## GtkApplication

GtkApplication — Application class

## Synopsis

    #include <gtk/gtk.h>

    struct              GtkApplication;
    GtkApplication *    gtk_application_new                 (const gchar *application_id,
                                                             GApplicationFlags flags);
    void                gtk_application_add_window          (GtkApplication *application,
                                                             GtkWindow *window);
    void                gtk_application_remove_window       (GtkApplication *application,
                                                             GtkWindow *window);
    GList *             gtk_application_get_windows         (GtkApplication *application);

    enum                GtkApplicationInhibitFlags;
    guint               gtk_application_inhibit             (GtkApplication *application,
                                                             GtkWindow *window,
                                                             GtkApplicationInhibitFlags flags,
                                                             const gchar *reason);
    void                gtk_application_uninhibit           (GtkApplication *application,
                                                             guint cookie);
    gboolean            gtk_application_is_inhibited        (GtkApplication *application,
                                                             GtkApplicationInhibitFlags flags);

    GMenuModel *        gtk_application_get_app_menu        (GtkApplication *application);
    void                gtk_application_set_app_menu        (GtkApplication *application,
                                                             GMenuModel *app_menu);
    GMenuModel *        gtk_application_get_menubar         (GtkApplication *application);
    void                gtk_application_set_menubar         (GtkApplication *application,
                                                             GMenuModel *menubar);

## Object Hierarchy

      GObject
       +----GApplication
             +----GtkApplication

## Implemented Interfaces

GtkApplication implements GActionGroup and GActionMap.

## Properties

      "app-menu"                 GMenuModel*           : Read / Write
      "menubar"                  GMenuModel*           : Read / Write
      "register-session"         gboolean              : Read / Write

## Signals

      "window-added"                                   : Run First
      "window-removed"                                 : Run First

## Description

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, session management, provides some basic scriptability and desktop shell integration by exporting actions and menus and manages a list of toplevel windows whose life-cycle is automatically tied to the life-cycle of your application.

While GtkApplication works fine with plain GtkWindows, it is recommended to use it together with GtkApplicationWindow.

When GDK threads are enabled, GtkApplication will acquire the GDK lock when invoking actions that arrive from other processes. The GDK lock is not touched for local action invocations. In order to have actions invoked in a predictable context it is therefore recommended that the GDK lock be held while invoking actions locally with `g_action_group_activate_action()`. The same applies to actions associated with GtkApplicationWindow and to the 'activate' and 'open' GApplication methods.

To set an application menu for a GtkApplication, use `gtk_application_set_app_menu()`. The GMenuModel that this function expects is usually constructed using GtkBuilder, as seen in the following example. To specify a menubar that will be shown by GApplicationWindows, use `gtk_application_set_menubar()`. Use the base GActionMap interface to add actions, to respond to the user selecting these menu items.

GTK+ displays these menus as expected, depending on the platform the application is running on.

Figure Menu integration in OS X.

Figure Menu integration in GNOME.

Figure Menu integration in Xfce.

Example 110. A simple application

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    #include <stdlib.h>
    #include <gtk/gtk.h>

    static void
    activate_toggle (GSimpleAction *action,
                     GVariant      *parameter,
                     gpointer       user_data)
    {
      GVariant *state;

      state = g_action_get_state (G_ACTION (action));
      g_action_change_state (G_ACTION (action), g_variant_new_boolean (!g_variant_get_boolean (state)));
      g_variant_unref (state);
    }

    static void
    activate_radio (GSimpleAction *action,
                    GVariant      *parameter,
                    gpointer       user_data)
    {
      g_action_change_state (G_ACTION (action), parameter);
    }

    static void
    change_fullscreen_state (GSimpleAction *action,
                             GVariant      *state,
                             gpointer       user_data)
    {
      if (g_variant_get_boolean (state))
        gtk_window_fullscreen (user_data);
      else
        gtk_window_unfullscreen (user_data);

      g_simple_action_set_state (action, state);
    }

    static void
    change_justify_state (GSimpleAction *action,
                          GVariant      *state,
                          gpointer       user_data)
    {
      GtkTextView *text = g_object_get_data (user_data, "bloatpad-text");
      const gchar *str;

