arc2d.java

JAVA基本类源代码,大家可以学习学习!

	}

        /**
         * Constructs a new arc, initialized to location (0, 0),
         * size (0, 0), angular extents (start = 0, extent = 0), and
         * the specified closure type.
         *
         * @param type The closure type for the arc: 
         * {@link #OPEN OPEN}, {@link #CHORD CHORD}, or {@link #PIE PIE}.
         */
	public Double(int type) {
	    super(type);
	}

        /**
         * Constructs a new arc, initialized to the specified location,
         * size, angular extents, and closure type.
         *
         * @param x, y The coordinates of the upper left corner  
         * of the arc. (Specified in double precision.)
         * @param w The overall width of the full ellipse of which this  
         * arc is a partial section. (Specified in double precision.)
         * @param h The overall height of the full ellipse of which this 
         * arc is a partial section. (Specified in double precision.)
         * @param start The starting angle of the arc in degrees.  
         * (Specified in double precision.)
         * @param extent The angular extent of the arc in degrees. 
         * (Specified  in double precision.)
         * @param type The closure type for the arc: 
         * {@link #OPEN OPEN}, {@link #CHORD CHORD}, or {@link #PIE PIE}.
         */
	public Double(double x, double y, double w, double h,
		      double start, double extent, int type) {
	    super(type);
	    this.x = x;
	    this.y = y;
	    this.width = w;
	    this.height = h;
	    this.start = start;
	    this.extent = extent;
	}

        /**
         * Constructs a new arc, initialized to the specified location,
         * size, angular extents, and closure type.
         *
         * @param ellipseBounds The bounding rectangle that defines the 
         * outer boundary of the full ellipse of which this arc is a 
         * partial section.
         * @param start The starting angle of the arc in degrees. 
         * (Specified in double precision.)
         * @param extent The angular extent of the arc in degrees. 
         * (Specified in double precision.)
         * @param type The closure type for the arc: 
         * {@link #OPEN OPEN}, {@link #CHORD CHORD}, or {@link #PIE PIE}.
         */
	public Double(Rectangle2D ellipseBounds,
		      double start, double extent, int type) {
	    super(type);
	    this.x = ellipseBounds.getX();
	    this.y = ellipseBounds.getY();
	    this.width = ellipseBounds.getWidth();
	    this.height = ellipseBounds.getHeight();
	    this.start = start;
	    this.extent = extent;
	}

        /**
         * Returns the x coordinate of the upper left corner of the arc.
         *
         * @return The x coordinate of arc's upper left coordinate in 
         * double precision.
         */
	public double getX() {
	    return x;
	}

        /**
         * Returns the y coordinate of the upper left corner of the arc.
         *
         * @return The y coordinate of arc's upper left coordinate in 
         * double precision.
         */
	public double getY() {
	    return y;
	}

        /**
         * Returns the width of the ellipse of which this arc is 
         * a partial section.
         *
         * @return A double value that represents the width of the full 
         * ellipse of which this arc is a partial section.
         */
	public double getWidth() {
	    return width;
	}

        /**
         * Returns the height of the ellipse of which this arc is 
         * a partial section.
         *
         * @return A double value that represents the height of the full 
         * ellipse of which this arc is a partial section.	 
         */
	public double getHeight() {
	    return height;
	}

        /**
         * Returns the starting angle of the arc.
         *
         * @return a double value that represents the starting angle 
         * of the arc in degrees.
	 * @see #setAngleStart
         */
	public double getAngleStart() {
	    return start;
	}

        /**
         * Returns the angular extent of the arc.
         *
         * @return A double value that represents the angular extent of 
         * the arc in degrees.
	 * @see #setAngleExtent
         */	
	public double getAngleExtent() {
	    return extent;
	}

        /**
         * Determines whether the arc is empty.
         *
         * @return <CODE>true</CODE> if the arc is empty, <CODE>false</CODE> 
         * if it not.
         */
	public boolean isEmpty() {
	    return (width <= 0.0 || height <= 0.0);
	}

        /**
         * Sets the location, size, angular extents, and closure type of
         * this arc to the specified double values.
         *
         * @param x,&nbsp;y The coordinates of the upper left corner 
         * of the arc.
         * @param w The overall width of the full ellipse of which 
         * this arc is a partial section.
         * @param h The overall height of the full ellipse of which 
         * this arc is a partial section.
         * @param angSt The starting angle of the arc in degrees.
         * @param angExt The angular extent of the arc in degrees.
         * @param closure The closure type for the arc: 
         * {@link #OPEN OPEN}, {@link #CHORD CHORD}, or {@link #PIE PIE}.
         */
	public void setArc(double x, double y, double w, double h,
			   double angSt, double angExt, int closure) {
	    this.setArcType(closure);
	    this.x = x;
	    this.y = y;
	    this.width = w;
	    this.height = h;
	    this.start = angSt;
	    this.extent = angExt;
	}

        /**
         * Sets the starting angle of this arc to the specified double
         * value.
         *
         * @param angSt The starting angle of the arc in degrees.
	 * @see #getAngleStart
         */
	public void setAngleStart(double angSt) {
	    this.start = angSt;
	}

        /**
         * Sets the angular extent of this arc to the specified double
         * value.
         *
         * @param angExt The angular extent of the arc in degrees.
	 * @see #getAngleExtent
         */
	public void setAngleExtent(double angExt) {
	    this.extent = angExt;
	}

