gtk2/docs/reference/gtk/tmpl/gtkuimanager.sgml

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GtkUIManager

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Constructing menus and toolbars from an XML description

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<para>
A #GtkUIManager constructs a user interface (menus and toolbars) from
one or more UI definitions, which reference actions from one or more 
action groups. 
</para>
<refsect2 id="XML-UI"><title>UI Definitions</title>
<para>
The UI definitions are specified in an XML format which can be
roughly described by the following DTD. 
<programlisting>
&lt;!ELEMENT ui          (menubar|toolbar|popup|accelerator)* &gt;
&lt;!ELEMENT menubar     (menuitem|separator|placeholder|menu)* &gt;
&lt;!ELEMENT menu        (menuitem|separator|placeholder|menu)* &gt;
&lt;!ELEMENT popup       (menuitem|separator|placeholder|menu)* &gt;
&lt;!ELEMENT toolbar     (toolitem|separator|placeholder)* &gt;
&lt;!ELEMENT placeholder (menuitem|toolitem|separator|placeholder|menu)* &gt;
&lt;!ELEMENT menuitem     EMPTY &gt;
&lt;!ELEMENT toolitem     EMPTY &gt;
&lt;!ELEMENT separator    EMPTY &gt;
&lt;!ELEMENT accelerator  EMPTY &gt;
&lt;!ATTLIST menubar      name                  &num;IMPLIED 
                       action                &num;IMPLIED &gt;
&lt;!ATTLIST toolbar      name                  &num;IMPLIED 
                       action                &num;IMPLIED &gt;
&lt;!ATTLIST popup        name                  &num;IMPLIED 
                       action                &num;IMPLIED &gt;
&lt;!ATTLIST placeholder  name                  &num;IMPLIED
                       action                &num;IMPLIED &gt;
&lt;!ATTLIST separator    name                  &num;IMPLIED
                       action                &num;IMPLIED
                       expand   (true|false) &num;IMPLIED &gt;
&lt;!ATTLIST menu         name                  &num;IMPLIED
                       action                &num;REQUIRED
                       position (top|bot)    &num;IMPLIED &gt;
&lt;!ATTLIST menuitem     name                  &num;IMPLIED
                       action                &num;REQUIRED
                       position (top|bot)    &num;IMPLIED &gt;
&lt;!ATTLIST toolitem     name                  &num;IMPLIED
                       action                &num;REQUIRED
                       position (top|bot)    &num;IMPLIED &gt;
&lt;!ATTLIST accelerator  name                  &num;IMPLIED
                       action                &num;REQUIRED &gt;
</programlisting>
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. 
</para>
<para>
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 &amp;quot; entity.
</para>
<example>
<title>A UI definition</title>
<programlisting>
&lt;ui&gt;
  &lt;menubar&gt;
    &lt;menu name="FileMenu" action="FileMenuAction"&gt;
      &lt;menuitem name="New" action="New2Action" /&gt;
      &lt;placeholder name="FileMenuAdditions" /&gt;
    &lt;/menu&gt;
    &lt;menu name="JustifyMenu" action="JustifyMenuAction"&gt;
      &lt;menuitem name="Left" action="justify-left"/&gt;
      &lt;menuitem name="Centre" action="justify-center"/&gt;
      &lt;menuitem name="Right" action="justify-right"/&gt;
      &lt;menuitem name="Fill" action="justify-fill"/&gt;
    &lt;/menu&gt;
  &lt;/menubar&gt;
  &lt;toolbar action="toolbar1"&gt;
    &lt;placeholder name="JustifyToolItems"&gt;
      &lt;separator/&gt;
      &lt;toolitem name="Left" action="justify-left"/&gt;
      &lt;toolitem name="Centre" action="justify-center"/&gt;
      &lt;toolitem name="Right" action="justify-right"/&gt;
      &lt;toolitem name="Fill" action="justify-fill"/&gt;
      &lt;separator/&gt;
    &lt;/placeholder&gt;
  &lt;/toolbar&gt;
&lt;/ui&gt;
</programlisting>
</example>
<para>
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: 
<variablelist>
<varlistentry><term>menubar</term>
<listitem><para>a #GtkMenuBar</para></listitem>
</varlistentry>
<varlistentry><term>toolbar</term>
<listitem><para>a #GtkToolbar</para></listitem>
</varlistentry>
<varlistentry><term>popup</term>
<listitem><para>a toplevel #GtkMenu</para></listitem>
</varlistentry>
<varlistentry><term>menu</term>
<listitem><para>a #GtkMenu attached to a menuitem</para></listitem>
</varlistentry>
<varlistentry><term>menuitem</term>
<listitem><para>a #GtkMenuItem subclass, the exact type depends on the
action</para></listitem> 
</varlistentry>
<varlistentry><term>toolitem</term>
<listitem><para>a #GtkToolItem subclass, the exact type depends on the
action</para></listitem> 
</varlistentry>
<varlistentry><term>separator</term>
<listitem><para>a #GtkSeparatorMenuItem or
#GtkSeparatorToolItem</para></listitem> 
</varlistentry>
<varlistentry><term>accelerator</term>
<listitem><para>a keyboard accelerator</para></listitem> 
</varlistentry>
</variablelist>
</para>
<para>
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.
</para>
</refsect2>
<refsect2 id="UI-Merging">
<title>UI Merging</title>
<para>
The most remarkable feature of #GtkUIManager is that it can overlay a set
of menuitems and toolitems over another one, and demerge them later.
</para>
<para>
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 <literal>/ui/menubar/JustifyMenu/Left</literal> and the
toolitem with the same name has path 
<literal>/ui/toolbar1/JustifyToolItems/Left</literal>.
</para>
</refsect2>
<refsect2>
<title>Accelerators</title>
<para>
Every action has an accelerator path. Accelerators are installed together with
menuitem proxies, but they can also be explicitly added with &lt;accelerator&gt;
elements in the UI definition. This makes it possible to have accelerators for
actions even if they have no visible proxies.
</para>
</refsect2>
<refsect2 id="Smart-Separators">
<title>Smart Separators</title>
<para>
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.
</para>

