All Documents

• dudraw
  index.html
  Package
  Package
  PUBLIC
  No package docstring; 2/2 modules documented
• dudraw.color
  dudraw.color.html
  ZopeInterfaceModule
  Module
  PUBLIC
  color.py
• dudraw.dudraw
  dudraw.dudraw.html
  ZopeInterfaceModule
  Module
  PUBLIC
  dudraw.py
• dudraw.color.Color
  dudraw.color.Color.html
  ZopeInterfaceClass
  Class
  PUBLIC
  A Color object models an RGB color.
• dudraw.color.Color.__init__
  dudraw.color.Color.html#__init__
  ZopeInterfaceFunction
  Method
  PUBLIC
  Construct self such that it has the given red (r), green (g), and blue (b) components.
• dudraw.color.Color._r
  dudraw.color.Color.html#_r
  ZopeInterfaceAttribute
  Instance Variable
  PRIVATE
  Undocumented
• dudraw.color.Color._g
  dudraw.color.Color.html#_g
  ZopeInterfaceAttribute
  Instance Variable
  PRIVATE
  Undocumented
• dudraw.color.Color._b
  dudraw.color.Color.html#_b
  ZopeInterfaceAttribute
  Instance Variable
  PRIVATE
  Undocumented
• dudraw.color.Color.get_red
  dudraw.color.Color.html#get_red
  ZopeInterfaceFunction
  Method
  PUBLIC
  Return the red component of self.
• dudraw.color.Color.get_green
  dudraw.color.Color.html#get_green
  ZopeInterfaceFunction
  Method
  PUBLIC
  Return the green component of self.
• dudraw.color.Color.get_blue
  dudraw.color.Color.html#get_blue
  ZopeInterfaceFunction
  Method
  PUBLIC
  Return the blue component of self.
• dudraw.color.Color.__str__
  dudraw.color.Color.html#__str__
  ZopeInterfaceFunction
  Method
  PUBLIC
  Return the string equivalent of self, that is, a string of the form '(r, g, b)'.
• dudraw.color.WHITE
  dudraw.color.html#WHITE
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.BLACK
  dudraw.color.html#BLACK
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.RED
  dudraw.color.html#RED
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.GREEN
  dudraw.color.html#GREEN
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.BLUE
  dudraw.color.html#BLUE
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.CYAN
  dudraw.color.html#CYAN
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.MAGENTA
  dudraw.color.html#MAGENTA
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.YELLOW
  dudraw.color.html#YELLOW
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.DARK_RED
  dudraw.color.html#DARK_RED
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.DARK_GREEN
  dudraw.color.html#DARK_GREEN
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.DARK_BLUE
  dudraw.color.html#DARK_BLUE
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.GRAY
  dudraw.color.html#GRAY
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.DARK_GRAY
  dudraw.color.html#DARK_GRAY
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.LIGHT_GRAY
  dudraw.color.html#LIGHT_GRAY
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.ORANGE
  dudraw.color.html#ORANGE
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.VIOLET
  dudraw.color.html#VIOLET
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.PINK
  dudraw.color.html#PINK
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.BOOK_BLUE
