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               Using Presentation Spaces and Device Contexts
 
You can use presentation-space and device-context functions to perform the
following tasks:
 
♦  Create a normal, micro, or cached-micro presentation space.
 
♦  Delete, save, or restore a presentation space.
 
♦  Create a standard or cached device context.
 
♦  Associate a presentation space or device context.
 
♦  Destroy a device context.
 
♦  Retrieve information about a device's capabilities.
 
Creating a Normal Presentation Space
 
The following code fragment shows how to create a presentation space with
page units of 0.01 inches and associate it with a printer device context:
 
HAB hab;          /* anchor-block handle       */
HPS hpsNormal;    /* presentation-space handle */
HDC hdcPrinter;   /* device-context handle     */
SIZEL sizlPage;   /* page structure            */
    .
    .
    .
hpsNormal = GpiCreatePS(hab, hdcPrinter, &sizlPage,
   PU_LOENGLISH | GPIA_ASSOC);
 
Creating a Standard Device Context for a Printer
 
The following code fragment shows how to create a printer device context:
 
HDC hdcPrinter;              /* handle of printer device context */
HAB hab;                     /* anchor-block handle              */
DEVOPENSTRUC dop;            /* device information               */
 
dop.pszLogAddress = "lpt1";      /* logical-device address */
dop.pszDriverName = "PSCRIPT";   /* device-driver name     */
dop.pdriv = NULL;                /* pointer to driver data */
dop.pszDataType = "PM_Q_STD";    /* standard queued data   */
 
hdcPrinter = DevOpenDC(hab,
    OD_DIRECT,                      /* direct device type */
    "*",                            /* no data in os2.ini */
    4L,
    (PDEVOPENDATA) &dop,
    (HDC) NULL);
 
Creating a Standard Device Context for a Metafile
 
The following code fragment shows how to create a standard device context:
HDC hdcMeta, hdcWin; /* handles of metafile and window DC */
HAB hab;             /* anchor-block handle               */
DEVOPENSTRUC dop;    /* device information                */
 
dop.pszLogAddress = NULL;          /* logical-device address */
dop.pszDriverName = "DISPLAY";     /* device-driver name     */
dop.pdriv = NULL;                  /* pointer to driver data */
dop.pszDataType = NULL;            /* no queued data         */
 
hdcMeta = DevOpenDC(hab,
    OD_METAFILE,           /* metafile DC                */
    "*",                   /* ignores os2.ini            */
    4L,                    /* uses first 4 fields in dop */
    (PDEVOPENDATA) &dop,   /* structure for system info  */
    NULL);                 /* compatible with screen     */
 
Reassociating a Normal Presentation Space
 
The following code fragment shows how to break the link between a normal
presentation space and a device context and reassociate the presentation
space with a metafile device context:
 
if (!GpiAssociate(hps, NULL))    /* breaks link between PS and DC   */
    ReportError(...);
if (!GpiAssociate(hps, hdcMeta)) /* reassociates PS and metafile DC */
    ReportError(...);
 
Associating a Device Context with a Presentation Space
 
The following code fragment shows how to open a cached device context and
associate it with a normal presentation space:
 
HDC hdcWin;         /* cached-device-context handle     */
HPS hpsWin;         /* normal-presentation-space handle */
HWND hwndClient;    /* client-window handle             */
HAB hab;            /* anchor-block handle              */
SIZEL sizlPage;     /* presentation page                */
 
hdcWin = WinOpenWindowDC(hwndClient);
hpsWin = GpiCreatePS(hab, hdcWin, &sizlPage,
    PU_LOENGLISH | GPIA_ASSOC);
 
 
                                      ♦