// Decodes and handles WM_TOUCH* messages.
private void DecodeTouch(ref WinApi.TOUCHINPUT touchInput)
{
// TOUCHINFO point coordinates and contact size is in 1/100 of a pixel; convert it to pixels.
// Also convert screen to client coordinates.
if ((touchInput.dwMask & WinApi.TOUCHINPUTMASKF_CONTACTAREA) != 0)
ContactSize = new Size(AdjustDpiX(touchInput.cyContact / 100), AdjustDpiY(touchInput.cyContact / 100));
Id = touchInput.dwID;
Point p = _ParentHandler.ParentControl.PointToClient(new Point(touchInput.x / 100, touchInput.y / 100));
Location = p;// new Point(AdjustDpiX(p.X), AdjustDpiY(p.Y));
Time = touchInput.dwTime;
TimeSpan ellapse = TimeSpan.FromMilliseconds(Environment.TickCount - touchInput.dwTime);
AbsoluteTime = DateTime.Now - ellapse;
Mask = touchInput.dwMask;
Flags = touchInput.dwFlags;
}
//Decode the gesture
private void ParseGesture(Control parentControl, ref WinApi.GESTUREINFO gestureInfo)
{
Location = parentControl.PointToClient(new Point(gestureInfo.ptsLocation.x, gestureInfo.ptsLocation.y));
Center = Location;
switch (GestureId)
{
case WinApi.GID_ROTATE:
ushort lastArguments = (ushort)(IsBegin ? 0 : LastEvent.GestureArguments);
RotateAngle = WinApi.GID_ROTATE_ANGLE_FROM_ARGUMENT((ushort)(gestureInfo.ullArguments - lastArguments));
break;
case WinApi.GID_ZOOM:
Point first = IsBegin ? Location : LastBeginEvent.Location;
Center = new Point((Location.X + first.X) / 2, (Location.Y + first.Y) / 2);
ZoomFactor = IsBegin ? 1 : (double)gestureInfo.ullArguments / LastEvent.GestureArguments;
//DistanceBetweenFingers = WinApi.LoDWord(gestureInfo.ullArguments);
break;
case WinApi.GID_PAN:
PanTranslation = IsBegin ? new Size(0, 0) :
new Size(Location.X - LastEvent.Location.X, Location.Y - LastEvent.Location.Y);
int panVelocity = WinApi.HiDWord((long)(gestureInfo.ullArguments));
PanVelocity = new Size(WinApi.LoWord(panVelocity), WinApi.HiWord(panVelocity));
//DistanceBetweenFingers = WinApi.LoDWord(gestureInfo.ullArguments);
break;
}
}
/// <summary>
/// Create new touch event argument instance
/// </summary>
/// <param name="hWndWrapper">The target control</param>
/// <param name="touchInput">one of the inner touch input in the message</param>
internal TouchEventArgs(TouchHandler parentHandler, float dpiX, float dpiY, ref WinApi.TOUCHINPUT touchInput)
{
_ParentHandler = parentHandler;
_dpiXFactor = 96F / dpiX;
_dpiYFactor = 96F / dpiY;
DecodeTouch(ref touchInput);
}
/// <summary>
/// Create new gesture event instance and decode the gesture info structure
/// </summary>
/// <param name="handler">The gesture handler</param>
/// <param name="gestureInfo">The gesture information</param>
internal GestureEventArgs(TouchHandler handler, ref WinApi.GESTUREINFO gestureInfo)
{
_Flags = gestureInfo.dwFlags;
GestureId = gestureInfo.dwID;
GestureArguments = gestureInfo.ullArguments;
//Get the last event from the handler
LastEvent = handler.LastEventArgs;
//Get the last begin event from the handler
LastBeginEvent = handler.LastBeginEventArgs;
ParseGesture(handler.ParentControl, ref gestureInfo);
//new gesture, clear last and first event fields
if (IsBegin)
{
LastBeginEvent = null;
LastEvent = null;
}
}