  dudraw.color.html#BOOK_BLUE
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.BOOK_LIGHT_BLUE
  dudraw.color.html#BOOK_LIGHT_BLUE
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color.BOOK_RED
  dudraw.color.html#BOOK_RED
  ZopeInterfaceAttribute
  Constant
  PUBLIC
  Undocumented
• dudraw.color._main
  dudraw.color.html#_main
  ZopeInterfaceFunction
  Function
  PRIVATE
  For testing:
• dudraw.dudraw._BORDER
  dudraw.dudraw.html#_BORDER
  ZopeInterfaceAttribute
  Constant
  PRIVATE
  Undocumented
• dudraw.dudraw._DEFAULT_XMIN
  dudraw.dudraw.html#_DEFAULT_XMIN
  ZopeInterfaceAttribute
  Constant
  PRIVATE
  Undocumented
• dudraw.dudraw._DEFAULT_XMAX
  dudraw.dudraw.html#_DEFAULT_XMAX
  ZopeInterfaceAttribute
  Constant
  PRIVATE
  Undocumented
• dudraw.dudraw._DEFAULT_YMIN
  dudraw.dudraw.html#_DEFAULT_YMIN
  ZopeInterfaceAttribute
  Constant
  PRIVATE
  Undocumented
• dudraw.dudraw._DEFAULT_YMAX
  dudraw.dudraw.html#_DEFAULT_YMAX
  ZopeInterfaceAttribute
  Constant
  PRIVATE
  Undocumented
• dudraw.dudraw._DEFAULT_CANVAS_SIZE
  dudraw.dudraw.html#_DEFAULT_CANVAS_SIZE
  ZopeInterfaceAttribute
  Constant
  PRIVATE
  Undocumented
• dudraw.dudraw._DEFAULT_PEN_WIDTH
  dudraw.dudraw.html#_DEFAULT_PEN_WIDTH
  ZopeInterfaceAttribute
  Constant
  PRIVATE
  Undocumented
• dudraw.dudraw._DEFAULT_FONT_FAMILY
  dudraw.dudraw.html#_DEFAULT_FONT_FAMILY
  ZopeInterfaceAttribute
  Constant
  PRIVATE
  Undocumented
• dudraw.dudraw._DEFAULT_FONT_SIZE
  dudraw.dudraw.html#_DEFAULT_FONT_SIZE
  ZopeInterfaceAttribute
  Constant
  PRIVATE
  Undocumented
• dudraw.dudraw._xmin
  dudraw.dudraw.html#_xmin
  ZopeInterfaceAttribute
  Variable
  PRIVATE
  Undocumented
• dudraw.dudraw._ymin
  dudraw.dudraw.html#_ymin
  ZopeInterfaceAttribute
  Variable
  PRIVATE
  Undocumented
• dudraw.dudraw._xmax
  dudraw.dudraw.html#_xmax
  ZopeInterfaceAttribute
  Variable
  PRIVATE
  Undocumented
• dudraw.dudraw._ymax
  dudraw.dudraw.html#_ymax
  ZopeInterfaceAttribute
  Variable
  PRIVATE
  Undocumented
• dudraw.dudraw._canvas_width
  dudraw.dudraw.html#_canvas_width
  ZopeInterfaceAttribute
  Variable
  PRIVATE
  Undocumented
• dudraw.dudraw._canvas_height
  dudraw.dudraw.html#_canvas_height
  ZopeInterfaceAttribute
  Variable
  PRIVATE
  Undocumented
• dudraw.dudraw._pen_width
  dudraw.dudraw.html#_pen_width
  ZopeInterfaceAttribute
  Variable
  PRIVATE
  Undocumented
• dudraw.dudraw._keys_typed
  dudraw.dudraw.html#_keys_typed
  ZopeInterfaceAttribute
  Variable
  PRIVATE
  Undocumented
• dudraw.dudraw._window_created
  dudraw.dudraw.html#_window_created
  ZopeInterfaceAttribute
  Variable
  PRIVATE
  Undocumented
• dudraw.dudraw._mouse_pressed
  dudraw.dudraw.html#_mouse_pressed
  ZopeInterfaceAttribute
  Variable
  PRIVATE
  Undocumented
• dudraw.dudraw._mouse_pos
  dudraw.dudraw.html#_mouse_pos
  ZopeInterfaceAttribute
  Variable
  PRIVATE
  Undocumented
• dudraw.dudraw._pygame_color
  dudraw.dudraw.html#_pygame_color
  ZopeInterfaceFunction
  Function
  PRIVATE
  Convert c, an object of type Color, to an equivalent object of type pygame.Color. Return the result.
