Is there any way to provide tk_messagebox an input from TCL itself and not by the click of button by user?

Question

I have a condition that triggers a tk_messageBox. Now, after staying for a period of let's say 10 seconds, I want it to disappear with an "ok" input without any click or interaction from the user. Is there a way that can be done?

        if {condition is matched} {
          set input [tk_messageBox -message $message -icon <iconType> -type <messageBoxType>]
         }

Answer 1

The standard message box does not support that, as the underlying OS dialog on at least one platform (can't remember if it is Windows or macOS) doesn't support such a thing.

But you can get access to the scripted version of the dialog (which is the default one on Linux) and inject the trigger:

# Set up the timeout; I got the widget name by reading the sources
set handle [after 10000 .__tk__messagebox.no invoke]

# This is the internal name of the implementation
set answer [tk::MessageBox -type yesno -message "Foo"]

# Make sure we clear our timeout in case the user *did* pick something
after cancel $handle

Different message box types have different names for the (final part of the name of the) default button, but they'll be one of ok, cancel, no or abort, depending on dialog type. It should be obvious which. (Alternatively, just destroy the .__tk_messagebox window. I think that also picks the default.)

Answer 2

This is another possible solution using toplevel:

set message "The quick brown fox jumps over the lazy dog"

if {condition is matched} {
    toplevel .new_window

    wm title      .new_window "Window title"
    wm geometry   .new_window 320x100
    wm minsize    .new_window 320 100
    wm maxsize    .new_window 320 100
    wm protocol   .new_window WM_DELETE_WINDOW {destroy .new_window}
    wm attributes .new_window -topmost yes

    set input -1

    pack [label .new_window.message -text $message] -fill none -expand 1
    pack [frame .new_window.buttons] -fill none -expand 1

    pack [ttk::button .new_window.buttons.button1 -text "OK" -command {
        set input 1
        destroy .new_window
    }] -side left -padx 5

    pack [ttk::button .new_window.buttons.button2 -text "Cancel" -command {
        set input 0
        destroy .new_window
    }] -side right -padx 5

    after 10000 {
        if {[winfo exists .new_window]} {
            destroy .new_window
            if {$input == -1} {
                set input 1
            }
        }
    }
}

The variable $input holds the user input value (0 or 1), after a timeout of ten seconds without a click the window will self-close with deafult value of 1 (ok).

Pay attention however, before the click or until the timeout expires the variable $input has the value of -1

EDIT: to avoid the latter uncertain behavior you'll probably want this:

set message "The quick brown fox jumps over the lazy dog"

if {condition is matched} {
    toplevel .new_window

    wm title      .new_window "Window title"
    wm geometry   .new_window 320x100
    wm minsize    .new_window 320 100
    wm maxsize    .new_window 320 100
    wm protocol   .new_window WM_DELETE_WINDOW {
        set input 1
        destroy .new_window
    }
    wm attributes .new_window -topmost yes

    if {[info exists input]} {
        unset input
    }

    pack [label .new_window.message -text $message] -fill none -expand 1
    pack [frame .new_window.buttons] -fill none -expand 1

    pack [ttk::button .new_window.buttons.button1 -text "OK" -command {
        set input 1
        destroy .new_window
    }] -side left -padx 5

    pack [ttk::button .new_window.buttons.button2 -text "Cancel" -command {
        set input 0
        destroy .new_window
    }] -side right -padx 5

    after 10000 {
        if {[winfo exists .new_window]} {
            set input 1
            destroy .new_window}
        }
    }
    vwait input
}

To pause execution waiting for user input or the dafault answer.

Bye