path: root/java/awt/geom/RoundRectangle2D.java

/* RoundRectangle2D.java -- represents a rectangle with rounded corners
   Copyright (C) 2000, 2002, 2003, 2004, 2006, Free Software Foundation

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
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02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
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this exception to your version of the library, but you are not
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exception statement from your version. */

package java.awt.geom;



/** This class implements a rectangle with rounded corners.
 * @author Tom Tromey (tromey@cygnus.com)
 * @date December 3, 2000
 */
public abstract class RoundRectangle2D extends RectangularShape
{
  /** 
   * Return the arc height of this round rectangle.  The arc height and width
   * control the roundness of the corners of the rectangle.
   * 
   * @return The arc height.
   * 
   * @see #getArcWidth()
   */
  public abstract double getArcHeight();

  /** 
   * Return the arc width of this round rectangle.  The arc width and height
   * control the roundness of the corners of the rectangle.
   * 
   * @return The arc width.
   * 
   * @see #getArcHeight()
   */
  public abstract double getArcWidth();

  /** 
   * Set the values of this round rectangle.
   * 
   * @param x The x coordinate
   * @param y The y coordinate
   * @param w The width
   * @param h The height
   * @param arcWidth The arc width
   * @param arcHeight The arc height
   */
  public abstract void setRoundRect(double x, double y, double w, double h,
                                    double arcWidth, double arcHeight);

  /** 
   * Create a RoundRectangle2D.  This is protected because this class
   * is abstract and cannot be instantiated.
   */
  protected RoundRectangle2D()
  {
  }

  /** 
   * Return true if this object contains the specified point.
   * @param x The x coordinate
   * @param y The y coordinate
   */
  public boolean contains(double x, double y)
  {
    double mx = getX();
    double mw = getWidth();
    if (x < mx || x >= mx + mw)
      return false;
    double my = getY();
    double mh = getHeight();
    if (y < my || y >= my + mh)
      return false;

    // Now check to see if the point is in range of an arc.
    double dy = Math.min(Math.abs(my - y), Math.abs(my + mh - y));
    double dx = Math.min(Math.abs(mx - x), Math.abs(mx + mw - x));

    // The arc dimensions are that of the corresponding ellipse
    // thus a 90 degree segment is half of that.
    double aw = getArcWidth() / 2.0;
    double ah = getArcHeight() / 2.0;
    if (dx > aw || dy > ah)
      return true;

    // At this point DX represents the distance from the nearest edge
    // of the rectangle.  But we want to transform it to represent the
    // scaled distance from the center of the ellipse that forms the
    // arc.  Hence this code:
    dy = (ah - dy) / ah;
    dx = (aw - dx) / aw;

    return dx * dx + dy * dy <= 1.0;
  }

  /** 
   * Return true if this object contains the specified rectangle
   * @param x The x coordinate
   * @param y The y coordinate
   * @param w The width
   * @param h The height
   */
  public boolean contains(double x, double y, double w, double h)
  {
    // We have to check all four points here (for ordinary rectangles
    // we can just check opposing corners).
    return (contains(x, y) && contains(x, y + h) && contains(x + w, y + h)
           && contains(x + w, y));
  }

  /** 
   * Return a new path iterator which iterates over this rectangle.
   * 
   * @param at An affine transform to apply to the object
   */
  public PathIterator getPathIterator(final AffineTransform at) 
  {
    double arcW = Math.min(getArcWidth(), getWidth());
    double arcH = Math.min(getArcHeight(), getHeight());
    
    // check for special cases...
    if (arcW <= 0 || arcH <= 0)
      {
        Rectangle2D r = new Rectangle2D.Double(getX(), getY(), getWidth(), 
                getHeight());
        return r.getPathIterator(at);
      }
    else if (arcW >= getWidth() && arcH >= getHeight()) 
      {
        Ellipse2D e = new Ellipse2D.Double(getX(), getY(), getWidth(), 
                getHeight());
        return e.getPathIterator(at);
      }
    
