Class Rectangle


  • public final class Rectangle
    extends java.lang.Object
    Instances of this class represent rectangular areas in an (x, y) coordinate system. The top left corner of the rectangle is specified by its x and y values, and the extent of the rectangle is specified by its width and height.

    The coordinate space for rectangles and points is considered to have increasing values downward and to the right from its origin making this the normal, computer graphics oriented notion of (x, y) coordinates rather than the strict mathematical one.

    The hashCode() method in this class uses the values of the public fields to compute the hash value. When storing instances of the class in hashed collections, do not modify these fields after the object has been inserted.

    Application code does not need to explicitly release the resources managed by each instance when those instances are no longer required, and thus no dispose() method is provided.

    Since:
    1.0
    See Also:
    Point
    • Field Summary

      Fields 
      Modifier and Type Field Description
      int height
      the height of the rectangle
      int width
      the width of the rectangle
      int x
      the x coordinate of the rectangle
      int y
      the y coordinate of the rectangle
    • Constructor Summary

      Constructors 
      Constructor Description
      Rectangle​(int x, int y, int width, int height)
      Construct a new instance of this class given the x, y, width and height values.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void add​(Rectangle rect)
      Destructively replaces the x, y, width and height values in the receiver with ones which represent the union of the rectangles specified by the receiver and the given rectangle.
      boolean contains​(int x, int y)
      Returns true if the point specified by the arguments is inside the area specified by the receiver, and false otherwise.
      boolean contains​(Point pt)
      Returns true if the given point is inside the area specified by the receiver, and false otherwise.
      boolean equals​(java.lang.Object object)
      Compares the argument to the receiver, and returns true if they represent the same object using a class specific comparison.
      int hashCode()
      Returns an integer hash code for the receiver.
      void intersect​(Rectangle rect)
      Destructively replaces the x, y, width and height values in the receiver with ones which represent the intersection of the rectangles specified by the receiver and the given rectangle.
      Rectangle intersection​(Rectangle rect)
      Returns a new rectangle which represents the intersection of the receiver and the given rectangle.
      boolean intersects​(int x, int y, int width, int height)
      Returns true if the rectangle described by the arguments intersects with the receiver and false otherwise.
      boolean intersects​(Rectangle rect)
      Returns true if the given rectangle intersects with the receiver and false otherwise.
      boolean isEmpty()
      Returns true if the receiver does not cover any area in the (x, y) coordinate plane, and false if the receiver does cover some area in the plane.
      java.lang.String toString()
      Returns a string containing a concise, human-readable description of the receiver.
      Rectangle union​(Rectangle rect)
      Returns a new rectangle which represents the union of the receiver and the given rectangle.
      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait
    • Field Detail

      • x

        public int x
        the x coordinate of the rectangle
      • y

        public int y
        the y coordinate of the rectangle
      • width

        public int width
        the width of the rectangle
      • height

        public int height
        the height of the rectangle
    • Constructor Detail

      • Rectangle

        public Rectangle​(int x,
                         int y,
                         int width,
                         int height)
        Construct a new instance of this class given the x, y, width and height values.
        Parameters:
        x - the x coordinate of the origin of the rectangle
        y - the y coordinate of the origin of the rectangle
        width - the width of the rectangle
        height - the height of the rectangle
    • Method Detail

      • add

        public void add​(Rectangle rect)
        Destructively replaces the x, y, width and height values in the receiver with ones which represent the union of the rectangles specified by the receiver and the given rectangle.

        The union of two rectangles is the smallest single rectangle that completely covers both of the areas covered by the two given rectangles.

        Parameters:
        rect - the rectangle to merge with the receiver
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the argument is null
      • contains

        public boolean contains​(int x,
                                int y)
        Returns true if the point specified by the arguments is inside the area specified by the receiver, and false otherwise.
        Parameters:
        x - the x coordinate of the point to test for containment
        y - the y coordinate of the point to test for containment
        Returns:
        true if the rectangle contains the point and false otherwise
      • contains

        public boolean contains​(Point pt)
        Returns true if the given point is inside the area specified by the receiver, and false otherwise.
        Parameters:
        pt - the point to test for containment
        Returns:
        true if the rectangle contains the point and false otherwise
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the argument is null
      • equals

        public boolean equals​(java.lang.Object object)
        Compares the argument to the receiver, and returns true if they represent the same object using a class specific comparison.
        Overrides:
        equals in class java.lang.Object
        Parameters:
        object - the object to compare with this object
        Returns:
        true if the object is the same as this object and false otherwise
        See Also:
        hashCode()
      • hashCode

        public int hashCode()
        Returns an integer hash code for the receiver. Any two objects that return true when passed to equals must return the same value for this method.
        Overrides:
        hashCode in class java.lang.Object
        Returns:
        the receiver's hash
        See Also:
        equals(Object)
      • intersect

        public void intersect​(Rectangle rect)
        Destructively replaces the x, y, width and height values in the receiver with ones which represent the intersection of the rectangles specified by the receiver and the given rectangle.
        Parameters:
        rect - the rectangle to intersect with the receiver
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the argument is null
        since 3.0
      • intersection

        public Rectangle intersection​(Rectangle rect)
        Returns a new rectangle which represents the intersection of the receiver and the given rectangle.

        The intersection of two rectangles is the rectangle that covers the area which is contained within both rectangles.

        Parameters:
        rect - the rectangle to intersect with the receiver
        Returns:
        the intersection of the receiver and the argument
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the argument is null
      • intersects

        public boolean intersects​(int x,
                                  int y,
                                  int width,
                                  int height)
        Returns true if the rectangle described by the arguments intersects with the receiver and false otherwise.

        Two rectangles intersect if the area of the rectangle representing their intersection is not empty.

        Parameters:
        x - the x coordinate of the origin of the rectangle
        y - the y coordinate of the origin of the rectangle
        width - the width of the rectangle
        height - the height of the rectangle
        Returns:
        true if the rectangle intersects with the receiver, and false otherwise
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the argument is null
        Since:
        1.0
        See Also:
        intersection(Rectangle), isEmpty()
      • intersects

        public boolean intersects​(Rectangle rect)
        Returns true if the given rectangle intersects with the receiver and false otherwise.

        Two rectangles intersect if the area of the rectangle representing their intersection is not empty.

        Parameters:
        rect - the rectangle to test for intersection
        Returns:
        true if the rectangle intersects with the receiver, and false otherwise
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the argument is null
        See Also:
        intersection(Rectangle), isEmpty()
      • isEmpty

        public boolean isEmpty()
        Returns true if the receiver does not cover any area in the (x, y) coordinate plane, and false if the receiver does cover some area in the plane.

        A rectangle is considered to cover area in the (x, y) coordinate plane if both its width and height are non-zero.

        Returns:
        true if the receiver is empty, and false otherwise
      • toString

        public java.lang.String toString()
        Returns a string containing a concise, human-readable description of the receiver.
        Overrides:
        toString in class java.lang.Object
        Returns:
        a string representation of the rectangle
      • union

        public Rectangle union​(Rectangle rect)
        Returns a new rectangle which represents the union of the receiver and the given rectangle.

        The union of two rectangles is the smallest single rectangle that completely covers both of the areas covered by the two given rectangles.

        Parameters:
        rect - the rectangle to perform union with
        Returns:
        the union of the receiver and the argument
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the argument is null
        See Also:
        add(Rectangle)