From: Joe Van Dyk <joevandyk@...>
Date: 2006-01-11T22:16:08+09:00
Subject: Re: dialog that pops up when window busy

On 1/10/06, David Vallner <david@vallner.net> wrote:
> Joe Van Dyk wrote:
>
> >Hi,
> >
> >In my window, I sometimes want to prevent the user from doing anything
> >while an action is occuring.  So I want to disable the window (using
> >Gtk::Widget#sensitive).
> >
> >But I also want to popup a little dialog saying why the window is
> >being disabled (and perhaps have a little progress indicator on it).
> >
> >Are there any Gtk widgets that could help me, or do I need to make a
> >custom dialog box for this?
> >
> >
> >
> A custom progress dialog should not be hard to implement. If you pop it
> up as a modal dialog, you'll also avoid having to desentivize the window
> by hand. You'll definitely need a separate thread for a progress dialog,
> and possibly wrap whatever you're doing that requires waiting in some
> sort of ProgressingTask object to get things completely done.
>
> That said, I do have a weird hunch I saw some existing implementations
> of the problem around, but can't for the heck of it figure out in what
> context. Brief googling would indicate that indeed Gtk has a "progress
> bar" widget, the documentation to that might provide some insights as to
> what you're looking at. And embedding one in a pop-up modal progress
> dialog should then be trivial.

Bleh, meant to send this to ruby-gnome2, not ruby-talk.  :-(

Anyway, here's how I solved it.  If there's a cleaner way to do it,
I'd love to hear about it.

class App
  def initialize
    Gtk::init
    @window = Gtk::Window.new "Joe's Crazy Application"
    @window.set_default_size 300, 300

    vbox = Gtk::VBox.new
    @window << vbox

    vbox << Gtk::Label.new("Stuff")
    vbox << Gtk::Label.new("More Stuff")
    vbox << Gtk::Button.new("Useless button")
    vbox << Gtk::Button.new("Another Useless button")

    lock_button = Gtk::Button.new "Lock window for three seconds"
    vbox << lock_button

    lock_button.signal_connect("clicked") do
      # Window gets locked while doing stuff
      @window.lock do
        start_time = Time.now
        # computationally heavy thing there
        loop do
          Gtk::process_gui_events # Any way I can get rid of this?
          rand 100000000
          break if Time.now - start_time >= 3
        end
      end
    end

    @window.signal_connect("delete-event") { Gtk::main_quit }
    @window.show_all
    Gtk::main
  end
end

module Gtk
  # Makes sure that Gtk has a change to draw stuff
  def self.process_gui_events
    while Gtk::events_pending?
      Gtk::main_iteration
    end
  end
end

class Gtk::Window
  # Locks the window
  def lock reason = "hold on there buddy", &block
    self.sensitive = false
    display_locking_dialog(reason) do
      block.call
    end
    self.sensitive = true
  end

  # Displays a locking dialog box with a
  # pulsing progress bar over the window
  def display_locking_dialog reason, &block
    dialog = Gtk::Dialog.new "", self, Gtk::Dialog::MODAL
    dialog.decorated = false
    vbox = Gtk::VBox.new
    reason_label = Gtk::Label.new reason
    progress_bar = Gtk::ProgressBar.new
    thread_id = Gtk::timeout_add(100) { progress_bar.pulse }
    vbox << reason_label << progress_bar
    dialog.action_area << vbox
    dialog.show_all
    block.call
    Gtk::timeout_remove(thread_id)
    dialog.destroy
  end

end

App.new if __FILE__ == $0