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# CAConstraintAttribute

The constraint attribute type.

```
enum CAConstraintAttribute
```

## Topics

### Enumeration Cases

[`CAConstraintAttribute.height`](/documentation/QuartzCore/CAConstraintAttribute/height)

The height of a layer.

[`CAConstraintAttribute.maxX`](/documentation/QuartzCore/CAConstraintAttribute/maxX)

The right edge of a layer’s frame.

[`CAConstraintAttribute.maxY`](/documentation/QuartzCore/CAConstraintAttribute/maxY)

The top edge of a layer’s frame.

[`CAConstraintAttribute.midX`](/documentation/QuartzCore/CAConstraintAttribute/midX)

The horizontal location of the center of a layer’s frame.

[`CAConstraintAttribute.midY`](/documentation/QuartzCore/CAConstraintAttribute/midY)

The vertical location of the center of a layer’s frame.

[`CAConstraintAttribute.minX`](/documentation/QuartzCore/CAConstraintAttribute/minX)

The left edge of a layer’s frame.

[`CAConstraintAttribute.minY`](/documentation/QuartzCore/CAConstraintAttribute/minY)

The bottom edge of a layer’s frame.

[`CAConstraintAttribute.width`](/documentation/QuartzCore/CAConstraintAttribute/width)

The width of a layer.


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