Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

                                                     ◄Up► ◄Next► ◄Previous►
────────────────────────────────────────────────────────────────────────────
 
#define MOUSETRAILS 39 WORD Control(lpDestDevice, MOUSETRAILS, lpTrailSize,
                                    NULL)
LPPDEVICE lpDestDevice;
LPINT lpTrailSize;
 
The MOUSETRAILS escape enables or disables mouse trails for the display
driver.
 
Parameter     Description
────────────────────────────────────────────────────────────────────────────
 
lpDestDevice  Points to a PDEVICE structure specifying the destination
              device.
 
lpTrailSize   Points to a 16-bit variable containing a value specifying the
              action to take, and the number of mouse cursor images to
              display (trail size). The variable can be one of the following
              values.
 
              Value        Meaning
              ──────────────────────────────────────────────────────────────
              1 through 7  Enables mouse trails and sets the trail size to
                           the specified number. A value of 1 requests a
                           single mouse cursor; 2 requests that one extra
                           mouse cursor be drawn behind the current mouse
                           cursor, and so on, up to a maximum of 7 total
                           cursor images. The function sets the MouseTrails
                           setting in the WIN.INI file to the given value.
                           The function then returns the new trail size.
 
              0            Disables mouse trails. The function sets the
                           MouseTrails setting to the negative value of the
                           current trail size (if positive). The function
                           then returns the negative value.
 
              -1           Enables mouse trails. The display driver reads
                           the MouseTrails setting from the [Windows]
                           section of the WIN.INI file. If the setting value
                           is positive, the function sets the trail size to
                           the given value. If the setting value is
                           negative, the function sets trail size to the
                           setting's absolute value and writes the positive
                           value back to WIN.INI. If the MouseTrails setting
                           is not found, the function sets the trail size to
                           7 and writes a new MouseTrails setting to the
                           WIN.INI file, setting its value to 7. The
                           function then returns the new trail size.
 
              -2           Disables mouse trails but does not cause the
                           driver to update the WIN.INI file.
 
              -3           Enables mouse trails but does not cause the
                           driver to update the WIN.INI file.
 
Return Value
 
The return value specifies the size of the escape if successful. Otherwise,
it is zero if the escape is not supported.
 
Comments
 
An application can retrieve the current trail size by calling the
QUERYESCSUPPORT escape as shown in the following example:
 
Escape(hDC, QUERYESCSUPPORT, sizeof(int), MOUSETRAILS, NULL);
 
The QUERYESCSUPPORT escape returns the current trail size without changing
to the current setting. If the escape returns zero, mouse trails are not
supported by the display driver. If the escape returns a positive value,
mouse trails are enabled and the value specifies the current trail size. If
the escape returns a negative value, mouse trails are currently disabled and
the value is the same as the negative MouseTrails value specified in the
WIN.INI file.
 
                                      ♦