## GtkUIManager

GtkUIManager — constructing menus and toolbars from an XML description

## Synopsis

    #include <gtk/gtk.h>

    struct      GtkUIManager;
    GtkUIManager* gtk_ui_manager_new            (void);
    void        gtk_ui_manager_set_add_tearoffs (GtkUIManager *self,
                                                 gboolean add_tearoffs);
    gboolean    gtk_ui_manager_get_add_tearoffs (GtkUIManager *self);
    void        gtk_ui_manager_insert_action_group
                                                (GtkUIManager *self,
                                                 GtkActionGroup *action_group,
                                                 gint pos);
    void        gtk_ui_manager_remove_action_group
                                                (GtkUIManager *self,
                                                 GtkActionGroup *action_group);
    GList*      gtk_ui_manager_get_action_groups
                                                (GtkUIManager *self);
    GtkAccelGroup* gtk_ui_manager_get_accel_group
                                                (GtkUIManager *self);
    GtkWidget*  gtk_ui_manager_get_widget       (GtkUIManager *self,
                                                 const gchar *path);
    GSList*     gtk_ui_manager_get_toplevels    (GtkUIManager *self,
                                                 GtkUIManagerItemType types);
    GtkAction*  gtk_ui_manager_get_action       (GtkUIManager *self,
                                                 const gchar *path);
    guint       gtk_ui_manager_add_ui_from_string
                                                (GtkUIManager *self,
                                                 const gchar *buffer,
                                                 gssize length,
                                                 GError **error);
    guint       gtk_ui_manager_add_ui_from_file (GtkUIManager *self,
                                                 const gchar *filename,
                                                 GError **error);
    guint       gtk_ui_manager_new_merge_id     (GtkUIManager *self);
    enum        GtkUIManagerItemType;
    void        gtk_ui_manager_add_ui           (GtkUIManager *self,
                                                 guint merge_id,
                                                 const gchar *path,
                                                 const gchar *name,
                                                 const gchar *action,
                                                 GtkUIManagerItemType type,
                                                 gboolean top);
    void        gtk_ui_manager_remove_ui        (GtkUIManager *self,
                                                 guint merge_id);
    gchar*      gtk_ui_manager_get_ui           (GtkUIManager *self);
    void        gtk_ui_manager_ensure_update    (GtkUIManager *self);

## Object Hierarchy

      GObject
       +----GtkUIManager

## Properties

      "add-tearoffs"         gboolean              : Read / Write
      "ui"                   gchararray            : Read

## Signal Prototypes

    "actions-changed"
                void        user_function      (GtkUIManager *merge,
                                                gpointer user_data);
    "add-widget"
                void        user_function      (GtkUIManager *merge,
                                                GtkWidget *widget,
                                                gpointer user_data);
    "connect-proxy"
                void        user_function      (GtkUIManager *uimanager,
                                                GtkAction *action,
                                                GtkWidget *proxy,
                                                gpointer user_data);
    "disconnect-proxy"
                void        user_function      (GtkUIManager *uimanager,
                                                GtkAction *action,
                                                GtkWidget *proxy,
                                                gpointer user_data);
    "post-activate"
                void        user_function      (GtkUIManager *uimanager,
                                                GtkAction *action,
                                                gpointer user_data);
    "pre-activate"
                void        user_function      (GtkUIManager *uimanager,
                                                GtkAction *action,
                                                gpointer user_data);

## Description

A GtkUIManager constructs a user interface (menus and toolbars) from one or more UI definitions, which reference actions from one or more action groups.

### UI Definitions

The UI definitions are specified in an XML format which can be roughly described by the following DTD.

