CS计算机代考程序代写 Java cache algorithm Hive /******************************************************************************

/******************************************************************************
* Compilation: javac StdDraw.java
* Execution: java StdDraw
* Dependencies: none
*
* Standard drawing library. This class provides a basic capability for
* creating drawings with your programs. It uses a simple graphics model that
* allows you to create drawings consisting of geometric shapes (e.g.,
* points, lines, circles, rectangles) in a window on your computer
* and to save the drawings to a file.
*
* Todo
* —-
* – Add support for gradient fill, etc.
* – Fix setCanvasSize() so that it can be called only once.
* – Should setCanvasSize() reset xScale(), yScale(), penRadius(),
* penColor(), and font()
* – On some systems, drawing a line (or other shape) that extends way
* beyond canvas (e.g., to infinity) dimensions does not get drawn.
*
* Remarks
* ——-
* – don’t use AffineTransform for rescaling since it inverts
* images and strings
*
******************************************************************************/

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Component;
import java.awt.FileDialog;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.RenderingHints;
import java.awt.Toolkit;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

import java.awt.geom.Arc2D;
import java.awt.geom.Ellipse2D;
import java.awt.geom.GeneralPath;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;

import java.awt.image.BufferedImage;
import java.awt.image.DirectColorModel;
import java.awt.image.WritableRaster;

import java.io.File;
import java.io.IOException;

import java.net.MalformedURLException;
import java.net.URL;

import java.util.LinkedList;
import java.util.TreeSet;
import java.util.NoSuchElementException;
import javax.imageio.ImageIO;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.KeyStroke;

/**
* The {@code StdDraw} class provides a basic capability for
* creating drawings with your programs. It uses a simple graphics model that
* allows you to create drawings consisting of points, lines, squares,
* circles, and other geometric shapes in a window on your computer and
* to save the drawings to a file. Standard drawing also includes
* facilities for text, color, pictures, and animation, along with
* user interaction via the keyboard and mouse.
*

* Getting started.
* To use this class, you must have {@code StdDraw.class} in your
* Java classpath. If you used our autoinstaller, you should be all set.
* Otherwise, either download
* stdlib.jar
* and add to your Java classpath or download
* StdDraw.java
* and put a copy in your working directory.
*

* Now, type the following short program into your editor:
*

 *   public class TestStdDraw {
 *       public static void main(String[] args) {
 *           StdDraw.setPenRadius(0.05);
 *           StdDraw.setPenColor(StdDraw.BLUE);
 *           StdDraw.point(0.5, 0.5);
 *           StdDraw.setPenColor(StdDraw.MAGENTA);
 *           StdDraw.line(0.2, 0.2, 0.8, 0.2);
 *       }
 *   }
 *  

* If you compile and execute the program, you should see a window
* appear with a thick magenta line and a blue point.
* This program illustrates the two main types of methods in standard
* drawing—methods that draw geometric shapes and methods that
* control drawing parameters.
* The methods {@code StdDraw.line()} and {@code StdDraw.point()}
* draw lines and points; the methods {@code StdDraw.setPenRadius()}
* and {@code StdDraw.setPenColor()} control the line thickness and color.
*

* Points and lines.
* You can draw points and line segments with the following methods:
*

    *

  • {@link #point(double x, double y)}
    *

  • {@link #line(double x1, double y1, double x2, double y2)}
    *

*

* The x– and y-coordinates must be in the drawing area
* (between 0 and 1 and by default) or the points and lines will not be visible.
*

* Squares, circles, rectangles, and ellipses.
* You can draw squares, circles, rectangles, and ellipses using
* the following methods:
*

    *

  • {@link #circle(double x, double y, double radius)}
    *

  • {@link #ellipse(double x, double y, double semiMajorAxis, double semiMinorAxis)}
    *

  • {@link #square(double x, double y, double halfLength)}
    *

  • {@link #rectangle(double x, double y, double halfWidth, double halfHeight)}
    *

*

* All of these methods take as arguments the location and size of the shape.
* The location is always specified by the x– and y-coordinates
* of its center.
* The size of a circle is specified by its radius and the size of an ellipse is
* specified by the lengths of its semi-major and semi-minor axes.
* The size of a square or rectangle is specified by its half-width or half-height.
* The convention for drawing squares and rectangles is parallel to those for
* drawing circles and ellipses, but may be unexpected to the uninitiated.
*

* The methods above trace outlines of the given shapes. The following methods
* draw filled versions:
*

    *

  • {@link #filledCircle(double x, double y, double radius)}
    *

  • {@link #filledEllipse(double x, double y, double semiMajorAxis, double semiMinorAxis)}
    *

  • {@link #filledSquare(double x, double y, double radius)}
    *

  • {@link #filledRectangle(double x, double y, double halfWidth, double halfHeight)}
    *

*

* Circular arcs.
* You can draw circular arcs with the following method:
*

    *

  • {@link #arc(double x, double y, double radius, double angle1, double angle2)}
    *

*

* The arc is from the circle centered at (x, y) of the specified radius.
* The arc extends from angle1 to angle2. By convention, the angles are
* polar (counterclockwise angle from the x-axis)
* and represented in degrees. For example, {@code StdDraw.arc(0.0, 0.0, 1.0, 0, 90)}
* draws the arc of the unit circle from 3 o’clock (0 degrees) to 12 o’clock (90 degrees).
*

* Polygons.
* You can draw polygons with the following methods:
*

    *

  • {@link #polygon(double[] x, double[] y)}
    *

  • {@link #filledPolygon(double[] x, double[] y)}
    *

*

* The points in the polygon are ({@code x[i]}, {@code y[i]}).
* For example, the following code fragment draws a filled diamond
* with vertices (0.1, 0.2), (0.2, 0.3), (0.3, 0.2), and (0.2, 0.1):
*

 *   double[] x = { 0.1, 0.2, 0.3, 0.2 };
 *   double[] y = { 0.2, 0.3, 0.2, 0.1 };
 *   StdDraw.filledPolygon(x, y);
 *  

*

* Pen size.
* The pen is circular, so that when you set the pen radius to r
* and draw a point, you get a circle of radius r. Also, lines are
* of thickness 2r and have rounded ends. The default pen radius
* is 0.005 and is not affected by coordinate scaling. This default pen
* radius is about 1/200 the width of the default canvas, so that if
* you draw 100 points equally spaced along a horizontal or vertical line,
* you will be able to see individual circles, but if you draw 200 such
* points, the result will look like a line.
*

    *

  • {@link #setPenRadius(double radius)}
    *

*

* For example, {@code StdDraw.setPenRadius(0.025)} makes
* the thickness of the lines and the size of the points to be five times
* the 0.005 default.
* To draw points with the minimum possible radius (one pixel on typical
* displays), set the pen radius to 0.0.
*

* Pen color.
* All geometric shapes (such as points, lines, and circles) are drawn using
* the current pen color. By default, it is black.
* You can change the pen color with the following methods:
*

    *

  • {@link #setPenColor(int red, int green, int blue)}
    *

  • {@link #setPenColor(Color color)}
    *

*

* The first method allows you to specify colors using the RGB color system.
* This color picker
* is a convenient way to find a desired color.
* The second method allows you to specify colors using the
* {@link Color} data type that is discussed in Chapter 3. Until then,
* you can use this method with one of these predefined colors in standard drawing:
* {@link #BLACK}, {@link #BLUE}, {@link #CYAN}, {@link #DARK_GRAY}, {@link #GRAY},
* {@link #GREEN}, {@link #LIGHT_GRAY}, {@link #MAGENTA}, {@link #ORANGE},
* {@link #PINK}, {@link #RED}, {@link #WHITE}, {@link #YELLOW},
* {@link #BOOK_BLUE}, {@link #BOOK_LIGHT_BLUE}, {@link #BOOK_RED}, and
* {@link #PRINCETON_ORANGE}.
* For example, {@code StdDraw.setPenColor(StdDraw.MAGENTA)} sets the
* pen color to magenta.
*

* Canvas size.
* By default, all drawing takes places in a 512-by-512 canvas.
* The canvas does not include the window title or window border.
* You can change the size of the canvas with the following method:
*

    *

  • {@link #setCanvasSize(int width, int height)}
    *

*

* This sets the canvas size to be width-by-height pixels.
* It also erases the current drawing and resets the coordinate system,
* pen radius, pen color, and font back to their default values.
* Ordinarly, this method is called once, at the very beginning of a program.
* For example, {@code StdDraw.setCanvasSize(800, 800)}
* sets the canvas size to be 800-by-800 pixels.
*

