[Gtk-sharp-list] GLib.Timerout How to use?

[Michael Hutchinson]

On Sun, Sep 14, 2008 at 4:37 AM, True Friend <true.friend2004 at gmail.com> wrote:
> Thanks a lot. It is working fine now. I used this code on windows and was
> trying to search something like it on mono as well.
> ----------------------------------------------
> void ToolStripMenuItemAutoSaveClick(object sender, EventArgs e)
>         {
>             ToolStripMenuItem item = (ToolStripMenuItem)sender;
>             if(item.Checked == true)
>             {
>             timer = new Timer();
>             timer.Interval = 6000;
>             timer.Start();
>             timer.Tick += AutoSaveEventHandler;
>             }
>             else
>             {
>                 timer.Stop();
>             }
>         }
>         //auto save event handler
>         void AutoSaveEventHandler(object sender, EventArgs e)
>         {
>             if(Form1.textFilePath != null)
>             {
>                 if(pattern.IsMatch(textFilePath) == true)
>                 {
>                     string f = File.ReadAllText(textFilePath);
>                     string pathg = textFilePath + "~";
>                     File.WriteAllText(pathg, f);
>                     urduRichTextBox1.SaveFile(textFilePath,
> RichTextBoxStreamType.RichText);
>                 }
>                 else{
>                     string f = File.ReadAllText(textFilePath);
>                     string pathg = textFilePath + "~";
>                     File.WriteAllText(pathg, f);
>                 urduRichTextBox1.SaveFile(textFilePath,
> RichTextBoxStreamType.UnicodePlainText);
>                 }
>             }
> ----------------------------------------------------
> You can see there is no separate thread involved here, System.Timers.Timer
> class is working fine. I tried to use this class but the event Timer.Tick
> wasn't available and when I tried to use Timer.Elapsed event.
> -----------------------------------------------------
> if(Action4.Active == true)
>             {
>
>             if(textFilePath == null)
>             {
>                 OnSaveActionActivated(sender, e);
>             }
>             timer = new Timer();
>             timer.Interval = 300;
>             timer.Start();
>             timer.Elapsed += AutoSaveEventHandler;
>             }
>             else
>             {
>                 timer.Stop();
>             }
> ------------------------------------------
> It was pretty much straight forward but I couldn't get it work on mono, it
> also frozen the GUI. Can you tell me whats wrong with this code?

System.Timers.Timer does use a thread internally, and the "Elapsed"
callback is invoked on this other thread.

See http://msdn.microsoft.com/en-us/library/system.timers.timer.aspx#remarksToggle
which says:

" If you use the Timer with a user interface element, such as a form
or control, assign the form or control that contains the Timer to the
SynchronizingObject property, so that the event is marshaled to the
user interface thread. "

You have been lucky that it works on winforms... it's still quite
possible that your code will hang, unless you add synchronisation.


You can still use timers with GTK#, but you will have to use
Gtk.Application.Invoke to run delegates on the GUI thread:
timer.Elapsed += delegate {
    Application.Invoke (delegate {
        AutoSave()();
    })
});

GLib.Timeouts are a much nicer (thread-less) model.

-- 
Michael Hutchinson
http://mjhutchinson.com