Ch 15 add new solutions

Author: HarryDulaney

ch_15/Exercise15_13.java

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+package ch_15;
+
+import javafx.application.Application;
+import javafx.scene.Scene;
+import javafx.scene.layout.Pane;
+import javafx.scene.paint.Color;
+import javafx.scene.shape.Rectangle;
+import javafx.scene.text.Text;
+import javafx.stage.Stage;
+
+/**
+ * *15.13 (Geometry: inside a rectangle?) Write a program that draws a fixed rectangle
+ * centered at (100, 60) with width 100 and height 40. Whenever the mouse is
+ * moved, display a message indicating whether the mouse point is inside the rectangle
+ * at the mouse point or outside of it, as shown in Figure 15.27b. To detect
+ * whether a point is inside a polygon, use the contains method defined in the
+ * Node class.
+ */
+public class Exercise15_13 extends Application {
+    static final double WIDTH = 400;
+    static final double HEIGHT = 150;
+    static double mouseX;
+    static double mouseY;
+
+    @Override
+    public void start(Stage primaryStage) throws Exception {
+        Pane pane = new Pane();
+        Rectangle rectangle = new Rectangle(100, 60, 100, 40);
+        rectangle.setFill(Color.TRANSPARENT);
+        rectangle.setStroke(Color.BLACK);
+
+        Text message = new Text(rectangle.getWidth() / 2, rectangle.getHeight() / 2, "");
+        pane.getChildren().add(rectangle);
+        pane.getChildren().add(message);
+        Scene scene = new Scene(pane, WIDTH, HEIGHT);
+
+        scene.setOnMouseMoved(mouseEvent -> {
+            mouseX = mouseEvent.getSceneX();
+            mouseY = mouseEvent.getSceneY();
+            if (isPointInRectangle(mouseX, mouseY, rectangle)) {
+                message.setText("Mouse point is inside the rectangle");
+            } else {
+                message.setText("Mouse point is outside the rectangle");
+            }
+            message.setX(mouseX);
+            message.setY(mouseY);
+        });
+
+        primaryStage.setTitle(getClass().getName());
+        primaryStage.setScene(scene);
+        primaryStage.show();
+    }
+
+    private boolean isPointInRectangle(double mouseX, double mouseY, Rectangle rectangle) {
+        return rectangle.contains(mouseX, mouseY);
+    }
+
+    public static void main(String[] args) {
+        launch(args);
+    }
+}

ch_15/Exercise15_14.java

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+package ch_15;
+
+import javafx.application.Application;
+import javafx.scene.Scene;
+import javafx.scene.layout.Pane;
+import javafx.scene.paint.Color;
+import javafx.scene.shape.Polygon;
+import javafx.scene.shape.Rectangle;
+import javafx.scene.text.Text;
+import javafx.stage.Stage;
+
+/**
+ * *15.14 (Geometry: inside a polygon?) Write a program that draws a fixed polygon
+ * with points at (40, 20), (70, 40), (60, 80), (45, 45), and (20, 60). Whenever the mouse is moved, display a message indicating whether the mouse
+ * point is inside the polygon at the mouse point or outside of it, as shown in
+ * Figure 15.27c. To detect whether a point is inside a polygon, use the contains
+ * method defined in the Node class.
+ */
+public class Exercise15_14 extends Application {
+    static final double WIDTH = 400;
+    static final double HEIGHT = 150;
+    static double mouseX;
+    static double mouseY;
+
+    @Override
+    public void start(Stage primaryStage) throws Exception {
+        Pane pane = new Pane();
+        Polygon polygon = new Polygon(40, 20, 70, 40, 60, 80, 45, 45, 20, 60);
+        polygon.setFill(Color.TRANSPARENT);
+        polygon.setStroke(Color.BLACK);
+
+
+        Text message = new Text(polygon.getStrokeWidth() / 2, polygon.getStrokeWidth() / 2, "");
+        pane.getChildren().add(polygon);
+        pane.getChildren().add(message);
+        Scene scene = new Scene(pane, WIDTH, HEIGHT);
+
+        scene.setOnMouseMoved(mouseEvent -> {
+            mouseX = mouseEvent.getSceneX();
+            mouseY = mouseEvent.getSceneY();
+            if (isPointInPolygon(mouseX, mouseY, polygon)) {
+                message.setText("Mouse point is inside the polygon");
+            } else {
+                message.setText("Mouse point is outside the polygon");
+            }
+            message.setX(mouseX);
+            message.setY(mouseY);
+        });
+
+        primaryStage.setTitle(getClass().getName());
+        primaryStage.setScene(scene);
+        primaryStage.show();
+    }
+
+    private boolean isPointInPolygon(double mouseX, double mouseY, Polygon polygon) {
+        return polygon.contains(mouseX, mouseY);
+    }
+
+    public static void main(String[] args) {
+        launch(args);
+    }
+}