Due Date: Friday April 9, midnight

Educational goals of this lab - verify that every student can

• write if statements
• understand while loops
• write some graphics
• get a mouse click
• write a boolean function

Preparation

• Using getMouse and Entry to interact with the user
• A program example of using getX and getY (from Lectures page)
• a program using getMouse on lectures page
• Hints about writing graphics programs on lectures page
• More hints about writing graphics programs on program assignments page

INSTRUCTIONS:

Description of the Problem:

• The problem is to implement a very small part of a Graphical User Interface. These usually have lots of buttons to click. They can have text on them or images. A button is really just a specified area of the graphics window. We'll use Rectangles for them. The user clicks anywhere in the window and the program gets the Point they clicked on with the getMouse method. The Point can be tested to see if it is in the bounds of the Rectangle. If it is, the user clicked the button, otherwise not.

  Use a large button to make it easier to visualize. Use text on the buttons, because it's more portable than having a gif file included.

  To make it a little more interesting, count the clicks the user makes and display the counter on the window.

  Screenshots

  • Starting the program
  • After 3 clicks
  • About to close after clicking in box
  Testing Grid

  (10 points) Problem #1: A test plan

  • These cases describe what will be the general behavior of the program.

    Description	Input User Click	Expected behavior/output
    Area 1, Yes box	Click in area 1	Add one to click counter, update display of counter
    Areas 2-8, Yes box	Click in area 2 - 8	Add one to click counter, update display of counter
    Click in Yes box	Click inside Yes box	Leave the loop, display 'click to close'
    Click count is 1	Click inside Yes box immediately	Leave the loop, display 'click to close'

    These points are given when your program is tested by the grader

  (10 points) Problem #2: Design

  • Copy and paste this design into a python file. Answer the questions in the design so that it solves the problem and shows the control structures (loop and ifs) and what they are supposed to do.

    # Prolog including 3 P's and Author's name
    
    # prepare window, at least 500 by 500
    #   make 2 variables, x and y for the upper left corner of the Yes box (pick your locations as you like)
    #   make a variable for the size of the box (assume it is going to be square) (length of the side)
    #   create 2 Points, for the upper left and lower right corners of the Yes box 
    #     use the variables in the previous lines to calculate where the lower right point will be
    
    # draw a box using those two Points
    # make it a color (your choice)
    # Label it Yes.  The label should be centered in the box.
    #   HOW will you center it?
    # Give the user a message "Click anywhere, ending in the box".
    # Draw the message
    # Get and store the user's mouse click. It's a Point object!
    #   WHAT method will you use here?
    # Initialize a click counter and draw it
    
    # while the Point the user clicked is NOT in the box
    #   (You MUST call inbetween (below) in the condition of the while loop!)
    #    let the user click again
    #    add one to the click counter
    
    # tell the user to click to close
    # close the window and exit properly
    

  (40 points) Problem #3: Complete the program.

  • You need to construct Points for the corners of the box (Rectangle). Put these in separate variables and use them to construct the box. This makes it easier to test for inside or outside of the box later.
  • Use this function! It needs to be called 1 time in the program.

    def inbetween (pt1, pt2, pt3):
        '''
        Purpose:  detect whether a Point pt2 is between Points pt1 and pt3
           assumes that pt1 is to the left of pt3 (x of pt1 is <= x of pt3)
           and that pt1 is above pt3 (y of pt1 is <= y of pt3)
        Preconditions:  pt1 and pt3 are the boundary Points, forming a rectangle.
           pt2 is the Point which is being tested for "betweenness".
        Postconditions:
           returns True if the Point pt2 lies in the rectangle formed by pt1 and pt3.
              This includes pt2 being exactly ON one side of the rectangle.
           returns False if this is not true.  
        '''
        between = False
        if (pt1.getX() <= pt2.getX() <= pt3.getX()) and (pt1.getY() <= pt2.getY() <= pt3.getY()):
               between = True
        return between
    

  • Implement the program starting with the .py file you have written the design in. The design steps are the comments.
  • Run the test cases! Try clicking all around the box before you click in the box. Try clicking in the box immediately, the first click.
  • Submit your finished program with the Canvas link.