• dudraw.dudraw._ccw
  dudraw.dudraw.html#_ccw
  ZopeInterfaceFunction
  Function
  PRIVATE
  Undocumented
• dudraw.dudraw._intersect
  dudraw.dudraw.html#_intersect
  ZopeInterfaceFunction
  Function
  PRIVATE
  Undocumented
• dudraw.dudraw._scale_x
  dudraw.dudraw.html#_scale_x
  ZopeInterfaceFunction
  Function
  PRIVATE
  Undocumented
• dudraw.dudraw._scale_y
  dudraw.dudraw.html#_scale_y
  ZopeInterfaceFunction
  Function
  PRIVATE
  Undocumented
• dudraw.dudraw._scale_point
  dudraw.dudraw.html#_scale_point
  ZopeInterfaceFunction
  Function
  PRIVATE
  Undocumented
• dudraw.dudraw._factor_x
  dudraw.dudraw.html#_factor_x
  ZopeInterfaceFunction
  Function
  PRIVATE
  Undocumented
• dudraw.dudraw._factor_y
  dudraw.dudraw.html#_factor_y
  ZopeInterfaceFunction
  Function
  PRIVATE
  Undocumented
• dudraw.dudraw._user_x
  dudraw.dudraw.html#_user_x
  ZopeInterfaceFunction
  Function
  PRIVATE
  Undocumented
• dudraw.dudraw._user_y
  dudraw.dudraw.html#_user_y
  ZopeInterfaceFunction
  Function
  PRIVATE
  Undocumented
• dudraw.dudraw._pen_width_pixels
  dudraw.dudraw.html#_pen_width_pixels
  ZopeInterfaceFunction
  Function
  PRIVATE
  Undocumented
• dudraw.dudraw._line_width_pixels
  dudraw.dudraw.html#_line_width_pixels
  ZopeInterfaceFunction
  Function
  PRIVATE
  Undocumented
• dudraw.dudraw.set_canvas_size
  dudraw.dudraw.html#set_canvas_size
  ZopeInterfaceFunction
  Function
  PUBLIC
  Set the size of the canvas to w pixels wide and h pixels high. Calling this function is optional. If you call it, you must do so before calling any drawing function.
• dudraw.dudraw.get_canvas_width
  dudraw.dudraw.html#get_canvas_width
  ZopeInterfaceFunction
  Function
  PUBLIC
  Return the width of the current canvas
• dudraw.dudraw.get_canvas_height
  dudraw.dudraw.html#get_canvas_height
  ZopeInterfaceFunction
  Function
  PUBLIC
  Return the height of the current canvas
• dudraw.dudraw.get_pixel_color
  dudraw.dudraw.html#get_pixel_color
  ZopeInterfaceFunction
  Function
  PUBLIC
  Return the color of the pixel at the given user coordinates
• dudraw.dudraw.set_x_scale
  dudraw.dudraw.html#set_x_scale
  ZopeInterfaceFunction
  Function
  PUBLIC
  Set the x-scale of the canvas such that the minimum x value is min and the maximum x value is max.
• dudraw.dudraw.set_y_scale
  dudraw.dudraw.html#set_y_scale
  ZopeInterfaceFunction
  Function
  PUBLIC
  Set the y-scale of the canvas such that the minimum y value is min and the maximum y value is max.
• dudraw.dudraw.set_scale 0
  dudraw.dudraw.html#set_scale%200
  ZopeInterfaceFunction
  Function
  PUBLIC
  Undocumented
• dudraw.dudraw.set_scale
  dudraw.dudraw.html#set_scale
  ZopeInterfaceFunction
  Function
  PUBLIC
  Undocumented
• dudraw.dudraw.set_pen_width
  dudraw.dudraw.html#set_pen_width
  ZopeInterfaceFunction
  Function
  PUBLIC
  Set the pen radius to r, thus affecting the subsequent drawing of points and lines. If r is 0.0, then points will be drawn with the minimum possible radius and lines with the minimum possible width.
• dudraw.dudraw.set_pen_color
  dudraw.dudraw.html#set_pen_color
  ZopeInterfaceFunction
  Function
  PUBLIC
  Set the pen color to c, where c is an object of class Color. c defaults to dudraw.BLACK.
• dudraw.dudraw.set_pen_color_rgb
  dudraw.dudraw.html#set_pen_color_rgb
  ZopeInterfaceFunction
  Function
  PUBLIC
  Set the pen color to c, where c is an object of class Color. c defaults to dudraw.BLACK.
• dudraw.dudraw.get_pen_color
  dudraw.dudraw.html#get_pen_color
  ZopeInterfaceFunction
  Function
  PUBLIC
  Returns the value of _penColor as an object of class Color.
• dudraw.dudraw.set_font_family
  dudraw.dudraw.html#set_font_family
  ZopeInterfaceFunction
  Function
  PUBLIC
  Set the font family to f (e.g. 'Helvetica' or 'Courier').
• dudraw.dudraw.set_font_size
  dudraw.dudraw.html#set_font_size
  ZopeInterfaceFunction
  Function
  PUBLIC
  Set the font size to s (e.g. 12 or 16).
• dudraw.dudraw._make_sure_window_created
  dudraw.dudraw.html#_make_sure_window_created
  ZopeInterfaceFunction
  Function
  PRIVATE
  Undocumented
• dudraw.dudraw._pixel
  dudraw.dudraw.html#_pixel
  ZopeInterfaceFunction
  Function
  PRIVATE
  Draw on the background canvas a pixel at (x, y).
