first commit

2024-01-15 20:14:10 +00:00
commit 8c81ee28b7
3106 changed files with 474415 additions and 0 deletions
--- a/1/Java/examples/picture/Circle.java
+++ b/1/Java/examples/picture/Circle.java
@@ -0,0 +1,192 @@
+import java.awt.*;
+import java.awt.geom.*;
+
+/**
+ * A circle that can be manipulated and that draws itself on a canvas.
+ * 
+ * @author	Michael Kolling and David J. Barnes
+ * @version 1.0  (15 July 2000)
+ */
+
+public class Circle
+{
+    private int diameter;
+	private int xPosition;
+	private int yPosition;
+	private String color;
+	private boolean isVisible;
+	
+    /**
+     * Create a new circle at default position with default color.
+     */
+    public Circle()
+    {
+		diameter = 30;
+		xPosition = 20;
+		yPosition = 60;
+		color = "blue";
+		isVisible = false;
+    }
+
+	/**
+	 * Make this circle visible. If it was already visible, do nothing.
+	 */
+	public void makeVisible()
+	{
+		isVisible = true;
+		draw();
+	}
+	
+	/**
+	 * Make this circle invisible. If it was already invisible, do nothing.
+	 */
+	public void makeInvisible()
+	{
+		erase();
+		isVisible = false;
+	}
+	
+    /**
+     * Move the circle a few pixels to the right.
+     */
+    public void moveRight()
+    {
+		moveHorizontal(20);
+    }
+
+    /**
+     * Move the circle a few pixels to the left.
+     */
+    public void moveLeft()
+    {
+		moveHorizontal(-20);
+    }
+
+    /**
+     * Move the circle a few pixels up.
+     */
+    public void moveUp()
+    {
+		moveVertical(-20);
+    }
+
+    /**
+     * Move the circle a few pixels down.
+     */
+    public void moveDown()
+    {
+		moveVertical(20);
+    }
+
+    /**
+     * Move the circle horizontally by 'distance' pixels.
+     */
+    public void moveHorizontal(int distance)
+    {
+		erase();
+		xPosition += distance;
+		draw();
+    }
+
+    /**
+     * Move the circle vertically by 'distance' pixels.
+     */
+    public void moveVertical(int distance)
+    {
+		erase();
+		yPosition += distance;
+		draw();
+    }
+
+    /**
+     * Slowly move the circle horizontally by 'distance' pixels.
+     */
+    public void slowMoveHorizontal(int distance)
+    {
+		int delta;
+
+		if(distance < 0) 
+		{
+			delta = -1;
+			distance = -distance;
+		}
+		else 
+		{
+			delta = 1;
+		}
+
+		for(int i = 0; i < distance; i++)
+		{
+			xPosition += delta;
+			draw();
+		}
+    }
+
+    /**
+     * Slowly move the circle vertically by 'distance' pixels.
+     */
+    public void slowMoveVertical(int distance)
+    {
+		int delta;
+
+		if(distance < 0) 
+		{
+			delta = -1;
+			distance = -distance;
+		}
+		else 
+		{
+			delta = 1;
+		}
+
+		for(int i = 0; i < distance; i++)
+		{
+			yPosition += delta;
+			draw();
+		}
+    }
+
+    /**
+     * Change the size to the new size (in pixels). Size must be >= 0.
+     */
+    public void changeSize(int newDiameter)
+    {
+		erase();
+		diameter = newDiameter;
+		draw();
+    }
+
+    /**
+     * Change the color. Valid colors are "red", "yellow", "blue", "green",
+	 * "magenta" and "black".
+     */
+    public void changeColor(String newColor)
+    {
+		color = newColor;
+		draw();
+    }
+
+	/*
+	 * Draw the circle with current specifications on screen.
+	 */
+	private void draw()
+	{
+		if(isVisible) {
+			Canvas canvas = Canvas.getCanvas();
+			canvas.draw(this, color, new Ellipse2D.Double(xPosition, yPosition, 
+														  diameter, diameter));
+			canvas.wait(10);
+		}
+	}
+
+	/*
+	 * Erase the circle on screen.
+	 */
+	private void erase()
+	{
+		if(isVisible) {
+			Canvas canvas = Canvas.getCanvas();
+			canvas.erase(this);
+		}
+	}
+}