      str = g_variant_get_string (state, NULL);

      if (g_str_equal (str, "left"))
        gtk_text_view_set_justification (text, GTK_JUSTIFY_LEFT);
      else if (g_str_equal (str, "center"))
        gtk_text_view_set_justification (text, GTK_JUSTIFY_CENTER);
      else if (g_str_equal (str, "right"))
        gtk_text_view_set_justification (text, GTK_JUSTIFY_RIGHT);
      else
        /* ignore this attempted change */
        return;

      g_simple_action_set_state (action, state);
    }

    static GtkClipboard *
    get_clipboard (GtkWidget *widget)
    {
      return gtk_widget_get_clipboard (widget, gdk_atom_intern_static_string ("CLIPBOARD"));
    }

    static void
    window_copy (GSimpleAction *action,
                 GVariant      *parameter,
                 gpointer       user_data)
    {
      GtkWindow *window = GTK_WINDOW (user_data);
      GtkTextView *text = g_object_get_data ((GObject*)window, "bloatpad-text");

      gtk_text_buffer_copy_clipboard (gtk_text_view_get_buffer (text),
                                      get_clipboard ((GtkWidget*) text));
    }

    static void
    window_paste (GSimpleAction *action,
                  GVariant      *parameter,
                  gpointer       user_data)
    {
      GtkWindow *window = GTK_WINDOW (user_data);
      GtkTextView *text = g_object_get_data ((GObject*)window, "bloatpad-text");

      gtk_text_buffer_paste_clipboard (gtk_text_view_get_buffer (text),
                                       get_clipboard ((GtkWidget*) text),
                                       NULL,
                                       TRUE);

    }

    static GActionEntry win_entries[] = {
      { "copy", window_copy, NULL, NULL, NULL },
      { "paste", window_paste, NULL, NULL, NULL },
      { "fullscreen", activate_toggle, NULL, "false", change_fullscreen_state },
      { "justify", activate_radio, "s", "'left'", change_justify_state }
    };

    static void
    new_window (GApplication *app,
                GFile        *file)
    {
      GtkWidget *window, *grid, *scrolled, *view;
      GtkWidget *toolbar;
      GtkToolItem *button;
      GtkWidget *sw, *box, *label;

      window = gtk_application_window_new (GTK_APPLICATION (app));
      gtk_window_set_default_size ((GtkWindow*)window, 640, 480);
      g_action_map_add_action_entries (G_ACTION_MAP (window), win_entries, G_N_ELEMENTS (win_entries), window);
      gtk_window_set_title (GTK_WINDOW (window), "Bloatpad");

      grid = gtk_grid_new ();
      gtk_container_add (GTK_CONTAINER (window), grid);

      toolbar = gtk_toolbar_new ();
      button = gtk_toggle_tool_button_new_from_stock (GTK_STOCK_JUSTIFY_LEFT);
      gtk_actionable_set_detailed_action_name (GTK_ACTIONABLE (button), "win.justify::left");
      gtk_container_add (GTK_CONTAINER (toolbar), GTK_WIDGET (button));

      button = gtk_toggle_tool_button_new_from_stock (GTK_STOCK_JUSTIFY_CENTER);
      gtk_actionable_set_detailed_action_name (GTK_ACTIONABLE (button), "win.justify::center");
      gtk_container_add (GTK_CONTAINER (toolbar), GTK_WIDGET (button));

      button = gtk_toggle_tool_button_new_from_stock (GTK_STOCK_JUSTIFY_RIGHT);
      gtk_actionable_set_detailed_action_name (GTK_ACTIONABLE (button), "win.justify::right");
      gtk_container_add (GTK_CONTAINER (toolbar), GTK_WIDGET (button));

      button = gtk_separator_tool_item_new ();
      gtk_separator_tool_item_set_draw (GTK_SEPARATOR_TOOL_ITEM (button), FALSE);
      gtk_tool_item_set_expand (GTK_TOOL_ITEM (button), TRUE);
      gtk_container_add (GTK_CONTAINER (toolbar), GTK_WIDGET (button));

