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sd-bus: Wrap add_object_vtable docs at 100 columns

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Daan De Meyer 2020-03-28 22:03:19 +01:00
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man/sd_bus_add_object_vtable.xml
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@ -188,40 +188,44 @@
<refsect1> <refsect1>
<title>Description</title> <title>Description</title>
<para><function>sd_bus_add_object_vtable()</function> is used to declare attributes for the path object <para><function>sd_bus_add_object_vtable()</function> is used to declare attributes for the path
path <parameter>path</parameter> connected to the bus connection <parameter>bus</parameter> under the object path <parameter>path</parameter> connected to the bus connection
interface <parameter>interface</parameter>. The table <parameter>vtable</parameter> may contain property <parameter>bus</parameter> under the interface <parameter>interface</parameter>. The table
declarations using <constant>SD_BUS_PROPERTY()</constant> or <parameter>vtable</parameter> may contain property declarations using
<constant>SD_BUS_WRITABLE_PROPERTY()</constant>, method declarations using <constant>SD_BUS_PROPERTY()</constant> or <constant>SD_BUS_WRITABLE_PROPERTY()</constant>,
<constant>SD_BUS_METHOD()</constant>, <constant>SD_BUS_METHOD_WITH_NAMES()</constant>, method declarations using <constant>SD_BUS_METHOD()</constant>,
<constant>SD_BUS_METHOD_WITH_NAMES()</constant>,
<constant>SD_BUS_METHOD_WITH_OFFSET()</constant>, or <constant>SD_BUS_METHOD_WITH_OFFSET()</constant>, or
<constant>SD_BUS_METHOD_WITH_NAMES_OFFSET()</constant>, and signal declarations using <constant>SD_BUS_METHOD_WITH_NAMES_OFFSET()</constant>, and signal declarations using
<constant>SD_BUS_SIGNAL_WITH_NAMES()</constant> or <constant>SD_BUS_SIGNAL()</constant>, see below. The <constant>SD_BUS_SIGNAL_WITH_NAMES()</constant> or <constant>SD_BUS_SIGNAL()</constant>, see
<replaceable>userdata</replaceable> parameter contains a pointer that will be passed to various callback below. The <replaceable>userdata</replaceable> parameter contains a pointer that will be passed
functions. It may be specified as <constant>NULL</constant> if no value is necessary.</para> to various callback functions. It may be specified as <constant>NULL</constant> if no value is
necessary.</para>
<para><function>sd_bus_add_fallback_vtable()</function> is similar to <para><function>sd_bus_add_fallback_vtable()</function> is similar to
<function>sd_bus_add_object_vtable()</function>, but is used to register "fallback" attributes. When <function>sd_bus_add_object_vtable()</function>, but is used to register "fallback" attributes.
looking for an attribute declaration, bus object paths registered with When looking for an attribute declaration, bus object paths registered with
<function>sd_bus_add_object_vtable()</function> are checked first. If no match is found, the fallback <function>sd_bus_add_object_vtable()</function> are checked first. If no match is found, the
vtables are checked for each prefix of the bus object path, i.e. with the last slash-separated components fallback vtables are checked for each prefix of the bus object path, i.e. with the last
successively removed. This allows the vtable to be used for an arbitrary number of dynamically created slash-separated components successively removed. This allows the vtable to be used for an
objects.</para> arbitrary number of dynamically created objects.</para>
<para>Parameter <replaceable>find</replaceable> is a function which is used to locate the target object <para>Parameter <replaceable>find</replaceable> is a function which is used to locate the target
based on the bus object path <replaceable>path</replaceable>. It must return <constant>1</constant> and object based on the bus object path <replaceable>path</replaceable>. It must return
set the <parameter>ret_found</parameter> output parameter if the object is found, return <constant>1</constant> and set the <parameter>ret_found</parameter> output parameter if the
<constant>0</constant> if the object was not found, and return a negative errno-style error code or object is found, return <constant>0</constant> if the object was not found, and return a
initialize the error structure <replaceable>ret_error</replaceable> on error. The pointer passed in negative errno-style error code or initialize the error structure
<parameter>ret_found</parameter> will be used as the <parameter>userdata</parameter> parameter for the <replaceable>ret_error</replaceable> on error. The pointer passed in
callback functions (offset by the <parameter>offset</parameter> offsets as specified in the vtable <parameter>ret_found</parameter> will be used as the <parameter>userdata</parameter> parameter
entries).</para> for the callback functions (offset by the <parameter>offset</parameter> offsets as specified in
the vtable entries).</para>
<para>For both functions, a match slot is created internally. If the output parameter <para>For both functions, a match slot is created internally. If the output parameter
<replaceable>slot</replaceable> is <constant>NULL</constant>, a "floating" slot object is created, see <replaceable>slot</replaceable> is <constant>NULL</constant>, a "floating" slot object is
created, see
<citerefentry><refentrytitle>sd_bus_slot_set_floating</refentrytitle><manvolnum>3</manvolnum></citerefentry>. <citerefentry><refentrytitle>sd_bus_slot_set_floating</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
Otherwise, a pointer to the slot object is returned. In that case, the reference to the slot object Otherwise, a pointer to the slot object is returned. In that case, the reference to the slot
should be dropped when the vtable is not needed anymore, see object should be dropped when the vtable is not needed anymore, see
<citerefentry><refentrytitle>sd_bus_slot_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>. <citerefentry><refentrytitle>sd_bus_slot_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
</para> </para>
@ -245,23 +249,25 @@
<term><constant>SD_BUS_METHOD_WITH_OFFSET()</constant></term> <term><constant>SD_BUS_METHOD_WITH_OFFSET()</constant></term>
<term><constant>SD_BUS_METHOD()</constant></term> <term><constant>SD_BUS_METHOD()</constant></term>
<listitem><para>Declare a D-Bus method with the name <replaceable>member</replaceable>, parameter <listitem><para>Declare a D-Bus method with the name <replaceable>member</replaceable>,
signature <replaceable>signature</replaceable>, result signature <replaceable>result</replaceable>. parameter signature <replaceable>signature</replaceable>, result signature
Parameters <replaceable>in_names</replaceable> and <replaceable>out_names</replaceable> specify the <replaceable>result</replaceable>. Parameters <replaceable>in_names</replaceable> and
argument names of the input and output arguments in the function signature. The handler function <replaceable>out_names</replaceable> specify the argument names of the input and output
<replaceable>handler</replaceable> must be of type <function>sd_bus_message_handler_t</function>. arguments in the function signature. The handler function
It will be called to handle the incoming messages that call this method. It receives a pointer that <replaceable>handler</replaceable> must be of type
is the <replaceable>userdata</replaceable> parameter passed to the registration function offset by <function>sd_bus_message_handler_t</function>. It will be called to handle the incoming
<replaceable>offset</replaceable> bytes. This may be used to pass pointers to different fields in messages that call this method. It receives a pointer that is the
the same data structure to different methods in the same <replaceable>userdata</replaceable> parameter passed to the registration function offset
vtable. <replaceable>in_names</replaceable> and <replaceable>out_names</replaceable> should be by <replaceable>offset</replaceable> bytes. This may be used to pass pointers to different
fields in the same data structure to different methods in the same vtable.
<replaceable>in_names</replaceable> and <replaceable>out_names</replaceable> should be
created using the <constant>SD_BUS_PARAM()</constant> macro, see below. Parameter created using the <constant>SD_BUS_PARAM()</constant> macro, see below. Parameter
<replaceable>flags</replaceable> is a combination of flags, see below.</para> <replaceable>flags</replaceable> is a combination of flags, see below.</para>
<para><constant>SD_BUS_METHOD_WITH_NAMES()</constant>, <para><constant>SD_BUS_METHOD_WITH_NAMES()</constant>,
<constant>SD_BUS_METHOD_WITH_OFFSET()</constant>, and <constant>SD_BUS_METHOD()</constant> are <constant>SD_BUS_METHOD_WITH_OFFSET()</constant>, and <constant>SD_BUS_METHOD()</constant>
variants which specify zero offset (<replaceable>userdata</replaceable> parameter is passed with are variants which specify zero offset (<replaceable>userdata</replaceable> parameter is
no change), leave the names unset (i.e. no parameter names), or both.</para> passed with no change), leave the names unset (i.e. no parameter names), or both.</para>
</listitem> </listitem>
</varlistentry> </varlistentry>
@ -285,29 +291,31 @@
<term><constant>SD_BUS_WRITABLE_PROPERTY()</constant></term> <term><constant>SD_BUS_WRITABLE_PROPERTY()</constant></term>
<term><constant>SD_BUS_PROPERTY()</constant></term> <term><constant>SD_BUS_PROPERTY()</constant></term>
<listitem><para>Declare a D-Bus property with the name <replaceable>member</replaceable> and value <listitem><para>Declare a D-Bus property with the name <replaceable>member</replaceable>
signature <replaceable>signature</replaceable>. Parameters <replaceable>get</replaceable> and and value signature <replaceable>signature</replaceable>. Parameters
<replaceable>set</replaceable> are the getter and setter methods. They are called with a pointer <replaceable>get</replaceable> and <replaceable>set</replaceable> are the getter and
that is the <replaceable>userdata</replaceable> parameter passed to the registration function setter methods. They are called with a pointer that is the
offset by <replaceable>offset</replaceable> bytes. This may be used pass pointers to different <replaceable>userdata</replaceable> parameter passed to the registration function offset
fields in the same data structure to different setters and getters in the same vtable. Parameter by <replaceable>offset</replaceable> bytes. This may be used pass pointers to different
<replaceable>flags</replaceable> is a combination of flags, see below.</para> fields in the same data structure to different setters and getters in the same vtable.