    <!ELEMENT ui          (menubar|toolbar|popup|accelerator)* >
    <!ELEMENT menubar     (menuitem|separator|placeholder|menu)* >
    <!ELEMENT menu        (menuitem|separator|placeholder|menu)* >
    <!ELEMENT popup       (menuitem|separator|placeholder|menu)* >
    <!ELEMENT toolbar     (toolitem|separator|placeholder)* >
    <!ELEMENT placeholder (menuitem|toolitem|separator|placeholder|menu)* >
    <!ELEMENT menuitem     EMPTY >
    <!ELEMENT toolitem     EMPTY >
    <!ELEMENT separator    EMPTY >
    <!ELEMENT accelerator  EMPTY >
    <!ATTLIST menubar      name               #IMPLIED
                           action             #IMPLIED >
    <!ATTLIST toolbar      name               #IMPLIED
                           action             #IMPLIED >
    <!ATTLIST popup        name               #IMPLIED
                           action             #IMPLIED >
    <!ATTLIST placeholder  name               #IMPLIED
                           action             #IMPLIED >
    <!ATTLIST separator    name               #IMPLIED
                           action             #IMPLIED >
    <!ATTLIST menu         name               #IMPLIED
                           action             #REQUIRED
                           position (top|bot) #IMPLIED >
    <!ATTLIST menuitem     name               #IMPLIED
                           action             #REQUIRED
                           position (top|bot) #IMPLIED >
    <!ATTLIST toolitem     name               #IMPLIED
                           action             #REQUIRED
                           position (top|bot) #IMPLIED >
    <!ATTLIST accelerator  name               #IMPLIED
                           action             #REQUIRED >

There are some additional restrictions beyond those specified in the DTD, e.g. every toolitem must have a toolbar in its anchestry and every menuitem must have a menubar or popup in its anchestry. Since a GMarkup parser is used to parse the UI description, it must not only be valid XML, but valid GMarkup.

If a name is not specified, it defaults to the action. If an action is not specified either, the element name is used. The name and action attributes must not contain '/' characters after parsing (since that would mess up path lookup) and must be usable as XML attributes when enclosed in doublequotes, thus they must not '"' characters or references to the &quot; entity.

Example 1. A UI definition

    <ui>
      <menubar>
        <menu name="FileMenu" action="FileMenuAction">
          <menuitem name="New" action="New2Action" />
          <placeholder name="FileMenuAdditions" />
        </menu>
        <menu name="JustifyMenu" action="JustifyMenuAction">
          <menuitem name="Left" action="justify-left"/>
          <menuitem name="Centre" action="justify-center"/>
          <menuitem name="Right" action="justify-right"/>
          <menuitem name="Fill" action="justify-fill"/>
        </menu>
      </menubar>
      <toolbar action="toolbar1">
        <placeholder name="JustifyToolItems">
          <separator/>
          <toolitem name="Left" action="justify-left"/>
          <toolitem name="Centre" action="justify-center"/>
          <toolitem name="Right" action="justify-right"/>
          <toolitem name="Fill" action="justify-fill"/>
          <separator/>
        </placeholder>
      </toolbar>
    </ui>

The constructed widget hierarchy is very similar to the element tree of the XML, with the exception that placeholders are merged into their parents. The correspondence of XML elements to widgets should be almost obvious:

menubar | a GtkMenuBar
toolbar | a GtkToolbar
popup | a toplevel GtkMenu
menu | a GtkMenu attached to a menuitem
menuitem | a GtkMenuItem subclass, the exact type depends on the action
toolitem | a GtkToolItem subclass, the exact type depends on the action
separator | a GtkSeparatorMenuItem or GtkSeparatorToolItem
accelerator | a keyboard accelerator

The "position" attribute determines where a constructed widget is positioned wrt. to its siblings in the partially constructed tree. If it is "top", the widget is prepended, otherwise it is appended.

### UI Merging

The most remarkable feature of GtkUIManager is that it can overlay a set of menuitems and toolitems over another one, and demerge them later.

Merging is done based on the names of the XML elements. Each element is identified by a path which consists of the names of its anchestors, separated by slashes. For example, the menuitem named "Left" in the example above has the path `/ui/menubar/JustifyMenu/Left` and the toolitem with the same name has path `/ui/toolbar1/JustifyToolItems/Left`.

### Accelerators

Every action has an accelerator path. Accelerators are installed together with menuitem proxies, but they can also be explicitly added with <accelerator> elements in the UI definition. This makes it possible to have accelerators for actions even if they have no visible proxies.

### Smart Separators

The separators created by GtkUIManager are "smart", i.e. they do not show up in the UI unless they end up between two visible menu or tool items. Separators which are located at the very beginning or end of the menu or toolbar containing them, or multiple separators next to each other, are hidden. This is a useful feature, since the merging of UI elements from multiple sources can make it hard or impossible to determine in advance whether a separator will end up in such an unfortunate position.

### Empty Menus

Submenus pose similar problems to separators inconnection with merging. It is impossible to know in advance whether they will end up empty after merging. GtkUIManager offers two ways to treat empty submenus:

- make them disappear by hiding the menu item they're attached to

- add an insensitive "Empty" item

The behaviour is chosen based on the "is_important" property of the action to which the submenu is associated.