• dudraw.dudraw.point
  dudraw.dudraw.html#point
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw on the background canvas a point at (x, y).
• dudraw.dudraw._thick_line
  dudraw.dudraw.html#_thick_line
  ZopeInterfaceFunction
  Function
  PRIVATE
  Draw on the background canvas a line from (x0, y0) to (x1, y1). Draw the line with a pen whose radius is r.
• dudraw.dudraw.line
  dudraw.dudraw.html#line
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw on the background canvas a line from (x0, y0) to (x1, y1).
• dudraw.dudraw.circle
  dudraw.dudraw.html#circle
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw on the background canvas a circle of radius r centered on (x, y).
• dudraw.dudraw.filled_circle
  dudraw.dudraw.html#filled_circle
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw on the background canvas a filled circle of radius r centered on (x, y).
• dudraw.dudraw.ellipse
  dudraw.dudraw.html#ellipse
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw on the background canvas an ellipse centered at (x, y) with a width of 2.0 * half_width, and a height of 2.0 * half_height.
• dudraw.dudraw.filled_ellipse
  dudraw.dudraw.html#filled_ellipse
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw on the background canvas a filled ellipse centered at (x, y) with a width of 2.0 * half_width, and a height of 2.0 * half_height.
• dudraw.dudraw.rectangle
  dudraw.dudraw.html#rectangle
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw on the background canvas a rectangle of width (2 * halfWidth and height (2 * halfHeight) centered at point (x, y).
• dudraw.dudraw.filled_rectangle
  dudraw.dudraw.html#filled_rectangle
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw on the background canvas a rectangle of width (2 * halfWidth and height (2 * halfHeight) centered at point (x, y).
• dudraw.dudraw.square
  dudraw.dudraw.html#square
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw on the background canvas a square whose sides are of length 2r, centered on (x, y).
• dudraw.dudraw.filled_square
  dudraw.dudraw.html#filled_square
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw on the background canvas a filled square whose sides are of length 2r, centered on (x, y).
• dudraw.dudraw.polyline
  dudraw.dudraw.html#polyline
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw on the background canvas a polyline with coordinates (x[i], y[i]).
• dudraw.dudraw.polygon
  dudraw.dudraw.html#polygon
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw on the background canvas a polygon with coordinates (x[i], y[i]).
• dudraw.dudraw.filled_polygon
  dudraw.dudraw.html#filled_polygon
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw on the background canvas a filled polygon with coordinates (x[i], y[i]).
• dudraw.dudraw.triangle
  dudraw.dudraw.html#triangle
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw a triangle on the canvas with corners at (x0, y0), (x1, y1), and (x2, y2).
• dudraw.dudraw.filled_triangle
  dudraw.dudraw.html#filled_triangle
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw a filled triangle on the canvas with corners at (x0, y0), (x1, y1), and (x2, y2).
• dudraw.dudraw.quadrilateral
  dudraw.dudraw.html#quadrilateral
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw a quadrilateral on the canvas with corners at (x0, y0), (x1, y1), (x2, y2), and (x3, y3).
• dudraw.dudraw.filled_quadrilateral
  dudraw.dudraw.html#filled_quadrilateral
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw a filled quadrilateral on the canvas with corners at (x0, y0), (x1, y1), (x2, y2), and (x3, y3).
• dudraw.dudraw.arc
  dudraw.dudraw.html#arc
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw an arc portion between angle1 and angle2, of the circumference of a circle centered at (x, y) with a radius r.
• dudraw.dudraw.elliptical_arc
  dudraw.dudraw.html#elliptical_arc
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw an arc portion between angle1 and angle2, of the circumference of an ellipse centered at (x, y) with a width of half_width, and a height of 2.0 * half_height.
• dudraw.dudraw.sector
  dudraw.dudraw.html#sector
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw a sector portion between angle1 and angle2, of the interior of a circle centered at (x, y) with a radius r.
• dudraw.dudraw.filled_sector
  dudraw.dudraw.html#filled_sector
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw a filled sector portion between angle1 and angle2, of the interior of a circle centered at (x, y) with a radius r.
• dudraw.dudraw.elliptical_sector
  dudraw.dudraw.html#elliptical_sector
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw a sector portion between angle1 and angle2, of the interior of an ellipse centered at (x, y) with a width of half_width, and a height of 2.0 * half_height.
