DevEscape - Remarks

The data fields for standard escapes are:

DEVESC_QUERYESCSUPPORT

Queries whether a particular escape is implemented by the presentation driver. The return value gives the result.

This escape is not metafiled or recorded.

lInCount

Number of bytes pointed to by pbInData.
pbInData
The buffer contains an escape code value specifying the escape function to be checked.
plOutCount
Not used; can be set to 0.
pbOutData
Not used; can be set to null.
DEVESC_GETSCALINGFACTOR
Returns the scaling factors for the x and y axes of a printing device. For each scaling factor, an exponent of two is put in pbOutData. Thus, the value 3 is used if the scaling factor is 8.

Scaling factors are used by devices that cannot support graphics at the same resolution as the device resolution.

This escape is not metafiled or recorded.

lInCount

Not used; can be set to 0.
pbInData
Not used; can be set to null.
plOutCount
The number of bytes of data pointed to by pbOutData. On return, this is updated to the number of bytes returned.
pbOutData
The address of a SFACTORS structure, which on return contains the scaling factors for the x and y axes.
DEVESC_STARTDOC
Indicates that a new print job is starting. All subsequent output to the device context is spooled under the same job identifier until a DEVESC_ENDDOC occurs.

GpiAssociate must be issued to associate the presentation space with the device context before issuing this escape.

This escape is metafiled but not recorded.

lInCount

Number of bytes pointed to by pbInData.
pbInData
The buffer contains a null-terminated string, specifying the name of the document.
plOutCount
Not used; can be set to 0.
pbOutData
Not used; can be set to null.
DEVESC_ENDDOC
Ends a print job started by DEVESC_STARTDOC.

This escape is metafiled but not recorded.

lInCount

Not used; can be set to 0.
pbInData
Not used; can be set to null.
plOutCount
Set equal to 2.
pbOutData
The buffer contains a USHORT specifying the job identifier if a spooler print job is created.
DEVESC_ABORTDOC
Aborts the current job, erasing everything the application has written to the device since the last DEVESC_STARTDOC, including the DEVESC_STARTDOC.

This escape is metafiled but not recorded.

lInCount

Not used; can be set to 0
pbInData
Not used; can be set to null
plOutCount
Not used; can be set to 0
pbOutData
Not used; can be set to null.
DEVESC_NEWFRAME
Signals when an application has finished writing to a page and wants to start a new page. It is similar to GpiErase processing for a screen device context, and causes a reset of the attributes. This escape is used with a printer device to advance to a new page.

This escape is metafiled and recorded.

lInCount

Not used; can be set to 0
pbInData
Not used; can be set to null
plOutCount
Not used; can be set to 0
pbOutData
Not used; can be set to null.
DEVESC_RAWDATA
Allows an application to send data directly to a presentation driver. For example, in the case of a printer driver, this could be a printer data stream.

If DEVESC_RAWDATA is mixed with other data (such as GPI data) being sent to the same page of a device context, the results are unpredictable and depend upon the action taken by the presentation driver. For example, a presentation driver might ignore GPI data if DEVESC_RAWDATA is mixed with it on the same page. In general, DEVESC_RAWDATA should be sent either to a separate page (using the DEVESC_NEWFRAME escape to obtain a new page) or to a separate document (using the DEVESC_STARTDOC and DEVESC_ENDDOC escapes to create a new document).

This escape is metafiled and recorded.

lInCount

Number of bytes pointed to by pbInData
pbInData
Pointer to the raw data
plOutCount
Not used; can be set to 0
pbOutData
Not used; can be set to null.
DEVESC_QUERYVIOCELLSIZES
Returns the VIO cell sizes supported by the presentation driver.

This escape is not metafiled or recorded.

lInCount

Not used; can be set to 0
pbInData
Not used; can be set to null.
plOutCount
The number of bytes of data pointed to by pbOutData. It must be an even multiple of the size in bytes of the LONG data type. On return, this is updated to the number of bytes returned.
pbOutData
The address of a buffer, which on return contains a VIOSIZECOUNT structure, immediately followed by count copies of a VIOFONTCELLSIZE structure.

If plOutCount is less than the size of a LONG data type, plOutCount is updated to zero, and nothing is returned in the buffer pointed to by pbOutData.

If plOutCount is equal to the size of a LONG data type, pbOutData returns the number of VIO cell sizes that can be returned by this escape. The buffer pointed to by pbOutData is updated so that maxcount is the number of VIO cell sizes that can be returned.

If plOutCount is greater than the size of a LONG data type, pbOutData returns the VIO cell sizes that are supported. The buffer pointed to by pbOutData is updated so that:

• maxcount is the number of VIO cell sizes that can be returned

• count is the number of VIO cell sizes returned (may be zero if plOutCount is equal to twice the size of a LONG data type)

• count copies of a VIOFONTCELLSIZE structure are returned.
DEVESC_SETMODE
Sets the printer into a particular mode. It is optional for printer drivers to support this escape, but those that do support it need to be aware of the code page of any built-in fonts. For example, if only code page 437 is built in, it is used if 437 is requested by DEVESC_SETMODE; however, if code page 865 is requested, a suitable code page/font could be downloaded.

This escape is metafiled and recorded.

lInCount

Number of bytes pointed to by pbInData
pbInData
Buffer contains an ESCSETMODE structure
plOutCount
Not used; can be set to 0
pbOutData
Not used; can be set to null.

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