## Details

### struct GtkUIManager

    struct GtkUIManager;

The GtkUIManager struct contains only private members and should not be accessed directly.

### gtk_ui_manager_new ()

    GtkUIManager* gtk_ui_manager_new            (void);

Creates a new ui manager object.

Returns : | a new ui manager object.

Since 2.4

### gtk_ui_manager_set_add_tearoffs ()

    void        gtk_ui_manager_set_add_tearoffs (GtkUIManager *self,
                                                 gboolean add_tearoffs);

Sets the "add_tearoffs" property, which controls whether menus generated by this GtkUIManager will have tearoff menu items.

Note that this only affects regular menus. Generated popup menus never have tearoff menu items.

`self` : | a GtkUIManager
`add_tearoffs` : | whether tearoff menu items are added

Since 2.4

### gtk_ui_manager_get_add_tearoffs ()

    gboolean    gtk_ui_manager_get_add_tearoffs (GtkUIManager *self);

Returns whether menus generated by this GtkUIManager will have tearoff menu items.

`self` : | a GtkUIManager
Returns : | whether tearoff menu items are added

Since 2.4

### gtk_ui_manager_insert_action_group ()

    void        gtk_ui_manager_insert_action_group
                                                (GtkUIManager *self,
                                                 GtkActionGroup *action_group,
                                                 gint pos);

Inserts an action group into the list of action groups associated with `self`. Actions in earlier groups hide actions with the same name in later groups.

`self` : | a GtkUIManager object
`action_group` : | the action group to be inserted
`pos` : | the position at which the group will be inserted.

Since 2.4

### gtk_ui_manager_remove_action_group ()

    void        gtk_ui_manager_remove_action_group
                                                (GtkUIManager *self,
                                                 GtkActionGroup *action_group);

Removes an action group from the list of action groups associated with `self`.

`self` : | a GtkUIManager object
`action_group` : | the action group to be removed

Since 2.4

### gtk_ui_manager_get_action_groups ()

    GList*      gtk_ui_manager_get_action_groups
                                                (GtkUIManager *self);

Returns the list of action groups associated with `self`.

`self` : | a GtkUIManager object
Returns : | a GList of action groups. The list is owned by GTK+ and should not be modified.

Since 2.4

### gtk_ui_manager_get_accel_group ()

    GtkAccelGroup* gtk_ui_manager_get_accel_group
                                                (GtkUIManager *self);

Returns the GtkAccelGroup associated with `self`.

`self` : | a GtkUIManager object
Returns : | the GtkAccelGroup.

Since 2.4

### gtk_ui_manager_get_widget ()

    GtkWidget*  gtk_ui_manager_get_widget       (GtkUIManager *self,
                                                 const gchar *path);

Looks up a widget by following a path. The path consists of the names specified in the XML description of the UI. separated by '/'. Elements which don't have a name or action attribute in the XML (e.g. <popup>) can be addressed by their XML element name (e.g. "popup"). The root element ("/ui") can be omitted in the path.

Note that the widget found by following a path that ends in a <menu> element is the menuitem to which the menu is attached, not the menu itself.

`self` : | a GtkUIManager
`path` : | a path
Returns : | the widget found by following the path, or `NULL` if no widget was found.

Since 2.4

### gtk_ui_manager_get_toplevels ()

    GSList*     gtk_ui_manager_get_toplevels    (GtkUIManager *self,
                                                 GtkUIManagerItemType types);

Obtains a list of all toplevel widgets of the requested types.

`self` : | a GtkUIManager
`types` : | specifies the types of toplevel widgets to include. Allowed types are GTK_UI_MANAGER_MENUBAR, GTK_UI_MANAGER_TOOLBAR and GTK_UI_MANAGER_POPUP.
Returns : | a newly-allocated of all toplevel widgets of the requested types.

Since 2.4

### gtk_ui_manager_get_action ()

    GtkAction*  gtk_ui_manager_get_action       (GtkUIManager *self,
                                                 const gchar *path);

Looks up an action by following a path. See `gtk_ui_manager_get_widget()` for more information about paths.

`self` : | a GtkUIManager
`path` : | a path
Returns : | the action whose proxy widget is found by following the path, or `NULL` if no widget was found.