      button = gtk_tool_item_new ();
      box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
      gtk_container_add (GTK_CONTAINER (button), box);
      label = gtk_label_new ("Fullscreen:");
      gtk_container_add (GTK_CONTAINER (box), label);
      sw = gtk_switch_new ();
      gtk_actionable_set_action_name (GTK_ACTIONABLE (sw), "win.fullscreen");
      gtk_container_add (GTK_CONTAINER (box), sw);
      gtk_container_add (GTK_CONTAINER (toolbar), GTK_WIDGET (button));

      gtk_grid_attach (GTK_GRID (grid), toolbar, 0, 0, 1, 1);

      scrolled = gtk_scrolled_window_new (NULL, NULL);
      gtk_widget_set_hexpand (scrolled, TRUE);
      gtk_widget_set_vexpand (scrolled, TRUE);
      view = gtk_text_view_new ();

      g_object_set_data ((GObject*)window, "bloatpad-text", view);

      gtk_container_add (GTK_CONTAINER (scrolled), view);

      gtk_grid_attach (GTK_GRID (grid), scrolled, 0, 1, 1, 1);

      if (file != NULL)
        {
          gchar *contents;
          gsize length;

          if (g_file_load_contents (file, NULL, &contents, &length, NULL, NULL))
            {
              GtkTextBuffer *buffer;

              buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (view));
              gtk_text_buffer_set_text (buffer, contents, length);
              g_free (contents);
            }
        }

      gtk_widget_show_all (GTK_WIDGET (window));
    }

    static void
    bloat_pad_activate (GApplication *application)
    {
      new_window (application, NULL);
    }

    static void
    bloat_pad_open (GApplication  *application,
                    GFile        **files,
                    gint           n_files,
                    const gchar   *hint)
    {
      gint i;

      for (i = 0; i < n_files; i++)
        new_window (application, files[i]);
    }

    typedef GtkApplication BloatPad;
    typedef GtkApplicationClass BloatPadClass;

    G_DEFINE_TYPE (BloatPad, bloat_pad, GTK_TYPE_APPLICATION)

    static void
    bloat_pad_finalize (GObject *object)
    {
      G_OBJECT_CLASS (bloat_pad_parent_class)->finalize (object);
    }

    static void
    new_activated (GSimpleAction *action,
                   GVariant      *parameter,
                   gpointer       user_data)
    {
      GApplication *app = user_data;

      g_application_activate (app);
    }

    static void
    about_activated (GSimpleAction *action,
                     GVariant      *parameter,
                     gpointer       user_data)
    {
      gtk_show_about_dialog (NULL,
                             "program-name", "Bloatpad",
                             "title", "About Bloatpad",
                             "comments", "Not much to say, really.",
                             NULL);
    }

    static void
    quit_activated (GSimpleAction *action,
                    GVariant      *parameter,
                    gpointer       user_data)
    {
      GApplication *app = user_data;

      g_application_quit (app);
    }

    static GActionEntry app_entries[] = {
      { "new", new_activated, NULL, NULL, NULL },
      { "about", about_activated, NULL, NULL, NULL },
      { "quit", quit_activated, NULL, NULL, NULL },
    };

    static void
    bloat_pad_startup (GApplication *application)
    {
      GtkBuilder *builder;

      G_APPLICATION_CLASS (bloat_pad_parent_class)
        ->startup (application);

      g_action_map_add_action_entries (G_ACTION_MAP (application), app_entries, G_N_ELEMENTS (app_entries), application);

