Jezra.net: simple two stage switch in python with GTK

simple two stage switch in python with GTK

2011-08-12

In the movies, when it is time to detonate the explosives, the person setting off the KABOOM has a sweet remote control with either a two part switch or with two separate switches. Damn, I love a good movie explosion.

The two part switch allows the user to:

activate the explosive
blow shit up

Because the switch has two components, activate and detonate, it is uncommon for there to be accidental explosions. This is a damn fine safety measure and when adding the ability to block an identi.ca user with heybuddy, I wanted a similar safety precaution; blocking someone by accident should not be possible. So that is what I did.

To accomplish this, it was necessary to do the following

create a disabled button that brings the hammer down!
create a checkbox that will activate the button

In GTK parlance, to disable a button, one needs to set the button sensitivity to false. Since I am using Python, this is accomplished thusly

widget.set_sensitive(False)

To show this idea as a small working bit of code, I wrote a quick Python-GTK app that almost does the bare minimum.

Enter the Python

#!/usr/bin/env python

import gtk
class application:
  def __init__(self):
    #I want to keep track of click counts
    self.click_count=0
    '''build the UI'''
    #make the window
    winder = gtk.Window(gtk.WINDOW_TOPLEVEL)
    winder.connect("destroy",self.quit)
    #winder.set_default_size(300,300)
    winder.set_title("Super Trigger")
    #make some boxes
    vbox = gtk.VBox()
    hbox = gtk.HBox()
    #make some buttons
    self.button = gtk.Button("Click Me")
    self.checkbutton = gtk.CheckButton(label="Enable Button")
    #add the buttons to the hbox
    hbox.pack_start(self.button,False,False)
    hbox.pack_start(self.checkbutton,False,False)
    #add the hbox to the vbox
    vbox.pack_start(hbox,False,False)
    #create a Label
    self.label = gtk.Label()
    #add the label to the vbox
    vbox.pack_start(self.label)
    #add the vbox to the window
    winder.add(vbox)

    #disable the button
    self.button.set_sensitive(False)

    #connect the buttons
    self.checkbutton.connect('toggled', self.toggle_clicked )
    self.button.connect('clicked', self.button_clicked)
    #show it all!
    winder.show_all()

  def toggle_clicked(self, widget):
    #is the checkbutton active?
    active = widget.get_active()
    self.button.set_sensitive(active)

  def button_clicked(self,widget):
    #increment the click count
    self.click_count+=1
    #make a string
    string = "clicks: %d" %(self.click_count)
    #set the label to the string
    self.label.set_text(string)

  def run(self):
    gtk.main()

  def quit(self,widget=None):
    gtk.main_quit()

if __name__=="__main__":
  a = application()
  a.run()

It may not be the best solution, but it is a solution and it works.

Well that's it for now. Quit reading, and go write some code.

simple two stage switch in python with GTK from jezra.net

Comments

Name:		not required
Email:		not required (will not be displayed)
Website:		not required (will link your name to your site)
Comment:		required Please do not post HTML code or bbcode unless you want it to show up as code in your post. (or if you are a blog spammer, in which case, you probably aren't reading this anyway).
Prove you are human by solving a math problem! I'm sorry, but due to an increase of blog spam, I've had to implement a CAPTCHA.
Problem:	2 plus 4
Answer:		required