; |
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| 100 | $this->helper = $helper; |
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| 101 | $this->userId = $userId; |
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| 102 | } |
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| 103 | |||
| 104 | /** |
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| 105 | * In order to improve lazy loading a closure can be registered which will be |
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| 106 | * called in case preview providers are actually requested |
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| 107 | * |
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| 108 | * $callable has to return an instance of \OCP\Preview\IProvider or \OCP\Preview\IProviderV2 |
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| 109 | * |
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| 110 | * @param string $mimeTypeRegex Regex with the mime types that are supported by this provider |
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| 111 | * @param \Closure $callable |
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| 112 | * @return void |
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| 113 | */ |
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| 114 | public function registerProvider($mimeTypeRegex, \Closure $callable) { |
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| 115 | if (!$this->config->getSystemValue('enable_previews', true)) { |
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| 116 | return; |
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| 117 | } |
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| 118 | |||
| 119 | if (!isset($this->providers[$mimeTypeRegex])) { |
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| 120 | $this->providers[$mimeTypeRegex] = []; |
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| 121 | } |
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| 122 | $this->providers[$mimeTypeRegex][] = $callable; |
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| 123 | $this->providerListDirty = true; |
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| 124 | } |
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| 125 | |||
| 126 | /** |
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| 127 | * Get all providers |
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| 128 | * @return array |
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| 129 | */ |
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| 130 | public function getProviders() { |
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| 131 | if (!$this->config->getSystemValue('enable_previews', true)) { |
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| 132 | return []; |
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| 133 | } |
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| 134 | |||
| 135 | $this->registerCoreProviders(); |
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| 136 | if ($this->providerListDirty) { |
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| 137 | $keys = array_map('strlen', array_keys($this->providers)); |
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| 138 | array_multisort($keys, SORT_DESC, $this->providers); |
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| 139 | $this->providerListDirty = false; |
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| 140 | } |
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| 141 | |||
| 142 | return $this->providers; |
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| 143 | } |
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| 144 | |||
| 145 | /** |
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| 146 | * Does the manager have any providers |
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| 147 | * @return bool |
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| 148 | */ |
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| 149 | public function hasProviders() { |
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| 150 | $this->registerCoreProviders(); |
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| 151 | return !empty($this->providers); |
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| 152 | } |
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| 153 | |||
| 154 | private function getGenerator(): Generator { |
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| 155 | if ($this->generator === null) { |
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| 156 | $this->generator = new Generator( |
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| 157 | $this->config, |
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| 158 | $this, |
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| 159 | $this->appData, |
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| 160 | new GeneratorHelper( |
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| 161 | $this->rootFolder, |
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| 162 | $this->config |
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| 163 | ), |
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| 164 | $this->eventDispatcher |
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| 165 | ); |
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| 166 | } |
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| 167 | return $this->generator; |
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| 168 | } |
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| 169 | |||
| 170 | /** |
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| 171 | * Returns a preview of a file |
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| 172 | * |
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| 173 | * The cache is searched first and if nothing usable was found then a preview is |
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| 174 | * generated by one of the providers |
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| 175 | * |
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| 176 | * @param File $file |
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| 177 | * @param int $width |
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| 178 | * @param int $height |
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| 179 | * @param bool $crop |
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| 180 | * @param string $mode |
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| 181 | * @param string $mimeType |
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| 182 | * @return ISimpleFile |
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| 183 | * @throws NotFoundException |
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| 184 | * @throws \InvalidArgumentException if the preview would be invalid (in case the original image is invalid) |
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| 185 | * @since 11.0.0 - \InvalidArgumentException was added in 12.0.0 |
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| 186 | */ |
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| 187 | public function getPreview(File $file, $width = -1, $height = -1, $crop = false, $mode = IPreview::MODE_FILL, $mimeType = null) { |
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| 188 | return $this->getGenerator()->getPreview($file, $width, $height, $crop, $mode, $mimeType); |
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| 189 | } |
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| 190 | |||
| 191 | /** |
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| 192 | * Generates previews of a file |
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| 193 | * |
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| 194 | * @param File $file |
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| 195 | * @param array $specifications |
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| 196 | * @param string $mimeType |
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| 197 | * @return ISimpleFile the last preview that was generated |
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| 198 | * @throws NotFoundException |
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| 199 | * @throws \InvalidArgumentException if the preview would be invalid (in case the original image is invalid) |
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| 200 | * @since 19.0.0 |
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| 201 | */ |
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| 202 | public function generatePreviews(File $file, array $specifications, $mimeType = null) { |
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| 203 | return $this->getGenerator()->generatePreviews($file, $specifications, $mimeType); |
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| 204 | } |
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| 205 | |||
| 206 | /** |
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| 207 | * returns true if the passed mime type is supported |
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| 208 | * |
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| 209 | * @param string $mimeType |
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| 210 | * @return boolean |
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| 211 | */ |
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| 212 | public function isMimeSupported($mimeType = '*') { |
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| 213 | if (!$this->config->getSystemValue('enable_previews', true)) { |
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| 214 | return false; |
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| 215 | } |
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| 216 | |||
| 217 | if (isset($this->mimeTypeSupportMap[$mimeType])) { |
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| 218 | return $this->mimeTypeSupportMap[$mimeType]; |
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| 219 | } |
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| 220 | |||
| 221 | $this->registerCoreProviders(); |
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| 222 | $providerMimeTypes = array_keys($this->providers); |
