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      1 /*
      2  * Copyright (C) 2004, 2005, 2006, 2009 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 COMPUTER, INC. ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #ifndef PlatformWheelEvent_h
     27 #define PlatformWheelEvent_h
     28 
     29 #include "platform/PlatformEvent.h"
     30 #include "platform/geometry/IntPoint.h"
     31 
     32 namespace blink {
     33 
     34 // Wheel events come in two flavors:
     35 // The ScrollByPixelWheelEvent is a fine-grained event that specifies the precise number of pixels to scroll. It is sent directly by MacBook touchpads on OS X,
     36 // and synthesized in other cases where platforms generate line-by-line scrolling events.
     37 // The ScrollByPageWheelEvent indicates that the wheel event should scroll an entire page. In this case WebCore's built in paging behavior is used to page
     38 // up and down (you get the same behavior as if the user was clicking in a scrollbar track to page up or page down).
     39 enum PlatformWheelEventGranularity {
     40     ScrollByPageWheelEvent,
     41     ScrollByPixelWheelEvent,
     42 };
     43 
     44 #if OS(MACOSX)
     45 enum PlatformWheelEventPhase {
     46     PlatformWheelEventPhaseNone        = 0,
     47     PlatformWheelEventPhaseBegan       = 1 << 0,
     48     PlatformWheelEventPhaseStationary  = 1 << 1,
     49     PlatformWheelEventPhaseChanged     = 1 << 2,
     50     PlatformWheelEventPhaseEnded       = 1 << 3,
     51     PlatformWheelEventPhaseCancelled   = 1 << 4,
     52     PlatformWheelEventPhaseMayBegin    = 1 << 5,
     53 };
     54 #endif
     55 
     56 class PlatformWheelEvent : public PlatformEvent {
     57 public:
     58     PlatformWheelEvent()
     59         : PlatformEvent(PlatformEvent::Wheel)
     60         , m_deltaX(0)
     61         , m_deltaY(0)
     62         , m_wheelTicksX(0)
     63         , m_wheelTicksY(0)
     64         , m_granularity(ScrollByPixelWheelEvent)
     65         , m_hasPreciseScrollingDeltas(false)
     66 #if OS(MACOSX)
     67         , m_phase(PlatformWheelEventPhaseNone)
     68         , m_momentumPhase(PlatformWheelEventPhaseNone)
     69         , m_scrollCount(0)
     70         , m_unacceleratedScrollingDeltaX(0)
     71         , m_unacceleratedScrollingDeltaY(0)
     72         , m_canRubberbandLeft(true)
     73         , m_canRubberbandRight(true)
     74 #endif
     75     {
     76     }
     77 
     78     PlatformWheelEvent(IntPoint position, IntPoint globalPosition, float deltaX, float deltaY, float wheelTicksX, float wheelTicksY, PlatformWheelEventGranularity granularity, bool shiftKey, bool ctrlKey, bool altKey, bool metaKey)
     79         : PlatformEvent(PlatformEvent::Wheel, shiftKey, ctrlKey, altKey, metaKey, 0)
     80         , m_position(position)
     81         , m_globalPosition(globalPosition)
     82         , m_deltaX(deltaX)
     83         , m_deltaY(deltaY)
     84         , m_wheelTicksX(wheelTicksX)
     85         , m_wheelTicksY(wheelTicksY)
     86         , m_granularity(granularity)
     87         , m_hasPreciseScrollingDeltas(false)
     88 #if OS(MACOSX)
     89         , m_phase(PlatformWheelEventPhaseNone)
     90         , m_momentumPhase(PlatformWheelEventPhaseNone)
     91         , m_scrollCount(0)
     92         , m_unacceleratedScrollingDeltaX(0)
     93         , m_unacceleratedScrollingDeltaY(0)
     94         , m_canRubberbandLeft(true)
     95         , m_canRubberbandRight(true)
     96 #endif
     97     {
     98     }
     99 
    100     const IntPoint& position() const { return m_position; } // PlatformWindow coordinates.
    101     const IntPoint& globalPosition() const { return m_globalPosition; } // Screen coordinates.
    102 
    103     float deltaX() const { return m_deltaX; }
    104     float deltaY() const { return m_deltaY; }
    105 
    106     float wheelTicksX() const { return m_wheelTicksX; }
    107     float wheelTicksY() const { return m_wheelTicksY; }
    108 
    109     PlatformWheelEventGranularity granularity() const { return m_granularity; }
    110 
    111     bool hasPreciseScrollingDeltas() const { return m_hasPreciseScrollingDeltas; }
    112     void setHasPreciseScrollingDeltas(bool b) { m_hasPreciseScrollingDeltas = b; }
    113 #if OS(MACOSX)
    114     PlatformWheelEventPhase phase() const { return m_phase; }
    115     PlatformWheelEventPhase momentumPhase() const { return m_momentumPhase; }
    116     unsigned scrollCount() const { return m_scrollCount; }
    117     float unacceleratedScrollingDeltaX() const { return m_unacceleratedScrollingDeltaX; }
    118     float unacceleratedScrollingDeltaY() const { return m_unacceleratedScrollingDeltaY; }
    119     bool useLatchedEventNode() const { return m_momentumPhase == PlatformWheelEventPhaseBegan || m_momentumPhase == PlatformWheelEventPhaseChanged; }
    120     bool canRubberbandLeft() const { return m_canRubberbandLeft; }
    121     bool canRubberbandRight() const { return m_canRubberbandRight; }
    122 #else
    123     bool useLatchedEventNode() const { return false; }
    124 #endif
    125 
    126 protected:
    127     IntPoint m_position;
    128     IntPoint m_globalPosition;
    129     float m_deltaX;
    130     float m_deltaY;
    131     float m_wheelTicksX;
    132     float m_wheelTicksY;
    133     PlatformWheelEventGranularity m_granularity;
    134     bool m_hasPreciseScrollingDeltas;
    135 #if OS(MACOSX)
    136     PlatformWheelEventPhase m_phase;
    137     PlatformWheelEventPhase m_momentumPhase;
    138     unsigned m_scrollCount;
    139     float m_unacceleratedScrollingDeltaX;
    140     float m_unacceleratedScrollingDeltaY;
    141     bool m_canRubberbandLeft;
    142     bool m_canRubberbandRight;
    143 #endif
    144 };
    145 
    146 } // namespace blink
    147 
    148 #endif // PlatformWheelEvent_h
    149