* Canvas scale and coordinate system.
* By default, all drawing takes places in the unit square, with (0, 0) at
* lower left and (1, 1) at upper right. You can change the default
* coordinate system with the following methods:
*

    *

  • {@link #setXscale(double xmin, double xmax)}
    *

  • {@link #setYscale(double ymin, double ymax)}
    *

  • {@link #setScale(double min, double max)}
    *

*

* The arguments are the coordinates of the minimum and maximum
* x– or y-coordinates that will appear in the canvas.
* For example, if you wish to use the default coordinate system but
* leave a small margin, you can call {@code StdDraw.setScale(-.05, 1.05)}.
*

* These methods change the coordinate system for subsequent drawing
* commands; they do not affect previous drawings.
* These methods do not change the canvas size; so, if the x
* and y-scales are different, squares will become rectangles
* and circles will become ellipses.
*

* Text.
* You can use the following methods to annotate your drawings with text:
*

    *

  • {@link #text(double x, double y, String text)}
    *

  • {@link #text(double x, double y, String text, double degrees)}
    *

  • {@link #textLeft(double x, double y, String text)}
    *

  • {@link #textRight(double x, double y, String text)}
    *

*

* The first two methods write the specified text in the current font,
* centered at (x, y).
* The second method allows you to rotate the text.
* The last two methods either left- or right-align the text at (x, y).
*

* The default font is a Sans Serif font with point size 16.
* You can use the following method to change the font:
*

    *

  • {@link #setFont(Font font)}
    *

*

* You use the {@link Font} data type to specify the font. This allows you to
* choose the face, size, and style of the font. For example, the following
* code fragment sets the font to Arial Bold, 60 point.
*

 *   Font font = new Font("Arial", Font.BOLD, 60);
 *   StdDraw.setFont(font);
 *   StdDraw.text(0.5, 0.5, "Hello, World");
 *  

*

* Images.
* You can use the following methods to add images to your drawings:
*

    *

  • {@link #picture(double x, double y, String filename)}
    *

  • {@link #picture(double x, double y, String filename, double degrees)}
    *

  • {@link #picture(double x, double y, String filename, double scaledWidth, double scaledHeight)}
    *

  • {@link #picture(double x, double y, String filename, double scaledWidth, double scaledHeight, double degrees)}
    *

*

* These methods draw the specified image, centered at (x, y).
* The supported image formats are JPEG, PNG, and GIF.
* The image will display at its native size, independent of the coordinate system.
* Optionally, you can rotate the image a specified number of degrees counterclockwise
* or rescale it to fit snugly inside a width-by-height bounding box.
*

* Saving to a file.
* You save your image to a file using the File → Save menu option.
* You can also save a file programatically using the following method:
*

    *

  • {@link #save(String filename)}
    *

*

* The supported image formats are JPEG and PNG. The filename must have either the
* extension .jpg or .png.
* We recommend using PNG for drawing that consist solely of geometric shapes and JPEG
* for drawings that contains pictures.
*

* Clearing the canvas.
* To clear the entire drawing canvas, you can use the following methods:
*

    *

  • {@link #clear()}
    *

  • {@link #clear(Color color)}
    *

*

* The first method clears the canvas to white; the second method
* allows you to specify a color of your choice. For example,
* {@code StdDraw.clear(StdDraw.LIGHT_GRAY)} clears the canvas to a shade
* of gray.
*

* Computer animations and double buffering.
* Double buffering is one of the most powerful features of standard drawing,
* enabling computer animations.
* The following methods control the way in which objects are drawn:
*

    *

  • {@link #enableDoubleBuffering()}
    *

  • {@link #disableDoubleBuffering()}
    *

  • {@link #show()}
    *

  • {@link #pause(int t)}
    *

*

* By default, double buffering is disabled, which means that as soon as you
* call a drawing
* method—such as {@code point()} or {@code line()}—the
* results appear on the screen.
*

* When double buffering is enabled by calling {@link #enableDoubleBuffering()},
* all drawing takes place on the offscreen canvas. The offscreen canvas
* is not displayed. Only when you call
* {@link #show()} does your drawing get copied from the offscreen canvas to
* the onscreen canvas, where it is displayed in the standard drawing window. You
* can think of double buffering as collecting all of the lines, points, shapes,
* and text that you tell it to draw, and then drawing them all
* simultaneously, upon request.
*

* The most important use of double buffering is to produce computer
* animations, creating the illusion of motion by rapidly
* displaying static drawings. To produce an animation, repeat
* the following four steps:
*

    *

  • Clear the offscreen canvas.
    *

  • Draw objects on the offscreen canvas.
    *

  • Copy the offscreen canvas to the onscreen canvas.
    *

  • Wait for a short while.
    *

*

* The {@link #clear()}, {@link #show()}, and {@link #pause(int t)} methods
* support the first, third, and fourth of these steps, respectively.
*

* For example, this code fragment animates two balls moving in a circle.
*

 *   StdDraw.setScale(-2, +2);
 *   StdDraw.enableDoubleBuffering();
 *
 *   for (double t = 0.0; true; t += 0.02) {
 *       double x = Math.sin(t);
 *       double y = Math.cos(t);
 *       StdDraw.clear();
 *       StdDraw.filledCircle(x, y, 0.05);
 *       StdDraw.filledCircle(-x, -y, 0.05);
 *       StdDraw.show();
 *       StdDraw.pause(20);
 *   }
 *  

*

* Keyboard and mouse inputs.
* Standard drawing has very basic support for keyboard and mouse input.
* It is much less powerful than most user interface libraries provide, but also much simpler.
* You can use the following methods to intercept mouse events:
*

    *

  • {@link #isMousePressed()}
    *

  • {@link #mouseX()}
    *

  • {@link #mouseY()}
    *

*

* The first method tells you whether a mouse button is currently being pressed.
* The last two methods tells you the x– and y-coordinates of the mouse’s
* current position, using the same coordinate system as the canvas (the unit square, by default).
* You should use these methods in an animation loop that waits a short while before trying
* to poll the mouse for its current state.
* You can use the following methods to intercept keyboard events:
*

    *

  • {@link #hasNextKeyTyped()}
    *

  • {@link #nextKeyTyped()}
    *

  • {@link #isKeyPressed(int keycode)}
    *

*

* If the user types lots of keys, they will be saved in a list until you process them.
* The first method tells you whether the user has typed a key (that your program has
* not yet processed).
* The second method returns the next key that the user typed (that your program has
* not yet processed) and removes it from the list of saved keystrokes.
* The third method tells you whether a key is currently being pressed.
*

* Accessing control parameters.
* You can use the following methods to access the current pen color, pen radius,
* and font:
*

    *

  • {@link #getPenColor()}
    *

  • {@link #getPenRadius()}
    *

  • {@link #getFont()}
    *

*

* These methods are useful when you want to temporarily change a
* control parameter and reset it back to its original value.
*

* Corner cases.
* Here are some corner cases.
*

    *

  • Drawing an object outside (or partly outside) the canvas is permitted.
    * However, only the part of the object that appears inside the canvas
    * will be visible.
    *

  • Any method that is passed a {@code null} argument will throw an
    * {@link IllegalArgumentException}.
    *

  • Any method that is passed a {@link Double#NaN},
    * {@link Double#POSITIVE_INFINITY}, or {@link Double#NEGATIVE_INFINITY}
    * argument will throw an {@link IllegalArgumentException}.
    *

  • Due to floating-point issues, an object drawn with an x– or
    * y-coordinate that is way outside the canvas (such as the line segment
    * from (0.5, –10^308) to (0.5, 10^308) may not be visible even in the
    * part of the canvas where it should be.
    *

*

* Performance tricks.
* Standard drawing is capable of drawing large amounts of data.
* Here are a few tricks and tips:
*

    *

  • Use double buffering for static drawing with a large
    * number of objects.
    * That is, call {@link #enableDoubleBuffering()} before
    * the sequence of drawing commands and call {@link #show()} afterwards.
    * Incrementally displaying a complex drawing while it is being
    * created can be intolerably inefficient on many computer systems.
    *

  • When drawing computer animations, call {@code show()}
    * only once per frame, not after drawing each individual object.
    *

  • If you call {@code picture()} multiple times with the same filename,
    * Java will cache the image, so you do not incur the cost of reading
    * from a file each time.
    *

