1/*
2 * Copyright (C) 2010 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 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "WebBackForwardList.h"
28
29#include "WebPageProxy.h"
30
31namespace WebKit {
32
33static const unsigned DefaultCapacity = 100;
34
35WebBackForwardList::WebBackForwardList(WebPageProxy* page)
36    : m_page(page)
37    , m_current(NoCurrentItemIndex)
38    , m_capacity(DefaultCapacity)
39    , m_closed(true)
40    , m_enabled(true)
41{
42    ASSERT(m_current == NoCurrentItemIndex || m_current < m_entries.size());
43}
44
45WebBackForwardList::~WebBackForwardList()
46{
47}
48
49void WebBackForwardList::pageClosed()
50{
51    if (m_page) {
52        size_t size = m_entries.size();
53        for (size_t i = 0; i < size; ++i)
54            m_page->backForwardRemovedItem(m_entries[i]->itemID());
55    }
56
57    m_page = 0;
58}
59
60void WebBackForwardList::addItem(WebBackForwardListItem* newItem)
61{
62    ASSERT(m_current == NoCurrentItemIndex || m_current < m_entries.size());
63
64    if (m_capacity == 0 || !m_enabled)
65        return;
66
67    Vector<RefPtr<APIObject> > removedItems;
68
69    // Toss anything in the forward list
70    if (m_current != NoCurrentItemIndex) {
71        unsigned targetSize = m_current + 1;
72        removedItems.reserveCapacity(m_entries.size() - targetSize);
73        while (m_entries.size() > targetSize) {
74            if (m_page)
75                m_page->backForwardRemovedItem(m_entries.last()->itemID());
76            removedItems.append(m_entries.last().release());
77            m_entries.removeLast();
78        }
79    }
80
81    // Toss the first item if the list is getting too big, as long as we're not using it
82    // (or even if we are, if we only want 1 entry).
83    if (m_entries.size() == m_capacity && (m_current != 0 || m_capacity == 1)) {
84        if (m_page)
85            m_page->backForwardRemovedItem(m_entries[0]->itemID());
86        removedItems.append(m_entries[0].release());
87        m_entries.remove(0);
88        m_current--;
89    }
90
91    m_entries.insert(m_current + 1, newItem);
92    m_current++;
93
94    if (m_page)
95        m_page->didChangeBackForwardList(newItem, &removedItems);
96
97    ASSERT(m_current == NoCurrentItemIndex || m_current < m_entries.size());
98}
99
100void WebBackForwardList::goToItem(WebBackForwardListItem* item)
101{
102    ASSERT(m_current == NoCurrentItemIndex || m_current < m_entries.size());
103
104    if (!m_entries.size() || !item)
105        return;
106
107    unsigned index = 0;
108    for (; index < m_entries.size(); ++index) {
109        if (m_entries[index] == item)
110            break;
111    }
112    if (index < m_entries.size()) {
113        m_current = index;
114        if (m_page)
115            m_page->didChangeBackForwardList(0, 0);
116    }
117}
118
119WebBackForwardListItem* WebBackForwardList::currentItem()
120{
121    ASSERT(m_current == NoCurrentItemIndex || m_current < m_entries.size());
122
123    if (m_current != NoCurrentItemIndex)
124        return m_entries[m_current].get();
125    return 0;
126}
127
128WebBackForwardListItem* WebBackForwardList::backItem()
129{
130    ASSERT(m_current == NoCurrentItemIndex || m_current < m_entries.size());
131
132    if (m_current && m_current != NoCurrentItemIndex)
133        return m_entries[m_current - 1].get();
134    return 0;
135}
136
137WebBackForwardListItem* WebBackForwardList::forwardItem()
138{
139    ASSERT(m_current == NoCurrentItemIndex || m_current < m_entries.size());
140
141    if (m_entries.size() && m_current < m_entries.size() - 1)
142        return m_entries[m_current + 1].get();
143    return 0;
144}
145
146WebBackForwardListItem* WebBackForwardList::itemAtIndex(int index)
147{
148    ASSERT(m_current == NoCurrentItemIndex || m_current < m_entries.size());
149
150    // Do range checks without doing math on index to avoid overflow.
151    if (index < -static_cast<int>(m_current))
152        return 0;
153
154    if (index > forwardListCount())
155        return 0;
156
157    return m_entries[index + m_current].get();
158}
159
160int WebBackForwardList::backListCount()
161{
162    ASSERT(m_current == NoCurrentItemIndex || m_current < m_entries.size());
163
164    return m_current == NoCurrentItemIndex ? 0 : m_current;
165}
166
167int WebBackForwardList::forwardListCount()
168{
169    ASSERT(m_current == NoCurrentItemIndex || m_current < m_entries.size());
170
171    return m_current == NoCurrentItemIndex ? 0 : static_cast<int>(m_entries.size()) - (m_current + 1);
172}
173
174PassRefPtr<ImmutableArray> WebBackForwardList::backListAsImmutableArrayWithLimit(unsigned limit)
175{
176    ASSERT(m_current == NoCurrentItemIndex || m_current < m_entries.size());
177
178    unsigned backListSize = static_cast<unsigned>(backListCount());
179    unsigned size = std::min(backListSize, limit);
180    if (!size)
181        return ImmutableArray::create();
182
183    Vector<RefPtr<APIObject> > vector;
184    vector.reserveInitialCapacity(size);
185
186    ASSERT(backListSize >= size);
187    for (unsigned i = backListSize - size; i < backListSize; ++i)
188        vector.uncheckedAppend(m_entries[i].get());
189
190    return ImmutableArray::adopt(vector);
191}
192
193PassRefPtr<ImmutableArray> WebBackForwardList::forwardListAsImmutableArrayWithLimit(unsigned limit)
194{
195    ASSERT(m_current == NoCurrentItemIndex || m_current < m_entries.size());
196
197    unsigned size = std::min(static_cast<unsigned>(forwardListCount()), limit);
198    if (!size)
199        return ImmutableArray::create();
200
201    Vector<RefPtr<APIObject> > vector;
202    vector.reserveInitialCapacity(size);
203
204    unsigned last = m_current + size;
205    ASSERT(last < m_entries.size());
206    for (unsigned i = m_current + 1; i <= last; ++i)
207        vector.uncheckedAppend(m_entries[i].get());
208
209    return ImmutableArray::adopt(vector);
210}
211
212void WebBackForwardList::clear()
213{
214    ASSERT(m_current == NoCurrentItemIndex || m_current < m_entries.size());
215
216    size_t size = m_entries.size();
217    if (size <= 1)
218        return;
219
220    RefPtr<WebBackForwardListItem> currentItem = this->currentItem();
221
222    if (m_page) {
223        for (size_t i = 0; i < size; ++i) {
224            if (m_entries[i] != currentItem)
225                m_page->backForwardRemovedItem(m_entries[i]->itemID());
226        }
227    }
228
229    Vector<RefPtr<APIObject> > removedItems;
230    removedItems.reserveCapacity(m_entries.size() - 1);
231    for (size_t i = 0; i < m_entries.size(); ++i) {
232        if (i != m_current)
233            removedItems.append(m_entries[i].release());
234    }
235
236    m_entries.shrink(1);
237    m_entries[0] = currentItem.release();
238
239    m_current = 0;
240
241    if (m_page)
242        m_page->didChangeBackForwardList(0, &removedItems);
243}
244
245} // namespace WebKit
246