      builder = gtk_builder_new ();
      gtk_builder_add_from_string (builder,
                                   "<interface>"
                                   "  <menu id='app-menu'>"
                                   "    <section>"
                                   "      <item>"
                                   "        <attribute name='label' translatable='yes'>_New Window</attribute>"
                                   "        <attribute name='action'>app.new</attribute>"
                                   "        <attribute name='accel'>&lt;Primary&gt;n</attribute>"
                                   "      </item>"
                                   "    </section>"
                                   "    <section>"
                                   "      <item>"
                                   "        <attribute name='label' translatable='yes'>_About Bloatpad</attribute>"
                                   "        <attribute name='action'>app.about</attribute>"
                                   "      </item>"
                                   "    </section>"
                                   "    <section>"
                                   "      <item>"
                                   "        <attribute name='label' translatable='yes'>_Quit</attribute>"
                                   "        <attribute name='action'>app.quit</attribute>"
                                   "        <attribute name='accel'>&lt;Primary&gt;q</attribute>"
                                   "      </item>"
                                   "    </section>"
                                   "  </menu>"
                                   "  <menu id='menubar'>"
                                   "    <submenu>"
                                   "      <attribute name='label' translatable='yes'>_Edit</attribute>"
                                   "      <section>"
                                   "        <item>"
                                   "          <attribute name='label' translatable='yes'>_Copy</attribute>"
                                   "          <attribute name='action'>win.copy</attribute>"
                                   "          <attribute name='accel'>&lt;Primary&gt;c</attribute>"
                                   "        </item>"
                                   "        <item>"
                                   "          <attribute name='label' translatable='yes'>_Paste</attribute>"
                                   "          <attribute name='action'>win.paste</attribute>"
                                   "          <attribute name='accel'>&lt;Primary&gt;v</attribute>"
                                   "        </item>"
                                   "      </section>"
                                   "    </submenu>"
                                   "    <submenu>"
                                   "      <attribute name='label' translatable='yes'>_View</attribute>"
                                   "      <section>"
                                   "        <item>"
                                   "          <attribute name='label' translatable='yes'>_Fullscreen</attribute>"
                                   "          <attribute name='action'>win.fullscreen</attribute>"
                                   "          <attribute name='accel'>F11</attribute>"
                                   "        </item>"
                                   "      </section>"
                                   "    </submenu>"
                                   "  </menu>"
                                   "</interface>", -1, NULL);
      gtk_application_set_app_menu (GTK_APPLICATION (application), G_MENU_MODEL (gtk_builder_get_object (builder, "app-menu")));
      gtk_application_set_menubar (GTK_APPLICATION (application), G_MENU_MODEL (gtk_builder_get_object (builder, "menubar")));
      g_object_unref (builder);
    }

    static void
    bloat_pad_init (BloatPad *app)
    {
    }

    static void
    bloat_pad_class_init (BloatPadClass *class)
    {
      GApplicationClass *application_class = G_APPLICATION_CLASS (class);
      GObjectClass *object_class = G_OBJECT_CLASS (class);

      application_class->startup = bloat_pad_startup;
      application_class->activate = bloat_pad_activate;
      application_class->open = bloat_pad_open;

      object_class->finalize = bloat_pad_finalize;

    }

    BloatPad *
    bloat_pad_new (void)
    {
      GtkApplication *bloat_pad;

      g_type_init ();

      g_set_application_name ("Bloatpad");

      bloat_pad = g_object_new (bloat_pad_get_type (),
                                "application-id", "org.gtk.Test.bloatpad",
                                "flags", G_APPLICATION_HANDLES_OPEN,
                                "inactivity-timeout", 30000,
                                "register-session", TRUE,
                                NULL);

      return bloat_pad;
    }

    int
    main (int argc, char **argv)
    {
      BloatPad *bloat_pad;
      int status;

      bloat_pad = bloat_pad_new ();

      gtk_application_add_accelerator (GTK_APPLICATION (bloat_pad),
                                       "F11", "win.fullscreen", NULL);

      status = g_application_run (G_APPLICATION (bloat_pad), argc, argv);

      g_object_unref (bloat_pad);

      return status;
    }

GtkApplication optionally registers with a session manager of the users session (if you set the "register-session" property) and offers various functionality related to the session life-cycle.

An application can block various ways to end the session with the `gtk_application_inhibit()` function. Typical use cases for this kind of inhibiting are long-running, uninterruptible operations, such as burning a CD or performing a disk backup. The session manager may not honor the inhibitor, but it can be expected to inform the user about the negative consequences of ending the session while inhibitors are present.

## Details

### struct GtkApplication

    struct GtkApplication;

### gtk_application_new ()

    GtkApplication *    gtk_application_new                 (const gchar *application_id,
                                                             GApplicationFlags 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.

