Gtk.ProgressBar.prototype.pulse

function pulse():void {
    // Gjs wrapper for gtk_progress_bar_pulse()
}

Indicates that some progress has been made, but you don't know how much. Causes the progress bar to enter "activity mode," where a block bounces back and forth. Each call to Gtk.ProgressBar.prototype.pulse causes the block to move by a little bit (the amount of movement per pulse is determined by Gtk.set_pulse_step).