Since 2.4

### gtk_ui_manager_add_ui_from_string ()

    guint       gtk_ui_manager_add_ui_from_string
                                                (GtkUIManager *self,
                                                 const gchar *buffer,
                                                 gssize length,
                                                 GError **error);

Parses a string containing a UI definition and merges it with the current contents of `self`. An enclosing <ui> element is added if it is missing.

`self` : | a GtkUIManager object
`buffer` : | the string to parse
`length` : | the length of `buffer` (may be -1 if `buffer` is nul-terminated)
`error` : | return location for an error
Returns : | The merge id for the merged UI. The merge id can be used to unmerge the UI with `gtk_ui_manager_remove_ui()`. If an error occurred, the return value is 0.

Since 2.4

### gtk_ui_manager_add_ui_from_file ()

    guint       gtk_ui_manager_add_ui_from_file (GtkUIManager *self,
                                                 const gchar *filename,
                                                 GError **error);

Parses a file containing a UI definition and merges it with the current contents of `self`.

`self` : | a GtkUIManager object
`filename` : | the name of the file to parse
`error` : | return location for an error
Returns : | The merge id for the merged UI. The merge id can be used to unmerge the UI with `gtk_ui_manager_remove_ui()`. If an error occurred, the return value is 0.

Since 2.4

### gtk_ui_manager_new_merge_id ()

    guint       gtk_ui_manager_new_merge_id     (GtkUIManager *self);

Returns an unused merge id, suitable for use with `gtk_ui_manager_add_ui()`.

`self` : | a GtkUIManager
Returns : | an unused merge id.

Since 2.4

### enum GtkUIManagerItemType

    typedef enum {
      GTK_UI_MANAGER_AUTO         = 0,
      GTK_UI_MANAGER_MENUBAR      = 1 << 0,
      GTK_UI_MANAGER_MENU         = 1 << 1,
      GTK_UI_MANAGER_TOOLBAR      = 1 << 2,
      GTK_UI_MANAGER_PLACEHOLDER  = 1 << 3,
      GTK_UI_MANAGER_POPUP        = 1 << 4,
      GTK_UI_MANAGER_MENUITEM     = 1 << 5,
      GTK_UI_MANAGER_TOOLITEM     = 1 << 6,
      GTK_UI_MANAGER_SEPARATOR    = 1 << 7,
      GTK_UI_MANAGER_ACCELERATOR  = 1 << 8
    } GtkUIManagerItemType;

These enumeration values are used by `gtk_ui_manager_add_ui()` to determine what UI element to create.

`GTK_UI_MANAGER_AUTO` | Pick the type of the UI element according to context.
`GTK_UI_MANAGER_MENUBAR` | Create a menubar.
`GTK_UI_MANAGER_MENU` | Create a menu.
`GTK_UI_MANAGER_TOOLBAR` | Create a toolbar.
`GTK_UI_MANAGER_PLACEHOLDER` | Insert a placeholder.
`GTK_UI_MANAGER_POPUP` | Create a popup menu.
`GTK_UI_MANAGER_MENUITEM` | Create a menuitem.
`GTK_UI_MANAGER_TOOLITEM` | Create a toolitem.
`GTK_UI_MANAGER_SEPARATOR` | Create a separator.
`GTK_UI_MANAGER_ACCELERATOR` | Install an accelerator.

### gtk_ui_manager_add_ui ()

    void        gtk_ui_manager_add_ui           (GtkUIManager *self,
                                                 guint merge_id,
                                                 const gchar *path,
                                                 const gchar *name,
                                                 const gchar *action,
                                                 GtkUIManagerItemType type,
                                                 gboolean top);

Adds a UI element to the current contents of `self`.

If `type` is `GTK_UI_MANAGER_AUTO`, GTK+ inserts a menuitem, toolitem or separator if such an element can be inserted at the place determined by `path`. Otherwise `type` must indicate an element that can be inserted at the place determined by `path`.

`self` : | a GtkUIManager
`merge_id` : | the merge id for the merged UI, see `gtk_ui_manager_new_merge_id()`
`path` : | a path
`name` : | the name for the added UI element
`action` : | the name of the action to be proxied, or `NULL` to add a separator
`type` : | the type of UI element to add.
`top` : | if `TRUE`, the UI element is added before its siblings, otherwise it is added after its siblings.