        /**
         * Returns the high-precision bounding box of the arc.
         * 
         * @param x,&nbsp;y The coordinates of the upper left corner 
         * of the arc.
         * @param w The overall width of the full ellipse of which 
         * this arc is a partial section.
         * @param h The overall height of the full ellipse of which 
         * this arc is a partial section.
         *
         * @return The bounding box as a <CODE>Rectangle2D</CODE> object.
         */
	protected Rectangle2D makeBounds(double x, double y,
					 double w, double h) {
	    return new Rectangle2D.Double(x, y, w, h);
	}
    }

    private int type;

    /**
     * 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.
     *
     * @param type The closure type of this arc: 
     * {@link #OPEN OPEN}, {@link #CHORD CHORD}, or {@link #PIE PIE}.
     * @see java.awt.geom.Arc2D.Float
     * @see java.awt.geom.Arc2D.Double
     */
    protected Arc2D(int type) {
	setArcType(type);
    }

    /**
     * Returns the starting angle of the arc.
     *
     * @return A double value that represents the starting angle 
     * of the arc in degrees.
     * @see #setAngleStart
     */
    public abstract double getAngleStart();

    /**
     * Returns the angular extent of the arc.
     *
     * @return A double value that represents the angular extent 
     * of the arc in degrees.
     * @see #setAngleExtent
     */
    public abstract double getAngleExtent();

    /**
     * Returns the arc closure type of the arc: {@link #OPEN OPEN}, 
     * {@link #CHORD CHORD}, or {@link #PIE PIE}.
     * @return One of the integer constant closure types defined 
     * in this class.
     * @see #setArcType
     */
    public int getArcType() {
	return type;
    }

    /**
     * Returns the starting point of the arc.  This point is the
     * intersection of the ray from the center defined by the
     * starting angle and the elliptical boundary of the arc.
     * 
     * @return A <CODE>Point2D</CODE> object representing the 
     * x,y coordinates of the starting point of the arc.
     */
    public Point2D getStartPoint() {
	double angle = Math.toRadians(-getAngleStart());
	double x = getX() + (Math.cos(angle) * 0.5 + 0.5) * getWidth();
	double y = getY() + (Math.sin(angle) * 0.5 + 0.5) * getHeight();
	return new Point2D.Double(x, y);
    }

    /**
     * Returns the ending point of the arc.  This point is the
     * intersection of the ray from the center defined by the
     * starting angle plus the angular extent of the arc and the
     * elliptical boundary of the arc.
     *
     * @return A <CODE>Point2D</CODE> object representing the 
     * x,y coordinates  of the ending point of the arc.
     */
    public Point2D getEndPoint() {
	double angle = Math.toRadians(-getAngleStart() - getAngleExtent());
	double x = getX() + (Math.cos(angle) * 0.5 + 0.5) * getWidth();
	double y = getY() + (Math.sin(angle) * 0.5 + 0.5) * getHeight();
	return new Point2D.Double(x, y);
    }

    /**
     * Sets the location, size, angular extents, and closure type of
     * this arc to the specified double values.
     *
     * @param x,&nbsp;y The coordinates of the upper left corner of 
     * the arc.
     * @param w The overall width of the full ellipse of which 
     * this arc is a partial section.
     * @param h The overall height of the full ellipse of which 
     * this arc is a partial section.
     * @param angSt The starting angle of the arc in degrees.
     * @param angExt The angular extent of the arc in degrees.
     * @param closure The closure type for the arc:
     * {@link #OPEN OPEN}, {@link #CHORD CHORD}, or {@link #PIE PIE}.
     */
    public abstract void setArc(double x, double y, double w, double h,
				double angSt, double angExt, int closure);

    /**
     * Sets the location, size, angular extents, and closure type of
     * this arc to the specified values.
     *
     * @param loc The <CODE>Point2D</CODE> representing the coordinates of 
     * the upper left corner of the arc.
     * @param size The <CODE>Dimension2D</CODE> representing the width 
     * and height of the full ellipse of which this arc is 
     * a partial section.
     * @param angSt The starting angle of the arc in degrees. 
     * (Specified in double precision.)
     * @param angExt The angular extent of the arc in degrees. 
     * (Specified in double precision.)
     * @param closure The closure type for the arc:
     * {@link #OPEN OPEN}, {@link #CHORD CHORD}, or {@link #PIE PIE}.
     */ 
    public void setArc(Point2D loc, Dimension2D size,
		       double angSt, double angExt, int closure) {
	setArc(loc.getX(), loc.getY(), size.getWidth(), size.getHeight(),
	       angSt, angExt, closure);
    }

    /**
     * Sets the location, size, angular extents, and closure type of
     * this arc to the specified values.
     *
     * @param rect The bounding rectangle that defines the 
     * outer boundary of the full ellipse of which this arc is a 
     * partial section.
     * @param angSt The starting angle of the arc in degrees. 
     * (Specified in double precision.)
     * @param angExt The angular extent of the arc in degrees. 
     * (Specified in double precision.)
     * @param closure The closure type for the arc:
     * {@link #OPEN OPEN}, {@link #CHORD CHORD}, or {@link #PIE PIE}.
     */ 
    public void setArc(Rectangle2D rect, double angSt, double angExt,
		       int closure) {
	setArc(rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight(),
	       angSt, angExt, closure);
    }

    /**
     * Sets this arc to be the same as the specified arc.