Win32: when used, SM_CXDRAG and SM_CYDRAG should be reduced to a half

Name: agR10216 Date: 04/03/2003



In the fix for 4731797[Mouse click/drag zone is not read
correctly from Win32] (see the comments section) the
x-distance between the point of pressing the mouse and its
current position is compared to ::GetSystemMetrics(SM_CXDRAG),
while MSDN for GetSystemMetrics says about SM_CXDRAG, SM_CYDRAG:
"Width and height, in pixels, of a rectangle CENTERED on a
drag point to allow for limited movement of the mouse
pointer before a drag operation begins. This allows the user
to click and release the mouse button easily without
unintentionally starting a drag operation."
It implies that we should compare that x-distance to
::GetSystemMetrics(SM_CXDRAG)/2 instead of
::GetSystemMetrics(SM_CXDRAG). (The same for Y, of course.)

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