Separating Concerns in Turtle

Also created TurtleFrame

Author: jamesrcounts

src/main/java/org/teachingextensions/approvals/lite/util/WindowUtils.java

@@ -1,11 +1,9 @@
 package org.teachingextensions.approvals.lite.util;
 
-import java.awt.Dimension;
+import javax.swing.*;
+import java.awt.*;
 import java.awt.event.WindowAdapter;
 
-import javax.swing.JFrame;
-import javax.swing.JOptionPane;
-
 public class WindowUtils
 {
   public static void centerWindow(java.awt.Window window)
@@ -16,7 +14,6 @@ public static void centerWindow(java.awt.Window window)
     int dy = (int) w.getHeight();
     int x = (int) ((d.getWidth() - dx) / 2);
     int y = (int) ((d.getHeight() - dy) / 2);
-    MySystem.variable(" size (" + x + "," + y + "," + dx + "," + dy + ")");
     window.setBounds(x, y, dx, dy + 1);
   }
   public static void testFrame(JFrame frame)
@@ -55,4 +52,4 @@ public static void testFrame(JFrame frame, WindowAdapter... array)
     WindowUtils.centerWindow(frame);
     //frame.setVisible(true);
   }
-}
+}

src/main/java/org/teachingextensions/logo/Turtle.java

@@ -1,22 +1,22 @@
 package org.teachingextensions.logo;
 
-import java.awt.Color;
-import java.awt.Component;
-import java.awt.Point;
-import java.awt.image.BufferedImage;
-import java.util.ArrayList;
-import java.util.List;
-
-import javax.swing.JFrame;
-
 import org.teachingextensions.WindowUtils.ProgramWindow;
 import org.teachingextensions.WindowUtils.TurtlePanel;
 import org.teachingextensions.approvals.lite.util.ThreadLauncher;
 import org.teachingextensions.approvals.lite.util.lambda.Action0;
 import org.teachingextensions.approvals.lite.util.persistence.Saver;
 import org.teachingextensions.approvals.lite.util.persistence.SavingException;
 import org.teachingextensions.approvals.lite.writers.ComponentApprovalWriter;
+import org.teachingextensions.logo.utils.DeltaCalculator;
+import org.teachingextensions.logo.utils.InterfaceUtils.TurtleFrame;
 import org.teachingextensions.logo.utils.LineAndShapeUtils.LineSegment;
+import org.teachingextensions.logo.utils.AngleCalculator;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.image.BufferedImage;
+import java.util.ArrayList;
+import java.util.List;
 
 /**
  * <img src="https://lh5.googleusercontent.com/-B3Q59gpYW8o/T4tA2k_TYUI/AAAAAAAAAjo/WiqdoXjbkb0/s65/Tortoise.png" style="text-align: left" alt="A turtle drawing a line" >
@@ -29,32 +29,16 @@ public class Turtle
   private double              x               = 640 / 2;
   private double              y               = 480 / 2;
   private double              angleInDegrees  = 0;
-  private JFrame              frame;
-  public TurtlePanel          panel;
+  private TurtleFrame frame = new TurtleFrame();
+  public  TurtlePanel panel;
   private int                 speed           = 1;
   public List<LineSegment>    trail           = new ArrayList<LineSegment>();
   private Color               color           = Color.black;
   private int                 width           = 2;
   private boolean             penDown         = true;
   private boolean             hidden;
   private Animals             animal;
-  public static double getDeltaY(double i, double angleInDegrees2)
-  {
-    return -i * Math.cos(Math.toRadians(angleInDegrees2));
-  }
-  public static double getDeltaX(double i, double angleInDegrees2)
-  {
-    return i * Math.sin(Math.toRadians(angleInDegrees2));
-  }
-  public static double angleCalculator(int x1, int y1, int x2, int y2)
-  {
-    int delta_x = x1 - x2;
-    int delta_y = y1 - y2;
-    double theta_radians = Math.atan2(delta_y, delta_x);
-    double degrees = Math.toDegrees(theta_radians);
-    double degreesWith0North = degrees - 90;
-    return degreesWith0North;
-  }
+
   public BufferedImage getImage()
   {
     BufferedImage image = ComponentApprovalWriter.drawComponent(getPanel());
@@ -73,18 +57,18 @@ private Component getPanel()
   {
     if (panel == null)
     {
-      String title = "TKPJava Turtle";
       panel = new TurtlePanel();
       if (speed != TEST_SPEED)
       {
-        frame = new JFrame(title);
-        frame.getContentPane().add(panel);
-        ProgramWindow.createStandardFrame(frame);
+        this.frame.addContent(panel);
+        this.frame.setStandardLayout();
+
       }
       panel.setTurtle(this);
     }
     return panel;
   }
+
   public void setPanel(TurtlePanel panel)
   {
     this.panel = panel;
@@ -210,8 +194,9 @@ public void move(Number amount)
   }
   private void moveWithoutAnimation(Double save)
   {
-    x += getDeltaX(save, angleInDegrees);
-    y += getDeltaY(save, angleInDegrees);
+    DeltaCalculator calculator = new DeltaCalculator(this.angleInDegrees, save);
+    x += calculator.getX();
+    y += calculator.getY();
   }
   public LineSegment[] getTrail()
   {
@@ -291,7 +276,8 @@ public void call()
   }
   public void moveSynchronized(int x, int y)
   {
-    double angleOfWherePointIs = angleCalculator(getX(), getY(), x, y);
+    AngleCalculator calculator = new AngleCalculator(getX(), getY(), x, y);
+    double angleOfWherePointIs = calculator.getDegreesWith0North();
     double direction = angleOfWherePointIs - getAngleInDegrees();
     turn(direction);
     // move the turtle the distance to the x y point
@@ -400,14 +386,14 @@ public void drawLightning(int length)
   }
   public void setFrameVisible(boolean b)
   {
-    frame.setVisible(b);
+    this.frame.setVisible(b);
   }
   public void setPanelVisible(boolean b)
   {
     panel.setVisible(b);
   }
   public void setFrame(JFrame frame2)
   {
-    this.frame = frame2;
+    this.frame = new TurtleFrame(frame2);
   }
 }

