←Select platform

In This Topic ▼

RasterImagePaintCallbackFunction Enumeration

Summary

Used to identify the callbacks in a RasterPaintCallbacks class.

Syntax

C++/CLI

Python

public enum RasterImagePaintCallbackFunction

public enum class RasterImagePaintCallbackFunction

class RasterImagePaintCallbackFunction(Enum): 
   IsCompatibleDCCallback = 0 
   GetDeviceCapsCallback = 1 
   SetStretchBltModeCallback = 2 
   IntersectClipRectCallback = 3 
   SaveDCCallback = 4 
   RestoreDCCallback = 5 
   StretchDIBitsCallback = 6 
   SetViewportOrgExCallback = 7 
   GetViewportOrgExCallback = 8 
   SelectPaletteCallback = 9 
   RealizePaletteCallback = 10 
   GetMapModeCallback = 11 
   ExtSelectClipRgnCallback = 12 
   GetGraphicsModeCallback = 13 
   GetWorldTransformCallback = 14 
   ConvertLineCallback = 15 
   GetDibInfoCallback = 16 
   PrePaintCallback = 17 
   PostPaintCallback = 18 
   FillRectCallback = 19

Members

Value	Member	Description
0	IsCompatibleDCCallback	This callback checks whether the DC is compatible with a particular RasterPaintDibInfo class.
1	GetDeviceCapsCallback	This callback replaces the GetDeviceCaps GDI function.
2	SetStretchBltModeCallback	This callback replaces the SetStretchBltMode GDI function.
3	IntersectClipRectCallback	This callback replaces the IntersectClipRect GDI function.
4	SaveDCCallback	This callback replaces the SaveDC GDI function.
5	RestoreDCCallback	This callback replaces the RestoreDC GDI function.
6	StretchDIBitsCallback	This callback replaces the StretchDIBits GDI function. Use it to perform the actual painting.
7	SetViewportOrgExCallback	This callback replaces the SetViewportOrgEx GDI function.
8	GetViewportOrgExCallback	This callback replaces the GetViewportOrgEx GDI function.
9	SelectPaletteCallback	This callback replaces the SelectPalette GDI function.
10	RealizePaletteCallback	This callback replaces the RealizePalette GDI function.
11	GetMapModeCallback	This callback replaces the GetMapMode GDI function.
12	ExtSelectClipRgnCallback	This callback replaces the ExtSelectClipRgn GDI function.
13	GetGraphicsModeCallback	This callback replaces the GetGraphicsMode GDI function.
14	GetWorldTransformCallback	This callback replaces the GetWorldTransform GDI function.
15	ConvertLineCallback	This callback converts a line of data.
16	GetDibInfoCallback	This callback provides information on the data expected by the device. See RasterPaintDibInfo for more details.
17	PrePaintCallback	This callback informs your RasterPaintCallbacks class that it has been selected for painting. It is called before painting starts. Use it to allocate any memory needed for painting.
18	PostPaintCallback	This callback gets called after painting is finished. Use it to free any memory allocated in PrePaintCallback.
19	FillRectCallback	This callback replaces the FillRect GDI function.

Remarks

The RasterPaintCallbacks class can contain a number of callbacks used for custom painting.

The number and parameter types for each callback is determined by the callback type using the values in this enumeration.

The number and parameter types for each callback are indicated below.

ConvertLineCallback

Parameter	Description
`IntPtr pOutScan`	The output buffer (pointer to an unmanaged array of bytes).
`IntPtr pInScan`	The input buffer (pointer to an unmanaged array of bytes).
`int nLeft`	Left offset of the first pixel in the input buffer to be used in conversion. (The pixels before this offset should be discarded).
`int nRight`	Right offset of the first pixel after the last pixel in the input buffer to be used in conversion. (Pixels nLeft..nRight-1 should be used in conversion).
`RasterPaintDibInfo pDibInfo`	Pointer to a RasterPaintDibInfo class returned by the GetDibInfoCallback callback. Contains information on the format of the output data. This is a read-only class, any changes made to it will be discarded.

ExtSelectClipRgnCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC
`IntPtr hRgn`	The region handle
`int nMode`	The selection mode

GetDeviceCapsCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC
`int nIndex`	Identifies which capability to return.

GetDibInfoCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC
`int nWidth`	The width of the image data to be painted. (Might be less than the image width).

The return value is a RasterPaintDibInfo class. It contains information about how the image data expected by the device looks like.

GetGraphicsModeCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC

GetMapModeCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC

GetViewportOrgExCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC

The return value is a System.Drawing.Point structure.

GetWorldTransformCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC

The return value is a Leadtools.RasterRegionXForm structure. This structure will be converted to the standard GDI XFORM structure by assigning each field from XFORM the corresponding field from Leadtools.RasterRegionXForm. The correspondence is as follows:

XScalarNumerator
XScalarDenominator
YScalarNumerator
YScalarDenominator
XOffset
YOffset

IntersectClipRectCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC
`int nLeft`	The left offset
`int nTop`	The top offset
`int nRight`	The right offset
`int nBottom`	The bottom offset

IsCompatibleDCCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC

PrePaintCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC
`IntPtr prcDestClip`	Unmanaged pointer to the destination clipping rectangle. It points to an RECT GDI structure.

PostPaintCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC

RealizePaletteCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC

RestoreDCCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC
`int nSaveDC`	Index of the DC to be restored.

SaveDCCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC

SelectPaletteCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC
`IntPtr hPal`	The palette handle. This is a native GDI HPALETTE handle.
`int bForceBackground`	Set to 1 to force the palette to be a background palette and match the existing colors. Set to 0 reset the DC colors to the colors in the palette.

SetStretchBltModeCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC
`int nStretchMode`	The stretch mode.

SetViewportOrgExCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC
`int nX`	The left offset of the new viewport origin.
`int nY`	The top offset of the new viewport origin.
`IntPtr lpPoint`	Pointer to an unmanaged GDI POINT structure.

StretchDIBitsCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC
`int nXDest`	The left offset of the destination.
`int nYDest`	The top offset of the destination.
`int nDestWidth`	The width of the destination.
`int nDestHeight`	The height of the destination
`int nXSrc`	The left offset in the source buffer
`int nYSrc`	The top offset in the source buffer.
`int nSrcWidth`	The width of the source buffer.
`int nSrcHeight`	The height of the source buffer.
`IntPtr lpvBits`	Pointer to data (unmanaged pointer to an array of bytes).
`IntPtr lpbmi`	Unmanaged pointer to a native GDI BITMAPINFO structure describing the image data.
`int fuColorUse`	Indicates how the palette colors are to be used.
`unsigned int ulROP3Code`	The ROP code

FillRectCallback

Parameter	Description
`IntPtr hdc`	The Windows HDC
`LPRECT lprc`	The rectangle coordinates to fill.
`COLORREF color`	The color to use. You must create a solid brush for this color.

Requirements

Target Platforms

Reference

Leadtools.Drawing Namespace

RasterPaintProperties.PaintCallbacks

RasterPaintCallbacks Class

Implementing custom paint

Download our FREE evaluation

Help Version 23.0.2024.2.29

Leadtools.Drawing Assembly

Introduction

Getting Started

Namespaces

Leadtools.Drawing Namespace

Assemblies