WebCore/PlatformWheelEvent.h

   1 /*
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   8  *    notice, this list of conditions and the following disclaimer.
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  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
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  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
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  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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  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 "IntPoint.h"
  30
  31 #import <GraphicsServices/GSEvent.h>
  32
  33 #if PLATFORM(MAC)
  34 #endif
  35
  36 #if PLATFORM(WIN)
  37 typedef struct HWND__* HWND;
  38 typedef unsigned WPARAM;
  39 typedef long LPARAM;
  40 #endif
  41
  42 #if PLATFORM(GTK)
  43 typedef struct _GdkEventScroll GdkEventScroll;
  44 #endif
  45
  46 #if PLATFORM(QT)
  47 QT_BEGIN_NAMESPACE
  48 class QWheelEvent;
  49 QT_END_NAMESPACE
  50 #endif
  51
  52 #if PLATFORM(WX)
  53 class wxMouseEvent;
  54 class wxPoint;
  55 #endif
  56
  57 namespace WebCore {
  58
  59     // Wheel events come in three flavors:
  60     // The ScrollByPixelWheelEvent is a fine-grained event that specifies the precise number of pixels to scroll.  It is sent by MacBook touchpads on OS X.
  61     // For ScrollByPixelWheelEvents, the delta values contain the precise number of pixels to scroll.
  62     // The ScrollByLineWheelEvent (the normal wheel event) sends a delta that can be corrected by a line multiplier to determine how many lines to scroll.
  63     //      If the platform has configurable line sensitivity (Windows), then the number of lines to scroll is used in order to behave like the platform.
  64     //      If the platform does not have configurable line sensitivity, then WebCore's default behavior is used (which scrolls 3 * the wheel line delta).
  65     // For ScrollByLineWheelEvents, the delta values represent the number of lines to scroll.
  66     // The ScrollByPageWheelEvent indicates that the wheel event should scroll an entire page instead.  In this case WebCore's built in paging behavior is used to page
  67     // up and down (you get the same behavior as if the user was clicking in a scrollbar track to page up or page down).  Page scrolling only works in the vertical direction.
  68     enum PlatformWheelEventGranularity { ScrollByLineWheelEvent, ScrollByPageWheelEvent, ScrollByPixelWheelEvent };
  69
  70     // WebCore uses a line multiple of ~3 (40px per line step) when doing arrowing with a scrollbar or line stepping via the arrow keys.  The delta for wheeling is expressed
  71     // as a # of actual lines (40 / 3 = 1 wheel line).  We use the horizontalLineMultiplier and verticalLineMultiplier methods to incorporate the line multiplier into the deltas.  On
  72     // platforms that do not support wheel sensitivity, we use this hardcoded constant value of 3 to ensure that wheeling by default matches the WebCore multiplier you
  73     // get when doing other kinds of line stepping.
  74     const int cLineMultiplier = 3;
  75
  76     class PlatformWheelEvent {
  77     public:
  78         const IntPoint& pos() const { return m_position; } // PlatformWindow coordinates.
  79         const IntPoint& globalPos() const { return m_globalPosition; } // Screen coordinates.
  80
  81         float deltaX() const { return m_deltaX; }
  82         float deltaY() const { return m_deltaY; }
  83
  84         PlatformWheelEventGranularity granularity() const { return m_granularity; }
  85
  86         bool isAccepted() const { return m_isAccepted; }
  87         bool shiftKey() const { return m_shiftKey; }
  88         bool ctrlKey() const { return m_ctrlKey; }
  89         bool altKey() const { return m_altKey; }
  90         bool metaKey() const { return m_metaKey; }
  91
  92         int x() const { return m_position.x(); } // PlatformWindow coordinates.
  93         int y() const { return m_position.y(); }
  94         int globalX() const { return m_globalPosition.x(); } // Screen coordinates.
  95         int globalY() const { return m_globalPosition.y(); }
  96
  97         void accept() { m_isAccepted = true; }
  98         void ignore() { m_isAccepted = false; }
  99
 100 #if PLATFORM(MAC)
 101         PlatformWheelEvent(GSEventRef);
 102 #endif
 103 #if PLATFORM(WIN)
 104         PlatformWheelEvent(HWND, WPARAM, LPARAM, bool isHorizontal);
 105 #endif
 106 #if PLATFORM(GTK)
 107         PlatformWheelEvent(GdkEventScroll*);
 108 #endif
 109 #if PLATFORM(QT)
 110         PlatformWheelEvent(QWheelEvent*);
 111 #endif
 112 #if PLATFORM(WX)
 113         PlatformWheelEvent(const wxMouseEvent&, const wxPoint&);
 114 #endif
 115
 116     protected:
 117 #if !PLATFORM(WIN)
 118         int horizontalLineMultiplier() const { return cLineMultiplier; }
 119         int verticalLineMultiplier() const { return cLineMultiplier; }
 120 #else
 121         int horizontalLineMultiplier() const;
 122         int verticalLineMultiplier() const;
 123 #endif
 124
 125         IntPoint m_position;
 126         IntPoint m_globalPosition;
 127         float m_deltaX;
 128         float m_deltaY;
 129         PlatformWheelEventGranularity m_granularity;
 130         bool m_isAccepted;
 131         bool m_shiftKey;
 132         bool m_ctrlKey;
 133         bool m_altKey;
 134         bool m_metaKey;
 135     };
 136
 137 } // namespace WebCore
 138
 139 #endif // PlatformWheelEvent_h