Chapter 18, Problem 18.19PE

Program Plan Intro

Sierpinski triangle

Program Plan:

• Import required packages.
• Declare a main class named “E19” which extends the “Application” class.
  • Declare required variables.
  • Declare a “start ()” method which overrides the “start ()” method in the “Application” class. Inside this method,
    • Create a triangle pane.
    • Create two buttons.
    • Create an hbox pane and align it to center. Add the buttons to the hbox pane.
    • Set the event handler for the buttons.
    • Create a border pane and align it to center.
    • Create a scene and place it on the stage.
    • Set the title as “Exercise18_19”.
    • Display the stage on the window using “primaryStage.show()” method.
    • Set the width and height property.
    • Set the event handler for the scene.
    • Check if the button is primary.
      • Set the order of the triangle.
    • Check if the button is secondary.
      • Set the order of the triangle.
    • Check if the button is up. If the condition is true then get and set the order by adding 1.
    • Check if the button is down. If the condition is true then get and set the order by subtracting 1.
    • Declare a class “SierpinskiTrianglePane”.
      • Declare a variable “order”.
      • Give function definition to get the order of the triangle.
        • Return the “order”.
      • Give function definition to set new order.
        • Check if the value of “order” is less than 0.
          • Assign 0 to the “order”.
        • Set the order.
        • Call the function “paint ()”.
      • Give the constructor for the class “SierpinskiTrianglePane”.
      • Give function definition for “paint ()”.
        • Create three points.
        • Clear the pane using “clear ()” function.
        • Call the function “displayTriangles ()”.
      • Give function definition for “displayTriangles ()”.
        • Check of the value of “order” is less than 0.
          • Return the statement.
        • Check if the value of “order” is equal to 0.
          • Create a polygon to draw a triangle.
          • Get the points for the triangle.
          • Set the color and stroke color.
          • Add the triangle to the pane.
        • Else,
          • Get the mid points for the three edges.
          • Call the function “displayTriangles ()” to display the triangles recursively.
  • Declare a main method using “public static main”.
    • Launch the method using “launch ()” method.