Issue 116 - Document the libadblockplus API

include/AdblockPlus/FilterEngine.h

Index: include/AdblockPlus/FilterEngine.h
===================================================================
--- a/include/AdblockPlus/FilterEngine.h
+++ b/include/AdblockPlus/FilterEngine.h
@@ -31,67 +31,266 @@
 {
   class FilterEngine;
 
+  /**
+   * Wrapper for a filter object.
+   */
   class Filter : public JsValue,
                  public std::tr1::enable_shared_from_this<Filter>
   {
   public:
+    /**
+     * Filter types, see https://adblockplus.org/en/filters.
+     */
     enum Type {TYPE_BLOCKING, TYPE_EXCEPTION,
                TYPE_ELEMHIDE, TYPE_ELEMHIDE_EXCEPTION,
                TYPE_COMMENT, TYPE_INVALID};
 
     Type GetType();
+
+    /**
+     * Checks whether this filter has been added to its subscription.
+     * @return `true` if this filter has been added to its subscription.
+     */
     bool IsListed();
+
+    /**
+     * Adds this filter to its subscription.
+     */
     void AddToList();
+
+    /**
+     * Removes this filter from its subscription.
+     */
     void RemoveFromList();
+
     bool operator==(const Filter& filter) const;
 
     Filter(JsValuePtr value);
   };
 
+  /**
+   * Wrapper for a subscription object.
+   */
   class Subscription : public JsValue,
                        public std::tr1::enable_shared_from_this<Subscription>
   {
   public:
+    /**
+     * Checks if this subscription has been added to the known subscriptions.
+     * @return `true` if this subscription has been added to the known
+     *         subscriptions.
+     */
     bool IsListed();
+
+    /**
+     * Adds this subscription to the known subscriptions.
+     */
     void AddToList();
+
+    /**
+     * Removes this subscription from the known subscriptions.
+     */
     void RemoveFromList();
+
+    /**
+     * Updates this subscription, i.e.\ retrieves the latest version from the
+     * subscription URL.
+     */
     void UpdateFilters();
+
+    /**
+     * Checks if this subscriptions is currently being updated.
+     * @return `true` if this subscriptions is currently being updated.
+     */
     bool IsUpdating();
+
     bool operator==(const Subscription& subscription) const;
 
     Subscription(JsValuePtr value);
   };
 
+  /**
+   * Shared smart pointer to a `Filter` instance.
+   */
   typedef std::tr1::shared_ptr<Filter> FilterPtr;
+
+  /**
+   * Shared smart pointer to a `Subscription` instance.
+   */
   typedef std::tr1::shared_ptr<Subscription> SubscriptionPtr;
 
+  /**
+   * Main component of Libadblockplus.
+   * It handles:
+   * - Filter management and matching.
+   * - Subscription management and synchronization.
+   * - Update checks for the application.
+   */
   class FilterEngine
   {
   public:
+    /**
+     * Callback invoked when an update is available.
+     */
     typedef std::tr1::function<void(const std::string&)> UpdaterCallback;
+
+    /**
+     * Callback invoked when the filters change.
+     */
     typedef std::tr1::function<void(const std::string&, const JsValuePtr)> FilterChangeCallback;
 