*

* Known bugs and issues.
*

    *

  • The {@code picture()} methods may not draw the portion of the image that is
    * inside the canvas if the center point (x, y) is outside the
    * canvas.
    * This bug appears only on some systems.
    *

*

* Reference.
* For additional documentation,
* see Section 1.5 of
* Computer Science: An Interdisciplinary Approach
* by Robert Sedgewick and Kevin Wayne.
*
* @author Robert Sedgewick
* @author Kevin Wayne
*/
public final class StdDraw implements ActionListener, MouseListener, MouseMotionListener, KeyListener {

/**
* The color black.
*/
public static final Color BLACK = Color.BLACK;

/**
* The color blue.
*/
public static final Color BLUE = Color.BLUE;

/**
* The color cyan.
*/
public static final Color CYAN = Color.CYAN;

/**
* The color dark gray.
*/
public static final Color DARK_GRAY = Color.DARK_GRAY;

/**
* The color gray.
*/
public static final Color GRAY = Color.GRAY;

/**
* The color green.
*/
public static final Color GREEN = Color.GREEN;

/**
* The color light gray.
*/
public static final Color LIGHT_GRAY = Color.LIGHT_GRAY;

/**
* The color magenta.
*/
public static final Color MAGENTA = Color.MAGENTA;

/**
* The color orange.
*/
public static final Color ORANGE = Color.ORANGE;

/**
* The color pink.
*/
public static final Color PINK = Color.PINK;

/**
* The color red.
*/
public static final Color RED = Color.RED;

/**
* The color white.
*/
public static final Color WHITE = Color.WHITE;

/**
* The color yellow.
*/
public static final Color YELLOW = Color.YELLOW;

/**
* Shade of blue used in Introduction to Programming in Java.
* It is Pantone 300U. The RGB values are approximately (9, 90, 166).
*/
public static final Color BOOK_BLUE = new Color(9, 90, 166);

/**
* Shade of light blue used in Introduction to Programming in Java.
* The RGB values are approximately (103, 198, 243).
*/
public static final Color BOOK_LIGHT_BLUE = new Color(103, 198, 243);

/**
* Shade of red used in Algorithms, 4th edition.
* It is Pantone 1805U. The RGB values are approximately (150, 35, 31).
*/
public static final Color BOOK_RED = new Color(150, 35, 31);

/**
* Shade of orange used in Princeton University’s identity.
* It is PMS 158. The RGB values are approximately (245, 128, 37).
*/
public static final Color PRINCETON_ORANGE = new Color(245, 128, 37);

// default colors
private static final Color DEFAULT_PEN_COLOR = BLACK;
private static final Color DEFAULT_CLEAR_COLOR = WHITE;

// current pen color
private static Color penColor;

// default canvas size is DEFAULT_SIZE-by-DEFAULT_SIZE
private static final int DEFAULT_SIZE = 512;
private static int width = DEFAULT_SIZE;
private static int height = DEFAULT_SIZE;

// default pen radius
private static final double DEFAULT_PEN_RADIUS = 0.002;

// current pen radius
private static double penRadius;

// show we draw immediately or wait until next show?
private static boolean defer = false;

// boundary of drawing canvas, 0% border
// private static final double BORDER = 0.05;
private static final double BORDER = 0.00;
private static final double DEFAULT_XMIN = 0.0;
private static final double DEFAULT_XMAX = 1.0;
private static final double DEFAULT_YMIN = 0.0;
private static final double DEFAULT_YMAX = 1.0;
private static double xmin, ymin, xmax, ymax;

// for synchronization
private static Object mouseLock = new Object();
private static Object keyLock = new Object();

// default font
private static final Font DEFAULT_FONT = new Font(“SansSerif”, Font.PLAIN, 16);

// current font
private static Font font;

// double buffered graphics
private static BufferedImage offscreenImage, onscreenImage;
private static Graphics2D offscreen, onscreen;

// singleton for callbacks: avoids generation of extra .class files
private static StdDraw std = new StdDraw();

// the frame for drawing to the screen
private static JFrame frame;

// mouse state
private static boolean isMousePressed = false;
private static double mouseX = 0;
private static double mouseY = 0;

// queue of typed key characters
private static LinkedList keysTyped;

// set of key codes currently pressed down
private static TreeSet keysDown;

// singleton pattern: client can’t instantiate
private StdDraw() { }

// static initializer
static {
init();
}

/**
* Sets the canvas (drawing area) to be 512-by-512 pixels.
* This also erases the current drawing and resets the coordinate system,
* pen radius, pen color, and font back to their default values.
* Ordinarly, this method is called once, at the very beginning
* of a program.
*/
public static void setCanvasSize() {
setCanvasSize(DEFAULT_SIZE, DEFAULT_SIZE);
}

/**
* Sets the canvas (drawing area) to be width-by-height pixels.
* This also erases the current drawing and resets the coordinate system,
* pen radius, pen color, and font back to their default values.
* Ordinarly, this method is called once, at the very beginning
* of a program.
*
* @param canvasWidth the width as a number of pixels
* @param canvasHeight the height as a number of pixels
* @throws IllegalArgumentException unless both {@code canvasWidth} and
* {@code canvasHeight} are positive
*/
public static void setCanvasSize(int canvasWidth, int canvasHeight) {
if (canvasWidth <= 0) throw new IllegalArgumentException("width must be positive"); if (canvasHeight <= 0) throw new IllegalArgumentException("height must be positive"); width = canvasWidth; height = canvasHeight; init(); } // init private static void init() { if (frame != null) frame.setVisible(false); frame = new JFrame(); offscreenImage = new BufferedImage(2*width, 2*height, BufferedImage.TYPE_INT_ARGB); onscreenImage = new BufferedImage(2*width, 2*height, BufferedImage.TYPE_INT_ARGB); offscreen = offscreenImage.createGraphics(); onscreen = onscreenImage.createGraphics(); offscreen.scale(2.0, 2.0); // since we made it 2x as big setXscale(); setYscale(); offscreen.setColor(DEFAULT_CLEAR_COLOR); offscreen.fillRect(0, 0, width, height); setPenColor(); setPenRadius(); setFont(); clear(); // initialize keystroke buffers keysTyped = new LinkedList();
keysDown = new TreeSet();

// add antialiasing
RenderingHints hints = new RenderingHints(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
hints.put(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
offscreen.addRenderingHints(hints);

// frame stuff
RetinaImageIcon icon = new RetinaImageIcon(onscreenImage);
JLabel draw = new JLabel(icon);

draw.addMouseListener(std);
draw.addMouseMotionListener(std);

frame.setContentPane(draw);
frame.addKeyListener(std); // JLabel cannot get keyboard focus
frame.setFocusTraversalKeysEnabled(false); // allow VK_TAB with isKeyPressed()
frame.setResizable(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // closes all windows
// frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); // closes only current window
frame.setTitle(“Standard Draw”);
frame.setJMenuBar(createMenuBar());
frame.pack();
frame.requestFocusInWindow();
frame.setVisible(true);
}

// create the menu bar (changed to private)
private static JMenuBar createMenuBar() {
JMenuBar menuBar = new JMenuBar();
JMenu menu = new JMenu(“File”);
menuBar.add(menu);
JMenuItem menuItem1 = new JMenuItem(” Save… “);
menuItem1.addActionListener(std);
// Java 10+: replace getMenuShortcutKeyMask() with getMenuShortcutKeyMaskEx()
menuItem1.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S,
Toolkit.getDefaultToolkit().getMenuShortcutKeyMaskEx()));
menu.add(menuItem1);
return menuBar;
}

/***************************************************************************
* User and screen coordinate systems.
***************************************************************************/

// throw an IllegalArgumentException if x is NaN or infinite
private static void validate(double x, String name) {
if (Double.isNaN(x)) throw new IllegalArgumentException(name + ” is NaN”);
if (Double.isInfinite(x)) throw new IllegalArgumentException(name + ” is infinite”);
}

// throw an IllegalArgumentException if s is null
private static void validateNonnegative(double x, String name) {
if (x < 0) throw new IllegalArgumentException(name + " negative"); } // throw an IllegalArgumentException if s is null private static void validateNotNull(Object x, String name) { if (x == null) throw new IllegalArgumentException(name + " is null"); } /** * Sets the x-scale to be the default (between 0.0 and 1.0).
*/
public static void setXscale() {
setXscale(DEFAULT_XMIN, DEFAULT_XMAX);
}

