michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "nsISupports.idl"
michael@0: 
michael@0: interface nsISHEntry;
michael@0: interface nsISHistoryListener;
michael@0: interface nsISimpleEnumerator;
michael@0: /**
michael@0:  * An interface to the primary properties of the Session History
michael@0:  * component. In an embedded browser environment, the nsIWebBrowser
michael@0:  * object creates an instance of session history for each open window.
michael@0:  * A handle to the session history object can be obtained from
michael@0:  * nsIWebNavigation. In a non-embedded situation, the  owner of the
michael@0:  * session history component must create a instance of it and set
michael@0:  * it in the nsIWebNavigation object.
michael@0:  * This interface is accessible from javascript.
michael@0:  */
michael@0:  
michael@0: 
michael@0: %{C++
michael@0: #define NS_SHISTORY_CID \
michael@0: {0x7b807041, 0xe60a, 0x4384, {0x93, 0x5f, 0xaf, 0x30, 0x61, 0xd8, 0xb8, 0x15}}
michael@0: 
michael@0: #define NS_SHISTORY_CONTRACTID "@mozilla.org/browser/shistory;1"
michael@0: %}
michael@0: 
michael@0: [scriptable, uuid(7b807041-e60a-4384-935f-af3061d8b815)]
michael@0: interface nsISHistory: nsISupports
michael@0: {
michael@0:   /**
michael@0:    * A readonly property of the interface that returns 
michael@0:    * the number of toplevel documents currently available
michael@0:    * in session history.
michael@0:    */
michael@0:    readonly attribute long count;
michael@0: 
michael@0:   /**
michael@0:    * A readonly property of the interface that returns 
michael@0:    * the index of the current document in session history.
michael@0:    */
michael@0:    readonly attribute long index;
michael@0: 
michael@0:   /**
michael@0:    * A readonly property of the interface that returns 
michael@0:    * the index of the last document that started to load and
michael@0:    * didn't finished yet. When document finishes the loading
michael@0:    * value -1 is returned.
michael@0:    */
michael@0:    readonly attribute long requestedIndex;
michael@0: 
michael@0:   /**
michael@0:    * A read/write property of the interface, used to Get/Set
michael@0:    * the maximum number of toplevel documents, session history 
michael@0:    * can hold for each instance. 
michael@0:    */
michael@0:    attribute long maxLength;
michael@0: 
michael@0:   /**
michael@0:    * Called to obtain handle to the history entry at a
michael@0:    * given index.
michael@0:    *
michael@0:    * @param index             The index value whose entry is requested.
michael@0:    *                          The oldest entry is located at index == 0.
michael@0:    * @param modifyIndex       A boolean flag that indicates if the current
michael@0:    *                          index of session history should be modified 
michael@0:    *                          to the parameter index.
michael@0:    *
michael@0:    * @return                  <code>NS_OK</code> history entry for 
michael@0:    *                          the index is obtained successfully.
michael@0:    *                          <code>NS_ERROR_FAILURE</code> Error in obtaining
michael@0:    *                          history entry for the given index.
michael@0:    */
michael@0:    nsISHEntry getEntryAtIndex(in long index, in boolean modifyIndex);
michael@0: 
michael@0: 
michael@0:   /**
michael@0:    * Called to purge older documents from history.
michael@0:    * Documents can be removed from session history for various 
michael@0:    * reasons. For example to  control memory usage of the browser, to 
michael@0:    * prevent users from loading documents from history, to erase evidence of
michael@0:    * prior page loads etc...
michael@0:    *
michael@0:    * @param numEntries        The number of toplevel documents to be
michael@0:    *                          purged from history. During purge operation,
michael@0:    *                          the latest documents are maintained and older 
michael@0:    *                          'numEntries' documents are removed from history.
michael@0:    * @throws                  <code>NS_SUCCESS_LOSS_OF_INSIGNIFICANT_DATA</code> Purge was vetod.
michael@0:    * @throws                  <code>NS_ERROR_FAILURE</code> numEntries is
michael@0:    *                          invalid or out of bounds with the size of history.
michael@0:    *                          
michael@0:    */
michael@0:    void PurgeHistory(in long numEntries);
michael@0: 
michael@0:   /**
michael@0:    * Called to register a listener for the session history component.
michael@0:    * Listeners are notified when pages are loaded or purged from history.
michael@0:    * 
michael@0:    * @param aListener         Listener object to be notified for all
michael@0:    *                          page loads that initiate in session history.
michael@0:    *
michael@0:    * @note                    A listener object must implement 
michael@0:    *                          nsISHistoryListener and nsSupportsWeakReference
michael@0:    *
michael@0:    * @see nsISHistoryListener
michael@0:    * @see nsSupportsWeakReference
michael@0:    */
michael@0:    void addSHistoryListener(in nsISHistoryListener aListener);
michael@0: 
michael@0:   /**
michael@0:    * Called to remove a listener for the session history component.
michael@0:    * Listeners are notified when pages are loaded from history.
michael@0:    * 
michael@0:    * @param aListener         Listener object to be removed from 
michael@0:    *                          session history.
michael@0:    *
michael@0:    * @note                    A listener object must implement 
michael@0:    *                          nsISHistoryListener and nsSupportsWeakReference
michael@0:    * @see nsISHistoryListener
michael@0:    * @see nsSupportsWeakReference
michael@0:    */ 
michael@0:    void removeSHistoryListener(in nsISHistoryListener aListener);
michael@0: 
michael@0:   /**
michael@0:    * Called to obtain a enumerator for all the  documents stored in 
michael@0:    * session history. The enumerator object thus returned by this method
michael@0:    * can be traversed using nsISimpleEnumerator. 
michael@0:    *
michael@0:    * @note  To access individual history entries of the enumerator, perform the
michael@0:    *        following steps:
michael@0:    *        1) Call nsISHistory->GetSHistoryEnumerator() to obtain handle 
michael@0:    *           the nsISimpleEnumerator object.
michael@0:    *        2) Use nsISimpleEnumerator->GetNext() on the object returned
michael@0:    *           by step #1 to obtain handle to the next object in the list. 
michael@0:    *           The object returned by this step is of type nsISupports.
michael@0:    *        3) Perform a QueryInterface on the object returned by step #2 
michael@0:    *           to nsISHEntry.
michael@0:    *        4) Use nsISHEntry to access properties of each history entry. 
michael@0:    *
michael@0:    * @see nsISimpleEnumerator
michael@0:    * @see nsISHEntry
michael@0:    * @see QueryInterface()
michael@0:    * @see do_QueryInterface()
michael@0:    */
michael@0:    readonly attribute nsISimpleEnumerator SHistoryEnumerator;
michael@0: 
michael@0:    void reloadCurrentEntry();
michael@0: 
michael@0:    /**
michael@0:    * Called to obtain the index to a given history entry.
michael@0:    *
michael@0:    * @param aEntry            The entry to obtain the index of.
michael@0:    *
michael@0:    * @return                  <code>NS_OK</code> index for the history entry
michael@0:    *                          is obtained successfully.
michael@0:    *                          <code>NS_ERROR_FAILURE</code> Error in obtaining
michael@0:    *                          index for the given history entry.
michael@0:    */
michael@0:    long getIndexOfEntry(in nsISHEntry aEntry);
michael@0: };