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NSShadow Class Reference

Overview

An NSShadow object encapsulates the attributes used to create a drop shadow during drawing operations.

Shadows are always drawn in the default user coordinate space, regardless of any transformations applied to that space. This means that rotations, translations and and other transformations of the current transformation matrix (the CTM) do not affect the resulting shadow. Another way to think about this is that changes to the CTM do not move or change the apparent position of the shadow’s light source.

There are two positional parameters for a shadow: an x-offset and a y-offset. These values are expressed using a single NSSize data type and using the units of the default user coordinate space. Positive values for these offsets extend up and to the right.

In addition to its positional parameters, a shadow also contains a blur radius, which specifies how much a drawn object's image mask is blurred before it is composited onto the destination. A value of 0 means there is no blur. Larger values give correspondingly larger amounts of blurring.

An NSShadow object may be used in one of two ways. First, it may be set, like a color or a font, in which case its attributes are applied to all content drawn thereafter—or at least until another shadow is applied or a previous graphics state is restored. Second, it may be used as the value for the NSShadowAttributeName text attribute, in which case it is applied to the glyphs corresponding to the characters bearing this attribute.

Adopted Protocols

• – encodeWithCoder:

• – initWithCoder:

• – copyWithZone:

Tasks

Managing a Shadow

• – setShadowOffset:
• – shadowOffset
• – setShadowBlurRadius:
• – shadowBlurRadius
• – setShadowColor:
• – shadowColor

Setting the Shadow

• – set

Instance Methods

set

Sets the shadow of subsequent drawing operations to the shadow represented by the receiver.

- (void)set

Discussion

The shadow attributes of the receiver are used until another shadow is set or until the graphics state is restored.

Availability

• Available in Mac OS X v10.3 and later.

Declared In

NSShadow.h

setShadowBlurRadius:

Sets the blur radius of the receiver.

- (void)setShadowBlurRadius:(CGFloat)val

Parameters

val

The blur radius, as measured in the default user coordinate space. A value of 0 indicates no blur, while larger values produce correspondingly larger blurring. This value must not be negative.

Availability

• Available in Mac OS X v10.3 and later.

See Also

• – shadowBlurRadius

Declared In

NSShadow.h

setShadowColor:

Sets the shadow color for the receiver.

- (void)setShadowColor:(NSColor *)color

Parameters

color

The shadow color, which must be convertible to an RGBA color. Specify nil if you do not want the shadow to be drawn. Your color may contain alpha information.

Availability

• Available in Mac OS X v10.3 and later.

See Also

• – shadowColor

Declared In

NSShadow.h

setShadowOffset:

Sets the offset values for the receiver.

- (void)setShadowOffset:(NSSize)offset

Parameters

offset

The horizontal and vertical offset values, specified using the width and height fields of the NSSize data type. These offsets are measured using the default user coordinate space and are not affected by custom transformations. This means that positive values always extend up and to the right from the user's perspective.

Availability

• Available in Mac OS X v10.3 and later.

See Also

• – shadowOffset

Declared In

NSShadow.h

shadowBlurRadius

Returns the blur radius of the receiver.

- (CGFloat)shadowBlurRadius

Return Value

The blur radius, as measured in the default user coordinate space. A value of 0 indicates no blur, while larger values produce correspondingly larger blurring. The default value is 0.

Availability

• Available in Mac OS X v10.3 and later.

See Also

• – setShadowBlurRadius:

Declared In

NSShadow.h

shadowColor

Returns the color for the receiver.

- (NSColor *)shadowColor

Return Value

The current shadow color. A nil shadow color indicates the shadow is not to be drawn. The default shadow color is black with an alpha of 1/3.

Availability

• Available in Mac OS X v10.3 and later.

See Also

• – setShadowColor:

Declared In

NSShadow.h

shadowOffset

Returns the offset values for the receiver.

- (NSSize)shadowOffset

Return Value

The horizontal and vertical offset values, specified using the width and height fields of the NSSize data type. These offsets are measured using the default user coordinate space and are not affected by custom transformations. This means that positive values always extend up and to the right from the user's perspective.

Availability

• Available in Mac OS X v10.3 and later.

See Also

• – setShadowOffset:

Declared In

NSShadow.h

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