Help with TkRoot

Hello,
I would like to write a program on the Mac which at the start only
shows the menubar: only after the user has selected an option from the
menu would the first window appear.

However I can't get that to work in Tk. It seems that a Tk GUI can't do
without a TkRoot widget and TkRoot is shown as a window.

Is there any way to make the TkRoot be the menubar itself? Or maybe to
make TkRoot invisible? Or any other solution to achieve the same goal?

Thank you.

Diego Virasoro

Yes, you can make the root window invisible. The following produces a default menu bar but no (visible) root window on my Mac:

    require 'tk'

    root = TkRoot.new
    root.withdraw
    Tk.mainloop

Regards, Morton

···

On Aug 19, 2006, at 4:20 AM, Diego Virasoro wrote:

Hello,
I would like to write a program on the Mac which at the start only
shows the menubar: only after the user has selected an option from the
menu would the first window appear.

However I can't get that to work in Tk. It seems that a Tk GUI can't do
without a TkRoot widget and TkRoot is shown as a window.

Is there any way to make the TkRoot be the menubar itself? Or maybe to
make TkRoot invisible? Or any other solution to achieve the same goal?

Diego Virasoro schrieb:

Hello,
I would like to write a program on the Mac which at the start only
shows the menubar: only after the user has selected an option from the
menu would the first window appear.

However I can't get that to work in Tk. It seems that a Tk GUI can't do
without a TkRoot widget and TkRoot is shown as a window.

Is there any way to make the TkRoot be the menubar itself? Or maybe to
make TkRoot invisible? Or any other solution to achieve the same goal?

Thank you.

Diego Virasoro

Maybe you could try to define the menubar in the root window with proper size and then, if the entry in the menu is selected you could make a toplevel.

Now that I've looked a little deeper into the problem, I see that Tk.root.withdraw wouldn't be useful, because in your case, if you use it, you won't see the root window's menu bar. What to do? Well, you might try something like the following:

<code>
root = TkRoot.new {title 'Ruby Tk'}

mnu_bar = TkMenu.new()
    windo_mnu = TkMenu.new(mnu_bar)
       windo_mnu.add_command(
          'label'=>"Show",
          'command'=>lambda {windo_mnu.show}
       )
       windo_mnu.add_command(
          'label'=>"Hide",
          'state'=>'disabled',
          'command'=>lambda {windo_mnu.hide}
       )
       def windo_mnu.show
          entryconfigure(0, 'state'=>'disabled') # disable show
          entryconfigure(1, 'state'=>'normal') # enable hide
          Tk.root.geometry($visible)
       end
       def windo_mnu.hide
          entryconfigure(1, 'state'=>'disabled') # disable hide
          entryconfigure(0, 'state'=>'normal') # enable show
          Tk.root.geometry("0x0+0+0")
       end
    mnu_bar.add_cascade('label'=>"Window", 'menu'=>windo_mnu)
root.menu(mnu_bar)

min_w, min_h = 200, 100
root.minsize(min_w, min_h)
root_x = (root.winfo_screenwidth - min_w) / 2
$visible = "#{min_w}x#{min_h}+#{root_x}+50"
root.geometry("0x0+0+0")

root.bind('Command-q') {exit}

Tk.mainloop
</code>

This is my best shot at the moment. It's not very elegant since you can still see the vestigial root window in the upper left-hand corner of the screen if you look hard, but perhaps it's good enough to fool your users :slight_smile:

Regards, Morton

···

On Aug 19, 2006, at 3:23 PM, Morton Goldberg wrote:

Yes, you can make the root window invisible. The following produces a default menu bar but no (visible) root window on my Mac:

   require 'tk'

   root = TkRoot.new
   root.withdraw
   Tk.mainloop