MANAGED DIALOG - A layer for simplified Tkinter dialogs

A Simple Example

from managed_dialog import *

def main():

  # test code follows
  def change_callback(dialog):
    dialog.change()
    print "change callback"
    print "int_val:",var_group.int_val
    print "float_val:",var_group.float_val
    print "bool_val:",var_group.bool_val
    print "str_val:",var_group.str_val
    print "selector_val:",var_group.selector_val
    print "list_val:",var_group.list_val
    print "radio_val:",var_group.radio_val

  def test_press():
    print "button pressed"

  root = Tk()

  class var_class:
    int_val = 1
    float_val = 2.34574563
    bool_val = True
    str_val = "Hello"
    selector_options = ("Aust","B","C")
    selector_val = "B"
    list_val = [False,True,True]
    radio_val = 0

  var_group = var_class()

  min_val = 1.3
  max_val = 3.4

  var_list = (("Just some text>>>",),
              ("Test button",None,test_press),
              ("Test Float:",(var_group,'float_val')),
              ("Test Bool:",(var_group,'bool_val')),
              ("Test String:",(var_group,'str_val')),
              (("Test selector box+-",)+var_group.selector_options,(var_group,'selector_val')),
              (("Test list>>>","Sydney","Melbourne","Adelaide"),(var_group,'list_val')),
              (("Test radio","One","Two","3"),(var_group,'radio_val')),
              ("Test Int:",(var_group,'int_val')))
  status_line = "This is the status line"
  dialog = ManagedDialog(root,var_list,"Control Dialog Test",change_callback,status_line,False)
  frame = 0
  while not dialog.exit_request:
    dialog.update()
    dialog.lift()
    sys.stdout.flush()
    dialog.setStatusLine('%10d' % frame)
    frame += 1
  dialog.destroy()  # don't need to do this here but it is good practice

if __name__ == '__main__': main()

From the users point of view there is no difference in the behaviour. But for the programmer you will note that when the initial value is a tuple containing the parent class and a string with the member name, then this variable will be managed.

The change_callback(dialog) is necessary both to call the dialog(change) function and to inform the application that a change may have occurred.

Variable List Protocol

Application Program Interface

As already shown in the example, it is necessary to call the change() function from the apply callback in order for the managed variables to be updated. It might have been possible to avoid this but this suite of dialog helpers is intended for real time applications, so the application needs to know that something has changed anyway - or it might forbid the change, for some reason, just by not calling change().

Apart from the essential constructor and the change()there are three useful functions:

setObj(old,new)

Should the application wish to change the values in the open dialog a call to setObj(old,new) for each object in the dialog will update the dialog. The old and new objects can be the same object.

setManaged(desc,value)

If just one value needs to be changed then the function setManaged(desc,value) could be used rather than using control_dialog's set(label,value). Note the use of desc used in the former rather than the label used in the latter. desc is a tuple or list containing a pointer to a managed object and the name (or index for lists) of the object member.

getManaged(desc,value)

As with setManaged this is an alternative to get(label,value).

Installation