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<div class="refentry">
<a name="AtkValue"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2><span class="refentrytitle"><a name="AtkValue.top_of_page"></a>AtkValue</span></h2>
<p>AtkValue — The ATK interface implemented by valuators and
components which display or select a value from a bounded range of
values.</p>
</td>
<td class="gallery_image" valign="top" align="right"></td>
</tr></table></div>
<div class="refsect1">
<a name="AtkValue.functions"></a><h2>Functions</h2>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="functions_return">
<col class="functions_name">
</colgroup>
<tbody>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="AtkValue.html#atk-value-get-current-value" title="atk_value_get_current_value ()">atk_value_get_current_value</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="AtkValue.html#atk-value-get-maximum-value" title="atk_value_get_maximum_value ()">atk_value_get_maximum_value</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="AtkValue.html#atk-value-get-minimum-value" title="atk_value_get_minimum_value ()">atk_value_get_minimum_value</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">gboolean</span>
</td>
<td class="function_name">
<a class="link" href="AtkValue.html#atk-value-set-current-value" title="atk_value_set_current_value ()">atk_value_set_current_value</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="AtkValue.html#atk-value-get-minimum-increment" title="atk_value_get_minimum_increment ()">atk_value_get_minimum_increment</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="AtkValue.html#atk-value-get-value-and-text" title="atk_value_get_value_and_text ()">atk_value_get_value_and_text</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">AtkRange</span> *
</td>
<td class="function_name">
<a class="link" href="AtkValue.html#atk-value-get-range" title="atk_value_get_range ()">atk_value_get_range</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">gdouble</span>
</td>
<td class="function_name">
<a class="link" href="AtkValue.html#atk-value-get-increment" title="atk_value_get_increment ()">atk_value_get_increment</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">GSList</span> *
</td>
<td class="function_name">
<a class="link" href="AtkValue.html#atk-value-get-sub-ranges" title="atk_value_get_sub_ranges ()">atk_value_get_sub_ranges</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="AtkValue.html#atk-value-set-value" title="atk_value_set_value ()">atk_value_set_value</a> <span class="c_punctuation">()</span>
</td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="AtkValue.signals"></a><h2>Signals</h2>
<div class="informaltable"><table class="informaltable" border="0">
<colgroup>
<col width="150px" class="signals_return">
<col width="300px" class="signals_name">
<col width="200px" class="signals_flags">
</colgroup>
<tbody><tr>
<td class="signal_type"><span class="returnvalue">void</span></td>
<td class="signal_name"><a class="link" href="AtkValue.html#AtkValue-value-changed" title="The “value-changed” signal">value-changed</a></td>
<td class="signal_flags">Run Last</td>
</tr></tbody>
</table></div>
</div>
<div class="refsect1">
<a name="AtkValue.other"></a><h2>Types and Values</h2>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="name">
<col class="description">
</colgroup>
<tbody><tr>
<td class="datatype_keyword"> </td>
<td class="function_name"><a class="link" href="AtkValue.html#AtkValue-struct" title="AtkValue">AtkValue</a></td>
</tr></tbody>
</table></div>
</div>
<div class="refsect1">
<a name="AtkValue.object-hierarchy"></a><h2>Object Hierarchy</h2>
<pre class="screen"> GInterface
<span class="lineart">╰──</span> AtkValue
</pre>
</div>
<div class="refsect1">
<a name="AtkValue.implementations"></a><h2>Known Implementations</h2>
<p>
AtkValue is implemented by
<a class="link" href="AtkNoOpObject.html" title="AtkNoOpObject">AtkNoOpObject</a>.</p>
</div>
<div class="refsect1">
<a name="AtkValue.description"></a><h2>Description</h2>
<p><a class="link" href="AtkValue.html" title="AtkValue"><span class="type">AtkValue</span></a> should be implemented for components which either display
a value from a bounded range, or which allow the user to specify a
value from a bounded range, or both. For instance, most sliders and
range controls, as well as dials, should have <a class="link" href="AtkObject.html" title="AtkObject"><span class="type">AtkObject</span></a>
representations which implement <a class="link" href="AtkValue.html" title="AtkValue"><span class="type">AtkValue</span></a> on the component's
behalf. <span class="type">AtKValues</span> may be read-only, in which case attempts to
alter the value return would fail.</p>
<p><refsect1 id="current-value-text">
<title>On the subject of current value text</title>
<para>
In addition to providing the current value, implementors can
optionally provide an end-user-consumable textual description
associated with this value. This description should be included
when the numeric value fails to convey the full, on-screen
representation seen by users.
