Ellipse2D (Java Platform SE 8 )
Keywords: java.awt.geom.Ellipse2D class
Date: 2015-05-24

java.awt.geom

## Class Ellipse2D

- java.lang.Object
- - java.awt.geom.RectangularShape
  - - java.awt.geom.Ellipse2D

- All Implemented Interfaces:
    Shape, Cloneable
  Direct Known Subclasses:
    Ellipse2D.Double, Ellipse2D.Float

      public abstract class Ellipse2D
      extends RectangularShape

  The `Ellipse2D` class describes an ellipse that is defined by a framing rectangle.

  This class is only the abstract superclass for all objects which store a 2D ellipse. The actual storage representation of the coordinates is left to the subclass.

  Since:
    1.2

- - ### Nested Class Summary

    Nested Classes
    Modifier and Type | Class and Description
    --- | ---
    `static class` | `Ellipse2D.Double` The `Double` class defines an ellipse specified in `double` precision.
    `static class` | `Ellipse2D.Float` The `Float` class defines an ellipse specified in `float` precision.

  - ### Constructor Summary

    Constructors
    Modifier | Constructor and Description
    --- | ---
    `protected` | `Ellipse2D()` This is an abstract class that cannot be instantiated directly.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `boolean` | `contains(double x, double y)` Tests if the specified coordinates are inside the boundary of the `Shape`, as described by the definition of insideness.
    `boolean` | `contains(double x, double y, double w, double h)` Tests if the interior of the `Shape` entirely contains the specified rectangular area.
    `boolean` | `equals(Object obj)` Determines whether or not the specified `Object` is equal to this `Ellipse2D`.
    `PathIterator` | `getPathIterator(AffineTransform at)` Returns an iteration object that defines the boundary of this `Ellipse2D`.
    `int` | `hashCode()` Returns the hashcode for this `Ellipse2D`.
    `boolean` | `intersects(double x, double y, double w, double h)` Tests if the interior of the `Shape` intersects the interior of a specified rectangular area.

    - ### Methods inherited from class java.awt.geom.RectangularShape

      `clone, contains, contains, getBounds, getCenterX, getCenterY, getFrame, getHeight, getMaxX, getMaxY, getMinX, getMinY, getPathIterator, getWidth, getX, getY, intersects, isEmpty, setFrame, setFrame, setFrame, setFrameFromCenter, setFrameFromCenter, setFrameFromDiagonal, setFrameFromDiagonal`

    - ### Methods inherited from class java.lang.Object

      `finalize, getClass, notify, notifyAll, toString, wait, wait, wait`

    - ### Methods inherited from interface java.awt.Shape

      `getBounds2D`

- - ### Constructor Detail

    - #### Ellipse2D

          protected Ellipse2D()

      This is an abstract class that cannot be instantiated directly. Type-specific implementation subclasses are available for instantiation and provide a number of formats for storing the information necessary to satisfy the various accessor methods below.
      Since:
        1.2
      See Also:
        `Ellipse2D.Float`, `Ellipse2D.Double`

  - ### Method Detail

    - #### contains

          public boolean contains(double x,
                                  double y)

      Tests if the specified coordinates are inside the boundary of the `Shape`, as described by the definition of insideness.
      Parameters:
        `x` - the specified X coordinate to be tested
        `y` - the specified Y coordinate to be tested
      Returns:
        `true` if the specified coordinates are inside the `Shape` boundary; `false` otherwise.
      Since:
        1.2

    - #### intersects

          public boolean intersects(double x,
                                    double y,
                                    double w,
                                    double h)

      Tests if the interior of the `Shape` intersects the interior of a specified rectangular area. The rectangular area is considered to intersect the `Shape` if any point is contained in both the interior of the `Shape` and the specified rectangular area.

      The `Shape.intersects()` method allows a `Shape` implementation to conservatively return `true` when:

      - there is a high probability that the rectangular area and the `Shape` intersect, but
      - the calculations to accurately determine this intersection are prohibitively expensive.
      This means that for some `Shapes` this method might return `true` even though the rectangular area does not intersect the `Shape`. The `Area` class performs more accurate computations of geometric intersection than most `Shape` objects and therefore can be used if a more precise answer is required.
      Parameters:
        `x` - the X coordinate of the upper-left corner of the specified rectangular area
        `y` - the Y coordinate of the upper-left corner of the specified rectangular area
        `w` - the width of the specified rectangular area
        `h` - the height of the specified rectangular area
      Returns:
        `true` if the interior of the `Shape` and the interior of the rectangular area intersect, or are both highly likely to intersect and intersection calculations would be too expensive to perform; `false` otherwise.
      Since:
        1.2
      See Also:
        `Area`

    - #### contains

          public boolean contains(double x,
                                  double y,
                                  double w,
                                  double h)

      Tests if the interior of the `Shape` entirely contains the specified rectangular area. All coordinates that lie inside the rectangular area must lie within the `Shape` for the entire rectangular area to be considered contained within the `Shape`.

      The `Shape.contains()` method allows a `Shape` implementation to conservatively return `false` when:

      - the `intersect` method returns `true` and
      - the calculations to determine whether or not the `Shape` entirely contains the rectangular area are prohibitively expensive.
      This means that for some `Shapes` this method might return `false` even though the `Shape` contains the rectangular area. The `Area` class performs more accurate geometric computations than most `Shape` objects and therefore can be used if a more precise answer is required.
      Parameters:
        `x` - the X coordinate of the upper-left corner of the specified rectangular area
        `y` - the Y coordinate of the upper-left corner of the specified rectangular area
        `w` - the width of the specified rectangular area
        `h` - the height of the specified rectangular area
      Returns:
        `true` if the interior of the `Shape` entirely contains the specified rectangular area; `false` otherwise or, if the `Shape` contains the rectangular area and the `intersects` method returns `true` and the containment calculations would be too expensive to perform.
      Since:
        1.2
      See Also:
        `Area`, `Shape.intersects(double, double, double, double)`

    - #### getPathIterator

          public PathIterator getPathIterator(AffineTransform at)

      Returns an iteration object that defines the boundary of this `Ellipse2D`. The iterator for this class is multi-threaded safe, which means that this `Ellipse2D` class guarantees that modifications to the geometry of this `Ellipse2D` object do not affect any iterations of that geometry that are already in process.
      Parameters:
        `at` - an optional `AffineTransform` to be applied to the coordinates as they are returned in the iteration, or `null` if untransformed coordinates are desired
      Returns:
        the `PathIterator` object that returns the geometry of the outline of this `Ellipse2D`, one segment at a time.
      Since:
        1.2

    - #### hashCode

          public int hashCode()

      Returns the hashcode for this `Ellipse2D`.
      Overrides:
        `hashCode` in class `Object`
      Returns:
        the hashcode for this `Ellipse2D`.
      Since:
        1.6
      See Also:
        `Object.equals(java.lang.Object)`, `System.identityHashCode(java.lang.Object)`

    - #### equals

          public boolean equals(Object obj)

      Determines whether or not the specified `Object` is equal to this `Ellipse2D`. The specified `Object` is equal to this `Ellipse2D` if it is an instance of `Ellipse2D` and if its location and size are the same as this `Ellipse2D`.
      Overrides:
        `equals` in class `Object`
      Parameters:
        `obj` - an `Object` to be compared with this `Ellipse2D`.
      Returns:
        `true` if `obj` is an instance of `Ellipse2D` and has the same values; `false` otherwise.
      Since:
        1.6
      See Also:
        `Object.hashCode()`, `HashMap`

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