src/cheese-countdown.vala

   1 /*
   2  * Copyright © 2010 Yuvaraj Pandian T <yuvipanda@yuvi.in>
   3  * Copyright © 2010 daniel g. siegel <dgsiegel@gnome.org>
   4  * Copyright © 2008 Filippo Argiolas <filippo.argiolas@gmail.com>
   5  *
   6  * Licensed under the GNU General Public License Version 2
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 internal class Cheese.Countdown : GLib.Object
  23 {
  24   public delegate void CountdownCallback ();
  25   private Clutter.Text countdown_actor;
  26   private unowned CountdownCallback completed_callback;
  27   private Clutter.PropertyTransition pulse_in;
  28   private Clutter.PropertyTransition pulse_out;
  29   private int current_value = 0;
  30   private GLib.Settings settings;
  31   public bool running;
  32
  33   public Countdown (Clutter.Text countdown_actor)
  34   {
  35     this.countdown_actor = countdown_actor;
  36     settings             = new GLib.Settings("org.gnome.Cheese");
  37   }
  38
  39   ~Countdown ()
  40   {
  41     stop ();
  42   }
  43
  44   /**
  45    * Fade the countdown text out, over 500 milliseconds.
  46    *
  47    * Once the fade-out is complete, this method calls fade_in().
  48    */
  49   private void fade_out ()
  50   {
  51     pulse_out = new Clutter.PropertyTransition ("opacity");
  52     pulse_out.set_duration (500);
  53     pulse_out.set_from_value (255);
  54     pulse_out.set_to_value (0);
  55     pulse_out.completed.connect (fade_in);
  56     pulse_out.animatable = countdown_actor;
  57     pulse_out.start ();
  58   }
  59
  60   /**
  61    * Decrement the countdown text and fade it in, over 500 milliseconds.
  62    *
  63    * Once the fade-in is complete, this method calls fade_out().
  64    */
  65   private void fade_in ()
  66   {
  67     if (this.current_value <= 0)
  68     {
  69       this.completed_callback ();
  70       running = false;
  71       return;
  72     }
  73     this.countdown_actor.text = this.current_value.to_string ();
  74     this.current_value--;
  75
  76     pulse_in = new Clutter.PropertyTransition ("opacity");
  77     pulse_in.set_duration (500);
  78     pulse_in.set_from_value (0);
  79     pulse_in.set_to_value (255);
  80     pulse_in.completed.connect (fade_out);
  81     pulse_in.animatable = countdown_actor;
  82     pulse_in.start ();
  83   }
  84
  85   /**
  86    * Start the countdown, using the countdown-duration GSetting for the time.
  87    *
  88    * @param completed_callback the callback to call upon countdown completion
  89    */
  90   public void start (CountdownCallback completed_callback)
  91   {
  92     this.completed_callback = completed_callback;
  93     this.current_value = settings.get_int("countdown-duration");
  94     running = true;
  95     countdown_actor.show ();
  96     fade_in ();
  97   }
  98
  99   /**
 100    * Stop the countdown, for example if it was interrupted by the user.
 101    */
 102   public void stop ()
 103   {
 104     countdown_actor.hide ();
 105     countdown_actor.remove_all_transitions ();
 106     running = false;
 107   }
 108 }