/**
* Sets the y-scale to be the default (between 0.0 and 1.0).
*/
public static void setYscale() {
setYscale(DEFAULT_YMIN, DEFAULT_YMAX);
}

/**
* Sets the x-scale and y-scale to be the default
* (between 0.0 and 1.0).
*/
public static void setScale() {
setXscale();
setYscale();
}

/**
* Sets the x-scale to the specified range.
*
* @param min the minimum value of the x-scale
* @param max the maximum value of the x-scale
* @throws IllegalArgumentException if {@code (max == min)}
* @throws IllegalArgumentException if either {@code min} or {@code max} is either NaN or infinite
*/
public static void setXscale(double min, double max) {
validate(min, “min”);
validate(max, “max”);
double size = max – min;
if (size == 0.0) throw new IllegalArgumentException(“the min and max are the same”);
synchronized (mouseLock) {
xmin = min – BORDER * size;
xmax = max + BORDER * size;
}
}

/**
* Sets the y-scale to the specified range.
*
* @param min the minimum value of the y-scale
* @param max the maximum value of the y-scale
* @throws IllegalArgumentException if {@code (max == min)}
* @throws IllegalArgumentException if either {@code min} or {@code max} is either NaN or infinite
*/
public static void setYscale(double min, double max) {
validate(min, “min”);
validate(max, “max”);
double size = max – min;
if (size == 0.0) throw new IllegalArgumentException(“the min and max are the same”);
synchronized (mouseLock) {
ymin = min – BORDER * size;
ymax = max + BORDER * size;
}
}

/**
* Sets both the x-scale and y-scale to the (same) specified range.
*
* @param min the minimum value of the x– and y-scales
* @param max the maximum value of the x– and y-scales
* @throws IllegalArgumentException if {@code (max == min)}
* @throws IllegalArgumentException if either {@code min} or {@code max} is either NaN or infinite
*/
public static void setScale(double min, double max) {
validate(min, “min”);
validate(max, “max”);
double size = max – min;
if (size == 0.0) throw new IllegalArgumentException(“the min and max are the same”);
synchronized (mouseLock) {
xmin = min – BORDER * size;
xmax = max + BORDER * size;
ymin = min – BORDER * size;
ymax = max + BORDER * size;
}
}

// helper functions that scale from user coordinates to screen coordinates and back
private static double scaleX(double x) { return width * (x – xmin) / (xmax – xmin); }
private static double scaleY(double y) { return height * (ymax – y) / (ymax – ymin); }
private static double factorX(double w) { return w * width / Math.abs(xmax – xmin); }
private static double factorY(double h) { return h * height / Math.abs(ymax – ymin); }
private static double userX(double x) { return xmin + x * (xmax – xmin) / width; }
private static double userY(double y) { return ymax – y * (ymax – ymin) / height; }

/**
* Clears the screen to the default color (white).
*/
public static void clear() {
clear(DEFAULT_CLEAR_COLOR);
}

/**
* Clears the screen to the specified color.
*
* @param color the color to make the background
* @throws IllegalArgumentException if {@code color} is {@code null}
*/
public static void clear(Color color) {
validateNotNull(color, “color”);
offscreen.setColor(color);
offscreen.fillRect(0, 0, width, height);
offscreen.setColor(penColor);
draw();
}

/**
* Returns the current pen radius.
*
* @return the current value of the pen radius
*/
public static double getPenRadius() {
return penRadius;
}

/**
* Sets the pen size to the default size (0.002).
* The pen is circular, so that lines have rounded ends, and when you set the
* pen radius and draw a point, you get a circle of the specified radius.
* The pen radius is not affected by coordinate scaling.
*/
public static void setPenRadius() {
setPenRadius(DEFAULT_PEN_RADIUS);
}

/**
* Sets the radius of the pen to the specified size.
* The pen is circular, so that lines have rounded ends, and when you set the
* pen radius and draw a point, you get a circle of the specified radius.
* The pen radius is not affected by coordinate scaling.
*
* @param radius the radius of the pen
* @throws IllegalArgumentException if {@code radius} is negative, NaN, or infinite
*/
public static void setPenRadius(double radius) {
validate(radius, “pen radius”);
validateNonnegative(radius, “pen radius”);

penRadius = radius;
float scaledPenRadius = (float) (radius * DEFAULT_SIZE);
BasicStroke stroke = new BasicStroke(scaledPenRadius, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND);
// BasicStroke stroke = new BasicStroke(scaledPenRadius);
offscreen.setStroke(stroke);
}

/**
* Returns the current pen color.
*
* @return the current pen color
*/
public static Color getPenColor() {
return penColor;
}

/**
* Sets the pen color to the default color (black).
*/
public static void setPenColor() {
setPenColor(DEFAULT_PEN_COLOR);
}

/**
* Sets the pen color to the specified color.
*

* The predefined pen colors are
* {@code StdDraw.BLACK}, {@code StdDraw.BLUE}, {@code StdDraw.CYAN},
* {@code StdDraw.DARK_GRAY}, {@code StdDraw.GRAY}, {@code StdDraw.GREEN},
* {@code StdDraw.LIGHT_GRAY}, {@code StdDraw.MAGENTA}, {@code StdDraw.ORANGE},
* {@code StdDraw.PINK}, {@code StdDraw.RED}, {@code StdDraw.WHITE}, and
* {@code StdDraw.YELLOW}.
*
* @param color the color to make the pen
* @throws IllegalArgumentException if {@code color} is {@code null}
*/
public static void setPenColor(Color color) {
validateNotNull(color, “color”);
penColor = color;
offscreen.setColor(penColor);
}

/**
* Sets the pen color to the specified RGB color.
*
* @param red the amount of red (between 0 and 255)
* @param green the amount of green (between 0 and 255)
* @param blue the amount of blue (between 0 and 255)
* @throws IllegalArgumentException if {@code red}, {@code green},
* or {@code blue} is outside its prescribed range
*/
public static void setPenColor(int red, int green, int blue) {
if (red < 0 || red >= 256) throw new IllegalArgumentException(“red must be between 0 and 255”);
if (green < 0 || green >= 256) throw new IllegalArgumentException(“green must be between 0 and 255”);
if (blue < 0 || blue >= 256) throw new IllegalArgumentException(“blue must be between 0 and 255”);
setPenColor(new Color(red, green, blue));
}

/**
* Returns the current font.
*
* @return the current font
*/
public static Font getFont() {
return font;
}

/**
* Sets the font to the default font (sans serif, 16 point).
*/
public static void setFont() {
setFont(DEFAULT_FONT);
}

/**
* Sets the font to the specified value.
*
* @param font the font
* @throws IllegalArgumentException if {@code font} is {@code null}
*/
public static void setFont(Font font) {
validateNotNull(font, “font”);
StdDraw.font = font;
}

/***************************************************************************
* Drawing geometric shapes.
***************************************************************************/

/**
* Draws a line segment between (x0, y0) and
* (x1, y1).
*
* @param x0 the x-coordinate of one endpoint
* @param y0 the y-coordinate of one endpoint
* @param x1 the x-coordinate of the other endpoint
* @param y1 the y-coordinate of the other endpoint
* @throws IllegalArgumentException if any coordinate is either NaN or infinite
*/
public static void line(double x0, double y0, double x1, double y1) {
validate(x0, “x0”);
validate(y0, “y0”);
validate(x1, “x1”);
validate(y1, “y1”);
offscreen.draw(new Line2D.Double(scaleX(x0), scaleY(y0), scaleX(x1), scaleY(y1)));
draw();
}

/**
* Draws one pixel at (x, y).
* This method is private because pixels depend on the display.
* To achieve the same effect, set the pen radius to 0 and call {@code point()}.
*
* @param x the x-coordinate of the pixel
* @param y the y-coordinate of the pixel
* @throws IllegalArgumentException if {@code x} or {@code y} is either NaN or infinite
*/
private static void pixel(double x, double y) {
validate(x, “x”);
validate(y, “y”);
offscreen.fillRect((int) Math.round(scaleX(x)), (int) Math.round(scaleY(y)), 1, 1);
}

/**
* Draws a point centered at (x, y).
* The point is a filled circle whose radius is equal to the pen radius.
* To draw a single-pixel point, first set the pen radius to 0.
*
* @param x the x-coordinate of the point
* @param y the y-coordinate of the point
* @throws IllegalArgumentException if either {@code x} or {@code y} is either NaN or infinite
*/
public static void point(double x, double y) {
validate(x, “x”);
validate(y, “y”);

double xs = scaleX(x);
double ys = scaleY(y);
double r = penRadius;
float scaledPenRadius = (float) (r * DEFAULT_SIZE);