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| 223 | foreach ($providerMimeTypes as $supportedMimeType) { |
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| 224 | if (preg_match($supportedMimeType, $mimeType)) { |
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| 225 | $this->mimeTypeSupportMap[$mimeType] = true; |
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| 226 | return true; |
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| 227 | } |
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| 228 | } |
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| 229 | $this->mimeTypeSupportMap[$mimeType] = false; |
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| 230 | return false; |
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| 231 | } |
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| 232 | |||
| 233 | /** |
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| 234 | * Check if a preview can be generated for a file |
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| 235 | * |
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| 236 | * @param \OCP\Files\FileInfo $file |
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| 237 | * @return bool |
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| 238 | */ |
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| 239 | public function isAvailable(\OCP\Files\FileInfo $file) { |
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| 240 | if (!$this->config->getSystemValue('enable_previews', true)) { |
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| 241 | return false; |
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| 242 | } |
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| 243 | |||
| 244 | $this->registerCoreProviders(); |
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| 245 | if (!$this->isMimeSupported($file->getMimetype())) { |
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| 246 | return false; |
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| 247 | } |
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| 248 | |||
| 249 | $mount = $file->getMountPoint(); |
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| 250 | if ($mount and !$mount->getOption('previews', true)){ |
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| 251 | return false; |
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| 252 | } |
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| 253 | |||
| 254 | foreach ($this->providers as $supportedMimeType => $providers) { |
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| 255 | if (preg_match($supportedMimeType, $file->getMimetype())) { |
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| 256 | foreach ($providers as $providerClosure) { |
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| 257 | $provider = $this->helper->getProvider($providerClosure); |
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| 258 | if (!($provider instanceof IProviderV2)) { |
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| 259 | continue; |
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| 260 | } |
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| 261 | |||
| 262 | /** @var $provider IProvider */ |
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| 263 | if ($provider->isAvailable($file)) { |
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| 264 | return true; |
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| 265 | } |
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| 266 | } |
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| 267 | } |
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| 268 | } |
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| 269 | return false; |
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| 270 | } |
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| 271 | |||
| 272 | /** |
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| 273 | * List of enabled default providers |
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| 274 | * |
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| 275 | * The following providers are enabled by default: |
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| 276 | * - OC\Preview\PNG |
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| 277 | * - OC\Preview\JPEG |
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| 278 | * - OC\Preview\GIF |
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| 279 | * - OC\Preview\BMP |
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| 280 | * - OC\Preview\HEIC |
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| 281 | * - OC\Preview\XBitmap |
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| 282 | * - OC\Preview\MarkDown |
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| 283 | * - OC\Preview\MP3 |
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| 284 | * - OC\Preview\TXT |
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| 285 | * |
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| 286 | * The following providers are disabled by default due to performance or privacy concerns: |
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| 287 | * - OC\Preview\Font |
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| 288 | * - OC\Preview\Illustrator |
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| 289 | * - OC\Preview\Movie |
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| 290 | * - OC\Preview\MSOfficeDoc |
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| 291 | * - OC\Preview\MSOffice2003 |
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| 292 | * - OC\Preview\MSOffice2007 |
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| 293 | * - OC\Preview\OpenDocument |
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| 294 | * - OC\Preview\PDF |
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| 295 | * - OC\Preview\Photoshop |
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| 296 | * - OC\Preview\Postscript |
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| 297 | * - OC\Preview\StarOffice |
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| 298 | * - OC\Preview\SVG |
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| 299 | * - OC\Preview\TIFF |
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| 300 | * |
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| 301 | * @return array |
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| 302 | */ |
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| 303 | protected function getEnabledDefaultProvider() { |
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| 304 | if ($this->defaultProviders !== null) { |
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| 305 | return $this->defaultProviders; |
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| 306 | } |
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| 307 | |||
| 308 | $imageProviders = [ |
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| 309 | Preview\PNG::class, |
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| 310 | Preview\JPEG::class, |
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| 311 | Preview\GIF::class, |
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| 312 | Preview\BMP::class, |
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| 313 | Preview\HEIC::class, |
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| 314 | Preview\XBitmap::class, |
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| 315 | Preview\Krita::class, |
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| 316 | ]; |
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| 317 | |||
| 318 | $this->defaultProviders = $this->config->getSystemValue('enabledPreviewProviders', array_merge([ |
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| 319 | Preview\MarkDown::class, |
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| 320 | Preview\MP3::class, |
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| 321 | Preview\TXT::class, |
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| 322 | Preview\OpenDocument::class, |
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| 323 | ], $imageProviders)); |
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| 324 | |||
| 325 | if (in_array(Preview\Image::class, $this->defaultProviders)) { |
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| 326 | $this->defaultProviders = array_merge($this->defaultProviders, $imageProviders); |
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| 327 | } |
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| 328 | $this->defaultProviders = array_unique($this->defaultProviders); |
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| 329 | return $this->defaultProviders; |
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| 330 | } |
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| 331 | |||
| 332 | /** |
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| 333 | * Register the default providers (if enabled) |
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| 334 | * |
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| 335 | * @param string $class |
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| 336 | * @param string $mimeType |
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| 337 | */ |
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| 338 | protected function registerCoreProvider($class, $mimeType, $options = []) { |
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| 342 | }); |
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| 343 | } |
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| 344 | } |
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| 345 | |||
| 346 | /** |
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| 347 | * Register the default providers (if enabled) |
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| 348 | */ |
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| 349 | protected function registerCoreProviders() { |
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| 428 | } |
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| 429 | } |
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| 430 | } |
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| 431 | } |
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| 432 |
