Package ej.mwt.style.background

Class NoBackground

  • All Implemented Interfaces:
    Background
    public final class NoBackground
extends java.lang.Object
implements Background
    A transparent background.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static NoBackground NO_BACKGROUND
      No background singleton to avoid creating several ones.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void apply​(ej.microui.display.GraphicsContext g, int width, int height)
      Applies the background on a graphics context.
      boolean equals​(java.lang.Object obj)
      Indicates whether some other object is "equal to" this one.
      int hashCode()
      Returns a hash code value for the object.
      boolean isTransparent​(int width, int height)
      Tells whether or not this background is transparent.

      • Methods inherited from class java.lang.Object

        clone, getClass, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • NO_BACKGROUND

        public static final NoBackground NO_BACKGROUND
        No background singleton to avoid creating several ones.

    • Method Detail

      • isTransparent

        public boolean isTransparent​(int width,
                             int height)
        Description copied from interface: Background
        Tells whether or not this background is transparent.

        A background is considered as transparent if it does not draw every pixel with maximal opacity when it is applied. If a widget has a transparent background, its parent has to be rendered before the widget.

        Specified by:
        isTransparent in interface Background
        Parameters:
        width - the width of the background.
        height - the height of the background.
        Returns:
        true if the background is transparent, false otherwise.

      • apply

        public void apply​(ej.microui.display.GraphicsContext g,
                  int width,
                  int height)
        Description copied from interface: Background
        Applies the background on a graphics context.
        Specified by:
        apply in interface Background
        Parameters:
        g - the graphics context.
        width - the width of the background.
        height - the height of the background.

      • equals

        public boolean equals​(@Nullable
                      java.lang.Object obj)
        Description copied from class: java.lang.Object
        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.

        Specified by:
        equals in interface Background
        Overrides:
        equals in class java.lang.Object
        Parameters:
        obj - 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()
        Description copied from class: java.lang.Object
        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. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the JavaTM programming language.)

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