Concretely, `gtk_init()` is called in the default handler for the "startup" signal. Therefore, GtkApplication subclasses should chain up in their "startup" handler before using any GTK+ API.

Note that commandline arguments are not passed to `gtk_init()`. All GTK+ functionality that is available via commandline arguments can also be achieved by setting suitable environment variables such as `G_DEBUG`, so this should not be a big problem. If you absolutely must support GTK+ commandline arguments, you can explicitly call `gtk_init()` before creating the application instance.

The application id must be valid. See `g_application_id_is_valid()`.

`application_id` : | the application id
`flags` : | the application flags
Returns : | a new GtkApplication instance

Since 3.0

### gtk_application_add_window ()

    void                gtk_application_add_window          (GtkApplication *application,
                                                             GtkWindow *window);

Adds a window to `application`.

This call is equivalent to setting the "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.

`application` : | a GtkApplication
`window` : | a GtkWindow

Since 3.0

### gtk_application_remove_window ()

    void                gtk_application_remove_window       (GtkApplication *application,
                                                             GtkWindow *window);

Remove a window from `application`.

If `window` belongs to `application` then this call is equivalent to setting the "application" property of `window` to `NULL`.

The application may stop running as a result of a call to this function.

`application` : | a GtkApplication
`window` : | a GtkWindow

Since 3.0

### gtk_application_get_windows ()

    GList *             gtk_application_get_windows         (GtkApplication *application);

Gets a list of the GtkWindows 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.

`application` : | a GtkApplication
Returns : | a GList of GtkWindow. [element-type GtkWindow][transfer none]

Since 3.0

### enum GtkApplicationInhibitFlags

    typedef enum {
      GTK_APPLICATION_INHIBIT_LOGOUT  = (1 << 0),
      GTK_APPLICATION_INHIBIT_SWITCH  = (1 << 1),
      GTK_APPLICATION_INHIBIT_SUSPEND = (1 << 2),
      GTK_APPLICATION_INHIBIT_IDLE    = (1 << 3)
    } GtkApplicationInhibitFlags;

Types of user actions that may be blocked by `gtk_application_inhibit()`.

`GTK_APPLICATION_INHIBIT_LOGOUT` | Inhibit ending the user session by logging out or by shutting down the computer
`GTK_APPLICATION_INHIBIT_SWITCH` | Inhibit user switching
`GTK_APPLICATION_INHIBIT_SUSPEND` | Inhibit suspending the session or computer
`GTK_APPLICATION_INHIBIT_IDLE` | Inhibit the session being marked as idle (and possibly locked)

Since 3.4

### gtk_application_inhibit ()

    guint               gtk_application_inhibit             (GtkApplication *application,
                                                             GtkWindow *window,
                                                             GtkApplicationInhibitFlags flags,
                                                             const gchar *reason);

Inform the session manager that certain types of actions should be inhibited. This is not guaranteed to work on all platforms and for all types of actions.

Applications should invoke this method when they begin an operation that should not be interrupted, such as creating a CD or DVD. The types of actions that may be blocked are specified by the `flags` parameter. When the application completes the operation it should call `g_application_uninhibit()` to remove the inhibitor. Note that an application can have multiple inhibitors, and all of the must be individually removed. Inhibitors are also cleared when the application exits.

Applications should not expect that they will always be able to block the action. In most cases, users will be given the option to force the action to take place.

Reasons should be short and to the point.

If `window` is given, the session manager may point the user to this window to find out more about why the action is inhibited.

`application` : | the GApplication
`window` : | a GtkWindow, or `NULL`. [allow-none]
`flags` : | what types of actions should be inhibited
`reason` : | a short, human-readable string that explains why these operations are inhibited. [allow-none]
Returns : | A non-zero cookie that is used to uniquely identify this request. It should be used as an argument to `g_application_uninhibit()` in order to remove the request. If the platform does not support inhibiting or the request failed for some reason, 0 is returned.

Since 3.4

### gtk_application_uninhibit ()

    void                gtk_application_uninhibit           (GtkApplication *application,
                                                             guint cookie);

Removes an inhibitor that has been established with `g_application_inhibit()`. Inhibitors are also cleared when the application exits.

