Merge pull request #840 from nextcloud/theming-icon-endpoint

Add dynamic icon creation

22 files changed, 1350 insertions, 6 deletions

diff --git a/apps/theming/appinfo/routes.php b/apps/theming/appinfo/routes.php
index 4a8d4bac5bc..f4aa2f93162 100644
--- a/apps/theming/appinfo/routes.php
+++ b/apps/theming/appinfo/routes.php
@@ -60,5 +60,23 @@ return ['routes' => [
 		'url' => '/js/theming',
 		'verb' => 'GET',
 	],
+	[
+		'name'	=> 'Icon#getFavicon',
+		'url' => '/favicon/{app}',
+		'verb' => 'GET',
+		'defaults' => array('app' => 'core'),
+	],
+	[
+		'name'	=> 'Icon#getTouchIcon',
+		'url' => '/icon/{app}',
+		'verb' => 'GET',
+		'defaults' => array('app' => 'core'),
+	],
+	[
+		'name'	=> 'Icon#getThemedIcon',
+		'url' => '/img/{app}/{image}',
+		'verb' => 'GET',
+		'requirements' => array('image' => '.+')
+	],
 ]];
 
diff --git a/apps/theming/lib/Controller/IconController.php b/apps/theming/lib/Controller/IconController.php
new file mode 100644
index 00000000000..4c25d911e5e
--- /dev/null
+++ b/apps/theming/lib/Controller/IconController.php
@@ -0,0 +1,174 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016 Julius Haertl <jus@bitgrid.net>
+ *
+ * @author Julius Haertl <jus@bitgrid.net>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+namespace OCA\Theming\Controller;
+
+use OCA\Theming\IconBuilder;
+use OCA\Theming\ImageManager;
+use OCA\Theming\ThemingDefaults;
+use OCP\AppFramework\Controller;
+use OCP\AppFramework\Http;
+use OCP\AppFramework\Http\NotFoundResponse;
+use OCP\AppFramework\Http\FileDisplayResponse;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\Files\NotFoundException;
+use OCP\IRequest;
+use OCA\Theming\Util;
+use OCP\IConfig;
+
+class IconController extends Controller {
+	/** @var ThemingDefaults */
+	private $themingDefaults;
+	/** @var Util */
+	private $util;
+	/** @var ITimeFactory */
+	private $timeFactory;
+	/** @var IConfig */
+	private $config;
+	/** @var IconBuilder */
+	private $iconBuilder;
+	/** @var ImageManager */
+	private $imageManager;
+
+	/**
+	 * IconController constructor.
+	 *
+	 * @param string $appName
+	 * @param IRequest $request
+	 * @param ThemingDefaults $themingDefaults
+	 * @param Util $util
+	 * @param ITimeFactory $timeFactory
+	 * @param IConfig $config
+	 * @param IconBuilder $iconBuilder
+	 * @param ImageManager $imageManager
+	 */
+	public function __construct(
+		$appName,
+		IRequest $request,
+		ThemingDefaults $themingDefaults,
+		Util $util,
+		ITimeFactory $timeFactory,
+		IConfig $config,
+		IconBuilder $iconBuilder,
+		ImageManager $imageManager
+	) {
+		parent::__construct($appName, $request);
+
+		$this->themingDefaults = $themingDefaults;
+		$this->util = $util;
+		$this->timeFactory = $timeFactory;
+		$this->config = $config;
+		$this->iconBuilder = $iconBuilder;
+		$this->imageManager = $imageManager;
+	}
+
+	/**
+	 * @PublicPage
+	 * @NoCSRFRequired
+	 *
+	 * @param $app string app name
+	 * @param $image string image file name (svg required)
+	 * @return FileDisplayResponse|NotFoundResponse
+	 */
+	public function getThemedIcon($app, $image) {
+		try {
+			$iconFile = $this->imageManager->getCachedImage("icon-" . $app . '-' . str_replace("/","_",$image));
+		} catch (NotFoundException $exception) {
+			$icon = $this->iconBuilder->colorSvg($app, $image);
+			$iconFile = $this->imageManager->setCachedImage("icon-" . $app . '-' . str_replace("/","_",$image), $icon);
+		}
+		if ($iconFile !== false) {
+			$response = new FileDisplayResponse($iconFile, Http::STATUS_OK, ['Content-Type' => 'image/svg+xml']);
+			$response->cacheFor(86400);
+			$expires = new \DateTime();
+			$expires->setTimestamp($this->timeFactory->getTime());
+			$expires->add(new \DateInterval('PT24H'));
+			$response->addHeader('Expires', $expires->format(\DateTime::RFC2822));
+			$response->addHeader('Pragma', 'cache');
+			return $response;
+		} else {
+			return new NotFoundResponse();
+		}
+	}
+
+	/**
+	 * Return a 32x32 favicon as png
+	 *
+	 * @PublicPage
+	 * @NoCSRFRequired
+	 *
+	 * @param $app string app name
+	 * @return FileDisplayResponse|NotFoundResponse
+	 */
+	public function getFavicon($app = "core") {
+		if ($this->themingDefaults->shouldReplaceIcons()) {
+			try {
+				$iconFile = $this->imageManager->getCachedImage('favIcon-' . $app);
+			} catch (NotFoundException $exception) {
+				$icon = $this->iconBuilder->getFavicon($app);
+				$iconFile = $this->imageManager->setCachedImage('favIcon-' . $app, $icon);
+			}
+			if ($iconFile !== false) {
+				$response = new FileDisplayResponse($iconFile, Http::STATUS_OK, ['Content-Type' => 'image/x-icon']);
+				$response->cacheFor(86400);
+				$expires = new \DateTime();
+				$expires->setTimestamp($this->timeFactory->getTime());
+				$expires->add(new \DateInterval('PT24H'));
+				$response->addHeader('Expires', $expires->format(\DateTime::RFC2822));
+				$response->addHeader('Pragma', 'cache');
+				return $response;
+			}
+		}
+		return new NotFoundResponse();
+	}
+
+	/**
+	 * Return a 512x512 icon for touch devices
+	 *
+	 * @PublicPage
+	 * @NoCSRFRequired
+	 *
+	 * @param $app string app name
+	 * @return FileDisplayResponse|NotFoundResponse
+	 */
+	public function getTouchIcon($app = "core") {
+		if ($this->themingDefaults->shouldReplaceIcons()) {
+			try {
+				$iconFile = $this->imageManager->getCachedImage('touchIcon-' . $app);
+			} catch (NotFoundException $exception) {
+				$icon = $this->iconBuilder->getTouchIcon($app);
+				$iconFile = $this->imageManager->setCachedImage('touchIcon-' . $app, $icon);
+			}
+			if ($iconFile !== false) {
+				$response = new FileDisplayResponse($iconFile, Http::STATUS_OK, ['Content-Type' => 'image/png']);
+				$response->cacheFor(86400);
+				$expires = new \DateTime();
+				$expires->setTimestamp($this->timeFactory->getTime());
+				$expires->add(new \DateInterval('PT24H'));
+				$response->addHeader('Expires', $expires->format(\DateTime::RFC2822));
+				$response->addHeader('Pragma', 'cache');
+				return $response;
+			}
+		}
+		return new NotFoundResponse();
+	}
+}
diff --git a/apps/theming/lib/Controller/ThemingController.php b/apps/theming/lib/Controller/ThemingController.php
index 1eefb2e3dd7..58e843c5d9d 100644
--- a/apps/theming/lib/Controller/ThemingController.php
+++ b/apps/theming/lib/Controller/ThemingController.php
@@ -410,6 +410,15 @@ class ThemingController extends Controller {
 			$responseCss .= '.nc-theming-contrast {color: #ffffff}' . "\n";
 		}
 