src/main/java/org/teachingextensions/logo/utils/AngleCalculator.java

@@ -0,0 +1,26 @@
+package org.teachingextensions.logo.utils;
+
+public class AngleCalculator {
+
+  private final int x1;
+  private final int y1;
+  private final int x2;
+  private final int y2;
+
+  public AngleCalculator(int x1, int y1, int x2, int y2) {
+    this.x1 = x1;
+    this.y1 = y1;
+    this.x2 = x2;
+    this.y2 = y2;
+  }
+
+  public double getDegreesWith0North(){
+    int delta_x = this.x1 - this.x2;
+    int delta_y = this.y1 - this.y2;
+    double theta_radians = Math.atan2(delta_y, delta_x);
+    double degrees = Math.toDegrees(theta_radians);
+    return degrees - 90;
+  }
+
+}
+

src/main/java/org/teachingextensions/logo/utils/DeltaCalculator.java

@@ -0,0 +1,19 @@
+package org.teachingextensions.logo.utils;
+
+public class DeltaCalculator {
+  private final double angleInDegrees;
+  private final double size;
+
+  public DeltaCalculator(double angleInDegrees, double size) {
+    this.angleInDegrees = angleInDegrees;
+    this.size = size;
+  }
+
+  public double getX() {
+    return this.size * Math.sin(Math.toRadians(this.angleInDegrees));
+  }
+
+  public double getY() {
+    return -this.size * Math.cos(Math.toRadians(this.angleInDegrees));
+  }
+}

src/main/java/org/teachingextensions/logo/utils/InterfaceUtils/TurtleFrame.java

@@ -0,0 +1,71 @@
+package org.teachingextensions.logo.utils.InterfaceUtils;
+
+import org.teachingextensions.WindowUtils.ProgramWindow;
+
+import javax.swing.*;
+
+public class TurtleFrame {
+  public static final String TITLE = "TKPJava Turtle";
+  private LazyFrame frame;
+  private String    title;
+
+  public TurtleFrame(JFrame frame) {
+    if (frame == null) {
+      throw new IllegalArgumentException("frame must not be null when creating a TurtleFrame");
+    }
+
+    this.frame = new LazyFrame(frame);
+  }
+
+  public TurtleFrame(String title) {
+    if (title == null) {
+      title = TITLE;
+    }
+
+    this.frame = new LazyFrame(title);
+  }
+
+  public TurtleFrame() {
+    this(TITLE);
+  }
+
+  public TurtleFrame addContent(JComponent panel) {
+    this.frame.getValue().getContentPane().add(panel);
+    return this;
+  }
+
+  public TurtleFrame setVisible(boolean visible) {
+    this.frame.getValue().setVisible(visible);
+    return this;
+  }
+
+  public TurtleFrame setStandardLayout() {
+    ProgramWindow.createStandardFrame(this.frame.getValue());
+    return this;
+  }
+
+  private class LazyFrame {
+    private String title;
+    private JFrame frame;
+
+    public LazyFrame(String title) {
+      if (title == null) {
+        throw new IllegalArgumentException("title must not be null when creating a LazyFrame");
+      }
+
+      this.title = title;
+    }
+
+    public LazyFrame(JFrame frame) {
+      this.frame = frame;
+    }
+
+    public JFrame getValue() {
+      if (this.frame == null) {
+        this.frame = new JFrame(this.title);
+      }
+
+      return this.frame;
+    }
+  }
+}

src/test/java/org/teachingextensions/logo/MultiTurtlePanelTest.java

@@ -1,7 +1,5 @@
 package org.teachingextensions.logo;
 
-import static org.junit.Assert.assertEquals;
-
 import org.junit.Test;
 import org.teachingextensions.WindowUtils.MultiTurtleWindow;
 import org.teachingextensions.approvals.lite.Approvals;
@@ -10,6 +8,8 @@
 import org.teachingextensions.approvals.lite.reporters.UseReporter;
 import org.teachingextensions.approvals.lite.util.JUnitUtils;
 
+import static org.junit.Assert.assertEquals;
+
 @UseReporter({DiffReporter.class, DelayedClipboardReporter.class})
 public class MultiTurtlePanelTest
 {
@@ -20,14 +20,8 @@ public void testPaintNoTurtles()
     MultiTurtleWindow panel = new MultiTurtleWindow();
     Approvals.verify(panel);
   }
-  @Test
-  public void testPaintOneTurtle()
-  {
-    JUnitUtils.assumeNotHeadless();
-    MultiTurtleWindow panel = new MultiTurtleWindow();
-    panel.addTurtle(new Turtle());
-    Approvals.verify(panel);
-  }
+
+
   @Test
   public void testPaintWithGhostTurtle()
   {