1 | /* |
2 | * Copyright (C) 2015 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 | #pragma once |
27 | |
28 | #include "FloatSize.h" |
29 | #include <wtf/Deque.h> |
30 | |
31 | namespace WebCore { |
32 | |
33 | class WheelEventDeltaFilter { |
34 | public: |
35 | WheelEventDeltaFilter(); |
36 | virtual ~WheelEventDeltaFilter(); |
37 | |
38 | WEBCORE_EXPORT static std::unique_ptr<WheelEventDeltaFilter> create(); |
39 | WEBCORE_EXPORT virtual void updateFromDelta(const FloatSize&) = 0; |
40 | WEBCORE_EXPORT virtual void beginFilteringDeltas() = 0; |
41 | WEBCORE_EXPORT virtual void endFilteringDeltas() = 0; |
42 | WEBCORE_EXPORT FloatSize filteredVelocity() const; |
43 | WEBCORE_EXPORT bool isFilteringDeltas() const; |
44 | WEBCORE_EXPORT FloatSize filteredDelta() const; |
45 | |
46 | protected: |
47 | FloatSize m_currentFilteredDelta; |
48 | FloatSize m_currentFilteredVelocity; |
49 | bool m_isFilteringDeltas { false }; |
50 | }; |
51 | |
52 | enum class DominantScrollGestureDirection { |
53 | None, |
54 | Vertical, |
55 | Horizontal |
56 | }; |
57 | |
58 | class BasicWheelEventDeltaFilter final : public WheelEventDeltaFilter { |
59 | WTF_MAKE_FAST_ALLOCATED; |
60 | public: |
61 | BasicWheelEventDeltaFilter(); |
62 | void updateFromDelta(const FloatSize&) override; |
63 | void beginFilteringDeltas() override; |
64 | void endFilteringDeltas() override; |
65 | |
66 | private: |
67 | DominantScrollGestureDirection dominantScrollGestureDirection() const; |
68 | |
69 | Deque<FloatSize> m_recentWheelEventDeltas; |
70 | }; |
71 | |
72 | } // namespace WebCore |
73 | |