+		if($logo !== '' or $color !== '') {
+			$responseCss .= '.icon-file,.icon-filetype-text {' .
+				'background-image: url(\'./img/core/filetypes/text.svg?v='.$cacheBusterValue.'\');' . "}\n" .
+				'.icon-folder, .icon-filetype-folder {' .
+				'background-image: url(\'./img/core/filetypes/folder.svg?v='.$cacheBusterValue.'\');' . "}\n" .
+				'.icon-filetype-folder-drag-accept {' .
+				'background-image: url(\'./img/core/filetypes/folder-drag-accept.svg?v='.$cacheBusterValue.'\')!important;' . "}\n";
+		}
+
 		$response = new DataDownloadResponse($responseCss, 'style', 'text/css');
 		$response->addHeader('Expires', date(\DateTime::RFC2822, $this->timeFactory->getTime()));
 		$response->addHeader('Pragma', 'cache');
@@ -423,6 +432,7 @@ class ThemingController extends Controller {
 	 * @return DataDownloadResponse
 	 */
 	public function getJavascript() {
+		$cacheBusterValue = $this->config->getAppValue('theming', 'cachebuster', '0');
 		$responseJS = '(function() {
 	OCA.Theming = {
 		name: ' . json_encode($this->template->getName()) . ',
@@ -430,6 +440,7 @@ class ThemingController extends Controller {
 		slogan: ' . json_encode($this->template->getSlogan()) . ',
 		color: ' . json_encode($this->template->getMailHeaderColor()) . ',
 		inverted: ' . json_encode($this->util->invertTextColor($this->template->getMailHeaderColor())) . ',
+		cacheBuster: ' . json_encode($cacheBusterValue). '
 	};
 })();';
 		$response = new Http\DataDisplayResponse($responseJS);
diff --git a/apps/theming/lib/IconBuilder.php b/apps/theming/lib/IconBuilder.php
new file mode 100644
index 00000000000..d8161051ebb
--- /dev/null
+++ b/apps/theming/lib/IconBuilder.php
@@ -0,0 +1,182 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016 Julius Härtl <jus@bitgrid.net>
+ *
+ * @author Julius Härtl <jus@bitgrid.net>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as
+ *  published by the Free Software Foundation, either version 3 of the
+ *  License, or (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\Theming;
+
+use Imagick;
+use ImagickPixel;
+use OCP\App\AppPathNotFoundException;
+
+class IconBuilder {
+	/** @var ThemingDefaults */
+	private $themingDefaults;
+	/** @var Util */
+	private $util;
+
+	/**
+	 * IconBuilder constructor.
+	 *
+	 * @param ThemingDefaults $themingDefaults
+	 * @param Util $util
+	 */
+	public function __construct(
+		ThemingDefaults $themingDefaults,
+		Util $util
+	) {
+		$this->themingDefaults = $themingDefaults;
+		$this->util = $util;
+	}
+
+	/**
+	 * @param $app string app name
+	 * @return string|false image blob
+	 */
+	public function getFavicon($app) {
+		$icon = $this->renderAppIcon($app);
+		if($icon === false) {
+			return false;
+		}
+		$icon->resizeImage(32, 32, Imagick::FILTER_LANCZOS, 1);
+		$icon->setImageFormat("png24");
+		$data = $icon->getImageBlob();
+		$icon->destroy();
+		return $data;
+	}
+
+	/**
+	 * @param $app string app name
+	 * @return string|false image blob
+	 */
+	public function getTouchIcon($app) {
+		$icon = $this->renderAppIcon($app);
+		if($icon === false) {
+			return false;
+		}
+		$icon->setImageFormat("png24");
+		$data = $icon->getImageBlob();
+		$icon->destroy();
+		return $data;
+	}
+
+	/**
+	 * Render app icon on themed background color
+	 * fallback to logo
+	 *
+	 * @param $app string app name
+	 * @return Imagick|false
+	 */
+	public function renderAppIcon($app) {
+		try {
+			$appIcon = $this->util->getAppIcon($app);
+			$appIconContent = file_get_contents($appIcon);
+		} catch (AppPathNotFoundException $e) {
+			return false;
+		}
+
+		if($appIconContent === false) {
+			return false;
+		}
+
+		$color = $this->themingDefaults->getMailHeaderColor();
+		$mime = mime_content_type($appIcon);
+
+		// generate background image with rounded corners
+		$background = '<?xml version="1.0" encoding="UTF-8"?>' .
+			'<svg xmlns="http://www.w3.org/2000/svg" version="1.1" xmlns:cc="http://creativecommons.org/ns#" width="512" height="512" xmlns:xlink="http://www.w3.org/1999/xlink">' .
+			'<rect x="0" y="0" rx="75" ry="75" width="512" height="512" style="fill:' . $color . ';" />' .
+			'</svg>';
+		// resize svg magic as this seems broken in Imagemagick
+		if($mime === "image/svg+xml" || substr($appIconContent, 0, 4) === "<svg") {
+			if(substr($appIconContent, 0, 5) !== "<?xml") {
+				$svg = "<?xml version=\"1.0\"?>".$appIconContent;
+			} else {
+				$svg = $appIconContent;
+			}
+			$tmp = new Imagick();
+			$tmp->readImageBlob($svg);
+			$x = $tmp->getImageWidth();
+			$y = $tmp->getImageHeight();
+			$res = $tmp->getImageResolution();
+			$tmp->destroy();
+
+			if($x>$y) {
+				$max = $x;
+			} else {
+				$max = $y;
+			}
+
+			// convert svg to resized image
+			$appIconFile = new Imagick();
+			$resX = (int)(512 * $res['x'] / $max * 2.53);
+			$resY = (int)(512 * $res['y'] / $max * 2.53);
+			$appIconFile->setResolution($resX, $resY);
+			$appIconFile->setBackgroundColor(new ImagickPixel('transparent'));
+			$appIconFile->readImageBlob($svg);
+			$appIconFile->scaleImage(512, 512, true);
+		} else {
+			$appIconFile = new Imagick();
+			$appIconFile->setBackgroundColor(new ImagickPixel('transparent'));
+			$appIconFile->readImageBlob(file_get_contents($appIcon));
+			$appIconFile->scaleImage(512, 512, true);
+		}
+
+		// offset for icon positioning
+		$border_w = (int)($appIconFile->getImageWidth() * 0.05);
+		$border_h = (int)($appIconFile->getImageHeight() * 0.05);
+		$innerWidth = (int)($appIconFile->getImageWidth() - $border_w * 2);
+		$innerHeight = (int)($appIconFile->getImageHeight() - $border_h * 2);
+		$appIconFile->adaptiveResizeImage($innerWidth, $innerHeight);
+		// center icon
+		$offset_w = 512 / 2 - $innerWidth / 2;
+		$offset_h = 512 / 2 - $innerHeight / 2;
+
+		$appIconFile->setImageFormat("png24");
+
+		$finalIconFile = new Imagick();
+		$finalIconFile->readImageBlob($background);
+		$finalIconFile->setImageVirtualPixelMethod(Imagick::VIRTUALPIXELMETHOD_TRANSPARENT);
+		$finalIconFile->setImageArtifact('compose:args', "1,0,-0.5,0.5");
+		$finalIconFile->compositeImage($appIconFile, Imagick::COMPOSITE_ATOP, $offset_w, $offset_h);
+		$finalIconFile->resizeImage(512, 512, Imagick::FILTER_LANCZOS, 1);
+
+		$appIconFile->destroy();
+		return $finalIconFile;
+	}
+
+	public function colorSvg($app, $image) {
+		try {
+			$imageFile = $this->util->getAppImage($app, $image);
+		} catch (AppPathNotFoundException $e) {
+			return false;
+		}
+		$svg = file_get_contents($imageFile);
+		if ($svg !== false) {
+			$color = $this->util->elementColor($this->themingDefaults->getMailHeaderColor());
+			$svg = $this->util->colorizeSvg($svg, $color);
+			return $svg;
+		} else {
+			return false;
+		}
+	}
+
+}
diff --git a/apps/theming/lib/ImageManager.php b/apps/theming/lib/ImageManager.php
new file mode 100644
index 00000000000..4cd43e02054
--- /dev/null
+++ b/apps/theming/lib/ImageManager.php
@@ -0,0 +1,112 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016 Julius Härtl <jus@bitgrid.net>
+ *
+ * @author Julius Härtl <jus@bitgrid.net>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as
+ *  published by the Free Software Foundation, either version 3 of the
+ *  License, or (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+
+namespace OCA\Theming;
+
+use OCP\IConfig;
+use OCP\Files\IAppData;
+use OCP\Files\NotFoundException;
+use OCP\Files\NotPermittedException;
+
+class ImageManager {
+
+	/** @var IConfig */
+	private $config;
+	/** @var IAppData */
+	private $appData;
+
+	/**
+	 * ImageManager constructor.
+	 *
+	 * @param IConfig $config
+	 * @param IAppData $appData
+	 */
+	public function __construct(IConfig $config,
+								IAppData $appData
+	) {
+		$this->config = $config;
+		$this->appData = $appData;
+	}
+
+	/**
+	 * Get folder for current theming files
+	 *
+	 * @return \OCP\Files\SimpleFS\ISimpleFolder
+	 * @throws NotPermittedException
+	 * @throws \RuntimeException
+	 */
+	public function getCacheFolder() {
+		$cacheBusterValue = $this->config->getAppValue('theming', 'cachebuster', '0');
+		try {
+			$folder = $this->appData->getFolder($cacheBusterValue);
+		} catch (NotFoundException $e) {
+			$folder = $this->appData->newFolder($cacheBusterValue);
+			$this->cleanup();
+		}
+		return $folder;
+	}
+
+	/**
+	 * Get a file from AppData
+	 *
+	 * @param string $filename
+	 * @throws NotFoundException
+	 * @return \OCP\Files\SimpleFS\ISimpleFile
+	 */
+	public function getCachedImage($filename) {
+		$currentFolder = $this->getCacheFolder();
+		return $currentFolder->getFile($filename);
+	}
+
+	/**
+	 * Store a file for theming in AppData
+	 *
+	 * @param string $filename
+	 * @param string $data
+	 * @return \OCP\Files\SimpleFS\ISimpleFile
+	 */
+	public function setCachedImage($filename, $data) {
+		$currentFolder = $this->getCacheFolder();
+		if ($currentFolder->fileExists($filename)) {
+			$file = $currentFolder->getFile($filename);
+		} else {
+			$file = $currentFolder->newFile($filename);
+		}
+		$file->putContent($data);
+		return $file;
+	}
+
+	/**
+	 * remove cached files that are not required any longer
+	 */
+	public function cleanup() {
+		$currentFolder = $this->getCacheFolder();
+		$folders = $this->appData->getDirectoryListing();
+		foreach ($folders as $folder) {
+			if ($folder->getName() !== $currentFolder->getName()) {
+				$folder->delete();
+			}
+		}
+	}
+}
diff --git a/apps/theming/lib/ThemingDefaults.php b/apps/theming/lib/ThemingDefaults.php
index 9139dd56247..36f19157637 100644
--- a/apps/theming/lib/ThemingDefaults.php
+++ b/apps/theming/lib/ThemingDefaults.php
@@ -23,6 +23,7 @@
 namespace OCA\Theming;
 
