Instance Property

opaque

A Boolean value that determines whether the view is opaque.

Declaration

@property(nonatomic, getter=isOpaque) BOOL opaque;

Discussion

This property provides a hint to the drawing system as to how it should treat the view. If set to YES, the drawing system treats the view as fully opaque, which allows the drawing system to optimize some drawing operations and improve performance. If set to NO, the drawing system composites the view normally with other content. The default value of this property is YES.

An opaque view is expected to fill its bounds with entirely opaque content—that is, the content should have an alpha value of 1.0. If the view is opaque and either does not fill its bounds or contains wholly or partially transparent content, the results are unpredictable. You should always set the value of this property to NO if the view is fully or partially transparent.

You only need to set a value for the opaque property in subclasses of UIView that draw their own content using the drawRect: method. The opaque property has no effect in system-provided classes such as UIButton, UILabel, UITableViewCell, and so on.

See Also

Configuring a View’s Visual Appearance

backgroundColor

The view’s background color.

hidden

A Boolean value that determines whether the view is hidden.

alpha

The view’s alpha value.

tintColor

The first nondefault tint color value in the view’s hierarchy, ascending from and starting with the view itself.

tintAdjustmentMode

The first non-default tint adjustment mode value in the view’s hierarchy, ascending from and starting with the view itself.

clipsToBounds

A Boolean value that determines whether subviews are confined to the bounds of the view.

clearsContextBeforeDrawing

A Boolean value that determines whether the view’s bounds should be automatically cleared before drawing.

maskView

An optional view whose alpha channel is used to mask a view’s content.

layerClass

Returns the class used to create the layer for instances of this class.

layer

The view’s Core Animation layer used for rendering.