    // otherwise return the standard case...
    return new PathIterator() 
      {
        double x = getX();
        double y = getY();
        double w = getWidth();
        double h = getHeight();
        double arcW = Math.min(getArcWidth(), w);
        double arcH = Math.min(getArcHeight(), h);
        Arc2D.Double arc = new Arc2D.Double();
        PathIterator corner;
        int step = -1;

        public int currentSegment(double[] coords) 
        {
          if (corner != null) // steps 1, 3, 5 and 7
          {
            int r = corner.currentSegment(coords);
            if (r == SEG_MOVETO)
              r = SEG_LINETO;
            return r;
          }
          if (step == -1) 
          {
            // move to the start position
            coords[0] = x + w - arcW / 2;
            coords[1] = y;
          }
          else if (step == 0)
          {
            // top line
            coords[0] = x + arcW / 2;
            coords[1] = y;
          }
          else if (step == 2) 
          {
            // left line
            coords[0] = x;
            coords[1] = y + h - arcH / 2;
          }
          else if (step == 4)
          {
            // bottom line
            coords[0] = x + w - arcW / 2;
            coords[1] = y + h;
          }
          else if (step == 6)
          {
            // right line
              coords[0] = x + w;
              coords[1] = y + arcH / 2;
          }
          if (at != null)
            at.transform(coords, 0, coords, 0, 1);
          return step == -1 ? SEG_MOVETO : SEG_LINETO;
        }

        public int currentSegment(float[] coords) {
          if (corner != null) // steps 1, 3, 5 and 7
          {
            int r = corner.currentSegment(coords);
            if (r == SEG_MOVETO)
              r = SEG_LINETO;
            return r;
          }
          if (step == -1) 
          {
            // move to the start position
            coords[0] = (float) (x + w - arcW / 2);
            coords[1] = (float) y;
          }
          else if (step == 0)
          {
            // top line
            coords[0] = (float) (x + arcW / 2);
            coords[1] = (float) y;
          }
          else if (step == 2) 
          {
            // left line
            coords[0] = (float) x;
            coords[1] = (float) (y + h - arcH / 2);
          }
          else if (step == 4)
          {
            // bottom line
            coords[0] = (float) (x + w - arcW / 2);
            coords[1] = (float) (y + h);
          }
          else if (step == 6)
          {
            // right line
            coords[0] = (float) (x + w);
            coords[1] = (float) (y + arcH / 2);
          }
        if (at != null)
          at.transform(coords, 0, coords, 0, 1);
        return step == -1 ? SEG_MOVETO : SEG_LINETO;
      }

      public int getWindingRule() {
        return WIND_NON_ZERO;
      }

      public boolean isDone() {
        return step >= 8;
      }

      public void next() 
      {
        if (corner != null)
          {
            corner.next();
            if (corner.isDone())
              {
                corner = null;
                step++;
              }
          }
        else
          {
            step++;
            if (step == 1) 
              {
                // create top left corner
                arc.setArc(x, y, arcW, arcH, 90, 90, Arc2D.OPEN);
                corner = arc.getPathIterator(at);
              }
            else if (step == 3)
              {
                // create bottom left corner  
                arc.setArc(x, y + h - arcH, arcW, arcH, 180, 90, 
                        Arc2D.OPEN);
                corner = arc.getPathIterator(at);
              }
            else if (step == 5)
              {
                // create bottom right corner  
                arc.setArc(x + w - arcW, y + h - arcH, arcW, arcH, 270, 90,
                        Arc2D.OPEN);
                corner = arc.getPathIterator(at);
              }
            else if (step == 7)
              {
                // create top right corner  
                arc.setArc(x + w - arcW, y, arcW, arcH, 0, 90, Arc2D.OPEN);
                corner = arc.getPathIterator(at);
              }
          }
      }
    };
  }

  /** 
   * Return true if the given rectangle intersects this shape.
   * @param x The x coordinate
   * @param y The y coordinate
   * @param w The width
   * @param h The height
   */
  public boolean intersects(double x, double y, double w, double h)
  {
    // Check if any corner is within the rectangle
    return (contains(x, y) || contains(x, y + h) || contains(x + w, y + h)
           || contains(x + w, y));
  }

  /** 
   * Set the boundary of this round rectangle.
   * @param x The x coordinate
   * @param y The y coordinate
   * @param w The width
   * @param h The height
   */
  public void setFrame(double x, double y, double w, double h)
  {
    // This is a bit lame.
    setRoundRect(x, y, w, h, getArcWidth(), getArcHeight());
  }

  /** 
   * Set the values of this round rectangle to be the same as those
   * of the argument.
   * @param rr The round rectangle to copy
   */
  public void setRoundRect(RoundRectangle2D rr)
  {
    setRoundRect(rr.getX(), rr.getY(), rr.getWidth(), rr.getHeight(),
                 rr.getArcWidth(), rr.getArcHeight());
  }