 
+use OCP\ICacheFactory;
 use OCP\IConfig;
 use OCP\IL10N;
 use OCP\IURLGenerator;
@@ -38,6 +39,8 @@ class ThemingDefaults extends \OC_Defaults {
 	private $urlGenerator;
 	/** @var IRootFolder */
 	private $rootFolder;
+	/** @var ICacheFactory */
+	private $cacheFactory;
 	/** @var string */
 	private $name;
 	/** @var string */
@@ -55,18 +58,21 @@ class ThemingDefaults extends \OC_Defaults {
 	 * @param IURLGenerator $urlGenerator
 	 * @param \OC_Defaults $defaults
 	 * @param IRootFolder $rootFolder
+	 * @param ICacheFactory $cacheFactory
 	 */
 	public function __construct(IConfig $config,
 								IL10N $l,
 								IURLGenerator $urlGenerator,
 								\OC_Defaults $defaults,
-								IRootFolder $rootFolder
+								IRootFolder $rootFolder,
+								ICacheFactory $cacheFactory
 	) {
 		parent::__construct();
 		$this->config = $config;
 		$this->l = $l;
 		$this->urlGenerator = $urlGenerator;
 		$this->rootFolder = $rootFolder;
+		$this->cacheFactory = $cacheFactory;
 
 		$this->name = $defaults->getName();
 		$this->url = $defaults->getBaseUrl();
@@ -145,6 +151,29 @@ class ThemingDefaults extends \OC_Defaults {
 	}
 
 	/**
+	 * Check if Imagemagick is enabled and if SVG is supported
+	 * otherwise we can't render custom icons
+	 *
+	 * @return bool
+	 */
+	public function shouldReplaceIcons() {
+		$cache = $this->cacheFactory->create('theming');
+		if($value = $cache->get('shouldReplaceIcons')) {
+			return (bool)$value;
+		}
+		$value = false;
+		if(extension_loaded('imagick')) {
+			$checkImagick = new \Imagick();
+			if (count($checkImagick->queryFormats('SVG')) >= 1) {
+				$value = true;
+			}
+			$checkImagick->clear();
+		}
+		$cache->set('shouldReplaceIcons', $value);
+		return $value;
+	}
+
+	/**
 	 * Increases the cache buster key
 	 */
 	private function increaseCacheBuster() {
diff --git a/apps/theming/lib/Util.php b/apps/theming/lib/Util.php
index 71ed0958e42..9fea56838ad 100644
--- a/apps/theming/lib/Util.php
+++ b/apps/theming/lib/Util.php
@@ -23,8 +23,35 @@
 
 namespace OCA\Theming;
 
+use OCP\App\AppPathNotFoundException;
+use OCP\App\IAppManager;
+use OCP\IConfig;
+use OCP\Files\IRootFolder;
+
 class Util {
 
+	/** @var IConfig */
+	private $config;
+
+	/** @var IRootFolder */
+	private $rootFolder;
+
+	/** @var IAppManager */
+	private $appManager;
+
+	/**
+	 * Util constructor.
+	 *
+	 * @param IConfig $config
+	 * @param IRootFolder $rootFolder
+	 * @param IAppManager $appManager
+	 */
+	public function __construct(IConfig $config, IRootFolder $rootFolder, IAppManager $appManager) {
+		$this->config = $config;
+		$this->rootFolder = $rootFolder;
+		$this->appManager = $appManager;
+	}
+
 	/**
 	 * @param string $color rgb color value
 	 * @return bool
@@ -81,4 +108,86 @@ class Util {
 		return base64_encode($radioButtonIcon);
 	}
 