Parameter <replaceable>flags</replaceable> is a combination of flags, see below.</para>
<para>The setter and getter methods may be omitted (specified as <constant>NULL</constant>), if the <para>The setter and getter methods may be omitted (specified as
property has one of the basic types or <literal>as</literal> in case of read-only properties. In <constant>NULL</constant>), if the property has one of the basic types or
those cases, the <replaceable>userdata</replaceable> and <replaceable>offset</replaceable> <literal>as</literal> in case of read-only properties. In those cases, the
parameters must together point to valid variable of the corresponding type. A default setter and <replaceable>userdata</replaceable> and <replaceable>offset</replaceable> parameters must
getters will be provided, which simply copy the argument between this variable and the message. together point to valid variable of the corresponding type. A default setter and getters
will be provided, which simply copy the argument between this variable and the message.
</para> </para>
<para><constant>SD_BUS_PROPERTY()</constant> is used to define a read-only property.</para> <para><constant>SD_BUS_PROPERTY()</constant> is used to define a read-only property.
</listitem> </para></listitem>
</varlistentry> </varlistentry>
<varlistentry> <varlistentry>
<term><constant>SD_BUS_PARAM()</constant></term> <term><constant>SD_BUS_PARAM()</constant></term>
<listitem><para>Parameter names should be wrapped in this macro, see the example below.</para> <listitem><para>Parameter names should be wrapped in this macro, see the example below.
</listitem> </para></listitem>
</varlistentry> </varlistentry>
</variablelist> </variablelist>
</refsect2> </refsect2>
@ -324,7 +332,7 @@
<term><constant>SD_BUS_VTABLE_DEPRECATED</constant></term> <term><constant>SD_BUS_VTABLE_DEPRECATED</constant></term>
<listitem><para>Mark this vtable entry as deprecated using the <listitem><para>Mark this vtable entry as deprecated using the
<constant>org.freedesktop.DBus.Deprecated</constant> annotation in introspection data. If <constant>org.freedesktop.DBus.Deprecated</constant> annotation in introspection data. If
specified for <constant>SD_BUS_VTABLE_START()</constant>, the annotation is applied to the specified for <constant>SD_BUS_VTABLE_START()</constant>, the annotation is applied to the
enclosing interface.</para></listitem> enclosing interface.</para></listitem>
</varlistentry> </varlistentry>
@ -332,10 +340,9 @@
<varlistentry> <varlistentry>
<term><constant>SD_BUS_VTABLE_HIDDEN</constant></term> <term><constant>SD_BUS_VTABLE_HIDDEN</constant></term>
<listitem><para>Make this vtable entry hidden. It will not be shown in introspection data. If <listitem><para>Make this vtable entry hidden. It will not be shown in introspection data.
specified for <constant>SD_BUS_VTABLE_START()</constant>, all entries in the array are hidden. If specified for <constant>SD_BUS_VTABLE_START()</constant>, all entries in the array are
</para> hidden.</para></listitem>
</listitem>
</varlistentry> </varlistentry>
<varlistentry> <varlistentry>
@ -343,8 +350,7 @@
<listitem><para>Mark this vtable entry as unprivileged. If not specified, the <listitem><para>Mark this vtable entry as unprivileged. If not specified, the
<constant>org.freedesktop.systemd1.Privileged</constant> annotation with value <constant>org.freedesktop.systemd1.Privileged</constant> annotation with value
<literal>true</literal> will be shown in introspection data.</para> <literal>true</literal> will be shown in introspection data.</para></listitem>
</listitem>
</varlistentry> </varlistentry>
<varlistentry> <varlistentry>
@ -361,27 +367,28 @@
<term><constant>SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION</constant></term> <term><constant>SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION</constant></term>
<listitem><para>Those three flags correspond to different values of the <listitem><para>Those three flags correspond to different values of the
<constant>org.freedesktop.DBus.Property.EmitsChangedSignal</constant> annotation, which specifies <constant>org.freedesktop.DBus.Property.EmitsChangedSignal</constant> annotation, which
whether the <constant>org.freedesktop.DBus.Properties.PropertiesChanged</constant> signal is specifies whether the
emitted whenever the property changes. <constant>SD_BUS_VTABLE_PROPERTY_CONST</constant> corresponds to <constant>org.freedesktop.DBus.Properties.PropertiesChanged</constant> signal is emitted
<constant>const</constant> and means that the property never changes during the lifetime of the whenever the property changes. <constant>SD_BUS_VTABLE_PROPERTY_CONST</constant>
object it belongs to, so no signal needs to be emitted. corresponds to <constant>const</constant> and means that the property never changes during
<constant>SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE</constant> corresponds to <constant>true</constant> and means the lifetime of the object it belongs to, so no signal needs to be emitted.