</para></p>
<p><example>
<title>Password strength</title>
A password strength meter whose value changes as the user types
their new password. Red is used for values less than 4.0, yellow
for values between 4.0 and 7.0, and green for values greater than
7.0. In this instance, value text should be provided by the
implementor. Appropriate value text would be "weak", "acceptable,"
and "strong" respectively.
</example></p>
<p>A level bar whose value changes to reflect the battery charge. The
color remains the same regardless of the charge and there is no
on-screen text reflecting the fullness of the battery. In this
case, because the position within the bar is the only indication
the user has of the current charge, value text should not be
provided by the implementor.</p>
<p><refsect2 id="implementor-notes">
<title>Implementor Notes</title>
<para>
Implementors should bear in mind that assistive technologies will
likely prefer the value text provided over the numeric value when
presenting a widget's value. As a result, strings not intended for
end users should not be exposed in the value text, and strings
which are exposed should be localized. In the case of widgets which
display value text on screen, for instance through a separate label
in close proximity to the value-displaying widget, it is still
expected that implementors will expose the value text using the
above API.
</para></p>
<p><para>
<a class="link" href="AtkValue.html" title="AtkValue"><span class="type">AtkValue</span></a> should NOT be implemented for widgets whose displayed
value is not reflective of a meaningful amount. For instance, a
progress pulse indicator whose value alternates between 0.0 and 1.0
to indicate that some process is still taking place should not
implement <a class="link" href="AtkValue.html" title="AtkValue"><span class="type">AtkValue</span></a> because the current value does not reflect
progress towards completion.
</para>
</refsect2>
</refsect1></p>
<p><refsect1 id="ranges">
<title>On the subject of ranges</title>
<para>
In addition to providing the minimum and maximum values,
implementors can optionally provide details about subranges
associated with the widget. These details should be provided by the
implementor when both of the following are communicated visually to
the end user:
</para>
<itemizedlist>
<listitem>The existence of distinct ranges such as "weak",
"acceptable", and "strong" indicated by color, bar tick marks,
and/or on-screen text.</listitem>
<listitem>Where the current value stands within a given subrange,
for instance illustrating progression from very "weak" towards
nearly "acceptable" through changes in shade and/or position on
the bar within the "weak" subrange.</listitem>
</itemizedlist>
<para>
If both of the above do not apply to the widget, it should be
sufficient to expose the numeric value, along with the value text
if appropriate, to make the widget accessible.
</para></p>
<p><refsect2 id="ranges-implementor-notes">
<title>Implementor Notes</title>
<para>
If providing subrange details is deemed necessary, all possible
values of the widget are expected to fall within one of the
subranges defined by the implementor.
