CGRectInset

Returns a rectangle that is smaller or larger than the source rectangle, with the same center point.

CGRect CGRectInset (
   CGRect rect,
   CGFloat dx,
   CGFloat dy
);

Parameters

rect

The source CGRect structure.

dx

The x-coordinate value to use for adjusting the source rectangle. To create an inset rectangle, specify a positive value. To create a larger, encompassing rectangle, specify a negative value.

dy

The y-coordinate value to use for adjusting the source rectangle. To create an inset rectangle, specify a positive value. To create a larger, encompassing rectangle, specify a negative value.

Return Value

A rectangle. The origin value is offset in the x-axis by the distance specified by the dx parameter and in the y-axis by the distance specified by the dyparameter, and its size adjusted by (2*dx,2*dy), relative to the source rectangle. If dx and dy are positive values, then the rectangle’s size is decreased. If dx and dy are negative values, the rectangle’s size is increased.

Discussion

The rectangle is standardized and then the inset parameters are applied. If the resulting rectangle would have a negative height or width, a null rectangle is returned.

Availability

• Available in iOS 2.0 and later.

Related Sample Code

• avTouch
• CoreTextPageViewer
• MoviePlayer
• QuartzDemo
• SpeakHere

Declared In

CGGeometry.h