     explicit FilterEngine(JsEnginePtr jsEngine);
     JsEnginePtr GetJsEngine() const { return jsEngine; }
+
+    /**
+     * Checks if this is the first run of the application.
+     * @return `true` if the application is running for the first time.
+     */
     bool IsFirstRun() const;
+
+    /**
+     * Retrieves a filter object from its text representation.
+     * @param text Text representation of the filter,
+     *        see https://adblockplus.org/en/filters.
+     * @return New filter object if the filter wasn't known, otherwise the
+     *         existing one.
+     */
     FilterPtr GetFilter(const std::string& text);
+
+    /**
+     * Retrieves a subscription object for the supplied URL.
+     * @param url Subscription URL.
+     * @return New subscription object if the subscription wasn't known,
+     *         otherwise the existing one.
+     */
     SubscriptionPtr GetSubscription(const std::string& url);
+
+    /**
+     * Retrieves all known filters.
+     * @return List of known filters.
+     */
     std::vector<FilterPtr> GetListedFilters() const;
+
+    /**
+     * Retrieves all known subscriptions.
+     * @return List of known subscriptions.
+     */
     std::vector<SubscriptionPtr> GetListedSubscriptions() const;
+
+    /**
+     * Retrieves all recommended subscriptions.
+     * This will parse all subscriptions listed in `subscriptions.xml`.
+     * @return List of recommended subscriptions.
+     */
     std::vector<SubscriptionPtr> FetchAvailableSubscriptions() const;
+
+    /**
+     * Checks if any active filter matches the supplied URL.
+     * @param url URL to match.
+     * @param contentType Content type of the requested resource, possible
+     *        values are:
+     *        - OTHER
+     *        - SCRIPT
+     *        - IMAGE
+     *        - STYLESHEET
+     *        - OBJECT
+     *        - SUBDOCUMENT
+     *        - DOCUMENT
+     *        - XMLHTTPREQUEST
+     *        - OBJECT_SUBREQUEST
+     *        - FONT
+     *        - MEDIA
+     * @param documentUrl URL of the document requesting the resource.
+     *        Note that there will be more than one document if frames are
+     *        involved, see
+     *        Matches(const std::string&, const std::string&, const std::vector<std::string>&) const.
+     * @return Matching filter, or `null` if there was no match.
+     */
     FilterPtr Matches(const std::string& url,
         const std::string& contentType,
         const std::string& documentUrl) const;
+
+    /**
+     * Checks if any active filter matches the supplied URL.
+     * @param url URL to match.
+     * @param contentType Content type of the requested resource, possible
+     *        values are:
+     *        - OTHER
+     *        - SCRIPT
+     *        - IMAGE
+     *        - STYLESHEET
+     *        - OBJECT
+     *        - SUBDOCUMENT
+     *        - DOCUMENT
+     *        - XMLHTTPREQUEST
+     *        - OBJECT_SUBREQUEST
+     *        - FONT
+     *        - MEDIA
+     * @param documentUrls Chain of documents requesting the resource.
+     *        This will typically be the frame structure. If the application is
+     *        not capable of identifying the frame structure, e.g. because it is
+     *        a proxy, it can be approximated using `ReferrerMapping`.
+     * @return Matching filter, or `null` if there was no match.
+     */
     FilterPtr Matches(const std::string& url,
         const std::string& contentType,
         const std::vector<std::string>& documentUrls) const;
+
+    /**
+     * Retrieves CSS selectors for all active element hiding filters.
+     * @param domain Domain to retrieve CSS selectors for.
+     * @return List of CSS selectors.
+     */
     std::vector<std::string> GetElementHidingSelectors(const std::string& domain) const;
+
+    /**
+     * Retrieves a preference value.
+     * @param pref Preference name.
+     * @return Preference value, or `null` if it doesn't exist.
+     */
     JsValuePtr GetPref(const std::string& pref) const;
+
+    /**
+     * Sets a preference value.
+     * @param pref Preference name.
+     * @param value New value of the preference.
+     */
     void SetPref(const std::string& pref, JsValuePtr value);
+
+    /**
+     * Extracts the host from an URL.
+     * @param url URL to extract the host from.
+     * @return Extracted host.
+     */
     std::string GetHostFromURL(const std::string& url);
+
+    /**
+     * Forces an immediate update check.
+     * @param Optional callback to invoke when updates are available.
+     */
     void ForceUpdateCheck(UpdaterCallback callback = 0);
+
+    /**
+     * Sets the callback invoked when the filters change.
+     * @param The callback to invoke.
+     */
     void SetFilterChangeCallback(FilterChangeCallback callback);
+
+    /**
+     * Removes the callback invoked when the filters change.
+     */
     void RemoveFilterChangeCallback();
+
+    /**
+     * Compares two version strings in
+     * [Mozilla toolkit version format](https://developer.mozilla.org/en/docs/Toolkit_version_format).
+     * @param v1 First version string.
+     * @param v2 Second version string.
+     * @return
+     *         - `0` if `v1` and `v2` are identical.
+     *         - A negative number if `v1` is less than `v2`.
+     *         - A positive number if `v1` is greater than `v2`.
+     */
     int CompareVersions(const std::string& v1, const std::string& v2);
 
   private: