Chapter 11, Problem 11PE

Program Plan Intro

Modified version of “RectangleComponent” class

Program plan:

• In a file “RectangleComponent.java”,
  • Create a package.
  • Import necessary default packages.
  • Create a class “RectangleComponent”,
    • Declare the necessary static variables.
    • Declare the “Rectangle” object.
    • Declare the necessary variables.
    • Define the constructor,
      • Create a rectangle.
      • Set the x, y positions to “1”.
    • Define the method “paintComponent()”,
      • Call the method “paintComponent()” of super class.
      • Create “Graphics2D” object.
      • Call the method “draw()”  to draw the rectangle.
    • Define a method “moveRectangle ()”,
      • Check whether the X position of rectangle is negative,
        • If it is true, set the value to “1”.
        • • Check whether the Y position of rectangle is negative,
            • If it is true, set the value to “1”.
          • Check whether the maximum X position of rectangle is greater than the width,
            • If it is true, set the value to “-1”.
          • Check whether the maximum Y position of rectangle is greater than the width,
            • If it is true, set the value to “-1”.
          • Call the method “translate()” to translate the rectangle.
          • Call the method “repaint()”.
• In a file “RectangleFrame.java”,
  • Create a package.
  • Import necessary packages.
  • Create a class “RectangleFrame”,
    • Declare the necessary static variables.
    • Declare the “RectangleComponent” object.
    • Create a class “TimerListener”,
      • Define the method “actionPerformed()” ,
        • Call the method “moveRectangle()”.
    • Define the constructor,
      • Create a rectangle.
      • Add the rectangle.
      • Set the size.
      • Create “ActionListener” object.
      • Set the delay, milliseconds between the timer ticks.
      • Call the method “start()” to start the timer.
• In a file “RectangleViewer.java”,
  • Create a package.
  • Import necessary package.
  • Create a class “RectangleViewer”,
    • Define the method “main()”,
      • Create object for “RectangleFrame”.
      • Set the title for the frame.
      • Set the operation for the frame.
      • Make the frame visible.