+
+	/**
+	 * @param $app string app name
+	 * @return string path to app icon / logo
+	 */
+	public function getAppIcon($app) {
+		$app = str_replace(array('\0', '/', '\\', '..'), '', $app);
+		try {
+			$appPath = $this->appManager->getAppPath($app);
+			$icon = $appPath . '/img/' . $app . '.svg';
+			if (file_exists($icon)) {
+				return $icon;
+			}
+			$icon = $appPath . '/img/app.svg';
+			if (file_exists($icon)) {
+				return $icon;
+			}
+		} catch (AppPathNotFoundException $e) {}
+
+		if($this->config->getAppValue('theming', 'logoMime', '') !== '' && $this->rootFolder->nodeExists('/themedinstancelogo')) {
+			return $this->config->getSystemValue('datadirectory', \OC::$SERVERROOT . '/data/') . '/themedinstancelogo';
+		}
+		return \OC::$SERVERROOT . '/core/img/logo.svg';
+	}
+
+	/**
+	 * @param $app string app name
+	 * @param $image string relative path to image in app folder
+	 * @return string|false absolute path to image
+	 */
+	public function getAppImage($app, $image) {
+		$app = str_replace(array('\0', '/', '\\', '..'), '', $app);
+		$image = str_replace(array('\0', '\\', '..'), '', $image);
+		if ($app === "core") {
+			$icon = \OC::$SERVERROOT . '/core/img/' . $image;
+			if (file_exists($icon)) {
+				return $icon;
+			}
+		}
+
+		try {
+			$appPath = $this->appManager->getAppPath($app);
+		} catch (AppPathNotFoundException $e) {
+			return false;
+		}
+
+		$icon = $appPath . '/img/' . $image;
+		if (file_exists($icon)) {
+			return $icon;
+		}
+		$icon = $appPath . '/img/' . $image . '.svg';
+		if (file_exists($icon)) {
+			return $icon;
+		}
+		$icon = $appPath . '/img/' . $image . '.png';
+		if (file_exists($icon)) {
+			return $icon;
+		}
+		$icon = $appPath . '/img/' . $image . '.gif';
+		if (file_exists($icon)) {
+			return $icon;
+		}
+		$icon = $appPath . '/img/' . $image . '.jpg';
+		if (file_exists($icon)) {
+			return $icon;
+		}
+
+		return false;
+	}
+
+	/**
+	 * replace default color with a custom one
+	 *
+	 * @param $svg string content of a svg file
+	 * @param $color string color to match
+	 * @return string
+	 */
+	public function colorizeSvg($svg, $color) {
+		$svg = preg_replace('/#0082c9/i', $color, $svg);
+		return $svg;
+	}
+
 }
diff --git a/apps/theming/tests/Controller/IconControllerTest.php b/apps/theming/tests/Controller/IconControllerTest.php
new file mode 100644
index 00000000000..591c1075492
--- /dev/null
+++ b/apps/theming/tests/Controller/IconControllerTest.php
@@ -0,0 +1,201 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016 Julius Härtl <jus@bitgrid.net>
+ *
+ * @author Julius Härtl <jus@bitgrid.net>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as
+ *  published by the Free Software Foundation, either version 3 of the
+ *  License, or (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+namespace OCA\Theming\Tests\Controller;
+
+
+use OC\Files\SimpleFS\SimpleFile;
+use OCA\Theming\ImageManager;
+use OCP\AppFramework\Http;
+use OCP\AppFramework\Http\DataDisplayResponse;
+use OCP\AppFramework\Http\NotFoundResponse;
+use OCP\Files\IRootFolder;
+use OCP\Files\NotFoundException;
+use OCP\IConfig;
+use OCP\IRequest;
+use Test\TestCase;
+use OCA\Theming\Util;
+use OCA\Theming\Controller\IconController;
+use OCP\AppFramework\Http\FileDisplayResponse;
+
+
+class IconControllerTest extends TestCase {
+	/** @var IRequest|\PHPUnit_Framework_MockObject_MockObject */
+	private $request;
+	/** @var IConfig|\PHPUnit_Framework_MockObject_MockObject */
+	private $themingDefaults;
+	/** @var Util */
+	private $util;
+	/** @var \OCP\AppFramework\Utility\ITimeFactory */
+	private $timeFactory;
+	/** @var IconController|\PHPUnit_Framework_MockObject_MockObject */
+	private $iconController;
+	/** @var IConfig|\PHPUnit_Framework_MockObject_MockObject */
+	private $config;
+	/** @var IRootFolder|\PHPUnit_Framework_MockObject_MockObject */
+	private $iconBuilder;
+	/** @var ImageManager */
+	private $imageManager;
+
+	public function setUp() {
+		$this->request = $this->getMockBuilder('OCP\IRequest')->getMock();
+		$this->themingDefaults = $this->getMockBuilder('OCA\Theming\ThemingDefaults')
+			->disableOriginalConstructor()->getMock();
+		$this->util = $this->getMockBuilder('\OCA\Theming\Util')->disableOriginalConstructor()
+			->setMethods(['getAppImage', 'getAppIcon', 'elementColor'])->getMock();
+		$this->timeFactory = $this->getMockBuilder('OCP\AppFramework\Utility\ITimeFactory')
+			->disableOriginalConstructor()
+			->getMock();
+		$this->config = $this->getMockBuilder('OCP\IConfig')->getMock();
+		$this->iconBuilder = $this->getMockBuilder('OCA\Theming\IconBuilder')
+			->disableOriginalConstructor()->getMock();
+		$this->imageManager = $this->getMockBuilder('OCA\Theming\ImageManager')->disableOriginalConstructor()->getMock();
+		$this->timeFactory->expects($this->any())
+			->method('getTime')
+			->willReturn(123);
+
+		$this->iconController = new IconController(
+			'theming',
+			$this->request,
+			$this->themingDefaults,
+			$this->util,
+			$this->timeFactory,
+			$this->config,
+			$this->iconBuilder,
+			$this->imageManager
+		);
+
+		parent::setUp();
+	}
+
+	private function iconFileMock($filename, $data) {
+		$icon = $this->getMockBuilder('OCP\Files\File')->getMock();
+		$icon->expects($this->any())->method('getContent')->willReturn($data);
+		$icon->expects($this->any())->method('getMimeType')->willReturn('image type');
+		$icon->expects($this->any())->method('getEtag')->willReturn('my etag');
+		$icon->method('getName')->willReturn($filename);
+		return new SimpleFile($icon);
+	}
+
+	public function testGetThemedIcon() {
+		$file = $this->iconFileMock('icon-core-filetypes_folder.svg', 'filecontent');
+		$this->imageManager->expects($this->once())
+			->method('getCachedImage')
+			->with('icon-core-filetypes_folder.svg')
+			->willReturn($file);
+		$expected = new FileDisplayResponse($file, Http::STATUS_OK, ['Content-Type' => 'image/svg+xml']);
+		$expected->cacheFor(86400);
+		$expires = new \DateTime();
+		$expires->setTimestamp($this->timeFactory->getTime());
+		$expires->add(new \DateInterval('PT24H'));
+		$expected->addHeader('Expires', $expires->format(\DateTime::RFC2822));
+		$expected->addHeader('Pragma', 'cache');
+		@$this->assertEquals($expected, $this->iconController->getThemedIcon('core', 'filetypes/folder.svg'));
+	}
+
+	public function testGetFaviconDefault() {
+		if (!extension_loaded('imagick')) {
+			$this->markTestSkipped('Imagemagick is required for dynamic icon generation.');
+		}
+		$checkImagick = new \Imagick();
+		if (count($checkImagick->queryFormats('SVG')) < 1) {
+			$this->markTestSkipped('No SVG provider present.');
+		}
+		$this->themingDefaults->expects($this->any())
+			->method('shouldReplaceIcons')
+			->willReturn(true);
+
+		$this->iconBuilder->expects($this->once())
+			->method('getFavicon')
+			->with('core')
+			->willReturn('filecontent');
+		$file = $this->iconFileMock('filename', 'filecontent');
+		$this->imageManager->expects($this->once())
+			->method('getCachedImage')
+			->will($this->throwException(new NotFoundException()));
+		$this->imageManager->expects($this->once())
+			->method('setCachedImage')
+			->willReturn($file);
+
+		$expected = new FileDisplayResponse($file, Http::STATUS_OK, ['Content-Type' => 'image/x-icon']);
+		$expected->cacheFor(86400);
+		$expires = new \DateTime();
+		$expires->setTimestamp($this->timeFactory->getTime());
+		$expires->add(new \DateInterval('PT24H'));
+		$expected->addHeader('Expires', $expires->format(\DateTime::RFC2822));
+		$expected->addHeader('Pragma', 'cache');
+		$this->assertEquals($expected, $this->iconController->getFavicon());
+	}
+
+	public function testGetFaviconFail() {
+		$this->themingDefaults->expects($this->any())
+			->method('shouldReplaceIcons')
+			->willReturn(false);
+		$expected = new Http\Response();
+		$expected->setStatus(Http::STATUS_NOT_FOUND);
+		$expected->cacheFor(0);
+		$expected->setLastModified(new \DateTime('now', new \DateTimeZone('GMT')));
+		$this->assertInstanceOf(NotFoundResponse::class, $this->iconController->getFavicon());
+	}
+
+	public function testGetTouchIconDefault() {
+		if (!extension_loaded('imagick')) {
+			$this->markTestSkipped('Imagemagick is required for dynamic icon generation.');
+		}
+		$checkImagick = new \Imagick();
+		if (count($checkImagick->queryFormats('SVG')) < 1) {
+			$this->markTestSkipped('No SVG provider present.');
+		}
+		$this->themingDefaults->expects($this->any())
+			->method('shouldReplaceIcons')
+			->willReturn(true);
+
+		$this->iconBuilder->expects($this->once())
+			->method('getTouchIcon')
+			->with('core')
+			->willReturn('filecontent');
+		$file = $this->iconFileMock('filename', 'filecontent');
+		$this->imageManager->expects($this->once())
+			->method('getCachedImage')
+			->will($this->throwException(new NotFoundException()));
+		$this->imageManager->expects($this->once())
+			->method('setCachedImage')
+			->willReturn($file);
+
+		$expected = new FileDisplayResponse($file, Http::STATUS_OK, ['Content-Type' => 'image/png']);
+		$expected->cacheFor(86400);
+		$expires = new \DateTime();
+		$expires->setTimestamp($this->timeFactory->getTime());
+		$expires->add(new \DateInterval('PT24H'));
+		$expected->addHeader('Expires', $expires->format(\DateTime::RFC2822));
+		$expected->addHeader('Pragma', 'cache');
+		$this->assertEquals($expected, $this->iconController->getTouchIcon());
+	}
+
+	public function testGetTouchIconFail() {
+		$this->themingDefaults->expects($this->any())
+			->method('shouldReplaceIcons')
+			->willReturn(false);
+		$this->assertInstanceOf(NotFoundResponse::class, $this->iconController->getTouchIcon());
+	}
+
+}
diff --git a/apps/theming/tests/Controller/ThemingControllerTest.php b/apps/theming/tests/Controller/ThemingControllerTest.php
index c9f6ff8a885..d42e5afb245 100644
--- a/apps/theming/tests/Controller/ThemingControllerTest.php
+++ b/apps/theming/tests/Controller/ThemingControllerTest.php
@@ -26,6 +26,7 @@ namespace OCA\Theming\Tests\Controller;
 