// double ws = factorX(2*r);
// double hs = factorY(2*r);
// if (ws <= 1 && hs <= 1) pixel(x, y); if (scaledPenRadius <= 1) pixel(x, y); else offscreen.fill(new Ellipse2D.Double(xs - scaledPenRadius/2, ys - scaledPenRadius/2, scaledPenRadius, scaledPenRadius)); draw(); } /** * Draws a circle of the specified radius, centered at (x, y).
*
* @param x the x-coordinate of the center of the circle
* @param y the y-coordinate of the center of the circle
* @param radius the radius of the circle
* @throws IllegalArgumentException if {@code radius} is negative
* @throws IllegalArgumentException if any argument is either NaN or infinite
*/
public static void circle(double x, double y, double radius) {
validate(x, “x”);
validate(y, “y”);
validate(radius, “radius”);
validateNonnegative(radius, “radius”);

double xs = scaleX(x);
double ys = scaleY(y);
double ws = factorX(2*radius);
double hs = factorY(2*radius);
if (ws <= 1 && hs <= 1) pixel(x, y); else offscreen.draw(new Ellipse2D.Double(xs - ws/2, ys - hs/2, ws, hs)); draw(); } /** * Draws a filled circle of the specified radius, centered at (x, y).
*
* @param x the x-coordinate of the center of the circle
* @param y the y-coordinate of the center of the circle
* @param radius the radius of the circle
* @throws IllegalArgumentException if {@code radius} is negative
* @throws IllegalArgumentException if any argument is either NaN or infinite
*/
public static void filledCircle(double x, double y, double radius) {
validate(x, “x”);
validate(y, “y”);
validate(radius, “radius”);
validateNonnegative(radius, “radius”);

double xs = scaleX(x);
double ys = scaleY(y);
double ws = factorX(2*radius);
double hs = factorY(2*radius);
if (ws <= 1 && hs <= 1) pixel(x, y); else offscreen.fill(new Ellipse2D.Double(xs - ws/2, ys - hs/2, ws, hs)); draw(); } /** * Draws an ellipse with the specified semimajor and semiminor axes, * centered at (x, y).
*
* @param x the x-coordinate of the center of the ellipse
* @param y the y-coordinate of the center of the ellipse
* @param semiMajorAxis is the semimajor axis of the ellipse
* @param semiMinorAxis is the semiminor axis of the ellipse
* @throws IllegalArgumentException if either {@code semiMajorAxis}
* or {@code semiMinorAxis} is negative
* @throws IllegalArgumentException if any argument is either NaN or infinite
*/
public static void ellipse(double x, double y, double semiMajorAxis, double semiMinorAxis) {
validate(x, “x”);
validate(y, “y”);
validate(semiMajorAxis, “semimajor axis”);
validate(semiMinorAxis, “semiminor axis”);
validateNonnegative(semiMajorAxis, “semimajor axis”);
validateNonnegative(semiMinorAxis, “semiminor axis”);

double xs = scaleX(x);
double ys = scaleY(y);
double ws = factorX(2*semiMajorAxis);
double hs = factorY(2*semiMinorAxis);
if (ws <= 1 && hs <= 1) pixel(x, y); else offscreen.draw(new Ellipse2D.Double(xs - ws/2, ys - hs/2, ws, hs)); draw(); } /** * Draws a filled ellipse with the specified semimajor and semiminor axes, * centered at (x, y).
*
* @param x the x-coordinate of the center of the ellipse
* @param y the y-coordinate of the center of the ellipse
* @param semiMajorAxis is the semimajor axis of the ellipse
* @param semiMinorAxis is the semiminor axis of the ellipse
* @throws IllegalArgumentException if either {@code semiMajorAxis}
* or {@code semiMinorAxis} is negative
* @throws IllegalArgumentException if any argument is either NaN or infinite
*/
public static void filledEllipse(double x, double y, double semiMajorAxis, double semiMinorAxis) {
validate(x, “x”);
validate(y, “y”);
validate(semiMajorAxis, “semimajor axis”);
validate(semiMinorAxis, “semiminor axis”);
validateNonnegative(semiMajorAxis, “semimajor axis”);
validateNonnegative(semiMinorAxis, “semiminor axis”);

double xs = scaleX(x);
double ys = scaleY(y);
double ws = factorX(2*semiMajorAxis);
double hs = factorY(2*semiMinorAxis);
if (ws <= 1 && hs <= 1) pixel(x, y); else offscreen.fill(new Ellipse2D.Double(xs - ws/2, ys - hs/2, ws, hs)); draw(); } /** * Draws a circular arc of the specified radius, * centered at (x, y), from angle1 to angle2 (in degrees).
*
* @param x the x-coordinate of the center of the circle
* @param y the y-coordinate of the center of the circle
* @param radius the radius of the circle
* @param angle1 the starting angle. 0 would mean an arc beginning at 3 o’clock.
* @param angle2 the angle at the end of the arc. For example, if
* you want a 90 degree arc, then angle2 should be angle1 + 90.
* @throws IllegalArgumentException if {@code radius} is negative
* @throws IllegalArgumentException if any argument is either NaN or infinite
*/
public static void arc(double x, double y, double radius, double angle1, double angle2) {
validate(x, “x”);
validate(y, “y”);
validate(radius, “arc radius”);
validate(angle1, “angle1”);
validate(angle2, “angle2”);
validateNonnegative(radius, “arc radius”);

while (angle2 < angle1) angle2 += 360; double xs = scaleX(x); double ys = scaleY(y); double ws = factorX(2*radius); double hs = factorY(2*radius); if (ws <= 1 && hs <= 1) pixel(x, y); else offscreen.draw(new Arc2D.Double(xs - ws/2, ys - hs/2, ws, hs, angle1, angle2 - angle1, Arc2D.OPEN)); draw(); } /** * Draws a square of the specified size, centered at (x, y).
*
* @param x the x-coordinate of the center of the square
* @param y the y-coordinate of the center of the square
* @param halfLength one half the length of any side of the square
* @throws IllegalArgumentException if {@code halfLength} is negative
* @throws IllegalArgumentException if any argument is either NaN or infinite
*/
public static void square(double x, double y, double halfLength) {
validate(x, “x”);
validate(y, “y”);
validate(halfLength, “halfLength”);
validateNonnegative(halfLength, “half length”);

double xs = scaleX(x);
double ys = scaleY(y);
double ws = factorX(2*halfLength);
double hs = factorY(2*halfLength);
if (ws <= 1 && hs <= 1) pixel(x, y); else offscreen.draw(new Rectangle2D.Double(xs - ws/2, ys - hs/2, ws, hs)); draw(); } /** * Draws a filled square of the specified size, centered at (x, y).
*
* @param x the x-coordinate of the center of the square
* @param y the y-coordinate of the center of the square
* @param halfLength one half the length of any side of the square
* @throws IllegalArgumentException if {@code halfLength} is negative
* @throws IllegalArgumentException if any argument is either NaN or infinite
*/
public static void filledSquare(double x, double y, double halfLength) {
validate(x, “x”);
validate(y, “y”);
validate(halfLength, “halfLength”);
validateNonnegative(halfLength, “half length”);

double xs = scaleX(x);
double ys = scaleY(y);
double ws = factorX(2*halfLength);
double hs = factorY(2*halfLength);
if (ws <= 1 && hs <= 1) pixel(x, y); else offscreen.fill(new Rectangle2D.Double(xs - ws/2, ys - hs/2, ws, hs)); draw(); } /** * Draws a rectangle of the specified size, centered at (x, y).
*
* @param x the x-coordinate of the center of the rectangle
* @param y the y-coordinate of the center of the rectangle
* @param halfWidth one half the width of the rectangle
* @param halfHeight one half the height of the rectangle
* @throws IllegalArgumentException if either {@code halfWidth} or {@code halfHeight} is negative
* @throws IllegalArgumentException if any argument is either NaN or infinite
*/
public static void rectangle(double x, double y, double halfWidth, double halfHeight) {
validate(x, “x”);
validate(y, “y”);
validate(halfWidth, “halfWidth”);
validate(halfHeight, “halfHeight”);
validateNonnegative(halfWidth, “half width”);
validateNonnegative(halfHeight, “half height”);

