added class OC_HOOK to base.php. It is in base.php because it is needed

very ofter and it is quite small.

lib/base.php

@@ -280,21 +280,75 @@ class OC_UTIL {
 			die($error);
 		}
 	}
+}
 
-  /**
-   * check if we need to use the layout optimized for smaller screen, currently only checks for iPhone/Android
-   * @return bool
-   */
-	public static function hasSmallScreen(){
-		$userAgent=strtolower($_SERVER['HTTP_USER_AGENT']);
-		if(strpos($userAgent,'android') or strpos($userAgent,'iphone') or strpos($userAgent,'ipod')){//todo, add support for more devices
-			return true;
+/**
+ * This class manages the hooks. It basically provides two functions: adding
+ * slots and emitting signals.
+ */
+class OC_HOOK{
+	static private $registered = array();
+
+	/**
+	 * @brief connects a function to a hook
+	 * @param $signalclass class name of emitter
+	 * @param $signalname name of signal
+	 * @param $slotclass class name of slot
+	 * @param $slotname name of slot
+	 * @returns true/false
+	 *
+	 * This function makes it very easy to connect to use hooks.
+	 *
+	 * TODO: write example
+	 */
+	public function connect( $signalclass, $signalname, $slotclass, $slotname ){
+		// Cerate the data structure
+		if( !array_key_exists( $signalclass, self::$registered )){
+			self::$registered[$signalclass] = array();
+		}
+		if( !array_key_exists( $signalname, self::$registered[$signalclass] )){
+			self::$registered[$signalclass][$signalname] = array();
+		}
+
+		// register hook
+		self::$registered[$signalclass][$signalname][] = array(
+		  "class" => $slotclass,
+		  "name" => $slotname );
+
+		// No chance for failure ;-)
+		return true;
+	}
+
+	/**
+	 * @brief emitts a signal
+	 * @param $signalclass class name of emitter
+	 * @param $signalname name of signal
+	 * @param $params defautl: array() array with additional data
+	 * @returns true if slots exists or false if not
+	 *
+	 * Emits a signal. To get data from the slot use references!
+	 *
+	 * TODO: write example
+	 */
+	public function emit( $signalclass, $signalname, $params = array()){
+		// Return false if there are no slots
+		if( !array_key_exists( $signalclass, self::$registered )){
+			return false;
 		}
-		return false;
+		if( !array_key_exists( $signalname, self::$registered[$signalclass] )){
+			return false;
+		}
+
+		// Call all slots
+		foreach( $registered[$signalclass][$signalname] as $i ){
+			call_user_func( array( $i["class"], $i["name"] ), $params );
+		}
+
+		// return true
+		return true;
 	}
 }
 
-
 /**
  * Class for database access
  *