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 "platform/UserGestureIndicator.h"
28
29#include "wtf/Assertions.h"
30#include "wtf/CurrentTime.h"
31#include "wtf/MainThread.h"
32
33namespace blink {
34
35namespace {
36
37// User gestures timeout in 1 second.
38const double userGestureTimeout = 1.0;
39
40// For out of process tokens we allow a 10 second delay.
41const double userGestureOutOfProcessTimeout = 10.0;
42
43class GestureToken : public UserGestureToken {
44public:
45    static PassRefPtr<UserGestureToken> create() { return adoptRef(new GestureToken); }
46
47    virtual ~GestureToken() { }
48    virtual bool hasGestures() const OVERRIDE
49    {
50        // Do not enforce timeouts for gestures which spawned javascript prompts.
51        if (m_consumableGestures < 1 || (WTF::currentTime() - m_timestamp > (m_outOfProcess ? userGestureOutOfProcessTimeout : userGestureTimeout) && !m_javascriptPrompt))
52            return false;
53        return true;
54    }
55
56    void addGesture()
57    {
58        m_consumableGestures++;
59        m_timestamp = WTF::currentTime();
60    }
61
62    void resetTimestamp()
63    {
64        m_timestamp = WTF::currentTime();
65    }
66
67    bool consumeGesture()
68    {
69        if (!m_consumableGestures)
70            return false;
71        m_consumableGestures--;
72        return true;
73    }
74
75    virtual void setOutOfProcess() OVERRIDE
76    {
77        if (WTF::currentTime() - m_timestamp > userGestureTimeout)
78            return;
79        if (hasGestures())
80            m_outOfProcess = true;
81    }
82
83    virtual void setJavascriptPrompt() OVERRIDE
84    {
85        if (WTF::currentTime() - m_timestamp > userGestureTimeout)
86            return;
87        if (hasGestures())
88            m_javascriptPrompt = true;
89    }
90
91private:
92    GestureToken()
93        : m_consumableGestures(0)
94        , m_timestamp(0)
95        , m_outOfProcess(false)
96        , m_javascriptPrompt(false)
97    {
98    }
99
100    size_t m_consumableGestures;
101    double m_timestamp;
102    bool m_outOfProcess;
103    bool m_javascriptPrompt;
104};
105
106}
107
108static bool isDefinite(ProcessingUserGestureState state)
109{
110    return state == DefinitelyProcessingNewUserGesture || state == DefinitelyProcessingUserGesture || state == DefinitelyNotProcessingUserGesture;
111}
112
113ProcessingUserGestureState UserGestureIndicator::s_state = DefinitelyNotProcessingUserGesture;
114UserGestureIndicator* UserGestureIndicator::s_topmostIndicator = 0;
115bool UserGestureIndicator::s_processedUserGestureSinceLoad = false;
116
117UserGestureIndicator::UserGestureIndicator(ProcessingUserGestureState state)
118    : m_previousState(s_state)
119{
120    // Silently ignore UserGestureIndicators on non-main threads.
121    if (!isMainThread())
122        return;
123
124    // We overwrite s_state only if the caller is definite about the gesture state.
125    if (isDefinite(state)) {
126        if (!s_topmostIndicator) {
127            s_topmostIndicator = this;
128            m_token = GestureToken::create();
129        } else {
130            m_token = s_topmostIndicator->currentToken();
131        }
132        s_state = state;
133    }
134
135    if (state == DefinitelyProcessingNewUserGesture) {
136        static_cast<GestureToken*>(m_token.get())->addGesture();
137        s_processedUserGestureSinceLoad = true;
138    } else if (state == DefinitelyProcessingUserGesture && s_topmostIndicator == this) {
139        static_cast<GestureToken*>(m_token.get())->addGesture();
140        s_processedUserGestureSinceLoad = true;
141    }
142    ASSERT(isDefinite(s_state));
143}
144
145UserGestureIndicator::UserGestureIndicator(PassRefPtr<UserGestureToken> token)
146    : m_previousState(s_state)
147{
148    // Silently ignore UserGestureIndicators on non-main threads.
149    if (!isMainThread())
150        return;
151
152    if (token) {
153        static_cast<GestureToken*>(token.get())->resetTimestamp();
154        if (!s_topmostIndicator) {
155            s_topmostIndicator = this;
156            m_token = token;
157        } else {
158            m_token = s_topmostIndicator->currentToken();
159            if (static_cast<GestureToken*>(token.get())->hasGestures()) {
160                static_cast<GestureToken*>(m_token.get())->addGesture();
161                static_cast<GestureToken*>(token.get())->consumeGesture();
162            }
163        }
164        s_state = DefinitelyProcessingUserGesture;
165    }
166
167    ASSERT(isDefinite(s_state));
168}
169
170UserGestureIndicator::~UserGestureIndicator()
171{
172    if (!isMainThread())
173        return;
174    s_state = m_previousState;
175    if (s_topmostIndicator == this)
176        s_topmostIndicator = 0;
177    ASSERT(isDefinite(s_state));
178}
179
180bool UserGestureIndicator::processingUserGesture()
181{
182    if (!isMainThread())
183        return false;
184    return s_topmostIndicator && static_cast<GestureToken*>(s_topmostIndicator->currentToken())->hasGestures() && (s_state == DefinitelyProcessingNewUserGesture || s_state == DefinitelyProcessingUserGesture);
185}
186
187bool UserGestureIndicator::consumeUserGesture()
188{
189    if (!isMainThread() || !s_topmostIndicator)
190        return false;
191    return static_cast<GestureToken*>(s_topmostIndicator->currentToken())->consumeGesture();
192}
193
194UserGestureToken* UserGestureIndicator::currentToken()
195{
196    if (!isMainThread() || !s_topmostIndicator)
197        return 0;
198    return s_topmostIndicator->m_token.get();
199}
200
201void UserGestureIndicator::clearProcessedUserGestureSinceLoad()
202{
203    if (isMainThread())
204        s_processedUserGestureSinceLoad = false;
205}
206
207bool UserGestureIndicator::processedUserGestureSinceLoad()
208{
209    if (!isMainThread())
210        return false;
211    return s_processedUserGestureSinceLoad;
212}
213
214UserGestureIndicatorDisabler::UserGestureIndicatorDisabler()
215    : m_savedState(UserGestureIndicator::s_state)
216    , m_savedIndicator(UserGestureIndicator::s_topmostIndicator)
217{
218    RELEASE_ASSERT(isMainThread());
219    UserGestureIndicator::s_state = DefinitelyNotProcessingUserGesture;
220    UserGestureIndicator::s_topmostIndicator = 0;
221}
222
223UserGestureIndicatorDisabler::~UserGestureIndicatorDisabler()
224{
225    RELEASE_ASSERT(isMainThread());
226    UserGestureIndicator::s_state = m_savedState;
227    UserGestureIndicator::s_topmostIndicator = m_savedIndicator;
228}
229
230}
231