/*
 * Copyright © 2010 Codethink Limited
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the licence, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * Author: Ryan Lortie <desrt@desrt.ca>
 */

#include "config.h"

#include <stdlib.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <string.h>

#include "gtkapplication.h"
#include "gtkmarshalers.h"
#include "gtkwindow.h"

#include <gdk/gdk.h>
#ifdef GDK_WINDOWING_X11
#include <gdk/x11/gdkx.h>
#endif

/**
 * SECTION:gtkapplication
 * @title: GtkApplication
 * @short_description: Application class
 *
 * #GtkApplication is a class that handles many important aspects
 * of a GTK+ application in a convenient fashion, without enforcing
 * a one-size-fits-all application model.
 *
 * Currently, GtkApplication handles GTK+ initialization, application
 * uniqueness, provides some basic scriptability by exporting 'actions',
 * and manages a list of toplevel windows whose life-cycle is automatically
 * tied to the life-cycle of your application.
 *
 * <example id="gtkapplication"><title>A simple application</title>
 * <programlisting>
 * <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" parse="text" href="../../../../examples/bloatpad.c">
 *  <xi:fallback>FIXME: MISSING XINCLUDE CONTENT</xi:fallback>
 * </xi:include>
 * </programlisting>
 * </example>
 */

enum {
  WINDOW_ADDED,
  WINDOW_REMOVED,
  LAST_SIGNAL
};

static guint gtk_application_signals[LAST_SIGNAL];

G_DEFINE_TYPE (GtkApplication, gtk_application, G_TYPE_APPLICATION)

struct _GtkApplicationPrivate
{
  GList *windows;
};

static gboolean
gtk_application_focus_in_event_cb (GtkWindow      *window,
                                   GdkEventFocus  *event,
                                   GtkApplication *application)
{
  GtkApplicationPrivate *priv = application->priv;
  GList *link;

  /* Keep the window list sorted by most-recently-focused. */
  link = g_list_find (priv->windows, window);
  if (link != NULL && link != priv->windows)
    {
      priv->windows = g_list_remove_link (priv->windows, link);
      priv->windows = g_list_concat (link, priv->windows);
    }

  return FALSE;
}

static void
gtk_application_startup (GApplication *application)
{
  G_APPLICATION_CLASS (gtk_application_parent_class)
    ->startup (application);

  gtk_init (0, 0);
}

static void
gtk_application_add_platform_data (GApplication    *application,
                                   GVariantBuilder *builder)
{
  const gchar *startup_id;

  startup_id = getenv ("DESKTOP_STARTUP_ID");
  
  if (startup_id && g_utf8_validate (startup_id, -1, NULL))
    g_variant_builder_add (builder, "{sv}", "desktop-startup-id",
                           g_variant_new_string (startup_id));
}

static void
gtk_application_before_emit (GApplication *application,
                             GVariant     *platform_data)
{
  GVariantIter iter;
  const gchar *key;
  GVariant *value;

  g_variant_iter_init (&iter, platform_data);
  while (g_variant_iter_loop (&iter, "{&sv}", &key, &value))
    {
#ifdef GDK_WINDOWING_X11
      if (strcmp (key, "desktop-startup-id") == 0)
        {
          GdkDisplay *display;
          const gchar *id;

          display = gdk_display_get_default ();
          id = g_variant_get_string (value, NULL);
          gdk_x11_display_set_startup_notification_id (display, id);
       }
#endif
    }
}

static void
gtk_application_after_emit (GApplication *application,
                            GVariant     *platform_data)
{
  gdk_notify_startup_complete ();
}

static void
gtk_application_init (GtkApplication *application)
{
  application->priv = G_TYPE_INSTANCE_GET_PRIVATE (application,
                                                   GTK_TYPE_APPLICATION,
                                                   GtkApplicationPrivate);
}

static void
gtk_application_window_added (GtkApplication *application,
                              GtkWindow      *window)
{
  GtkApplicationPrivate *priv = application->priv;

  priv->windows = g_list_prepend (priv->windows, window);
  gtk_window_set_application (window, application);
  g_application_hold (G_APPLICATION (application));

  g_signal_connect (window, "focus-in-event",
                    G_CALLBACK (gtk_application_focus_in_event_cb),
                    application);
}

static void
gtk_application_window_removed (GtkApplication *application,
                                GtkWindow      *window)
{
  GtkApplicationPrivate *priv = application->priv;

  g_signal_handlers_disconnect_by_func (window,
                                        gtk_application_focus_in_event_cb,
                                        application);

  g_application_release (G_APPLICATION (application));
  priv->windows = g_list_remove (priv->windows, window);
  gtk_window_set_application (window, NULL);
}

static void
gtk_application_class_init (GtkApplicationClass *class)
{
  GApplicationClass *application_class = G_APPLICATION_CLASS (class);

  application_class->add_platform_data = gtk_application_add_platform_data;
  application_class->before_emit = gtk_application_before_emit;
  application_class->after_emit = gtk_application_after_emit;
  application_class->startup = gtk_application_startup;

  class->window_added = gtk_application_window_added;
  class->window_removed = gtk_application_window_removed;

  g_type_class_add_private (class, sizeof (GtkApplicationPrivate));