double xs = scaleX(x);
double ys = scaleY(y);
double ws = factorX(2*halfWidth);
double hs = factorY(2*halfHeight);
if (ws <= 1 && hs <= 1) pixel(x, y); else offscreen.draw(new Rectangle2D.Double(xs - ws/2, ys - hs/2, ws, hs)); draw(); } /** * Draws a filled rectangle of the specified size, centered at (x, y).
*
* @param x the x-coordinate of the center of the rectangle
* @param y the y-coordinate of the center of the rectangle
* @param halfWidth one half the width of the rectangle
* @param halfHeight one half the height of the rectangle
* @throws IllegalArgumentException if either {@code halfWidth} or {@code halfHeight} is negative
* @throws IllegalArgumentException if any argument is either NaN or infinite
*/
public static void filledRectangle(double x, double y, double halfWidth, double halfHeight) {
validate(x, “x”);
validate(y, “y”);
validate(halfWidth, “halfWidth”);
validate(halfHeight, “halfHeight”);
validateNonnegative(halfWidth, “half width”);
validateNonnegative(halfHeight, “half height”);

double xs = scaleX(x);
double ys = scaleY(y);
double ws = factorX(2*halfWidth);
double hs = factorY(2*halfHeight);
if (ws <= 1 && hs <= 1) pixel(x, y); else offscreen.fill(new Rectangle2D.Double(xs - ws/2, ys - hs/2, ws, hs)); draw(); } /** * Draws a polygon with the vertices * (x0, y0),
* (x1, y1), …,
* (xn–1, yn–1).
*
* @param x an array of all the x-coordinates of the polygon
* @param y an array of all the y-coordinates of the polygon
* @throws IllegalArgumentException unless {@code x[]} and {@code y[]}
* are of the same length
* @throws IllegalArgumentException if any coordinate is either NaN or infinite
* @throws IllegalArgumentException if either {@code x[]} or {@code y[]} is {@code null}
*/
public static void polygon(double[] x, double[] y) {
validateNotNull(x, “x-coordinate array”);
validateNotNull(y, “y-coordinate array”);
for (int i = 0; i < x.length; i++) validate(x[i], "x[" + i + "]"); for (int i = 0; i < y.length; i++) validate(y[i], "y[" + i + "]"); int n1 = x.length; int n2 = y.length; if (n1 != n2) throw new IllegalArgumentException("arrays must be of the same length"); int n = n1; if (n == 0) return; GeneralPath path = new GeneralPath(); path.moveTo((float) scaleX(x[0]), (float) scaleY(y[0])); for (int i = 0; i < n; i++) path.lineTo((float) scaleX(x[i]), (float) scaleY(y[i])); path.closePath(); offscreen.draw(path); draw(); } /** * Draws a filled polygon with the vertices * (x0, y0),
* (x1, y1), …,
* (xn–1, yn–1).
*
* @param x an array of all the x-coordinates of the polygon
* @param y an array of all the y-coordinates of the polygon
* @throws IllegalArgumentException unless {@code x[]} and {@code y[]}
* are of the same length
* @throws IllegalArgumentException if any coordinate is either NaN or infinite
* @throws IllegalArgumentException if either {@code x[]} or {@code y[]} is {@code null}
*/
public static void filledPolygon(double[] x, double[] y) {
validateNotNull(x, “x-coordinate array”);
validateNotNull(y, “y-coordinate array”);
for (int i = 0; i < x.length; i++) validate(x[i], "x[" + i + "]"); for (int i = 0; i < y.length; i++) validate(y[i], "y[" + i + "]"); int n1 = x.length; int n2 = y.length; if (n1 != n2) throw new IllegalArgumentException("arrays must be of the same length"); int n = n1; if (n == 0) return; GeneralPath path = new GeneralPath(); path.moveTo((float) scaleX(x[0]), (float) scaleY(y[0])); for (int i = 0; i < n; i++) path.lineTo((float) scaleX(x[i]), (float) scaleY(y[i])); path.closePath(); offscreen.fill(path); draw(); } /*************************************************************************** * Drawing images. ***************************************************************************/ // get an image from the given filename private static Image getImage(String filename) { if (filename == null) throw new IllegalArgumentException(); // to read from file ImageIcon icon = new ImageIcon(filename); // try to read from URL if ((icon == null) || (icon.getImageLoadStatus() != MediaTracker.COMPLETE)) { try { URL url = new URL(filename); icon = new ImageIcon(url); } catch (MalformedURLException e) { /* not a url */ } } // in case file is inside a .jar (classpath relative to StdDraw) if ((icon == null) || (icon.getImageLoadStatus() != MediaTracker.COMPLETE)) { URL url = StdDraw.class.getResource(filename); if (url != null) icon = new ImageIcon(url); } // in case file is inside a .jar (classpath relative to root of jar) if ((icon == null) || (icon.getImageLoadStatus() != MediaTracker.COMPLETE)) { URL url = StdDraw.class.getResource("/" + filename); if (url == null) throw new IllegalArgumentException("image " + filename + " not found"); icon = new ImageIcon(url); } return icon.getImage(); } /*************************************************************************** * [Summer 2016] Should we update to use ImageIO instead of ImageIcon()? * Seems to have some issues loading images on some systems * and slows things down on other systems. * especially if you don't call ImageIO.setUseCache(false) * One advantage is that it returns a BufferedImage. ***************************************************************************/ /* private static BufferedImage getImage(String filename) { if (filename == null) throw new IllegalArgumentException(); // from a file or URL try { URL url = new URL(filename); BufferedImage image = ImageIO.read(url); return image; } catch (IOException e) { // ignore } // in case file is inside a .jar (classpath relative to StdDraw) try { URL url = StdDraw.class.getResource(filename); BufferedImage image = ImageIO.read(url); return image; } catch (IOException e) { // ignore } // in case file is inside a .jar (classpath relative to root of jar) try { URL url = StdDraw.class.getResource("/" + filename); BufferedImage image = ImageIO.read(url); return image; } catch (IOException e) { // ignore } throw new IllegalArgumentException("image " + filename + " not found"); } */ /** * Draws the specified image centered at (x, y).
* The supported image formats are JPEG, PNG, and GIF.
* As an optimization, the picture is cached, so there is no performance
* penalty for redrawing the same image multiple times (e.g., in an animation).
* However, if you change the picture file after drawing it, subsequent
* calls will draw the original picture.
*
* @param x the center x-coordinate of the image
* @param y the center y-coordinate of the image
* @param filename the name of the image/picture, e.g., “ball.gif”
* @throws IllegalArgumentException if the image filename is invalid
* @throws IllegalArgumentException if either {@code x} or {@code y} is either NaN or infinite
*/
public static void picture(double x, double y, String filename) {
validate(x, “x”);
validate(y, “y”);
validateNotNull(filename, “filename”);

// BufferedImage image = getImage(filename);
Image image = getImage(filename);
double xs = scaleX(x);
double ys = scaleY(y);
// int ws = image.getWidth(); // can call only if image is a BufferedImage
// int hs = image.getHeight();
int ws = image.getWidth(null);
int hs = image.getHeight(null);
if (ws < 0 || hs < 0) throw new IllegalArgumentException("image " + filename + " is corrupt"); offscreen.drawImage(image, (int) Math.round(xs - ws/2.0), (int) Math.round(ys - hs/2.0), null); draw(); } /** * Draws the specified image centered at (x, y),
* rotated given number of degrees.
* The supported image formats are JPEG, PNG, and GIF.
*
* @param x the center x-coordinate of the image
* @param y the center y-coordinate of the image
* @param filename the name of the image/picture, e.g., “ball.gif”
* @param degrees is the number of degrees to rotate counterclockwise
* @throws IllegalArgumentException if the image filename is invalid
* @throws IllegalArgumentException if {@code x}, {@code y}, {@code degrees} is NaN or infinite
* @throws IllegalArgumentException if {@code filename} is {@code null}
*/
public static void picture(double x, double y, String filename, double degrees) {
validate(x, “x”);
validate(y, “y”);
validate(degrees, “degrees”);
validateNotNull(filename, “filename”);

// BufferedImage image = getImage(filename);
Image image = getImage(filename);
double xs = scaleX(x);
double ys = scaleY(y);
// int ws = image.getWidth(); // can call only if image is a BufferedImage
// int hs = image.getHeight();
int ws = image.getWidth(null);
int hs = image.getHeight(null);
if (ws < 0 || hs < 0) throw new IllegalArgumentException("image " + filename + " is corrupt"); offscreen.rotate(Math.toRadians(-degrees), xs, ys); offscreen.drawImage(image, (int) Math.round(xs - ws/2.0), (int) Math.round(ys - hs/2.0), null); offscreen.rotate(Math.toRadians(+degrees), xs, ys); draw(); } /** * Draws the specified image centered at (x, y),
* rescaled to the specified bounding box.
* The supported image formats are JPEG, PNG, and GIF.
*
* @param x the center x-coordinate of the image
* @param y the center y-coordinate of the image
* @param filename the name of the image/picture, e.g., “ball.gif”
* @param scaledWidth the width of the scaled image (in screen coordinates)
* @param scaledHeight the height of the scaled image (in screen coordinates)
* @throws IllegalArgumentException if either {@code scaledWidth}
* or {@code scaledHeight} is negative
* @throws IllegalArgumentException if the image filename is invalid
* @throws IllegalArgumentException if {@code x} or {@code y} is either NaN or infinite
* @throws IllegalArgumentException if {@code filename} is {@code null}
*/
public static void picture(double x, double y, String filename, double scaledWidth, double scaledHeight) {
validate(x, “x”);
validate(y, “y”);
validate(scaledWidth, “scaled width”);
validate(scaledHeight, “scaled height”);
validateNotNull(filename, “filename”);
validateNonnegative(scaledWidth, “scaled width”);
validateNonnegative(scaledHeight, “scaled height”);

Image image = getImage(filename);
double xs = scaleX(x);
double ys = scaleY(y);
double ws = factorX(scaledWidth);
double hs = factorY(scaledHeight);
if (ws < 0 || hs < 0) throw new IllegalArgumentException("image " + filename + " is corrupt"); if (ws <= 1 && hs <= 1) pixel(x, y); else { offscreen.drawImage(image, (int) Math.round(xs - ws/2.0), (int) Math.round(ys - hs/2.0), (int) Math.round(ws), (int) Math.round(hs), null); } draw(); } /** * Draws the specified image centered at (x, y), rotated
* given number of degrees, and rescaled to the specified bounding box.
* The supported image formats are JPEG, PNG, and GIF.
*
* @param x the center x-coordinate of the image
* @param y the center y-coordinate of the image
* @param filename the name of the image/picture, e.g., “ball.gif”
* @param scaledWidth the width of the scaled image (in screen coordinates)
* @param scaledHeight the height of the scaled image (in screen coordinates)
* @param degrees is the number of degrees to rotate counterclockwise
* @throws IllegalArgumentException if either {@code scaledWidth}
* or {@code scaledHeight} is negative
* @throws IllegalArgumentException if the image filename is invalid
*/
public static void picture(double x, double y, String filename, double scaledWidth, double scaledHeight, double degrees) {
validate(x, “x”);
validate(y, “y”);
validate(scaledWidth, “scaled width”);
validate(scaledHeight, “scaled height”);
validate(degrees, “degrees”);
validateNotNull(filename, “filename”);
validateNonnegative(scaledWidth, “scaled width”);
validateNonnegative(scaledHeight, “scaled height”);

Image image = getImage(filename);
double xs = scaleX(x);
double ys = scaleY(y);
double ws = factorX(scaledWidth);
double hs = factorY(scaledHeight);
if (ws < 0 || hs < 0) throw new IllegalArgumentException("image " + filename + " is corrupt"); if (ws <= 1 && hs <= 1) pixel(x, y); offscreen.rotate(Math.toRadians(-degrees), xs, ys); offscreen.drawImage(image, (int) Math.round(xs - ws/2.0), (int) Math.round(ys - hs/2.0), (int) Math.round(ws), (int) Math.round(hs), null); offscreen.rotate(Math.toRadians(+degrees), xs, ys); draw(); } /*************************************************************************** * Drawing text. ***************************************************************************/ /** * Writes the given text string in the current font, centered at (x, y).
*
* @param x the center x-coordinate of the text
* @param y the center y-coordinate of the text
* @param text the text to write
* @throws IllegalArgumentException if {@code text} is {@code null}
* @throws IllegalArgumentException if {@code x} or {@code y} is either NaN or infinite
*/
public static void text(double x, double y, String text) {
validate(x, “x”);
validate(y, “y”);
validateNotNull(text, “text”);

offscreen.setFont(font);
FontMetrics metrics = offscreen.getFontMetrics();
double xs = scaleX(x);
double ys = scaleY(y);
int ws = metrics.stringWidth(text);
int hs = metrics.getDescent();
offscreen.drawString(text, (float) (xs – ws/2.0), (float) (ys + hs));
draw();
}

/**
* Writes the given text string in the current font, centered at (x, y) and
* rotated by the specified number of degrees.
* @param x the center x-coordinate of the text
* @param y the center y-coordinate of the text
* @param text the text to write
* @param degrees is the number of degrees to rotate counterclockwise
* @throws IllegalArgumentException if {@code text} is {@code null}
* @throws IllegalArgumentException if {@code x}, {@code y}, or {@code degrees} is either NaN or infinite
*/
public static void text(double x, double y, String text, double degrees) {
validate(x, “x”);
validate(y, “y”);
validate(degrees, “degrees”);
validateNotNull(text, “text”);

double xs = scaleX(x);
double ys = scaleY(y);
offscreen.rotate(Math.toRadians(-degrees), xs, ys);
text(x, y, text);
offscreen.rotate(Math.toRadians(+degrees), xs, ys);
}

/**
* Writes the given text string in the current font, left-aligned at (x, y).
* @param x the x-coordinate of the text
* @param y the y-coordinate of the text
* @param text the text
* @throws IllegalArgumentException if {@code text} is {@code null}
* @throws IllegalArgumentException if {@code x} or {@code y} is either NaN or infinite
*/
public static void textLeft(double x, double y, String text) {
validate(x, “x”);
validate(y, “y”);
validateNotNull(text, “text”);

offscreen.setFont(font);
FontMetrics metrics = offscreen.getFontMetrics();
double xs = scaleX(x);
double ys = scaleY(y);
int hs = metrics.getDescent();
offscreen.drawString(text, (float) xs, (float) (ys + hs));
draw();
}

/**
* Writes the given text string in the current font, right-aligned at (x, y).
*
* @param x the x-coordinate of the text
* @param y the y-coordinate of the text
* @param text the text to write
* @throws IllegalArgumentException if {@code text} is {@code null}
* @throws IllegalArgumentException if {@code x} or {@code y} is either NaN or infinite
*/
public static void textRight(double x, double y, String text) {
validate(x, “x”);
validate(y, “y”);
validateNotNull(text, “text”);

offscreen.setFont(font);
FontMetrics metrics = offscreen.getFontMetrics();
double xs = scaleX(x);
double ys = scaleY(y);
int ws = metrics.stringWidth(text);
int hs = metrics.getDescent();
offscreen.drawString(text, (float) (xs – ws), (float) (ys + hs));
draw();
}

/**
* Copies the offscreen buffer to the onscreen buffer, pauses for t milliseconds
* and enables double buffering.
* @param t number of milliseconds
* @deprecated replaced by {@link #enableDoubleBuffering()}, {@link #show()}, and {@link #pause(int t)}
*/
@Deprecated
public static void show(int t) {
validateNonnegative(t, “t”);
show();
pause(t);
enableDoubleBuffering();
}

/**
* Pauses for t milliseconds. This method is intended to support computer animations.
* @param t number of milliseconds
*/
public static void pause(int t) {
validateNonnegative(t, “t”);
try {
Thread.sleep(t);
}
catch (InterruptedException e) {
System.out.println(“Error sleeping”);
}
}

/**
* Copies offscreen buffer to onscreen buffer. There is no reason to call
* this method unless double buffering is enabled.
*/
public static void show() {
onscreen.drawImage(offscreenImage, 0, 0, null);
frame.repaint();
}

// draw onscreen if defer is false
private static void draw() {
if (!defer) show();
}

/**
* Enables double buffering. All subsequent calls to
* drawing methods such as {@code line()}, {@code circle()},
* and {@code square()} will be deferred until the next call
* to show(). Useful for animations.
*/
public static void enableDoubleBuffering() {
defer = true;
}

/**
* Disables double buffering. All subsequent calls to
* drawing methods such as {@code line()}, {@code circle()},
* and {@code square()} will be displayed on screen when called.
* This is the default.
*/
public static void disableDoubleBuffering() {
defer = false;
}

/***************************************************************************
* Save drawing to a file.
***************************************************************************/

/**
* Saves the drawing to using the specified filename.
* The supported image formats are JPEG and PNG;
* the filename suffix must be {@code .jpg} or {@code .png}.
*
* @param filename the name of the file with one of the required suffixes
* @throws IllegalArgumentException if {@code filename} is {@code null}
*/
public static void save(String filename) {
validateNotNull(filename, “filename”);
File file = new File(filename);
String suffix = filename.substring(filename.lastIndexOf(‘.’) + 1);

// png files
if (“png”.equalsIgnoreCase(suffix)) {
try {
ImageIO.write(onscreenImage, suffix, file);
}
catch (IOException e) {
e.printStackTrace();
}
}

// need to change from ARGB to RGB for JPEG
// reference: http://archives.java.sun.com/cgi-bin/wa?A2=ind0404&L=java2d-interest&D=0&P=2727
else if (“jpg”.equalsIgnoreCase(suffix)) {
WritableRaster raster = onscreenImage.getRaster();
WritableRaster newRaster;
newRaster = raster.createWritableChild(0, 0, width, height, 0, 0, new int[] {0, 1, 2});
DirectColorModel cm = (DirectColorModel) onscreenImage.getColorModel();
DirectColorModel newCM = new DirectColorModel(cm.getPixelSize(),
cm.getRedMask(),
cm.getGreenMask(),
cm.getBlueMask());
BufferedImage rgbBuffer = new BufferedImage(newCM, newRaster, false, null);
try {
ImageIO.write(rgbBuffer, suffix, file);
}
catch (IOException e) {
e.printStackTrace();
}
}

else {
System.out.println(“Invalid image file type: ” + suffix);
}
}

/**
* This method cannot be called directly.
*/
@Override
public void actionPerformed(ActionEvent e) {
FileDialog chooser = new FileDialog(StdDraw.frame, “Use a .png or .jpg extension”, FileDialog.SAVE);
chooser.setVisible(true);
String filename = chooser.getFile();
if (filename != null) {
StdDraw.save(chooser.getDirectory() + File.separator + chooser.getFile());
}
}

/***************************************************************************
* Mouse interactions.
***************************************************************************/

/**
* Returns true if the mouse is being pressed.
*
* @return {@code true} if the mouse is being pressed; {@code false} otherwise
*/
public static boolean isMousePressed() {
synchronized (mouseLock) {
return isMousePressed;
}
}

/**
* Returns true if the mouse is being pressed.
*
* @return {@code true} if the mouse is being pressed; {@code false} otherwise
* @deprecated replaced by {@link #isMousePressed()}
*/
@Deprecated
public static boolean mousePressed() {
synchronized (mouseLock) {
return isMousePressed;
}
}

/**
* Returns the x-coordinate of the mouse.
*
* @return the x-coordinate of the mouse
*/
public static double mouseX() {
synchronized (mouseLock) {
return mouseX;
}
}

/**
* Returns the y-coordinate of the mouse.
*
* @return y-coordinate of the mouse
*/
public static double mouseY() {
synchronized (mouseLock) {
return mouseY;
}
}

/**
* This method cannot be called directly.
*/
@Override
public void mouseClicked(MouseEvent e) {
// this body is intentionally left empty
}

/**
* This method cannot be called directly.
*/
@Override
public void mouseEntered(MouseEvent e) {
// this body is intentionally left empty
}

/**
* This method cannot be called directly.
*/
@Override
public void mouseExited(MouseEvent e) {
// this body is intentionally left empty
}

/**
* This method cannot be called directly.
*/
@Override
public void mousePressed(MouseEvent e) {
synchronized (mouseLock) {
mouseX = StdDraw.userX(e.getX());
mouseY = StdDraw.userY(e.getY());
isMousePressed = true;
}
}

/**
* This method cannot be called directly.
*/
@Override
public void mouseReleased(MouseEvent e) {
synchronized (mouseLock) {
isMousePressed = false;
}
}

/**
* This method cannot be called directly.
*/
@Override
public void mouseDragged(MouseEvent e) {
synchronized (mouseLock) {
mouseX = StdDraw.userX(e.getX());
mouseY = StdDraw.userY(e.getY());
}
}

/**
* This method cannot be called directly.
*/
@Override
public void mouseMoved(MouseEvent e) {
synchronized (mouseLock) {
mouseX = StdDraw.userX(e.getX());
mouseY = StdDraw.userY(e.getY());
}
}

/***************************************************************************
* Keyboard interactions.
***************************************************************************/

/**
* Returns true if the user has typed a key (that has not yet been processed).
*
* @return {@code true} if the user has typed a key (that has not yet been processed
* by {@link #nextKeyTyped()}; {@code false} otherwise
*/
public static boolean hasNextKeyTyped() {
synchronized (keyLock) {
return !keysTyped.isEmpty();
}
}

/**
* Returns the next key that was typed by the user (that your program has not already processed).
* This method should be preceded by a call to {@link #hasNextKeyTyped()} to ensure
* that there is a next key to process.
* This method returns a Unicode character corresponding to the key
* typed (such as {@code ‘a’} or {@code ‘A’}).
* It cannot identify action keys (such as F1 and arrow keys)
* or modifier keys (such as control).
*
* @return the next key typed by the user (that your program has not already processed).
* @throws NoSuchElementException if there is no remaining key
*/
public static char nextKeyTyped() {
synchronized (keyLock) {
if (keysTyped.isEmpty()) {
throw new NoSuchElementException(“your program has already processed all keystrokes”);
}
return keysTyped.remove(keysTyped.size() – 1);
// return keysTyped.removeLast();
}
}

/**
* Returns true if the given key is being pressed.
*

* This method takes the keycode (corresponding to a physical key)
* as an argument. It can handle action keys
* (such as F1 and arrow keys) and modifier keys (such as shift and control).
* See {@link KeyEvent} for a description of key codes.
*
* @param keycode the key to check if it is being pressed
* @return {@code true} if {@code keycode} is currently being pressed;
* {@code false} otherwise
*/
public static boolean isKeyPressed(int keycode) {
synchronized (keyLock) {
return keysDown.contains(keycode);
}
}

/**
* This method cannot be called directly.
*/
@Override
public void keyTyped(KeyEvent e) {
synchronized (keyLock) {
keysTyped.addFirst(e.getKeyChar());
}
}

/**
* This method cannot be called directly.
*/
@Override
public void keyPressed(KeyEvent e) {
synchronized (keyLock) {
keysDown.add(e.getKeyCode());
}
}

/**
* This method cannot be called directly.
*/
@Override
public void keyReleased(KeyEvent e) {
synchronized (keyLock) {
keysDown.remove(e.getKeyCode());
}
}

/***************************************************************************
* For improved resolution on Mac Retina displays.
***************************************************************************/

private static class RetinaImageIcon extends ImageIcon {

public RetinaImageIcon(Image image) {
super(image);
}

public int getIconWidth() {
return super.getIconWidth() / 2;
}

/**
* Gets the height of the icon.
*
* @return the height in pixels of this icon
*/
public int getIconHeight() {
return super.getIconHeight() / 2;
}

public synchronized void paintIcon(Component c, Graphics g, int x, int y) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,RenderingHints.VALUE_INTERPOLATION_BICUBIC);
g2.setRenderingHint(RenderingHints.KEY_RENDERING,RenderingHints.VALUE_RENDER_QUALITY);
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
g2.scale(0.5, 0.5);
super.paintIcon(c, g2, x * 2, y * 2);
g2.dispose();
}
}

/**
* Test client.
*
* @param args the command-line arguments
*/
public static void main(String[] args) {
StdDraw.square(0.2, 0.8, 0.1);
StdDraw.filledSquare(0.8, 0.8, 0.2);
StdDraw.circle(0.8, 0.2, 0.2);

StdDraw.setPenColor(StdDraw.BOOK_RED);
StdDraw.setPenRadius(0.02);
StdDraw.arc(0.8, 0.2, 0.1, 200, 45);

// draw a blue diamond
StdDraw.setPenRadius();
StdDraw.setPenColor(StdDraw.BOOK_BLUE);
double[] x = { 0.1, 0.2, 0.3, 0.2 };
double[] y = { 0.2, 0.3, 0.2, 0.1 };
StdDraw.filledPolygon(x, y);

// text
StdDraw.setPenColor(StdDraw.BLACK);
StdDraw.text(0.2, 0.5, “black text”);
StdDraw.setPenColor(StdDraw.WHITE);
StdDraw.text(0.8, 0.8, “white text”);
}

}