Module javafx.graphics
Package javafx.scene.layout

Class Background


  • public final class Background
extends Object
    The Background of a Region. A Background is an immutable object which encapsulates the entire set of data required to render the background of a Region. Because this class is immutable, you can freely reuse the same Background on many different Regions. Please refer to JavaFX CSS Reference Guide for a complete description of the CSS rules for styling the background of a Region.

    Every Background is comprised of fills and / or images. Neither list will ever be null, but either or both may be empty. Each defined BackgroundFill is rendered in order, followed by each defined BackgroundImage.

    The Background's outsets define any extension of the drawing area of a Region which is necessary to account for all background drawing. These outsets are strictly defined by the BackgroundFills that are specified on this Background, if any, because all BackgroundImages are clipped to the drawing area, and do not define it. The outsets values are strictly non-negative.

    Since:
    JavaFX 8.0

    • Field Detail

      • EMPTY

        public static final Background EMPTY
        An empty Background, useful to use instead of null.

    • Constructor Detail

      • Background

        public Background​(BackgroundFill... fills)
        Create a new Background by supplying an array of BackgroundFills. This array may be null, or may contain null values. Any null values will be ignored and will not contribute to the fills or outsets.
        Parameters:
        fills - The fills. This may be null, and may contain nulls. Any contained nulls are filtered out and not included in the final List of fills. A null array becomes an empty List.

      • Background

        public Background​(BackgroundImage... images)
        Create a new Background by supplying an array of BackgroundImages. This array may be null, or may contain null values. Any null values will be ignored and will not contribute to the images.
        Parameters:
        images - The images. This may be null, and may contain nulls. Any contained nulls are filtered out and not included in the final List of images. A null array becomes an empty List.

      • Background

        public Background​(List<BackgroundFill> fills,
                  List<BackgroundImage> images)
        Create a new Background supply two Lists, one for background fills and one for background images. Either list may be null, and may contain nulls. Any null values in these lists will be ignored and will not contribute to the fills, images, or outsets.
        Parameters:
        fills - The fills. This may be null, and may contain nulls. Any contained nulls are filtered out and not included in the final List of fills. A null List becomes an empty List.
        images - The images. This may be null, and may contain nulls. Any contained nulls are filtered out and not included in the final List of images. A null List becomes an empty List.

      • Background

        public Background​(BackgroundFill[] fills,
                  BackgroundImage[] images)
        Create a new Background by supplying two arrays, one for background fills, and one for background images. Either array may be null, and may contain null values. Any null values in these arrays will be ignored and will not contribute to the fills, images, or outsets.
        Parameters:
        fills - The fills. This may be null, and may contain nulls. Any contained nulls are filtered out and not included in the final List of fills. A null array becomes an empty List.
        images - The images. This may be null, and may contain nulls. Any contained nulls are filtered out and not included in the final List of images. A null array becomes an empty List.

    • Method Detail

      • getClassCssMetaData

        public static List<CssMetaData<? extends Styleable,?>> getClassCssMetaData​()
        Returns:
        The CssMetaData associated with this class, which may include the CssMetaData of its superclasses.

      • getFills

        public final List<BackgroundFill> getFills​()
        The list of BackgroundFills which together define the filled portion of this Background. This List is unmodifiable and immutable. It will never be null. The elements of this list will also never be null.
        Returns:
        the list of BackgroundFills

      • getImages

        public final List<BackgroundImage> getImages​()
        The list of BackgroundImages which together define the image portion of this Background. This List is unmodifiable and immutable. It will never be null. The elements of this list will also never be null.
        Returns:
        the list of BackgroundImages

      • getOutsets

        public final Insets getOutsets​()
        The outsets of this Background. This represents the largest bounding rectangle within which all drawing for the Background will take place. The outsets will never be negative, and represent the distance from the edge of the Region outward. Any BackgroundImages which would extend beyond the outsets will be clipped. Only the BackgroundFills contribute to the outsets.
        Returns:
        the outsets

      • isEmpty

        public final boolean isEmpty​()
        Gets whether the background is empty. It is empty if there are no fills or images.
        Returns:
        true if the Background is empty, false otherwise.

      • isFillPercentageBased

        public boolean isFillPercentageBased​()
        Gets whether the fill of this Background is based on percentages (that is, relative to the size of the region being styled). Specifically, this returns true if any of the CornerRadii on any of the fills on this Background has a radius that is based on percentages.
        Returns:
        True if any CornerRadii of any BackgroundFill on this background would return true, false otherwise.
        Since:
        JavaFX 8.0

      • equals

        public boolean equals​(Object o)
        Indicates whether some other object is "equal to" this one.

        The equals method implements an equivalence relation on non-null object references:

        • It is reflexive: for any non-null reference value x, x.equals(x) should return true.
        • It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
        • It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
        • It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
        • For any non-null reference value x, x.equals(null) should return false.

        The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value true).

        Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.

        Overrides:
        equals in class Object
        Parameters:
        o - the reference object with which to compare.
        Returns:
        true if this object is the same as the obj argument; false otherwise.
        See Also:
        Object.hashCode(), HashMap

      • hashCode

        public int hashCode​()
        Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

        The general contract of hashCode is:

        • Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
        • If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
        • It is not required that if two objects are unequal according to the Object.equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

        As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (The hashCode may or may not be implemented as some function of an object's memory address at some point in time.)

        Overrides:
        hashCode in class Object
        Returns:
        a hash code value for this object.
        See Also:
        Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)