Polygon

Name

Description

The Polygon class encapsulates a collection of points used to create a series of line segments.

Class Definition

public class java.awt.Polygon extends java.lang.Object implements java.awt.Shape, java.io.Serializable {
 // Variables protected Rectangle bounds; public int npoints;
public int xpoints[];
public int ypoints[]; // Constructors public Polygon();
public Polygon (int xpoints[], int ypoints, int npoints); // Instance Methods public void addPoint (int x, int y);
public boolean contains (int x, int y); public boolean contains (Point p); public Rectangle getBoundingBox();  public Rectangle getBounds(); public boolean inside (int x,int y);  public void translate (int deltaX, int deltaY);
}

Variables

bounds

protected Rectangle bounds

The rectangle that describes the boundaries of the Polygon.

npoints

public int npoints

The number of elements to use in the xpoints and ypoints arrays.

xpoints

public int xpoints[]

The array of x coordinates for each point.

ypoints

public int ypoints[]

The array of y coordinates for each point.

Constructors

Polygon

public Polygon()

• Description
• Constructs an empty Polygon object with no points.

public Polygon (int xPoints[], int yPoints[], int numPoints)

• Parameters
• • xPoints[]
  • The initial array of x coordinates for each point.
  • yPoints[]
  • The initial array of y coordinates for each point.
  • numPoints
  • The number of elements in both xPoints and yPoints arrays to use.
• Throws
• • ArrayIndexOutOfBoundsException
  • If numPoints > xPoints.length or numPoints > yPoints.length.
• Description
• Constructs a Polygon object with the set of points provided.

Instance Methods

addPoint

public void addPoint (int x, int y)

• Parameters
• • x
  • The x coordinate of the point to be added.
  • y
  • The y coordinate of the point to be added.
• Description
• Adds the point (x, y) to the end of the list of points for the Polygon.

contains

public boolean contains (int x, int y)

• Parameters
• • x
  • The x coordinate to test.
  • y
  • The y coordinate to test.
• Returns
• true if the Polygon contains the point; false otherwise.

public boolean contains (Point p)

• Parameters
• • p
  • The point to be tested.
• Returns
• true if the Polygon contains the point; false otherwise.

getBoundingBox

public Rectangle getBoundingBox()

• Returns
• Bounding Rectangle of the points within the Polygon.
• Description
• Returns the smallest Rectangle that contains all the points within the Polygon. Replaced by getBounds().

getBounds

public Rectangle getBounds()

• Implements
• Shape.getBounds()
• Returns
• Bounding Rectangle of the points within the Polygon.
• Description
• Returns the smallest Rectangle that contains all the points within the Polygon.

inside

public boolean inside (int x,int y)

• Parameters
• • x
  • The x coordinate of the point to be checked.
  • y
  • The y coordinate of the point to be checked.
• Returns
• true if (x, y) within Polygon, false otherwise.
• Description
• Checks to see if the (x, y) point is within an area that would be filled if the Polygon was drawn with Graphics.fillPolygon(). Replaced by contains(int, int).

translate

public void translate (int deltaX, int deltaY)

• Parameters
• • deltaX
  • Amount to move horizontally.
  • deltaY
  • Amount to move vertically.
• Description
• Moves the Polygon to the location (x+deltaX, y+deltaY).

See Also

Graphics, Object, Rectangle