<para>
For separators in toolbars, you can set <literal>expand="true"</literal> to
turn them from a small, visible separator to an expanding, invisible one.
Toolitems following an expanding separator are effectively right-aligned.
</para>
</refsect2>
<refsect2>
<title>Empty Menus</title>
<para>
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:
<itemizedlist>
<listitem><para>make them disappear by hiding the menu item they're attached to
</para></listitem>
<listitem><para>add an insensitive "Empty" item
</para></listitem>
</itemizedlist>
The behaviour is chosen based on the "hide_if_empty" property of the action 
to which the submenu is associated.
</para>
</refsect2>

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<para>

</para>

<!-- ##### STRUCT GtkUIManager ##### -->
<para>
The <structname>GtkUIManager</structname> struct contains only private
members and should not be accessed directly.
</para>


<!-- ##### SIGNAL GtkUIManager::actions-changed ##### -->
<para>

</para>

@uimanager: the object which received the signal.

<!-- ##### SIGNAL GtkUIManager::add-widget ##### -->
<para>

</para>

@uimanager: the object which received the signal.
@widget: 

<!-- ##### SIGNAL GtkUIManager::connect-proxy ##### -->
<para>

</para>

@uimanager: the object which received the signal.
@arg1: 
@widget: 

<!-- ##### SIGNAL GtkUIManager::disconnect-proxy ##### -->
<para>

</para>

@uimanager: the object which received the signal.
@arg1: 
@widget: 

<!-- ##### SIGNAL GtkUIManager::post-activate ##### -->
<para>

</para>

@uimanager: the object which received the signal.
@arg1: 

<!-- ##### SIGNAL GtkUIManager::pre-activate ##### -->
<para>

</para>

@uimanager: the object which received the signal.
@arg1: 

<!-- ##### ARG GtkUIManager:add-tearoffs ##### -->
<para>

</para>

<!-- ##### ARG GtkUIManager:ui ##### -->
<para>

</para>

<!-- ##### FUNCTION gtk_ui_manager_new ##### -->
<para>

</para>

@Returns: 


<!-- ##### FUNCTION gtk_ui_manager_set_add_tearoffs ##### -->
<para>

</para>

@self: 
@add_tearoffs: 


<!-- ##### FUNCTION gtk_ui_manager_get_add_tearoffs ##### -->
<para>

</para>

@self: 
@Returns: 


<!-- ##### FUNCTION gtk_ui_manager_insert_action_group ##### -->
<para>

</para>

@self: 
@action_group: 
@pos: 


<!-- ##### FUNCTION gtk_ui_manager_remove_action_group ##### -->
<para>

</para>

@self: 
@action_group: 


<!-- ##### FUNCTION gtk_ui_manager_get_action_groups ##### -->
<para>

</para>

@self: 
@Returns: 


<!-- ##### FUNCTION gtk_ui_manager_get_accel_group ##### -->
<para>

</para>

@self: 
@Returns: 


<!-- ##### FUNCTION gtk_ui_manager_get_widget ##### -->
<para>

</para>

@self: 
@path: 
@Returns: 


<!-- ##### FUNCTION gtk_ui_manager_get_toplevels ##### -->
<para>

</para>

@self: 
@types: 
@Returns: 


<!-- ##### FUNCTION gtk_ui_manager_get_action ##### -->
<para>

</para>

@self: 
@path: 
@Returns: 


<!-- ##### FUNCTION gtk_ui_manager_add_ui_from_string ##### -->
<para>

</para>

@self: 
@buffer: 
@length: 
@error: 
@Returns: 


<!-- ##### FUNCTION gtk_ui_manager_add_ui_from_file ##### -->
<para>

</para>

@self: 
@filename: 
@error: 
@Returns: 


<!-- ##### FUNCTION gtk_ui_manager_new_merge_id ##### -->
<para>

</para>

@self: 
@Returns: 


<!-- ##### ENUM GtkUIManagerItemType ##### -->
<para>
These enumeration values are used by gtk_ui_manager_add_ui() to determine
what UI element to create.
</para>

@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.

<!-- ##### FUNCTION gtk_ui_manager_add_ui ##### -->
<para>

</para>

@self: 
@merge_id: 
@path: 
@name: 
@action: 
@type: 
@top: 


<!-- ##### FUNCTION gtk_ui_manager_remove_ui ##### -->
<para>

</para>

@self: 
@merge_id: 


<!-- ##### FUNCTION gtk_ui_manager_get_ui ##### -->
<para>

</para>

@self: 
@Returns: 


<!-- ##### FUNCTION gtk_ui_manager_ensure_update ##### -->
<para>

</para>

@self: