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PAINTCALLBACKDATA

Summary

The PAINTCALLBACKDATA structure describes the format of PAINTCALLBACKDATA, * pPAINTCALLBACKDATA;

The PAINTCALLBACKDATA structure contains the callbacks used for custom painting.

Syntax

typedef struct _PAINTCALLBACKDATA 
{ 
   L_UINT uStructSize; 
   L_UINT32 uFlags; 
   L_VOID *pDisplay; 
   L_VOID *pUserData; 
   PAINTCALLBACK_GETDEVICECAPS pGetDeviceCaps; 
   PAINTCALLBACK_GETMAPMODE pGetMapMode; 
   PAINTCALLBACK_SETSTRETCHBLTMODE pSetStretchBltMode; 
   PAINTCALLBACK_INTERSECTCLIPRECT pIntersectClipRect; 
   PAINTCALLBACK_SAVEDC pSaveDC; 
   PAINTCALLBACK_RESTOREDC pRestoreDC; 
   PAINTCALLBACK_STRETCHDIBITS pStretchDIBits; 
   PAINTCALLBACK_SETVIEWPORTORGEX pSetViewportOrgEx; 
   PAINTCALLBACK_GETVIEWPORTORGEX pGetViewportOrgEx; 
   PAINTCALLBACK_EXTSELECTCLIPRGN pExtSelectClipRgn; 
   PAINTCALLBACK_SELECTPALETTE pSelectPalette; 
   PAINTCALLBACK_REALIZEPALETTE pRealizePalette; 
   PAINTCALLBACK_GETGRAPHICSMODE pGetGraphicsMode; 
   PAINTCALLBACK_GETWORLDTRANSFORM pGetWorldTransform; 
   PAINTCALLBACK_ISCOMPATIBLEDC pIsCompatibleDC; 
   PAINTCALLBACK_CONVERTLINE pConvertLine; 
   PAINTCALLBACK_GETDIBINFO pGetDibInfo; 
   PAINTCALLBACK_PREPAINT pPrePaint; 
   PAINTCALLBACK_POSTPAINT pPostPaint; 
   PAINTCALLBACK_FILLRECT pFillRect; 
} PAINTCALLBACKDATA, * pPAINTCALLBACKDATA;

Members

uStructSize

Size of the PAINTCALLBACKDATA structure. This should be sizeof(PAINTCALLBACKDATA).

uFlags

Any of the following flags. (You can use a bitwise OR to specify more than one value.).

Value	Meaning
PAINTCALLBACKDATA_NO_INDEXEDPAINT	[0x00000001] Do not use indexed paint. The palette colors should be passed as RGB colors, not palette indices.

pDisplay

The device context to paint on. The predefined callbacks expect this value to be a valid DC handle. But, if you redirect all the callbacks, this can be a pointer to any structure you want. This value will be passed to all the paint callbacks that take a pDisplay parameter.

pUserData

Pointer to a user-defined structure that will be passed to all the callback functions as the pUserData parameter.

pGetDeviceCaps

Pointer to a function that will replace the GetDeviceCaps GDI function.

pGetMapMode

Pointer to a function that will replace the GetMapMode GDI function.

pSetStretchBltMode

Pointer to a function that will replace the SetStretchBltMode GDI function.

pIntersectClipRect

Pointer to a function that will replace the IntersectClipRect GDI function.

pSaveDC

Pointer to a function that will replace the SaveDC GDI function.

pRestoreDC

Pointer to a function that will replace the RestoreDC GDI function.

pStretchDIBits

Pointer to a function that will replace the StretchDIBits GDI function.

pSetViewportOrgEx

Pointer to a function that will replace the SetViewportOrgEx GDI function.

pGetViewportOrgEx

Pointer to a function that will replace the GetViewportOrgEx GDI function.

pExtSelectClipRgn

Pointer to a function that will replace the ExtSelectClipRgn GDI function.

pSelectPalette

Pointer to a function that will replace the SelectPalette GDI function.

pRealizePalette

Pointer to a function that will replace the RealizePalette GDI function.

pGetGraphicsMode

Pointer to a function that will replace the GetGraphicsMode GDI function.

pGetWorldTransform

Pointer to a function that will replace the GetWorldTransform GDI function.

pIsCompatibleDC

Pointer to a function that determines whether the DC and bitmap are compatible with my callbacks.

pConvertLine

Pointer to a function that converts the image data to display data.

pGetDibInfo

Pointer to a function that will tell the raster engine the format of display data. This function must be provided if you provide the pConvertLine function.

pPrePaint

Pointer to a function that can be used for initialization.

pPostPaint

Pointer to a function that can be used for cleanup.

pFillRect

Pointer to a function that will replace the FillRect GDI function.

Comments

You do not need to provide every callback. You can set to NULL any callbacks that you do not wish to replace. If you pass NULL for a certain callback, the default GDI function will be used.

If you do pass NULL for some of the GDI callbacks, then you should set pDisplay to a valid HDC handle. The default GDI functions expect pDisplay to be a HDC handle.

If you set pIsCompatibleDC to a valid function pointer, that function will be called before any other callback function to determine whether the DC is compatible with your callbacks. If this function returns FALSE, then no other callback will be called and the default GDI functions will be used.

If you set pConvertLine to a valid function pointer, you must also set pGetDibInfo to a valid function pointer so LEADTOOLS will know the format of the image data expected by the painting functions.

If you set pPrePaint to a valid function pointer, it will be called once after pIsCompatibleDC and before any other callback.

If you set pPostPaint to a valid function pointer, it will be called once any other callback.