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docs: Break down the constraints example

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Emmanuele Bassi 2010-11-16 17:18:50 +00:00
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clutter/clutter-constraint.c
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@ -55,6 +55,37 @@
* <para>The example below uses various #ClutterConstraint<!-- -->s to
* lay out three actors on a resizable stage. Only the central actor has
* an explicit size, and no actor has an explicit position.</para>
* <orderedlist>
* <listitem><simpara>The #ClutterRectangle with #ClutterActor:name
* <emphasis>layerA</emphasis> is explicitly sized to 100 pixels by 25
* pixels, and it's added to the #ClutterStage;</simpara></listitem>
* <listitem><simpara>two #ClutterAlignConstraint<!-- -->s are used
* to anchor <emphasis>layerA</emphasis> to the center of the stage,
* by using 0.5 as the alignment #ClutterAlignConstraint:factor on
* both the X and Y axis.</simpara></listitem>
* <listitem><simpara>the #ClutterRectangle with #ClutterActor:name
* <emphasis>layerB</emphasis> is added to the #ClutterStage with
* no explicit size;</simpara></listitem>
* <listitem><simpara>the #ClutterActor:x and #ClutterActor:width
* of <emphasis>layerB</emphasis> are bound to the same properties
* of <emphasis>layerA</emphasis> using two #ClutterBindConstraint
* objects, thus keeping <emphasis>layerB</emphasis> aligned to
* <emphasis>layerA</emphasis>;</simpara></listitem>
* <listitem><simpara>the top edge of <emphasis>layerB</emphasis> is
* snapped together with the bottom edge of <emphasis>layerA</emphasis>;
* the bottom edge of <emphasis>layerB</emphasis> is also snapped
* together with the bottom edge of the #ClutterStage; an offset is
* given to the two #ClutterSnapConstraint<!-- -->s to allow for some
* padding; since <emphasis>layerB</emphasis> is snapped between two
* different #ClutterActor<!-- -->s, its height is stretched to match
* the gap;</simpara></listitem>
* <listitem><simpara>the #ClutterRectangle with #ClutterActor:name
* <emphasis>layerC</emphasis> mirrors <emphasis>layerB</emphasis>,
* snapping the top edge of the #ClutterStage to the top edge of
* <emphasis>layerC</emphasis> and the top edge of
* <emphasis>layerA</emphasis> to the bottom edge of
* <emphasis>layerC</emphasis>;/simpara></listitem>
* </orderedlist>
* <programlisting>
* <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="../../../../tests/interactive/test-snap-constraint.c" parse="text"><xi:fallback>FIXME: MISSING XINCLUDE CONTENT</xi:fallback></xi:include>
* </programlisting>
@ -62,6 +93,9 @@
* <title>Constraints</title>
* <graphic fileref="constraints-example.png" format="PNG"/>
* </figure>
* <para>You can try resizing interactively the #ClutterStage and verify
* that the three #ClutterActor<!-- -->s maintain the same position and
* size relative to each other, and to the #CLutterStage.</para>
* </example>
* <warning><para>It's important to note that Clutter does not avoid loops
* or competing constraints; if two or more #ClutterConstraint<!-- -->s