  /**
   * GtkApplication::window-added:
   * @application: the #GtkApplication which emitted the signal
   * @window: the newly-added #GtkWindow
   *
   * Emitted when a #GtkWindow is added to @application through
   * gtk_application_add_wi!ndow().
   *
   * Since: 3.2
   */
  gtk_application_signals[WINDOW_ADDED] =
    g_signal_new ("window-added", GTK_TYPE_APPLICATION, G_SIGNAL_RUN_FIRST,
                  G_STRUCT_OFFSET (GtkApplicationClass, window_added),
                  NULL, NULL,
                  g_cclosure_marshal_VOID__OBJECT,
                  G_TYPE_NONE, 1, GTK_TYPE_WINDOW);

  /**
   * GtkApplication::window-removed:
   * @application: the #GtkApplication which emitted the signal
   * @window: the #GtkWindow that is being removed
   *
   * Emitted when a #GtkWindow is removed from @application,
   * either as a side-effect of being destroyed or explicitly
   * through gtk_application_remove_window().
   *
   * Since: 3.2
   */
  gtk_application_signals[WINDOW_REMOVED] =
    g_signal_new ("window-removed", GTK_TYPE_APPLICATION, G_SIGNAL_RUN_FIRST,
                  G_STRUCT_OFFSET (GtkApplicationClass, window_removed),
                  NULL, NULL,
                  g_cclosure_marshal_VOID__OBJECT,
                  G_TYPE_NONE, 1, GTK_TYPE_WINDOW);
}

/**
 * gtk_application_new:
 * @application_id: the application id
 * @flags: the application flags
 *
 * Creates a new #GtkApplication instance.
 *
 * This function calls g_type_init() for you. gtk_init() is called
 * as soon as the application gets registered as the primary instance.
 *
 * The application id must be valid. See g_application_id_is_valid().
 *
 * Returns: a new #GtkApplication instance
 */
GtkApplication *
gtk_application_new (const gchar       *application_id,
                     GApplicationFlags  flags)
{
  g_return_val_if_fail (g_application_id_is_valid (application_id), NULL);

  g_type_init ();

  return g_object_new (GTK_TYPE_APPLICATION,
                       "application-id", application_id,
                       "flags", flags,
                       NULL);
}

/**
 * gtk_application_add_window:
 * @application: a #GtkApplication
 * @window: a #GtkWindow
 *
 * Adds a window from @application.
 *
 * This call is equivalent to setting the #GtkWindow:application
 * property of @window to @application.
 *
 * Normally, the connection between the application and the window
 * will remain until the window is destroyed, but you can explicitly
 * remove it with gtk_application_remove_window().
 *
 * GTK+ will keep the application running as long as it has
 * any windows.
 *
 * Since: 3.0
 **/
void
gtk_application_add_window (GtkApplication *application,
                            GtkWindow      *window)
{
  g_return_if_fail (GTK_IS_APPLICATION (application));

  if (!g_list_find (application->priv->windows, window))
    g_signal_emit (application,
                   gtk_application_signals[WINDOW_ADDED], 0, window);
}

/**
 * gtk_application_remove_window:
 * @application: a #GtkApplication
 * @window: a #GtkWindow
 *
 * Remove a window from @application.
 *
 * If @window belongs to @application then this call is equivalent to
 * setting the #GtkWindow:application property of @window to
 * %NULL.
 *
 * The application may stop running as a result of a call to this
 * function.
 *
 * Since: 3.0
 **/
void
gtk_application_remove_window (GtkApplication *application,
                               GtkWindow      *window)
{
  g_return_if_fail (GTK_IS_APPLICATION (application));

  if (g_list_find (application->priv->windows, window))
    g_signal_emit (application,
                   gtk_application_signals[WINDOW_REMOVED], 0, window);
}

/**
 * gtk_application_get_windows:
 * @application: a #GtkApplication
 *
 * Gets a list of the #GtkWindow<!-- -->s associated with @application.
 *
 * The list is sorted by most recently focused window, such that the first
 * element is the currently focused window.  (Useful for choosing a parent
 * for a transient window.)
 *
 * The list that is returned should not be modified in any way. It will
 * only remain valid until the next focus change or window creation or
 * deletion.
 *
 * Returns: (element-type GtkWindow) (transfer none): a #GList of #GtkWindow
 *
 * Since: 3.0
 **/
GList *
gtk_application_get_windows (GtkApplication *application)
{
  g_return_val_if_fail (GTK_IS_APPLICATION (application), NULL);

  return application->priv->windows;
}