Re: Feedback messages to user using Tk

Ruby
1
  1. Now call Tk.mainloop

^^ I think maybe that’s where I was going wrong. I wrote a unit test to
test the updating of the label. My code looked something like this:

class GraphicalProgress
def initialize
root = TkRoot.new { title ‘Progress’ }
@my_label = tkLabel.new(root)
@my_label.configure(‘text’=>‘Waiting for something to report…’)
@my_label.pack

Tk.mainloop

end

def update(message)
@my_label.configure(‘text’=>‘Waiting for something to report…’)
end
end

Unit Test:

@progress = GraphicalProgress.new
@progress.update(‘I’m doing something’)
@progress.update(‘I’m done’)

And because the loop is in the initialize method, only when the app is
closed do we get to the line which requests the text is update. Of
course this falls over as the widget has been destroyed…

So with your suggestion the code should be something like this…

class GraphicalProgress
def initialize
root = TkRoot.new { title ‘Progress’ }
@my_label = tkLabel.new(root)
@my_label.configure(‘text’=>‘Waiting for something to report…’)
@my_label.pack
end

def update(message)
@my_label.configure(‘text’=>‘Waiting for something to report…’)
end
end

Unit Test:

@progress = GraphicalProgress.new
@progress.update(‘I’m doing something’)
@progress.update(‘I’m done’)
Tk.mainloop

Or have I got the wrong end of the stick?

Thanks so much for your help!

Gem

2

On Sep 27, 2006, at 10:57 AM, Cameron, Gemma (UK) wrote:

@my_label.configure('text'=>'Waiting for something to report...')

Unit Test:

end

Thanks so much for your help!

There are quite a few errors in that code. Even if you fixed its
syntax, you’d have a conceptual error. You’d only see the last
message: “I’m done”. The initial message would be replaced by the
first update call and the second message would then be replaced by
the second update call before the window got on the screen. But
you’re moving in the right direction.

You need something to delay the updates until the window gets
displayed. A timer is one way to do it.

#! /usr/bin/ruby -w

require ‘tk’

class GraphicalProgress
def initialize
root = TkRoot.new { title ‘Progress’ }
@my_label = TkLabel.new(root) {
text ‘Waiting for something to report…’
}
@my_label.pack(:pady=>20)
# Set initial window geometry; i.e., size and placement.
win_w, win_h = 300, 80
# root.minsize(win_w, win_h)
win_x = (root.winfo_screenwidth - win_w) / 2
root.geometry("#{win_w}x#{win_h}+#{win_x}+50")
root.resizable(false, false)
end

def update(message)
   @my_label.text = message
end

end

msgs = [“I’m doing something”, “I’m done”]
indx = 0
progress = GraphicalProgress.new
timer = TkTimer.start(1000, 2) do
progress.update(msgs[indx])
indx += 1
end

Tk.mainloop

Regards, Morton