Small additions and corrections

[~andy/gtk] / docs / reference / gtk / tmpl / gtkbindings.sgml

<!-- ##### SECTION Title ##### -->
Bindings

<!-- ##### SECTION Short_Description ##### -->
Key bindings for individual widgets

<!-- ##### SECTION Long_Description ##### -->
<para>
GtkBinding provides a mechanism for configuring GTK+ key bindings through 
RC files. This eases key binding adjustments for application developers as 
well as users and provides GTK+ users or administrators with high key 
binding configurability which requires no application or toolkit side changes.
</para>

<refsect2>
<anchor id="gtk-bindings-install"/>
<title>Installing a key binding</title>

<para>
A resource file binding consists of a 'binding' definition and a match 
statement to apply the binding to specific widget types. Details on the 
matching mechanism are described under 
<link linkend="gtkrc-pathnames-and-patterns">Pathnames and patterns</link>.
Inside the binding definition, key combinations are bound to specific signal 
emissions on the target widget. Key combinations are strings consisting of 
an optional #GdkModifierType name and 
<link linkend="gdk-Keyboard-Handling">key names</link> such as those defined 
in <filename>&lt;gdk/gdkkeysyms.h&gt;</filename> or returned from 
gdk_keyval_name(), they have to be parsable by gtk_accelerator_parse().
Specifications of signal emissions consist of a string identifying the signal 
name, and a list of signal specific arguments in parenthesis.
</para>
<para>
For example for binding Control and the left or right cursor keys of a 
#GtkEntry widget to the #GtkEntry::move-cursor signal, so movement occurs 
in 3 letter steps, the following binding can be used:

<informalexample><programlisting>
binding "MoveCursor3" {
  bind "&lt;Control&gt;Right" {
    "move-cursor" (visual-positions, 3, 0)
  }
  bind "&lt;Control&gt;Left" {
    "move-cursor" (visual-positions, -3, 0)
  }
}
class "GtkEntry" binding "MoveCursor3"
</programlisting></informalexample>
</para>


<anchor id="gtk-bindings-unbind"/>
<title>Unbinding existing key bindings</title>
<para>
GTK+ already defines a number of useful bindings for the widgets it provides.
Because custom bindings set up in RC files take precedence over the default 
bindings shipped with GTK+, overriding existing bindings as demonstrated in 
<link linkend="gtk-bindings-install">Installing a key binding</link>
works as expected. The same mechanism can not be used to "unbind" existing 
bindings, however.

<informalexample><programlisting>
binding "MoveCursor3" {
  bind "&lt;Control&gt;Right" { }
  bind "&lt;Control&gt;Left" { }
}
class "GtkEntry" binding "MoveCursor3"
</programlisting></informalexample>

The above example will not have the desired effect of causing 
"&lt;Control&gt;Right" and "&lt;Control&gt;Left" key presses to be ignored 
by GTK+. Instead, it just causes any existing bindings from the bindings 
set "MoveCursor3" to be deleted, so when "&lt;Control&gt;Right" or 
"&lt;Control&gt;Left" are pressed, no binding for these keys is found in 
binding set "MoveCursor3". GTK+ will thus continue to search for matching
key bindings, and will eventually lookup and find the default GTK+ bindings 
for entries which implement word movement. To keep GTK+ from activating its 
default bindings, the "unbind" keyword can be used like this:

<informalexample><programlisting>
binding "MoveCursor3" {
  unbind "&lt;Control&gt;Right"
  unbind "&lt;Control&gt;Left"
}
class "GtkEntry" binding "MoveCursor3"
</programlisting></informalexample>

Now, GTK+ will find a match when looking up "&lt;Control&gt;Right" and 
"&lt;Control&gt;Left" key presses before it resorts to its default 
bindings, and the match instructs it to abort ("unbind") the search, so 
the key presses are not consumed by this widget. As usual, further processing 
of the key presses, e.g. by an entry's parent widget, is now possible.
</para>

<para>
The "unbind" functionality has been introduced in GTK+ 2.12.
</para>

</refsect2>

<!-- ##### SECTION See_Also ##### -->
<para>
<variablelist>

<varlistentry>
<term><link linkend="gtk-keyboard-accelerators">Keyboard Accelerators</link>
</term>
<listitem><para>installing and using keyboard short-cuts.</para></listitem>
</varlistentry>