 use OCA\Theming\Controller\ThemingController;
 use OCA\Theming\Util;
+use OCP\App\IAppManager;
 use OCP\AppFramework\Http;
 use OCP\AppFramework\Http\DataResponse;
 use OCP\Files\File;
@@ -57,18 +58,21 @@ class ThemingControllerTest extends TestCase {
 	private $rootFolder;
 	/** @var ITempManager */
 	private $tempManager;
+	/** @var IAppManager */
+	private $appManager;
 
 	public function setUp() {
 		$this->request = $this->getMockBuilder('OCP\IRequest')->getMock();
 		$this->config = $this->getMockBuilder('OCP\IConfig')->getMock();
 		$this->template = $this->getMockBuilder('OCA\Theming\ThemingDefaults')
 			->disableOriginalConstructor()->getMock();
-		$this->util = new Util();
 		$this->timeFactory = $this->getMockBuilder('OCP\AppFramework\Utility\ITimeFactory')
 			->disableOriginalConstructor()
 			->getMock();
 		$this->l10n = $this->getMockBuilder('OCP\IL10N')->getMock();
 		$this->rootFolder = $this->getMockBuilder('OCP\Files\IRootFolder')->getMock();
+		$this->appManager = $this->getMockBuilder('OCP\App\IAppManager')->getMock();
+		$this->util = new Util($this->config, $this->rootFolder, $this->appManager);
 		$this->timeFactory->expects($this->any())
 			->method('getTime')
 			->willReturn(123);
@@ -484,6 +488,12 @@ class ThemingControllerTest extends TestCase {
 		$expectedData .= sprintf('.nc-theming-main-background {background-color: %s}' . "\n", $color);
 		$expectedData .= sprintf('.nc-theming-main-text {color: %s}' . "\n", $color);
 		$expectedData .= '.nc-theming-contrast {color: #ffffff}' . "\n";
+		$expectedData .= '.icon-file,.icon-filetype-text {' .
+			'background-image: url(\'./img/core/filetypes/text.svg?v=0\');' . "}\n" .
+			'.icon-folder, .icon-filetype-folder {' .
+			'background-image: url(\'./img/core/filetypes/folder.svg?v=0\');' . "}\n" .
+			'.icon-filetype-folder-drag-accept {' .
+			'background-image: url(\'./img/core/filetypes/folder-drag-accept.svg?v=0\')!important;' . "}\n";
 
 		$expected = new Http\DataDownloadResponse($expectedData, 'style', 'text/css');
 
@@ -578,6 +588,12 @@ class ThemingControllerTest extends TestCase {
 		$expectedData .= '#body-login input.login { background-image: url(\'' . \OC::$WEBROOT . '/core/img/actions/confirm.svg?v=2\'); }' . "\n";
 		$expectedData .= '.nc-theming-contrast {color: #000000}' . "\n";
 		$expectedData .= '.ui-widget-header { color: #000000; }' . "\n";
+		$expectedData .= '.icon-file,.icon-filetype-text {' .
+			'background-image: url(\'./img/core/filetypes/text.svg?v=0\');' . "}\n" .
+			'.icon-folder, .icon-filetype-folder {' .
+			'background-image: url(\'./img/core/filetypes/folder.svg?v=0\');' . "}\n" .
+			'.icon-filetype-folder-drag-accept {' .
+			'background-image: url(\'./img/core/filetypes/folder-drag-accept.svg?v=0\')!important;' . "}\n";
 
 
 		$expected = new Http\DataDownloadResponse($expectedData, 'style', 'text/css');
@@ -623,6 +639,12 @@ class ThemingControllerTest extends TestCase {
 			'background-size: contain;' .
 			'}' . "\n";
 		$expectedData .= '.nc-theming-contrast {color: #ffffff}' . "\n";
+		$expectedData .= '.icon-file,.icon-filetype-text {' .
+			'background-image: url(\'./img/core/filetypes/text.svg?v=0\');' . "}\n" .
+			'.icon-folder, .icon-filetype-folder {' .
+			'background-image: url(\'./img/core/filetypes/folder.svg?v=0\');' . "}\n" .
+			'.icon-filetype-folder-drag-accept {' .
+			'background-image: url(\'./img/core/filetypes/folder-drag-accept.svg?v=0\')!important;' . "}\n";
 
 		$expected = new Http\DataDownloadResponse($expectedData, 'style', 'text/css');
 
@@ -765,6 +787,12 @@ class ThemingControllerTest extends TestCase {
 			'background-image: url(\'./loginbackground?v=0\');' .
 			'}' . "\n";
 		$expectedData .= '.nc-theming-contrast {color: #ffffff}' . "\n";
+		$expectedData .= '.icon-file,.icon-filetype-text {' .
+			'background-image: url(\'./img/core/filetypes/text.svg?v=0\');' . "}\n" .
+			'.icon-folder, .icon-filetype-folder {' .
+			'background-image: url(\'./img/core/filetypes/folder.svg?v=0\');' . "}\n" .
+			'.icon-filetype-folder-drag-accept {' .
+			'background-image: url(\'./img/core/filetypes/folder-drag-accept.svg?v=0\')!important;' . "}\n";
 		$expected = new Http\DataDownloadResponse($expectedData, 'style', 'text/css');
 
 		$expected->cacheFor(3600);
@@ -876,6 +904,13 @@ class ThemingControllerTest extends TestCase {
 		$expectedData .= '#body-login input.login { background-image: url(\'' . \OC::$WEBROOT . '/core/img/actions/confirm.svg?v=2\'); }' . "\n";
 		$expectedData .= '.nc-theming-contrast {color: #000000}' . "\n";
 		$expectedData .= '.ui-widget-header { color: #000000; }' . "\n";
+		$expectedData .= '.icon-file,.icon-filetype-text {' .
+			'background-image: url(\'./img/core/filetypes/text.svg?v=0\');' . "}\n" .
+			'.icon-folder, .icon-filetype-folder {' .
+			'background-image: url(\'./img/core/filetypes/folder.svg?v=0\');' . "}\n" .
+			'.icon-filetype-folder-drag-accept {' .
+			'background-image: url(\'./img/core/filetypes/folder-drag-accept.svg?v=0\')!important;' . "}\n";
+		$expected = new Http\DataDownloadResponse($expectedData, 'style', 'text/css');
 
 		$expected = new Http\DataDownloadResponse($expectedData, 'style', 'text/css');
 		$expected->cacheFor(3600);
@@ -910,6 +945,7 @@ class ThemingControllerTest extends TestCase {
 		slogan: "",
 		color: "#000",
 		inverted: false,
+		cacheBuster: null
 	};
 })();';
 		$expected = new Http\DataDisplayResponse($expectedResponse);
@@ -944,6 +980,7 @@ class ThemingControllerTest extends TestCase {
 		slogan: "awesome",
 		color: "#ffffff",
 		inverted: true,
+		cacheBuster: null
 	};
 })();';
 		$expected = new Http\DataDisplayResponse($expectedResponse);
diff --git a/apps/theming/tests/IconBuilderTest.php b/apps/theming/tests/IconBuilderTest.php
new file mode 100644
index 00000000000..54850c8f3c2
--- /dev/null
+++ b/apps/theming/tests/IconBuilderTest.php
@@ -0,0 +1,192 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016 Julius Härtl <jus@bitgrid.net>
+ *
+ * @author Julius Härtl <jus@bitgrid.net>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as
+ *  published by the Free Software Foundation, either version 3 of the
+ *  License, or (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+namespace OCA\Theming\Tests;
+
+use OCA\Theming\IconBuilder;
+use OCA\Theming\ThemingDefaults;
+use OCA\Theming\Util;
+use OCP\App\IAppManager;
+use OCP\AppFramework\Http\NotFoundResponse;
+use OCP\Files\IRootFolder;
+use OCP\IConfig;
+use Test\TestCase;
+
+class IconBuilderTest extends TestCase {
+
+	/** @var IConfig */
+	protected $config;
+	/** @var IRootFolder */
+	protected $rootFolder;
+	/** @var ThemingDefaults */
+	protected $themingDefaults;
+	/** @var Util */
+	protected $util;
+	/** @var IconBuilder */
+	protected $iconBuilder;
+	/** @var IAppManager */
+	protected $appManager;
+
+	protected function setUp() {
+		parent::setUp();
+
+		$this->config = $this->getMockBuilder('\OCP\IConfig')->getMock();
+		$this->rootFolder = $this->getMockBuilder('OCP\Files\IRootFolder')->getMock();
+		$this->themingDefaults = $this->getMockBuilder('OCA\Theming\ThemingDefaults')
+			->disableOriginalConstructor()->getMock();
+		$this->appManager = $this->getMockBuilder('OCP\App\IAppManager')->getMock();
+		$this->util = new Util($this->config, $this->rootFolder, $this->appManager);
+		$this->iconBuilder = new IconBuilder($this->themingDefaults, $this->util);
+	}
+
+	private function checkImagick() {
+		if(!extension_loaded('imagick')) {
+			$this->markTestSkipped('Imagemagick is required for dynamic icon generation.');
+		}
+		$checkImagick = new \Imagick();
+		if (count($checkImagick->queryFormats('SVG')) < 1) {
+			$this->markTestSkipped('No SVG provider present.');
+		}
+	}
+
+	public function dataRenderAppIcon() {
+		return [
+			['core', '#0082c9', 'touch-original.png'],
+			['core', '#FF0000', 'touch-core-red.png'],
+			['testing', '#FF0000', 'touch-testing-red.png'],
+			['comments', '#0082c9', 'touch-comments.png'],
+			['core', '#0082c9', 'touch-original-png.png'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataRenderAppIcon
+	 * @param $app
+	 * @param $color
+	 * @param $file
+	 */
+	public function testRenderAppIcon($app, $color, $file) {
+		$this->checkImagick();
+		$this->themingDefaults->expects($this->once())
+			->method('getMailHeaderColor')
+			->willReturn($color);
+
+		$expectedIcon = new \Imagick(realpath(dirname(__FILE__)). "/data/" . $file);
+		$icon = $this->iconBuilder->renderAppIcon($app);
+
+		$this->assertEquals(true, $icon->valid());
+		$this->assertEquals(512, $icon->getImageWidth());
+		$this->assertEquals(512, $icon->getImageHeight());
+		$this->assertEquals($icon, $expectedIcon);
+		$icon->destroy();
+		$expectedIcon->destroy();
+		// FIXME: We may need some comparison of the generated and the test images
+		// cloud be something like $expectedIcon->compareImages($icon, Imagick::METRIC_MEANABSOLUTEERROR)[1])
+	}
+
+	/**
+	 * @dataProvider dataRenderAppIcon
+	 * @param $app
+	 * @param $color
+	 * @param $file
+	 */
+	public function testGetTouchIcon($app, $color, $file) {
+		$this->checkImagick();
+		$this->themingDefaults->expects($this->once())
+			->method('getMailHeaderColor')
+			->willReturn($color);
+
+		$expectedIcon = new \Imagick(realpath(dirname(__FILE__)). "/data/" . $file);
+		$icon = new \Imagick();
+		$icon->readImageBlob($this->iconBuilder->getTouchIcon($app));
+
+		$this->assertEquals(true, $icon->valid());
+		$this->assertEquals(512, $icon->getImageWidth());
+		$this->assertEquals(512, $icon->getImageHeight());
+		$this->assertEquals($icon, $expectedIcon);
+		$icon->destroy();
+		$expectedIcon->destroy();
+		// FIXME: We may need some comparison of the generated and the test images
+		// cloud be something like $expectedIcon->compareImages($icon, Imagick::METRIC_MEANABSOLUTEERROR)[1])
+	}
+
+	/**
+	 * @dataProvider dataRenderAppIcon
+	 * @param $app
+	 * @param $color
+	 * @param $file
+	 */
+	public function testGetFavicon($app, $color, $file) {
+		$this->checkImagick();
+		$this->themingDefaults->expects($this->once())
+			->method('getMailHeaderColor')
+			->willReturn($color);
+
+		$expectedIcon = new \Imagick(realpath(dirname(__FILE__)). "/data/" . $file);
+		$icon = new \Imagick();
+		$icon->readImageBlob($this->iconBuilder->getFavicon($app));
+
+		$this->assertEquals(true, $icon->valid());
+		$this->assertEquals(32, $icon->getImageWidth());
+		$this->assertEquals(32, $icon->getImageHeight());
+		$icon->destroy();
+		$expectedIcon->destroy();
+		// FIXME: We may need some comparison of the generated and the test images
+		// cloud be something like $expectedIcon->compareImages($icon, Imagick::METRIC_MEANABSOLUTEERROR)[1])
+	}
+
+	/**
+	 * @expectedException \PHPUnit_Framework_Error_Warning
+	 */
+	public function testGetFaviconNotFound() {
+		$util = $this->getMockBuilder(Util::class)->disableOriginalConstructor()->getMock();
+		$iconBuilder = new IconBuilder($this->themingDefaults, $util);
+		$util->expects($this->once())
+			->method('getAppIcon')
+			->willReturn('notexistingfile');
+		$this->assertFalse($iconBuilder->getFavicon('noapp'));
+	}
+
+	/**
+	 * @expectedException \PHPUnit_Framework_Error_Warning
+	 */
+	public function testGetTouchIconNotFound() {
+		$util = $this->getMockBuilder(Util::class)->disableOriginalConstructor()->getMock();
+		$iconBuilder = new IconBuilder($this->themingDefaults, $util);
+		$util->expects($this->once())
+			->method('getAppIcon')
+			->willReturn('notexistingfile');
+		$this->assertFalse($iconBuilder->getTouchIcon('noapp'));
+	}
+
+	/**
+	 * @expectedException \PHPUnit_Framework_Error_Warning
+	 */
+	public function testColorSvgNotFound() {
+		$util = $this->getMockBuilder(Util::class)->disableOriginalConstructor()->getMock();
+		$iconBuilder = new IconBuilder($this->themingDefaults, $util);
+		$util->expects($this->once())
+			->method('getAppImage')
+			->willReturn('notexistingfile');
+		$this->assertFalse($iconBuilder->colorSvg('noapp','noimage'));
+	}
+}
diff --git a/apps/theming/tests/ImageManagerTest.php b/apps/theming/tests/ImageManagerTest.php
new file mode 100644
index 00000000000..4df49633d80
--- /dev/null
+++ b/apps/theming/tests/ImageManagerTest.php
@@ -0,0 +1,183 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016 Julius Härtl <jus@bitgrid.net>
+ *
+ * @author Julius Härtl <jus@bitgrid.net>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as
+ *  published by the Free Software Foundation, either version 3 of the
+ *  License, or (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+namespace OCA\Theming\Tests;
+
+use OCP\Files\SimpleFS\ISimpleFile;
+use OCP\IConfig;
+use Test\TestCase;
+use OCP\Files\SimpleFS\ISimpleFolder;
+use OCP\Files\IAppData;
+use OCP\Files\NotFoundException;
+
+class ImageManager extends TestCase {
+
+	/** @var IConfig|\PHPUnit_Framework_MockObject_MockObject */
+	protected $config;
+	/** @var IAppData|\PHPUnit_Framework_MockObject_MockObject */
+	protected $appData;
+	/** @var ImageManager */
+	protected $imageManager;
+
+	protected function setUp() {
+		parent::setUp();
+		$this->config = $this->getMockBuilder('\OCP\IConfig')->getMock();
+		$this->appData = $this->getMockBuilder('OCP\Files\IAppData')->getMock();
+		$this->imageManager = new \OCA\Theming\ImageManager(
+			$this->config,
+			$this->appData
+		);
+	}
+
+	public function testGetCacheFolder() {
+		$folder = $this->createMock(ISimpleFolder::class);
+		$this->config->expects($this->once())
+			->method('getAppValue')
+			->with('theming', 'cachebuster', '0')
+			->willReturn('0');
+		$this->appData->expects($this->at(0))
+			->method('getFolder')
+			->with('0')
+			->willReturn($folder);
+		$this->assertEquals($folder, $this->imageManager->getCacheFolder());
+	}
+	public function testGetCacheFolderCreate() {
+		$folder = $this->createMock(ISimpleFolder::class);
+		$this->config->expects($this->exactly(2))
+			->method('getAppValue')
+			->with('theming', 'cachebuster', '0')
+			->willReturn('0');
+		$this->appData->expects($this->at(0))
+			->method('getFolder')
+			->willThrowException(new NotFoundException());
+		$this->appData->expects($this->at(1))
+			->method('newFolder')
+			->with('0')
+			->willReturn($folder);
+		$this->appData->expects($this->at(2))
+			->method('getFolder')
+			->with('0')
+			->willReturn($folder);
+		$this->appData->expects($this->once())
+			->method('getDirectoryListing')
+			->willReturn([]);
+		$this->assertEquals($folder, $this->imageManager->getCacheFolder());
+	}
+
+	public function testGetCachedImage() {
+		$folder = $this->setupCacheFolder();
+		$folder->expects($this->once())
+			->method('getFile')
+			->with('filename')
+			->willReturn('filecontent');
+		$expected = 'filecontent';
+		$this->assertEquals($expected, $this->imageManager->getCachedImage('filename'));
+	}
+
+	/**
+	 * @expectedException \OCP\Files\NotFoundException
+	 */
+	public function testGetCachedImageNotFound() {
+		$folder = $this->setupCacheFolder();
+		$folder->expects($this->once())
+			->method('getFile')
+			->with('filename')
+			->will($this->throwException(new \OCP\Files\NotFoundException()));
+		$image = $this->imageManager->getCachedImage('filename');
+	}
+
+	public function testSetCachedImage() {
+		$folder = $this->setupCacheFolder();
+		$file = $this->createMock(ISimpleFile::class);
+		$folder->expects($this->once())
+			->method('fileExists')
+			->with('filename')
+			->willReturn(true);
+		$folder->expects($this->once())
+			->method('getFile')
+			->with('filename')
+			->willReturn($file);
+		$file->expects($this->once())
+			->method('putContent')
+			->with('filecontent');
+		$this->assertEquals($file, $this->imageManager->setCachedImage('filename', 'filecontent'));
+	}
+
+	public function testSetCachedImageCreate() {
+		$folder = $this->setupCacheFolder();
+		$file = $this->createMock(ISimpleFile::class);
+		$folder->expects($this->once())
+			->method('fileExists')
+			->with('filename')
+			->willReturn(false);
+		$folder->expects($this->once())
+			->method('newFile')
+			->with('filename')
+			->willReturn($file);
+		$file->expects($this->once())
+			->method('putContent')
+			->with('filecontent');
+		$this->assertEquals($file, $this->imageManager->setCachedImage('filename', 'filecontent'));
+	}
+
+	private function setupCacheFolder() {
+		$folder = $this->createMock(ISimpleFolder::class);
+		$this->config->expects($this->once())
+			->method('getAppValue')
+			->with('theming', 'cachebuster', '0')
+			->willReturn('0');
+		$this->appData->expects($this->at(0))
+			->method('getFolder')
+			->with('0')
+			->willReturn($folder);
+		return $folder;
+	}
+
+	public function testCleanup() {
+		$folders = [
+			$this->createMock(ISimpleFolder::class),
+			$this->createMock(ISimpleFolder::class),
+			$this->createMock(ISimpleFolder::class)
+			];
+		foreach ($folders as $index=>$folder) {
+			$folder->expects($this->any())
+				->method('getName')
+				->willReturn($index);
+		}
+		$folders[0]->expects($this->once())->method('delete');
+		$folders[1]->expects($this->once())->method('delete');
+		$folders[2]->expects($this->never())->method('delete');
+		$this->config->expects($this->once())
+			->method('getAppValue')
+			->with('theming','cachebuster','0')
+			->willReturn('2');
+		$this->appData->expects($this->once())
+			->method('getDirectoryListing')
+			->willReturn($folders);
+		$this->appData->expects($this->once())
+			->method('getFolder')
+			->with('2')
+			->willReturn($folders[2]);
+		$this->imageManager->cleanup();
+	}
+
+}
diff --git a/apps/theming/tests/ThemingDefaultsTest.php b/apps/theming/tests/ThemingDefaultsTest.php
index 204c96d86d5..cd3a90e760a 100644
--- a/apps/theming/tests/ThemingDefaultsTest.php
+++ b/apps/theming/tests/ThemingDefaultsTest.php
@@ -24,6 +24,7 @@
 namespace OCA\Theming\Tests;
 
 use OCA\Theming\ThemingDefaults;
+use OCP\ICacheFactory;
 use OCP\IConfig;
 use OCP\IL10N;
 use OCP\IURLGenerator;
@@ -43,6 +44,8 @@ class ThemingDefaultsTest extends TestCase {
 	private $template;
 	/** @var IRootFolder */
 	private $rootFolder;
+	/** @var ICacheFactory */
+	private $cacheFactory;
 
 	public function setUp() {
 		parent::setUp();
@@ -52,6 +55,7 @@ class ThemingDefaultsTest extends TestCase {
 		$this->rootFolder = $this->getMockBuilder(IRootFolder::class)
 			->disableOriginalConstructor()
 			->getMock();
+		$this->cacheFactory = $this->getMockBuilder(ICacheFactory::class)->getMock();
 		$this->defaults = $this->getMockBuilder(\OC_Defaults::class)
 			->disableOriginalConstructor()
 			->getMock();
@@ -76,7 +80,8 @@ class ThemingDefaultsTest extends TestCase {
 			$this->l10n,
 			$this->urlGenerator,
 			$this->defaults,
-			$this->rootFolder
+			$this->rootFolder,
+			$this->cacheFactory
 		);
 	}
 
diff --git a/apps/theming/tests/UtilTest.php b/apps/theming/tests/UtilTest.php
index c7fc385d25d..83895208fea 100644
--- a/apps/theming/tests/UtilTest.php
+++ b/apps/theming/tests/UtilTest.php
@@ -23,16 +23,28 @@
 namespace OCA\Theming\Tests;
 
 use OCA\Theming\Util;
+use OCP\App\IAppManager;
+use OCP\IConfig;
+use OCP\Files\IRootFolder;
 use Test\TestCase;
 
 class UtilTest extends TestCase {
 
 	/** @var Util */
 	protected $util;
+	/** @var IConfig */
+	protected $config;
+	/** @var IRootFolder */
+	protected $rootFolder;
+	/** @var IAppManager */
+	protected $appManager;
 
 	protected function setUp() {
 		parent::setUp();
-		$this->util = new Util();
+		$this->config = $this->getMockBuilder('\OCP\IConfig')->getMock();
+		$this->rootFolder = $this->getMockBuilder('OCP\Files\IRootFolder')->getMock();
+		$this->appManager = $this->getMockBuilder('OCP\App\IAppManager')->getMock();
+		$this->util = new Util($this->config, $this->rootFolder, $this->appManager);
 	}
 