Since 2.4

### gtk_ui_manager_remove_ui ()

    void        gtk_ui_manager_remove_ui        (GtkUIManager *self,
                                                 guint merge_id);

Unmerges the part of `self`s content identified by `merge_id`.

`self` : | a GtkUIManager object
`merge_id` : | a merge id as returned by `gtk_ui_manager_add_ui_from_string()`

Since 2.4

### gtk_ui_manager_get_ui ()

    gchar*      gtk_ui_manager_get_ui           (GtkUIManager *self);

Creates a UI definition of the merged UI.

`self` : | a GtkUIManager
Returns : | A newly allocated string containing an XML representation of the merged UI.

Since 2.4

### gtk_ui_manager_ensure_update ()

    void        gtk_ui_manager_ensure_update    (GtkUIManager *self);

Makes sure that all pending updates to the UI have been completed.

This may occasionally be necessary, since GtkUIManager updates the UI in an idle function. A typical example where this function is useful is to enforce that the menubar and toolbar have been added to the main window before showing it:

    gtk_container_add (GTK_CONTAINER (window), vbox);
    g_signal_connect (merge, "add_widget",
                      G_CALLBACK (add_widget), vbox);
    gtk_ui_manager_add_ui_from_file (merge, "my-menus");
    gtk_ui_manager_add_ui_from_file (merge, "my-toolbars");
    gtk_ui_manager_ensure_update (merge);
    gtk_widget_show (window);

`self` : | a GtkUIManager

Since 2.4

## Properties

### The "`add-tearoffs`" property

      "add-tearoffs"         gboolean              : Read / Write

The "add-tearoffs" property controls whether generated menus have tearoff menu items.

Note that this only affects regular menus. Generated popup menus never have tearoff menu items.

Default value: FALSE

Since 2.4

### The "`ui`" property

      "ui"                   gchararray            : Read

An XML string describing the merged UI.

Default value: NULL

## Signals

### The "actions-changed" signal

    void        user_function                  (GtkUIManager *merge,
                                                gpointer user_data);

The "actions-changed" signal is emitted whenever the set of actions changes.

`merge` : | a GtkUIManager
`user_data` : | user data set when the signal handler was connected.

Since 2.4

### The "add-widget" signal

    void        user_function                  (GtkUIManager *merge,
                                                GtkWidget *widget,
                                                gpointer user_data);

The add_widget signal is emitted for each generated menubar and toolbar. It is not emitted for generated popup menus, which can be obtained by `gtk_ui_manager_get_widget()`.

`merge` : | a GtkUIManager
`widget` : | the added widget
`user_data` : | user data set when the signal handler was connected.

Since 2.4

### The "connect-proxy" signal

    void        user_function                  (GtkUIManager *uimanager,
                                                GtkAction *action,
                                                GtkWidget *proxy,
                                                gpointer user_data);

The connect_proxy signal is emitted after connecting a proxy to an action in the group.

This is intended for simple customizations for which a custom action class would be too clumsy, e.g. showing tooltips for menuitems in the statusbar.

`uimanager` : | the ui manager
`action` : | the action
`proxy` : | the proxy
`user_data` : | user data set when the signal handler was connected.

Since 2.4

### The "disconnect-proxy" signal

    void        user_function                  (GtkUIManager *uimanager,
                                                GtkAction *action,
                                                GtkWidget *proxy,
                                                gpointer user_data);

The disconnect_proxy signal is emitted after disconnecting a proxy from an action in the group.

`uimanager` : | the ui manager
`action` : | the action
`proxy` : | the proxy
`user_data` : | user data set when the signal handler was connected.

Since 2.4

### The "post-activate" signal

    void        user_function                  (GtkUIManager *uimanager,
                                                GtkAction *action,
                                                gpointer user_data);

The post_activate signal is emitted just after the `action` is activated.

This is intended for applications to get notification just after any action is activated.

`uimanager` : | the ui manager
`action` : | the action
`user_data` : | user data set when the signal handler was connected.

Since 2.4

### The "pre-activate" signal

    void        user_function                  (GtkUIManager *uimanager,
                                                GtkAction *action,
                                                gpointer user_data);

The pre_activate signal is emitted just before the `action` is activated.

This is intended for applications to get notification just before any action is activated.

`uimanager` : | the ui manager
`action` : | the action
`user_data` : | user data set when the signal handler was connected.

Since 2.4