• dudraw.dudraw.filled_elliptical_sector
  dudraw.dudraw.html#filled_elliptical_sector
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw a filled sector portion between angle1 and angle2, of the interior of an ellipse centered at (x, y) with a width of half_width, and a height of 2.0 * half_height.
• dudraw.dudraw.annulus
  dudraw.dudraw.html#annulus
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw an annulus centered at (x, y) with outer radius r1, and inner radius r2.
• dudraw.dudraw.filled_annulus
  dudraw.dudraw.html#filled_annulus
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw a filled annulus centered at (x, y) with outer radius r1, and inner radius r2.
• dudraw.dudraw.text
  dudraw.dudraw.html#text
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw string s on the background canvas centered at (x, y).
• dudraw.dudraw.picture
  dudraw.dudraw.html#picture
  ZopeInterfaceFunction
  Function
  PUBLIC
  Draw pic on the background canvas centered at (x, y). pic is an object of class picture.Picture. x and y default to the midpoint of the background canvas.
• dudraw.dudraw.clear
  dudraw.dudraw.html#clear
  ZopeInterfaceFunction
  Function
  PUBLIC
  Clear the background canvas to color c, where c is an object of class Color. c defaults to dudraw.WHITE.
• dudraw.dudraw.clear_rgb
  dudraw.dudraw.html#clear_rgb
  ZopeInterfaceFunction
  Function
  PUBLIC
  Clear the background canvas to color c, where c is an object of class Color. c defaults to dudraw.WHITE.
• dudraw.dudraw.save
  dudraw.dudraw.html#save
  ZopeInterfaceFunction
  Function
  PUBLIC
  Save the window canvas to file f.
• dudraw.dudraw._show
  dudraw.dudraw.html#_show
  ZopeInterfaceFunction
  Function
  PRIVATE
  Copy the background canvas to the window canvas.
• dudraw.dudraw._show_and_wait_forever
  dudraw.dudraw.html#_show_and_wait_forever
  ZopeInterfaceFunction
  Function
  PRIVATE
  Copy the background canvas to the window canvas. Then wait forever, that is, until the user closes the dudraw window.
• dudraw.dudraw.show
  dudraw.dudraw.html#show
  ZopeInterfaceFunction
  Function
  PUBLIC
  Copy the background canvas to the window canvas, and then wait for msec milliseconds. msec defaults to infinity.
• dudraw.dudraw._check_for_events
  dudraw.dudraw.html#_check_for_events
  ZopeInterfaceFunction
  Function
  PRIVATE
  Check if any new event has occured (such as a key typed or button pressed). If a key has been typed, then put that key in a queue.
• dudraw.dudraw.has_next_key_typed
  dudraw.dudraw.html#has_next_key_typed
  ZopeInterfaceFunction
  Function
  PUBLIC
  Return True if the queue of keys the user typed is not empty. Otherwise return False.
• dudraw.dudraw.next_key_typed
  dudraw.dudraw.html#next_key_typed
  ZopeInterfaceFunction
  Function
  PUBLIC
  Remove the first key from the queue of keys that the the user typed, and return that key.
• dudraw.dudraw.mouse_pressed
  dudraw.dudraw.html#mouse_pressed
  ZopeInterfaceFunction
  Function
  PUBLIC
  Return True if the mouse has been left-clicked since the last time mousePressed was called, and False otherwise.
• dudraw.dudraw.mouse_x
  dudraw.dudraw.html#mouse_x
  ZopeInterfaceFunction
  Function
  PUBLIC
  Return the x coordinate in user space of the location at which the mouse was most recently left-clicked. If a left-click hasn't happened yet, raise an exception, since mouseX() shouldn't be called until mousePressed() returns True.
• dudraw.dudraw.mouse_y
  dudraw.dudraw.html#mouse_y
  ZopeInterfaceFunction
  Function
  PUBLIC
  Return the y coordinate in user space of the location at which the mouse was most recently left-clicked. If a left-click hasn't happened yet, raise an exception, since mouseY() shouldn't be called until mousePressed() returns True.
• dudraw.dudraw._regression_test
  dudraw.dudraw.html#_regression_test
  ZopeInterfaceFunction
  Function
  PRIVATE
  Perform regression testing.
• dudraw.dudraw._main
  dudraw.dudraw.html#_main
  ZopeInterfaceFunction
  Function
  PRIVATE
  Dispatch to a function that does regression testing, or to a dialog-box-handling function.