1/*
2 * Copyright (C) 2012 Google 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 are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 *     * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include "config.h"
32#include "core/inspector/InspectorHistory.h"
33
34#include "bindings/core/v8/ExceptionState.h"
35#include "bindings/core/v8/ExceptionStatePlaceholder.h"
36#include "core/dom/Node.h"
37
38namespace blink {
39
40namespace {
41
42class UndoableStateMark FINAL : public InspectorHistory::Action {
43public:
44    UndoableStateMark() : InspectorHistory::Action("[UndoableState]") { }
45
46    virtual bool perform(ExceptionState&) OVERRIDE { return true; }
47
48    virtual bool undo(ExceptionState&) OVERRIDE { return true; }
49
50    virtual bool redo(ExceptionState&) OVERRIDE { return true; }
51
52    virtual bool isUndoableStateMark() OVERRIDE { return true; }
53};
54
55}
56
57InspectorHistory::Action::Action(const String& name) : m_name(name)
58{
59}
60
61InspectorHistory::Action::~Action()
62{
63}
64
65void InspectorHistory::Action::trace(Visitor* visitor)
66{
67}
68
69String InspectorHistory::Action::toString()
70{
71    return m_name;
72}
73
74bool InspectorHistory::Action::isUndoableStateMark()
75{
76    return false;
77}
78
79String InspectorHistory::Action::mergeId()
80{
81    return "";
82}
83
84void InspectorHistory::Action::merge(PassRefPtrWillBeRawPtr<Action>)
85{
86}
87
88InspectorHistory::InspectorHistory() : m_afterLastActionIndex(0) { }
89
90bool InspectorHistory::perform(PassRefPtrWillBeRawPtr<Action> action, ExceptionState& exceptionState)
91{
92    if (!action->perform(exceptionState))
93        return false;
94
95    if (!action->mergeId().isEmpty() && m_afterLastActionIndex > 0 && action->mergeId() == m_history[m_afterLastActionIndex - 1]->mergeId())
96        m_history[m_afterLastActionIndex - 1]->merge(action);
97    else {
98        m_history.resize(m_afterLastActionIndex);
99        m_history.append(action);
100        ++m_afterLastActionIndex;
101    }
102    return true;
103}
104
105void InspectorHistory::markUndoableState()
106{
107    perform(adoptRefWillBeNoop(new UndoableStateMark()), IGNORE_EXCEPTION);
108}
109
110bool InspectorHistory::undo(ExceptionState& exceptionState)
111{
112    while (m_afterLastActionIndex > 0 && m_history[m_afterLastActionIndex - 1]->isUndoableStateMark())
113        --m_afterLastActionIndex;
114
115    while (m_afterLastActionIndex > 0) {
116        Action* action = m_history[m_afterLastActionIndex - 1].get();
117        if (!action->undo(exceptionState)) {
118            reset();
119            return false;
120        }
121        --m_afterLastActionIndex;
122        if (action->isUndoableStateMark())
123            break;
124    }
125
126    return true;
127}
128
129bool InspectorHistory::redo(ExceptionState& exceptionState)
130{
131    while (m_afterLastActionIndex < m_history.size() && m_history[m_afterLastActionIndex]->isUndoableStateMark())
132        ++m_afterLastActionIndex;
133
134    while (m_afterLastActionIndex < m_history.size()) {
135        Action* action = m_history[m_afterLastActionIndex].get();
136        if (!action->redo(exceptionState)) {
137            reset();
138            return false;
139        }
140        ++m_afterLastActionIndex;
141        if (action->isUndoableStateMark())
142            break;
143    }
144    return true;
145}
146
147void InspectorHistory::reset()
148{
149    m_afterLastActionIndex = 0;
150    m_history.clear();
151}
152
153void InspectorHistory::trace(Visitor* visitor)
154{
155    visitor->trace(m_history);
156}
157
158} // namespace blink
159
160