PRB: mouse_event and Absolute Moves on Secondary Monitors (193003)
The information in this article applies to:
- Microsoft Platform Software Development Kit (SDK) 1.0, when used with:
- the operating system: Microsoft Windows 98
This article was previously published under Q193003 SYMPTOMS
When you use mouse_event with absolute positions on Windows 98, the mouse
cursor only moves over the primary monitor. If you try to move the cursor
onto a secondary monitor attached to the desktop, the cursor stops at the
edge of the primary monitor. Relative mouse movements move the cursor to
the primary or secondary monitor as appropriate. The behavior of moving the
cursor over an area of the desktop that is not on any monitor is undefined.
CAUSE
This behavior is by design for backward compatibility with Windows 95.
RESOLUTION
In some cases, this behavior is not desired. You can use the following
sample code to emulate absolute movement over the entire virtual desktop:
Sample Code
// Visual C++ 5.0 does not define these constants. Visual C++ 6.0 does,
// so you need to allow for both possibilities.
#ifndef SPI_GETMOUSESPEED
#define SPI_GETMOUSESPEED 112
#endif
#ifndef SPI_SETMOUSESPEED
#define SPI_SETMOUSESPEED 113
#endif
int oldAccel[3], newAccel[3], oldSpeed, newSpeed, x, y;
BOOL bResult;
// The following values set mouse ballistics to 1 mickey/pixel.
newAccel[0] = 0;
newAccel[1] = 0;
newAccel[2] = 0;
newSpeed = 1;
// Save the Current Mouse Acceleration Constants
bResult = SystemParametersInfo(SPI_GETMOUSE,0, oldAccel,0);
bResult = SystemParametersInfo(SPI_GETMOUSESPEED, 0, &oldSpeed,0);
// Set the new Mouse Acceleration Constants (Disabled).
bResult = SystemParametersInfo(SPI_SETMOUSE, 0, newAccel,
SPIF_SENDCHANGE);
bResult = SystemParametersInfo(SPI_SETMOUSESPEED, 0, newSpeed,
SPIF_SENDCHANGE);
//Pick some arbitrary x & y values.
x = -100;
y = -150;
// Move cursor to UL of primary monitor (origin).
mouse_event(MOUSEEVENTF_ABSOLUTE,0,0,0,0);
// Move the cursor to the desired coordinates.
mouse_event(0,x,y,0,0);
// Restore the old Mouse Acceleration Constants.
bResult = SystemParametersInfo(SPI_SETMOUSE,0, oldAccel,
SPIF_SENDCHANGE);
bResult = SystemParametersInfo(SPI_SETMOUSESPEED, 0, oldSpeed,
SPIF_SENDCHANGE);
MORE INFORMATION
Windows NT allows absolute mouse moves onto any monitor that is part of the
desktop.
| Modification Type: | Minor | Last Reviewed: | 7/11/2005 |
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| Keywords: | kbcode kbInput kbprb KB193003 |
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