Class WorldRectangle

src/csm/ch03/WorldRectangle.java:18–55

WorldRectangle demonstrates how to draw an object using a drawing panel's world coordinates. @author Wolfgang Christian, Jan Tobochnik, Harvey Gould @version 1.0 05/16/05

 * @version 1.0  05/16/05
 */
public class WorldRectangle implements Drawable {
  double left, top;     // position of rectangle in world coordinates
  double width, height; // size of rectangle in world units

  /**
   * Constructs a WorldRectangle with position and dimensions values given in world coordinates.
   *
   * @param left double
   * @param top double
   * @param width double
   * @param height double
   */
  public WorldRectangle(double left, double top, double width, double height) {
    this.left = left; // location of left edge
    this.top = top;   // location of top edge
    this.width = width;
    this.height = height;
  }

  /**
   * Draws this rectangle using a drawing panel's world coordinates.
   * Required to implement the Drawable interface.
   *
   * @param panel DrawingPanel
   * @param g Graphics
   */
  @Override
public void draw(DrawingPanel panel, Graphics g) {
    // This method implements the Drawable interface
    g.setColor(Color.RED); // set drawing color to red
    // convert from world to pixel coordinates
    int leftPixels = panel.xToPix(left);
    int topPixels = panel.yToPix(top);
    int widthPixels = (int) (panel.getXPixPerUnit()*width);
    int heightPixels = (int) (panel.getYPixPerUnit()*height);
    g.fillRect(leftPixels, topPixels, widthPixels, heightPixels); // draws rectangle
  }
}

/* 
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