1/*
2 * Copyright (C) 2003 Apple Inc.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1.  Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions and the following disclaimer.
10 * 2.  Redistributions in binary form must reproduce the above copyright
11 *     notice, this list of conditions and the following disclaimer in the
12 *     documentation and/or other materials provided with the distribution.
13 * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
14 *     its contributors may be used to endorse or promote products derived
15 *     from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#import <Foundation/Foundation.h>
30
31@class WebHistoryItem;
32@class WebBackForwardListPrivate;
33
34/*!
35    @class WebBackForwardList
36    WebBackForwardList holds an ordered list of WebHistoryItems that comprises the back and
37    forward lists.
38
39    Note that the methods which modify instances of this class do not cause
40    navigation to happen in other layers of the stack;  they are only for maintaining this data
41    structure.
42*/
43@interface WebBackForwardList : NSObject {
44@private
45    WebBackForwardListPrivate *_private;
46}
47
48/*!
49    @method addItem:
50    @abstract Adds an entry to the list.
51    @param entry The entry to add.
52    @discussion The added entry is inserted immediately after the current entry.
53    If the current position in the list is not at the end of the list, elements in the
54    forward list will be dropped at this point.  In addition, entries may be dropped to keep
55    the size of the list within the maximum size.
56*/
57- (void)addItem:(WebHistoryItem *)item;
58
59/*!
60    @method goBack
61    @abstract Move the current pointer back to the entry before the current entry.
62*/
63- (void)goBack;
64
65/*!
66    @method goForward
67    @abstract Move the current pointer ahead to the entry after the current entry.
68*/
69- (void)goForward;
70
71/*!
72    @method goToItem:
73    @abstract Move the current pointer to the given entry.
74    @param item The history item to move the pointer to
75*/
76- (void)goToItem:(WebHistoryItem *)item;
77
78/*!
79    @property backItem
80    @abstract The entry right before the current entry, or nil if there isn't one.
81*/
82@property (nonatomic, readonly, strong) WebHistoryItem *backItem;
83
84/*!
85    @property currentItem
86    @abstract Returns the current entry.
87*/
88@property (nonatomic, readonly, strong) WebHistoryItem *currentItem;
89
90/*!
91    @property forwardItem
92    @abstract The entry right after the current entry, or nil if there isn't one.
93*/
94@property (nonatomic, readonly, strong) WebHistoryItem *forwardItem;
95
96/*!
97    @method backListWithLimit:
98    @abstract Returns a portion of the list before the current entry.
99    @param limit A cap on the size of the array returned.
100    @result An array of items before the current entry, or nil if there are none.  The entries are in the order that they were originally visited.
101*/
102- (NSArray *)backListWithLimit:(int)limit;
103
104/*!
105    @method forwardListWithLimit:
106    @abstract Returns a portion of the list after the current entry.
107    @param limit A cap on the size of the array returned.
108    @result An array of items after the current entry, or nil if there are none.  The entries are in the order that they were originally visited.
109*/
110- (NSArray *)forwardListWithLimit:(int)limit;
111
112/*!
113    @property capacity
114    @abstract The list's maximum size.
115*/
116@property (nonatomic) int capacity;
117
118/*!
119    @property backListCount
120    @abstract The number of items in the list.
121*/
122@property (nonatomic, readonly) int backListCount;
123
124/*!
125    @property forwardListCount
126    @result The number of items in the list.
127*/
128@property (nonatomic, readonly) int forwardListCount;
129
130/*!
131    @method containsItem:
132    @param item The item that will be checked for presence in the WebBackForwardList.
133    @result Returns YES if the item is in the list.
134*/
135- (BOOL)containsItem:(WebHistoryItem *)item;
136
137/*!
138    @method itemAtIndex:
139    @abstract Returns an entry the given distance from the current entry.
140    @param index Index of the desired list item relative to the current item; 0 is current item, -1 is back item, 1 is forward item, etc.
141    @result The entry the given distance from the current entry. If index exceeds the limits of the list, nil is returned.
142*/
143- (WebHistoryItem *)itemAtIndex:(int)index;
144
145@end
146
147@interface WebBackForwardList(WebBackForwardListDeprecated)
148
149// The following methods are deprecated, and exist for backward compatibility only.
150// Use -[WebPreferences setUsesPageCache] and -[WebPreferences usesPageCache]
151// instead.
152
153/*!
154    @method setPageCacheSize:
155    @abstract The size passed to this method determines whether the WebView
156    associated with this WebBackForwardList will use the shared page cache.
157    @param size If size is 0, the WebView associated with this WebBackForwardList
158    will not use the shared page cache. Otherwise, it will.
159*/
160- (void)setPageCacheSize:(NSUInteger)size;
161
162/*!
163    @method pageCacheSize
164    @abstract Returns the size of the shared page cache, or 0.
165    @result The size of the shared page cache (in pages), or 0 if the WebView
166    associated with this WebBackForwardList will not use the shared page cache.
167*/
168- (NSUInteger)pageCacheSize;
169@end
170