`application` : | the GApplication
`cookie` : | a cookie that was returned by `g_application_inhibit()`

Since 3.4

### gtk_application_is_inhibited ()

    gboolean            gtk_application_is_inhibited        (GtkApplication *application,
                                                             GtkApplicationInhibitFlags flags);

Determines if any of the actions specified in `flags` are currently inhibited (possibly by another application).

`application` : | the GApplication
`flags` : | what types of actions should be queried
Returns : | `TRUE` if any of the actions specified in `flags` are inhibited

Since 3.4

### gtk_application_get_app_menu ()

    GMenuModel *        gtk_application_get_app_menu        (GtkApplication *application);

Returns the menu model that has been set with `gtk_application_set_app_menu()`.

`application` : | a GtkApplication
Returns : | the application menu of `application`. [transfer none]

Since 3.4

### gtk_application_set_app_menu ()

    void                gtk_application_set_app_menu        (GtkApplication *application,
                                                             GMenuModel *app_menu);

Sets or unsets the application menu for `application`.

This can only be done in the primary instance of the application, after it has been registered. "startup" is a good place to call this.

The application menu is a single menu containing items that typically impact the application as a whole, rather than acting on a specific window or document. For example, you would expect to see "Preferences" or "Quit" in an application menu, but not "Save" or "Print".

If supported, the application menu will be rendered by the desktop environment.

Use the base GActionMap interface to add actions, to respond to the user selecting these menu items.

`application` : | a GtkApplication
`app_menu` : | a GMenuModel, or `NULL`. [allow-none]

Since 3.4

### gtk_application_get_menubar ()

    GMenuModel *        gtk_application_get_menubar         (GtkApplication *application);

Returns the menu model that has been set with `gtk_application_set_menubar()`.

`application` : | a GtkApplication
Returns : | the menubar for windows of `application`. [transfer none]

Since 3.4

### gtk_application_set_menubar ()

    void                gtk_application_set_menubar         (GtkApplication *application,
                                                             GMenuModel *menubar);

Sets or unsets the menubar for windows of `application`.

This is a menubar in the traditional sense.

This can only be done in the primary instance of the application, after it has been registered. "startup" is a good place to call this.

Depending on the desktop environment, this may appear at the top of each window, or at the top of the screen. In some environments, if both the application menu and the menubar are set, the application menu will be presented as if it were the first item of the menubar. Other environments treat the two as completely separate -- for example, the application menu may be rendered by the desktop shell while the menubar (if set) remains in each individual window.

Use the base GActionMap interface to add actions, to respond to the user selecting these menu items.

`application` : | a GtkApplication
`menubar` : | a GMenuModel, or `NULL`. [allow-none]

Since 3.4

## Property Details

### The `"app-menu"` property

      "app-menu"                 GMenuModel*           : Read / Write

The GMenuModel for the application menu.

### The `"menubar"` property

      "menubar"                  GMenuModel*           : Read / Write

The GMenuModel for the menubar.

### The `"register-session"` property

      "register-session"         gboolean              : Read / Write

Set this property to `TRUE` to register with the session manager.

Default value: FALSE

Since 3.4

## Signal Details

### The `"window-added"` signal

    void                user_function                      (GtkApplication *application,
                                                            GtkWindow      *window,
                                                            gpointer        user_data)        : Run First

Emitted when a GtkWindow is added to `application` through `gtk_application_add_window()`.

`application` : | the GtkApplication which emitted the signal
`window` : | the newly-added GtkWindow
`user_data` : | user data set when the signal handler was connected.

Since 3.2

### The `"window-removed"` signal

    void                user_function                      (GtkApplication *application,
                                                            GtkWindow      *window,
                                                            gpointer        user_data)        : Run First

Emitted when a GtkWindow is removed from `application`, either as a side-effect of being destroyed or explicitly through `gtk_application_remove_window()`.

`application` : | the GtkApplication which emitted the signal
`window` : | the GtkWindow that is being removed
`user_data` : | user data set when the signal handler was connected.

Since 3.2