#include "PlatformWheelEvent.h"
#include <windows.h>
#include <windowsx.h>
namespace WebCore {
#define HIGH_BIT_MASK_SHORT 0x8000
#define SPI_GETWHEELSCROLLCHARS 0x006C
static IntPoint positionForEvent(HWND hWnd, LPARAM lParam)
{
POINT point = {GET_X_LPARAM(lParam), GET_Y_LPARAM(lParam)};
ScreenToClient(hWnd, &point);
return point;
}
static IntPoint globalPositionForEvent(HWND hWnd, LPARAM lParam)
{
POINT point = {GET_X_LPARAM(lParam), GET_Y_LPARAM(lParam)};
return point;
}
int PlatformWheelEvent::horizontalLineMultiplier() const
{
static ULONG scrollChars;
if (!scrollChars && !SystemParametersInfo(SPI_GETWHEELSCROLLCHARS, 0, &scrollChars, 0))
scrollChars = cLineMultiplier;
return scrollChars;
}
int PlatformWheelEvent::verticalLineMultiplier() const
{
static ULONG scrollLines;
if (!scrollLines && !SystemParametersInfo(SPI_GETWHEELSCROLLLINES, 0, &scrollLines, 0))
scrollLines = cLineMultiplier;
return scrollLines;
}
PlatformWheelEvent::PlatformWheelEvent(HWND hWnd, WPARAM wParam, LPARAM lParam, bool isHorizontal)
: m_position(positionForEvent(hWnd, lParam))
, m_globalPosition(globalPositionForEvent(hWnd, lParam))
, m_isAccepted(false)
, m_shiftKey(wParam & MK_SHIFT)
, m_ctrlKey(wParam & MK_CONTROL)
, m_altKey(GetKeyState(VK_MENU) & HIGH_BIT_MASK_SHORT)
, m_metaKey(m_altKey) {
static ULONG scrollLines, scrollChars;
float delta = GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA;
if (isHorizontal) {
m_deltaX = -delta * horizontalLineMultiplier();
m_deltaY = 0;
m_granularity = ScrollByLineWheelEvent;
} else {
m_deltaX = 0;
m_deltaY = delta;
int verticalMultiplier = verticalLineMultiplier();
m_granularity = (verticalMultiplier == -1) ? ScrollByPageWheelEvent : ScrollByLineWheelEvent;
if (m_granularity == ScrollByLineWheelEvent)
m_deltaY *= verticalMultiplier;
}
}
}