that the signal is emitted. <constant>SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION</constant> corresponds to <constant>SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE</constant> corresponds to
<constant>invalidates</constant> and means that the signal is emitted, but the value is not included <constant>true</constant> and means that the signal is emitted.
in the signal.</para> <constant>SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION</constant> corresponds to
</listitem> <constant>invalidates</constant> and means that the signal is emitted, but the value is
not included in the signal.</para></listitem>
</varlistentry> </varlistentry>
<varlistentry> <varlistentry>
<term><constant>SD_BUS_VTABLE_PROPERTY_EXPLICIT</constant></term> <term><constant>SD_BUS_VTABLE_PROPERTY_EXPLICIT</constant></term>
<listitem><para>Mark this vtable property entry as requiring explicit request to for the value to <listitem><para>Mark this vtable property entry as requiring explicit request to for the
be shown (generally because the value is large or slow to calculate). This entry cannot be combined value to be shown (generally because the value is large or slow to calculate). This entry
with <constant>SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE</constant>, and will not be shown in property listings by cannot be combined with <constant>SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE</constant>, and will
default (e.g. <command>busctl introspect</command>). This corresponds to the not be shown in property listings by default (e.g. <command>busctl introspect</command>).
<constant>org.freedesktop.systemd1.Explicit</constant> annotation in introspection data.</para> This corresponds to the <constant>org.freedesktop.systemd1.Explicit</constant> annotation
</listitem> in introspection data.</para></listitem>
</varlistentry> </varlistentry>
</variablelist> </variablelist>
</refsect2> </refsect2>
@ -395,9 +402,9 @@
<programlisting><xi:include href="vtable-example.c" parse="text" /></programlisting> <programlisting><xi:include href="vtable-example.c" parse="text" /></programlisting>
<para>This creates a simple client on the bus (the user bus, when run as normal user). <para>This creates a simple client on the bus (the user bus, when run as normal user). We may
We may use the D-Bus <constant>org.freedesktop.DBus.Introspectable.Introspect</constant> use the D-Bus <constant>org.freedesktop.DBus.Introspectable.Introspect</constant> call to
call to acquire the XML description of the interface:</para> acquire the XML description of the interface:</para>
<programlisting><xi:include href="vtable-example.xml" parse="text" /></programlisting> <programlisting><xi:include href="vtable-example.xml" parse="text" /></programlisting>
</example> </example>
@ -407,8 +414,8 @@
<title>Return Value</title> <title>Return Value</title>
<para>On success, <function>sd_bus_add_object_vtable</function> and <para>On success, <function>sd_bus_add_object_vtable</function> and
<function>sd_bus_add_fallback_vtable</function> calls return 0 or a positive integer. On failure, they <function>sd_bus_add_fallback_vtable</function> calls return 0 or a positive integer. On
return a negative errno-style error code.</para> failure, they return a negative errno-style error code.</para>
<refsect2> <refsect2>
<title>Errors</title> <title>Errors</title>
@ -419,8 +426,9 @@
<varlistentry> <varlistentry>
<term><constant>-EINVAL</constant></term> <term><constant>-EINVAL</constant></term>
<listitem><para>One of the required parameters is <constant>NULL</constant> or invalid. A reserved <listitem><para>One of the required parameters is <constant>NULL</constant> or invalid. A
D-Bus interface was passed as the <replaceable>interface</replaceable> parameter.</para></listitem> reserved D-Bus interface was passed as the <replaceable>interface</replaceable> parameter.
</para></listitem>
</varlistentry> </varlistentry>
<varlistentry> <varlistentry>
@ -445,8 +453,8 @@
<term><constant>-EPROTOTYPE</constant></term> <term><constant>-EPROTOTYPE</constant></term>
<listitem><para><function>sd_bus_add_object_vtable</function> and <listitem><para><function>sd_bus_add_object_vtable</function> and
<function>sd_bus_add_fallback_vtable</function> have been both called <function>sd_bus_add_fallback_vtable</function> have been both called for the same bus
for the same bus object path, which is not allowed.</para></listitem> object path, which is not allowed.</para></listitem>
</varlistentry> </varlistentry>
<varlistentry> <varlistentry>