</para>
</refsect2>
</refsect1></p>
<p><refsect1 id="localization">
<title>On the subject of localization of end-user-consumable text
values</title>
<para>
Because value text and subrange descriptors are human-consumable,
implementors are expected to provide localized strings which can be
directly presented to end users via their assistive technology. In
order to simplify this for implementors, implementors can use
<code class="function">atk_value_type_get_localized_name()</code> with the following
already-localized constants for commonly-needed values can be used:
</para></p>
<p><itemizedlist>
<listitem>ATK_VALUE_VERY_WEAK</listitem>
<listitem>ATK_VALUE_WEAK</listitem>
<listitem>ATK_VALUE_ACCEPTABLE</listitem>
<listitem>ATK_VALUE_STRONG</listitem>
<listitem>ATK_VALUE_VERY_STRONG</listitem>
<listitem>ATK_VALUE_VERY_LOW</listitem>
<listitem>ATK_VALUE_LOW</listitem>
<listitem>ATK_VALUE_MEDIUM</listitem>
<listitem>ATK_VALUE_HIGH</listitem>
<listitem>ATK_VALUE_VERY_HIGH</listitem>
<listitem>ATK_VALUE_VERY_BAD</listitem>
<listitem>ATK_VALUE_BAD</listitem>
<listitem>ATK_VALUE_GOOD</listitem>
<listitem>ATK_VALUE_VERY_GOOD</listitem>
<listitem>ATK_VALUE_BEST</listitem>
<listitem>ATK_VALUE_SUBSUBOPTIMAL</listitem>
<listitem>ATK_VALUE_SUBOPTIMAL</listitem>
<listitem>ATK_VALUE_OPTIMAL</listitem>
</itemizedlist>
<para>
Proposals for additional constants, along with their use cases,
should be submitted to the GNOME Accessibility Team.
</para>
</refsect1></p>
<p><refsect1 id="changes">
<title>On the subject of changes</title>
<para>
Note that if there is a textual description associated with the new
numeric value, that description should be included regardless of
whether or not it has also changed.
</para>
</refsect1></p>
</div>
<div class="refsect1">
<a name="AtkValue.functions_details"></a><h2>Functions</h2>
<div class="refsect2">
<a name="atk-value-get-current-value"></a><h3>atk_value_get_current_value ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
atk_value_get_current_value (<em class="parameter"><code><a class="link" href="AtkValue.html" title="AtkValue"><span class="type">AtkValue</span></a> *obj</code></em>,
<em class="parameter"><code><span class="type">GValue</span> *value</code></em>);</pre>
<div class="warning">
<p><code class="literal">atk_value_get_current_value</code> is deprecated and should not be used in newly-written code.</p>
<p>Since 2.12. Use <a class="link" href="AtkValue.html#atk-value-get-value-and-text" title="atk_value_get_value_and_text ()"><code class="function">atk_value_get_value_and_text()</code></a>
instead.</p>
</div>
<p>Gets the value of this object.</p>
<div class="refsect3">
<a name="atk-value-get-current-value.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>obj</p></td>
<td class="parameter_description"><p>a GObject instance that implements AtkValueIface</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>value</p></td>
<td class="parameter_description"><p>a <span class="type">GValue</span> representing the current accessible value. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>]</span></td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="atk-value-get-maximum-value"></a><h3>atk_value_get_maximum_value ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
atk_value_get_maximum_value (<em class="parameter"><code><a class="link" href="AtkValue.html" title="AtkValue"><span class="type">AtkValue</span></a> *obj</code></em>,
<em class="parameter"><code><span class="type">GValue</span> *value</code></em>);</pre>
<div class="warning">
<p><code class="literal">atk_value_get_maximum_value</code> is deprecated and should not be used in newly-written code.</p>
<p>Since 2.12. Use <a class="link" href="AtkValue.html#atk-value-get-range" title="atk_value_get_range ()"><code class="function">atk_value_get_range()</code></a> instead.</p>
</div>
<p>Gets the maximum value of this object.</p>
<div class="refsect3">
<a name="atk-value-get-maximum-value.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>obj</p></td>
<td class="parameter_description"><p>a GObject instance that implements AtkValueIface</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>value</p></td>
<td class="parameter_description"><p>a <span class="type">GValue</span> representing the maximum accessible value. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>]</span></td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="atk-value-get-minimum-value"></a><h3>atk_value_get_minimum_value ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
atk_value_get_minimum_value (<em class="parameter"><code><a class="link" href="AtkValue.html" title="AtkValue"><span class="type">AtkValue</span></a> *obj</code></em>,
<em class="parameter"><code><span class="type">GValue</span> *value</code></em>);</pre>
<div class="warning">
<p><code class="literal">atk_value_get_minimum_value</code> is deprecated and should not be used in newly-written code.</p>
<p>Since 2.12. Use <a class="link" href="AtkValue.html#atk-value-get-range" title="atk_value_get_range ()"><code class="function">atk_value_get_range()</code></a> instead.</p>
</div>
<p>Gets the minimum value of this object.</p>
<div class="refsect3">
<a name="atk-value-get-minimum-value.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>obj</p></td>
<td class="parameter_description"><p>a GObject instance that implements AtkValueIface</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>value</p></td>
<td class="parameter_description"><p>a <span class="type">GValue</span> representing the minimum accessible value. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>]</span></td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="atk-value-set-current-value"></a><h3>atk_value_set_current_value ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>
atk_value_set_current_value (<em class="parameter"><code><a class="link" href="AtkValue.html" title="AtkValue"><span class="type">AtkValue</span></a> *obj</code></em>,
<em class="parameter"><code>const <span class="type">GValue</span> *value</code></em>);</pre>
<div class="warning">
<p><code class="literal">atk_value_set_current_value</code> is deprecated and should not be used in newly-written code.</p>
<p>Since 2.12. Use <a class="link" href="AtkValue.html#atk-value-set-value" title="atk_value_set_value ()"><code class="function">atk_value_set_value()</code></a> instead.</p>
</div>
<p>Sets the value of this object.</p>
<div class="refsect3">
<a name="atk-value-set-current-value.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>obj</p></td>
<td class="parameter_description"><p>a GObject instance that implements AtkValueIface</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>value</p></td>
<td class="parameter_description"><p>a <span class="type">GValue</span> which is the desired new accessible value.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="atk-value-set-current-value.returns"></a><h4>Returns</h4>
<p> <code class="literal">TRUE</code> if new value is successfully set, <code class="literal">FALSE</code> otherwise.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="atk-value-get-minimum-increment"></a><h3>atk_value_get_minimum_increment ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
atk_value_get_minimum_increment (<em class="parameter"><code><a class="link" href="AtkValue.html" title="AtkValue"><span class="type">AtkValue</span></a> *obj</code></em>,
<em class="parameter"><code><span class="type">GValue</span> *value</code></em>);</pre>
<div class="warning">
<p><code class="literal">atk_value_get_minimum_increment</code> is deprecated and should not be used in newly-written code.</p>
<p>Since 2.12. Use <a class="link" href="AtkValue.html#atk-value-get-increment" title="atk_value_get_increment ()"><code class="function">atk_value_get_increment()</code></a> instead.</p>
</div>
<p>Gets the minimum increment by which the value of this object may be changed. If zero,
the minimum increment is undefined, which may mean that it is limited only by the
floating point precision of the platform.</p>
<div class="refsect3">
<a name="atk-value-get-minimum-increment.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>obj</p></td>
<td class="parameter_description"><p>a GObject instance that implements AtkValueIface</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>value</p></td>
<td class="parameter_description"><p>a <span class="type">GValue</span> representing the minimum increment by which the accessible value may be changed. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>]</span></td>
</tr>
</tbody>
</table></div>
</div>
<p class="since">Since: 1.12</p>
</div>
<hr>
<div class="refsect2">
<a name="atk-value-get-value-and-text"></a><h3>atk_value_get_value_and_text ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
atk_value_get_value_and_text (<em class="parameter"><code><a class="link" href="AtkValue.html" title="AtkValue"><span class="type">AtkValue</span></a> *obj</code></em>,
<em class="parameter"><code><span class="type">gdouble</span> *value</code></em>,
<em class="parameter"><code><span class="type">gchar</span> **text</code></em>);</pre>
<p>Gets the current value and the human readable text alternative of
<em class="parameter"><code>obj</code></em>
. <em class="parameter"><code>text</code></em>
is a newly created string, that must be freed by the
caller. Can be NULL if no descriptor is available.</p>
<div class="refsect3">
<a name="atk-value-get-value-and-text.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>obj</p></td>
<td class="parameter_description"><p>a GObject instance that implements AtkValueIface</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>value</p></td>
<td class="parameter_description"><p>address of <span class="type">gdouble</span> to put the current value of <em class="parameter"><code>obj</code></em>
. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>text</p></td>
<td class="parameter_description"><p>address of <span class="type">gchar</span> to put the human
readable text alternative for <em class="parameter"><code>value</code></em>
. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>][<acronym title="NULL is OK, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span></td>
</tr>
</tbody>
</table></div>
</div>
<p class="since">Since: 2.12</p>
</div>
<hr>
<div class="refsect2">
<a name="atk-value-get-range"></a><h3>atk_value_get_range ()</h3>
<pre class="programlisting"><span class="returnvalue">AtkRange</span> *
atk_value_get_range (<em class="parameter"><code><a class="link" href="AtkValue.html" title="AtkValue"><span class="type">AtkValue</span></a> *obj</code></em>);</pre>
<p>Gets the range of this object.</p>
<div class="refsect3">
<a name="atk-value-get-range.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>obj</p></td>
<td class="parameter_description"><p>a GObject instance that implements AtkValueIface</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="atk-value-get-range.returns"></a><h4>Returns</h4>
<p>a newly allocated <span class="type">AtkRange</span>
that represents the minimum, maximum and descriptor (if available)
of <em class="parameter"><code>obj</code></em>
. NULL if that range is not defined. </p>
<p><span class="annotation">[<acronym title="NULL may be passed as the value in, out, in-out; or as a return value."><span class="acronym">nullable</span></acronym>][<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span></p>
</div>
<p class="since">Since: 2.12</p>
</div>
<hr>
<div class="refsect2">
<a name="atk-value-get-increment"></a><h3>atk_value_get_increment ()</h3>
<pre class="programlisting"><span class="returnvalue">gdouble</span>
atk_value_get_increment (<em class="parameter"><code><a class="link" href="AtkValue.html" title="AtkValue"><span class="type">AtkValue</span></a> *obj</code></em>);</pre>
<p>Gets the minimum increment by which the value of this object may be
changed. If zero, the minimum increment is undefined, which may
mean that it is limited only by the floating point precision of the
platform.</p>
<div class="refsect3">
<a name="atk-value-get-increment.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>obj</p></td>
<td class="parameter_description"><p>a GObject instance that implements AtkValueIface</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="atk-value-get-increment.returns"></a><h4>Returns</h4>
<p> the minimum increment by which the value of this
object may be changed. zero if undefined.</p>
</div>
<p class="since">Since: 2.12</p>
</div>
<hr>
<div class="refsect2">
<a name="atk-value-get-sub-ranges"></a><h3>atk_value_get_sub_ranges ()</h3>
<pre class="programlisting"><span class="returnvalue">GSList</span> *
atk_value_get_sub_ranges (<em class="parameter"><code><a class="link" href="AtkValue.html" title="AtkValue"><span class="type">AtkValue</span></a> *obj</code></em>);</pre>
<p>Gets the list of subranges defined for this object. See <a class="link" href="AtkValue.html" title="AtkValue"><span class="type">AtkValue</span></a>
introduction for examples of subranges and when to expose them.</p>
<div class="refsect3">
<a name="atk-value-get-sub-ranges.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>obj</p></td>
<td class="parameter_description"><p>a GObject instance that implements AtkValueIface</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="atk-value-get-sub-ranges.returns"></a><h4>Returns</h4>
<p>an <span class="type">GSList</span> of
<span class="type">AtkRange</span> which each of the subranges defined for this object. Free
the returns list with <code class="function">g_slist_free()</code>. </p>
<p><span class="annotation">[<acronym title="Generics and defining elements of containers and arrays."><span class="acronym">element-type</span></acronym> AtkRange][<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span></p>
</div>
<p class="since">Since: 2.12</p>
</div>
<hr>
<div class="refsect2">
<a name="atk-value-set-value"></a><h3>atk_value_set_value ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
atk_value_set_value (<em class="parameter"><code><a class="link" href="AtkValue.html" title="AtkValue"><span class="type">AtkValue</span></a> *obj</code></em>,
<em class="parameter"><code>const <span class="type">gdouble</span> new_value</code></em>);</pre>
<p>Sets the value of this object.</p>
<p>This method is intended to provide a way to change the value of the
object. In any case, it is possible that the value can't be
modified (ie: a read-only component). If the value changes due this
call, it is possible that the text could change, and will trigger
an <a class="link" href="AtkValue.html#AtkValue-value-changed" title="The “value-changed” signal"><span class="type">“value-changed”</span></a> signal emission.</p>
<p>Note for implementors: the deprecated <a class="link" href="AtkValue.html#atk-value-set-current-value" title="atk_value_set_current_value ()"><code class="function">atk_value_set_current_value()</code></a>
method returned TRUE or FALSE depending if the value was assigned
or not. In the practice several implementors were not able to
decide it, and returned TRUE in any case. For that reason it is not
required anymore to return if the value was properly assigned or
not.</p>
<div class="refsect3">
<a name="atk-value-set-value.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>obj</p></td>
<td class="parameter_description"><p>a GObject instance that implements AtkValueIface</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>new_value</p></td>
<td class="parameter_description"><p>a double which is the desired new accessible value.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<p class="since">Since: 2.12</p>
</div>
</div>
<div class="refsect1">
<a name="AtkValue.other_details"></a><h2>Types and Values</h2>
<div class="refsect2">
<a name="AtkValue-struct"></a><h3>AtkValue</h3>
<pre class="programlisting">typedef struct _AtkValue AtkValue;</pre>
</div>
</div>
<div class="refsect1">
<a name="AtkValue.signal-details"></a><h2>Signal Details</h2>
<div class="refsect2">
<a name="AtkValue-value-changed"></a><h3>The <code class="literal">“value-changed”</code> signal</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
user_function (<a class="link" href="AtkValue.html" title="AtkValue"><span class="type">AtkValue</span></a> *atkvalue,
<span class="type">gdouble</span> value,
<span class="type">gchar</span> *text,
<span class="type">gpointer</span> user_data)</pre>
<p>The 'value-changed' signal is emitted when the current value
that represent the object changes. <em class="parameter"><code>value</code></em>
is the numerical
representation of this new value. <em class="parameter"><code>text</code></em>
is the human
readable text alternative of <em class="parameter"><code>value</code></em>
, and can be NULL if it is
not available. Note that if there is a textual description
associated with the new numeric value, that description
should be included regardless of whether or not it has also
changed.</p>
<p>Example: a password meter whose value changes as the user
types their new password. Appropiate value text would be
"weak", "acceptable" and "strong".</p>
<div class="refsect3">
<a name="AtkValue-value-changed.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>atkvalue</p></td>
<td class="parameter_description"><p>the object on which the signal was emitted.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>value</p></td>
<td class="parameter_description"><p>the new value in a numerical form.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>text</p></td>
<td class="parameter_description"><p>human readable text alternative (also called
description) of this object. NULL if not available.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>user_data</p></td>
<td class="parameter_description"><p>user data set when the signal handler was connected.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<p>Flags: Run Last</p>
<p class="since">Since: 2.12</p>
</div>
</div>
</div>
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