  /** 
   * A subclass of RoundRectangle which keeps its parameters as
   * doubles.  
   */
  public static class Double extends RoundRectangle2D
  {
    /** The height of the corner arc.  */
    public double archeight;

    /** The width of the corner arc.  */
    public double arcwidth;

    /** The x coordinate of this object.  */
    public double x;

    /** The y coordinate of this object.  */
    public double y;

    /** The width of this object.  */
    public double width;

    /** The height of this object.  */
    public double height;

    /** 
     * Construct a new instance, with all parameters set to 0.  
     */
    public Double()
    {
    }

    /** 
     * Construct a new instance with the given arguments.
     * @param x The x coordinate
     * @param y The y coordinate
     * @param w The width
     * @param h The height
     * @param arcWidth The arc width
     * @param arcHeight The arc height
     */
    public Double(double x, double y, double w, double h, double arcWidth,
                  double arcHeight)
    {
      this.x = x;
      this.y = y;
      this.width = w;
      this.height = h;
      this.arcwidth = arcWidth;
      this.archeight = arcHeight;
    }

    public double getArcHeight()
    {
      return archeight;
    }

    public double getArcWidth()
    {
      return arcwidth;
    }

    public Rectangle2D getBounds2D()
    {
      return new Rectangle2D.Double(x, y, width, height);
    }

    public double getX()
    {
      return x;
    }

    public double getY()
    {
      return y;
    }

    public double getWidth()
    {
      return width;
    }

    public double getHeight()
    {
      return height;
    }

    public boolean isEmpty()
    {
      return width <= 0 || height <= 0;
    }

    public void setRoundRect(double x, double y, double w, double h,
                             double arcWidth, double arcHeight)
    {
      this.x = x;
      this.y = y;
      this.width = w;
      this.height = h;
      this.arcwidth = arcWidth;
      this.archeight = arcHeight;
    }
  } // class Double

  /** 
   * A subclass of RoundRectangle which keeps its parameters as
   * floats.  
   */
  public static class Float extends RoundRectangle2D
  {
    /** The height of the corner arc.  */
    public float archeight;

    /** The width of the corner arc.  */
    public float arcwidth;

    /** The x coordinate of this object.  */
    public float x;

    /** The y coordinate of this object.  */
    public float y;

    /** The width of this object.  */
    public float width;

    /** The height of this object.  */
    public float height;

    /** 
     * Construct a new instance, with all parameters set to 0.  
     */
    public Float()
    {
    }

    /** 
     * Construct a new instance with the given arguments.
     * @param x The x coordinate
     * @param y The y coordinate
     * @param w The width
     * @param h The height
     * @param arcWidth The arc width
     * @param arcHeight The arc height
     */
    public Float(float x, float y, float w, float h, float arcWidth,
                 float arcHeight)
    {
      this.x = x;
      this.y = y;
      this.width = w;
      this.height = h;
      this.arcwidth = arcWidth;
      this.archeight = arcHeight;
    }

    public double getArcHeight()
    {
      return archeight;
    }

    public double getArcWidth()
    {
      return arcwidth;
    }

    public Rectangle2D getBounds2D()
    {
      return new Rectangle2D.Float(x, y, width, height);
    }

    public double getX()
    {
      return x;
    }

    public double getY()
    {
      return y;
    }

    public double getWidth()
    {
      return width;
    }

    public double getHeight()
    {
      return height;
    }

    public boolean isEmpty()
    {
      return width <= 0 || height <= 0;
    }

    /**
     * Sets the dimensions for this rounded rectangle.
     * 
     * @param x  the x-coordinate of the top left corner.
     * @param y  the y-coordinate of the top left corner.
     * @param w  the width of the rectangle.
     * @param h  the height of the rectangle.
     * @param arcWidth  the arc width.
     * @param arcHeight  the arc height.
     * 
     * @see #setRoundRect(double, double, double, double, double, double)
     */
    public void setRoundRect(float x, float y, float w, float h,
                             float arcWidth, float arcHeight)
    {
      this.x = x;
      this.y = y;
      this.width = w;
      this.height = h;
      this.arcwidth = arcWidth;
      this.archeight = arcHeight;
    }

    public void setRoundRect(double x, double y, double w, double h,
                             double arcWidth, double arcHeight)
    {
      this.x = (float) x;
      this.y = (float) y;
      this.width = (float) w;
      this.height = (float) h;
      this.arcwidth = (float) arcWidth;
      this.archeight = (float) arcHeight;
    }
  } // class Float
} // class RoundRectangle2D