 	public function testInvertTextColorLight() {
@@ -89,9 +101,70 @@ class UtilTest extends TestCase {
 		$expected = 'PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIGhlaWdodD0iMTYiIHdpZHRoPSIxNiI+PHBhdGggZD0iTTggMWE3IDcgMCAwIDAtNyA3IDcgNyAwIDAgMCA3IDcgNyA3IDAgMCAwIDctNyA3IDcgMCAwIDAtNy03em0wIDFhNiA2IDAgMCAxIDYgNiA2IDYgMCAwIDEtNiA2IDYgNiAwIDAgMS02LTYgNiA2IDAgMCAxIDYtNnptMCAyYTQgNCAwIDEgMCAwIDggNCA0IDAgMCAwIDAtOHoiIGZpbGw9IiNmZmZmZmYiLz48L3N2Zz4=';
 		$this->assertEquals($expected, $button);
 	}
+
 	public function testGenerateRadioButtonBlack() {
 		$button = $this->util->generateRadioButton('#000000');
 		$expected = 'PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIGhlaWdodD0iMTYiIHdpZHRoPSIxNiI+PHBhdGggZD0iTTggMWE3IDcgMCAwIDAtNyA3IDcgNyAwIDAgMCA3IDcgNyA3IDAgMCAwIDctNyA3IDcgMCAwIDAtNy03em0wIDFhNiA2IDAgMCAxIDYgNiA2IDYgMCAwIDEtNiA2IDYgNiAwIDAgMS02LTYgNiA2IDAgMCAxIDYtNnptMCAyYTQgNCAwIDEgMCAwIDggNCA0IDAgMCAwIDAtOHoiIGZpbGw9IiMwMDAwMDAiLz48L3N2Zz4=';
 		$this->assertEquals($expected, $button);
 	}
+
+	/**
+	 * @dataProvider dataGetAppIcon
+	 */
+	public function testGetAppIcon($app, $expected) {
+		$this->appManager->expects($this->once())
+			->method('getAppPath')
+			->with($app)
+			->willReturn(\OC_App::getAppPath($app));
+		$icon = $this->util->getAppIcon($app);
+		$this->assertEquals($expected, $icon);
+	}
+
+	public function dataGetAppIcon() {
+		return [
+			['user_ldap', \OC_App::getAppPath('user_ldap') . '/img/app.svg'],
+			['noapplikethis', \OC::$SERVERROOT . '/core/img/logo.svg'],
+			['comments', \OC_App::getAppPath('comments') . '/img/comments.svg'],
+		];
+	}
+
+	public function testGetAppIconThemed() {
+		$this->rootFolder->expects($this->once())
+			->method('nodeExists')
+			->with('/themedinstancelogo')
+			->willReturn(true);
+		$expected = '/themedinstancelogo';
+		$icon = $this->util->getAppIcon('noapplikethis');
+		$this->assertEquals($expected, $icon);
+	}
+
+	/**
+	 * @dataProvider dataGetAppImage
+	 */
+	public function testGetAppImage($app, $image, $expected) {
+		if($app !== 'core') {
+			$this->appManager->expects($this->once())
+				->method('getAppPath')
+				->with($app)
+				->willReturn(\OC_App::getAppPath($app));
+		}
+		$this->assertEquals($expected, $this->util->getAppImage($app, $image));
+	}
+
+	public function dataGetAppImage() {
+		return [
+			['core', 'logo.svg', \OC::$SERVERROOT . '/core/img/logo.svg'],
+			['files', 'external', \OC::$SERVERROOT . '/apps/files/img/external.svg'],
+			['files', 'external.svg', \OC::$SERVERROOT . '/apps/files/img/external.svg'],
+			['noapplikethis', 'foobar.svg', false],
+		];
+	}
+
+	public function testColorizeSvg() {
+		$input = "#0082c9 #0082C9 #000000 #FFFFFF";
+		$expected = "#AAAAAA #AAAAAA #000000 #FFFFFF";
+		$result = $this->util->colorizeSvg($input, '#AAAAAA');
+		$this->assertEquals($expected, $result);
+	}
+
 }
diff --git a/apps/theming/tests/data/favicon-original.ico b/apps/theming/tests/data/favicon-original.ico
new file mode 100644
index 00000000000..fab2f7f0231
--- /dev/null
+++ b/apps/theming/tests/data/favicon-original.ico
diff --git a/apps/theming/tests/data/touch-comments.png b/apps/theming/tests/data/touch-comments.png
new file mode 100644
index 00000000000..af0d2ca579b
--- /dev/null
+++ b/apps/theming/tests/data/touch-comments.png
diff --git a/apps/theming/tests/data/touch-core-red.png b/apps/theming/tests/data/touch-core-red.png
new file mode 100644
index 00000000000..7a492f10e21
--- /dev/null
+++ b/apps/theming/tests/data/touch-core-red.png
diff --git a/apps/theming/tests/data/touch-original-png.png b/apps/theming/tests/data/touch-original-png.png
new file mode 100644
index 00000000000..6997dfc6b88
--- /dev/null
+++ b/apps/theming/tests/data/touch-original-png.png
diff --git a/apps/theming/tests/data/touch-original.png b/apps/theming/tests/data/touch-original.png
new file mode 100644
index 00000000000..ac39872aa6e
--- /dev/null
+++ b/apps/theming/tests/data/touch-original.png
diff --git a/apps/theming/tests/data/touch-testing-red.png b/apps/theming/tests/data/touch-testing-red.png
new file mode 100644
index 00000000000..4cbdfbbb42c
--- /dev/null
+++ b/apps/theming/tests/data/touch-testing-red.png
diff --git a/core/js/mimetype.js b/core/js/mimetype.js
index 0d30da26c26..8920fe09a7e 100644
--- a/core/js/mimetype.js
+++ b/core/js/mimetype.js
@@ -91,6 +91,11 @@ OC.MimeType = {
 				path += icon;
 			}
 		}
+		if(OCA.Theming) {
+			path = OC.generateUrl('/apps/theming/img/core/filetypes/');
+			path += OC.MimeType._getFile(mimeType, OC.MimeTypeList.files);
+			gotIcon = true;
+		}
 
 		// If we do not yet have an icon fall back to the default
 		if (gotIcon === null) {
@@ -100,6 +105,10 @@ OC.MimeType = {
 
 		path += '.svg';
 
+		if(OCA.Theming) {
+			path += "?v=" + OCA.Theming.cacheBuster;
+		}
+
 		// Cache the result
 		OC.MimeType._mimeTypeIcons[mimeType] = path;
 		return path;
diff --git a/lib/private/Server.php b/lib/private/Server.php
index c6755357a1d..c6cfa018be5 100644
--- a/lib/private/Server.php
+++ b/lib/private/Server.php
@@ -703,7 +703,8 @@ class Server extends ServerContainer implements IServerContainer {
 					$c->getL10N('theming'),
 					$c->getURLGenerator(),
 					new \OC_Defaults(),
-					$c->getLazyRootFolder()
+					$c->getLazyRootFolder(),
+					$c->getMemCacheFactory()
 				);
 			}
 			return new \OC_Defaults();
diff --git a/lib/private/URLGenerator.php b/lib/private/URLGenerator.php
index 93517dc9f7e..bdf7bdafae3 100644
--- a/lib/private/URLGenerator.php
+++ b/lib/private/URLGenerator.php
@@ -157,7 +157,15 @@ class URLGenerator implements IURLGenerator {
 
 		// Check if the app is in the app folder
 		$path = '';
-		if (file_exists(\OC::$SERVERROOT . "/themes/$theme/apps/$app/img/$image")) {
+		if(\OCP\App::isEnabled('theming') && $image === "favicon.ico" && \OC::$server->getThemingDefaults()->shouldReplaceIcons()) {
+			$cacheBusterValue = $this->config->getAppValue('theming', 'cachebuster', '0');
+			if($app==="") { $app = "core"; }
+			$path = $this->linkToRoute('theming.Icon.getFavicon', [ 'app' => $app ]) . '?v='. $cacheBusterValue;
+		} elseif(\OCP\App::isEnabled('theming') && $image === "favicon-touch.png" && \OC::$server->getThemingDefaults()->shouldReplaceIcons()) {
+			$cacheBusterValue = $this->config->getAppValue('theming', 'cachebuster', '0');
+			if($app==="") { $app = "core"; }
+			$path = $this->linkToRoute('theming.Icon.getTouchIcon', [ 'app' => $app ]) . '?v='. $cacheBusterValue;
+		} elseif (file_exists(\OC::$SERVERROOT . "/themes/$theme/apps/$app/img/$image")) {
 			$path = \OC::$WEBROOT . "/themes/$theme/apps/$app/img/$image";
 		} elseif (!file_exists(\OC::$SERVERROOT . "/themes/$theme/apps/$app/img/$basename.svg")
 			&& file_exists(\OC::$SERVERROOT . "/themes/$theme/apps/$app/img/$basename.png")) {