<varlistentry>
<term><link linkend="Resource-Files">Resource Files</link>
</term>
<listitem><para>GTK+ Resource Files - behavior and style definitions.</para></listitem>
</varlistentry>

</variablelist>
</para>

<!-- ##### SECTION Stability_Level ##### -->


<!-- ##### STRUCT GtkBindingSet ##### -->
<para>
A binding set maintains a list of activatable key bindings.
A single binding set can match multiple types of widgets.
Similar to styles, widgets can be mapped by widget name paths, widget 
class paths or widget class types.  When a binding within a set is 
matched upon activation, an action signal is emitted on the target 
widget to carry out the actual activation.
</para>

@set_name:              unique binding set name
@priority:              unused
@widget_path_pspecs:    widgets matched by path that this binding set applies to
@widget_class_pspecs:   widgets matched by class path that this binding set applies to
@class_branch_pspecs:   widgets matched by class that this binding set applies to
@entries:               the key binding entries in this binding set
@current:               implementation detail
@parsed:                whether this binding set stems from an RC file and is reset upon theme changes

<!-- ##### STRUCT GtkBindingEntry ##### -->
<para>
Each key binding element of a binding sets binding list is represented by 
a #GtkBindingEntry.
</para>

@keyval:        key value to match
@modifiers:     key modifier to match
@binding_set:   binding set this entry belongs to
@destroyed:     implementation detail
@in_emission:   implementation detail
@marks_unbound: implementation detail
@set_next:      linked list of entries maintained by binding set
@hash_next:     implementation detail
@signals:       action signals of this entry

<!-- ##### STRUCT GtkBindingSignal ##### -->
<para>
A #GtkBindingSignal stores the necessary information to activate a widget
in response to a key press via a signal emission.
</para>

@next:          implementation detail
@signal_name:   the action signal to be emitted
@n_args:        number of arguments specified for the signal
@args:          the arguments specified for the signal

<!-- ##### STRUCT GtkBindingArg ##### -->
<para>
A #GtkBindingArg holds the data associated with an argument for a
key binding signal emission as stored in #GtkBindingSignal.
</para>

@arg_type: implementation detail

<!-- ##### MACRO gtk_binding_entry_add ##### -->
<para>
Deprecated.
</para>



<!-- ##### FUNCTION gtk_binding_entry_add_signall ##### -->
<para>

</para>

@binding_set: 
@keyval: 
@modifiers: 
@signal_name: 
@binding_args: 


<!-- ##### FUNCTION gtk_binding_entry_clear ##### -->
<para>

</para>

@binding_set: 
@keyval: 
@modifiers: 


<!-- ##### FUNCTION gtk_binding_parse_binding ##### -->
<para>

</para>

@scanner: 
@Returns: 


<!-- ##### FUNCTION gtk_binding_set_new ##### -->
<para>

</para>

@set_name: 
@Returns: 


<!-- ##### FUNCTION gtk_binding_set_by_class ##### -->
<para>

</para>

@object_class: 
@Returns: 


<!-- ##### FUNCTION gtk_binding_set_find ##### -->
<para>

</para>

@set_name: 
@Returns: 


<!-- ##### FUNCTION gtk_bindings_activate ##### -->
<para>

</para>

@object: 
@keyval: 
@modifiers: 
@Returns: 


<!-- ##### FUNCTION gtk_bindings_activate_event ##### -->
<para>

</para>

@object: 
@event: 
@Returns: 


<!-- ##### FUNCTION gtk_binding_set_activate ##### -->
<para>

</para>

@binding_set: 
@keyval: 
@modifiers: 
@object: 
@Returns: 


<!-- ##### FUNCTION gtk_binding_entry_add_signal ##### -->
<para>

</para>

@binding_set: 
@keyval: 
@modifiers: 
@signal_name: 
@n_args: 
@Varargs: 


<!-- ##### FUNCTION gtk_binding_entry_skip ##### -->
<para>

</para>

@binding_set: 
@keyval: 
@modifiers: 


<!-- ##### FUNCTION gtk_binding_entry_remove ##### -->
<para>

</para>

@binding_set: 
@keyval: 
@modifiers: 


<!-- ##### FUNCTION gtk_binding_set_add_path ##### -->
<para>

</para>

@binding_set: 
@path_type: 
@path_pattern: 
@priority: