first commit

2024-01-15 20:14:10 +00:00
commit 8c81ee28b7
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--- a/1/Java/examples/projects/chapter06/scribble/Pen.java
+++ b/1/Java/examples/projects/chapter06/scribble/Pen.java
@@ -0,0 +1,148 @@
+import java.awt.Color;
+import java.util.Random;
+
+/**
+ * A pen can be used to draw on a canvas. The pen maintains a position, direction, color,
+ * and an up/down state. The pen can be moved across the canvas. If the pen is down, it 
+ * leaves a line on the canvas when moved. (If it is up, it will not draw a line.)
+ * 
+ * @author Michael Kölling & David J. Barnes
+ * @version 2016.02.29
+ */
+public class Pen
+{
+    // constants for randomSquiggle method
+    private static final int SQIGGLE_SIZE = 40;
+    private static final int SQIGGLE_COUNT = 30;
+    
+    private int xPosition;
+    private int yPosition;
+    private int rotation;
+    private Color color;
+    private boolean penDown;
+
+    private Canvas canvas;
+    private Random random;
+
+    /**
+     * Create a new Pen with its own canvas. The pen will create a new canvas for 
+     * itself to draw on, and start in the default state (centre of canvas, direction
+     * right, color black, pen down).
+     */
+    public Pen()
+    {
+        this (280, 220, new Canvas("My Canvas", 560, 440));
+    }
+
+    /**
+     * Create a new Pen for a given canvas. The direction is initially 0 (to the right),
+     * the color is black, and the pen is down.
+     *
+     * @param xPos  the initial horizontal coordinate of the pen
+     * @param yPos  the initial vertical coordinate of the pen
+     * @param drawingCanvas  the canvas to draw on
+     */
+    public Pen(int xPos, int yPos, Canvas drawingCanvas)
+    {
+        xPosition = xPos;
+        yPosition = yPos;
+        rotation = 0;
+        penDown = true;
+        color = Color.BLACK;
+        canvas = drawingCanvas;
+        random = new Random();
+    }
+
+    /**
+     * Move the specified distance in the current direction. If the pen is down, 
+     * leave a line on the canvas.
+     * 
+     * @param distance  The distance to move forward from the current location.
+     */
+    public void move(int distance)
+    {
+        double angle = Math.toRadians(rotation);
+        int newX = (int) Math.round(xPosition + Math.cos(angle) * distance);
+        int newY = (int) Math.round(yPosition + Math.sin(angle) * distance);
+        
+        moveTo(newX, newY);
+    }
+
+    /**
+     * Move to the specified location. If the pen is down, leave a line on the canvas.
+     * 
+     * @param x   The x-coordinate to move to.
+     * @param y   The y-coordinate to move to.
+     */
+    public void moveTo(int x, int y)
+    {
+        if (penDown) {
+            canvas.setForegroundColor(color);
+            canvas.drawLine(xPosition, yPosition, x, y);
+        }
+
+        xPosition = x;
+        yPosition = y;
+    }
+
+    /**
+     * Turn the specified amount (out of a 360 degree circle) clockwise from the current 
+     * rotation.
+     * 
+     * @param degrees  The amount of degrees to turn. (360 is a full circle.)
+     */
+    public void turn(int degrees)
+    {
+        rotation = rotation + degrees;
+    }
+
+    /**
+     * Turn to the specified direction. 0 is right, 90 is down, 180 is left, 270 is up.
+     * 
+     * @param angle  The angle to turn to.
+     */
+    public void turnTo(int angle)
+    {
+        rotation = angle;
+    }
+
+    /**
+     * Set the drawing color.
+     * 
+     * @param newColor  The color to use for subsequent drawing operations.
+     */
+    public void setColor(Color newColor)
+    {
+        color = newColor;
+    }
+
+    /**
+     * Lift the pen up. Moving afterwards will not leave a line on the canvas.
+     */
+    public void penUp()
+    {
+        penDown = false;
+    }
+
+    /**
+     * Put the pen down. Moving afterwards will leave a line on the canvas.
+     */
+    public void penDown()
+    {
+        penDown = true;
+    }
+
+    /**
+     * Scribble on the canvas in the current color. The size and complexity of the 
+     * squiggle produced is defined by the constants SQIGGLE_SIZE and SQIGGLE_COUNT.
+     */
+    public void randomSquiggle()
+    {
+        for (int i=0; i<SQIGGLE_COUNT; i++) {
+            move(random.nextInt(SQIGGLE_SIZE));
+            turn(160 + random.nextInt(40));
+        }
+
+    }
+
+}