---
title: CGPatternDrawPatternCallback
framework: coregraphics
role: symbol
role_heading: Type Alias
path: coregraphics/cgpatterndrawpatterncallback
---

# CGPatternDrawPatternCallback

Draws a pattern cell.

## Declaration

```swift
typealias CGPatternDrawPatternCallback = (UnsafeMutableRawPointer?, CGContext) -> Void
```

## Parameters

- `info`: A generic pointer to private data associated with the pattern. This is the same pointer you supplied to doc://com.apple.coregraphics/documentation/CoreGraphics/CGPattern/init(info:bounds:matrix:xStep:yStep:tiling:isColored:callbacks:).
- `context`: The graphics context for drawing the pattern cell.

## Discussion

Discussion When a pattern is used to stroke or fill a graphics path,Quartz calls your custom drawing function at the appropriatetime to draw the pattern cell. The cell should be drawn exactly thesame way each time the drawing function is called. In a drawing function associated with an uncolored pattern,you should not attempt to set a stroke or fill color or color space—ifyou do so, the result is undefined. To learn how to associate your drawing function with a Quartzpattern, see init(info:bounds:matrix:xStep:yStep:tiling:isColored:callbacks:) and CGPatternCallbacks.

## See Also

### Callbacks

- [CGPatternCallbacks](coregraphics/cgpatterncallbacks.md)
- [CGPatternReleaseInfoCallback](coregraphics/cgpatternreleaseinfocallback.md)