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>Chapter 22. Writing a Manager</H1
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> Managers are elements that add a function or unify the function of
another (series of) element(s). Managers are generally a
<CODE
CLASS="classname"
>GstBin</CODE
> with one or more ghostpads. Inside them
is/are the actual element(s) that matters. There is several cases where
this is useful. For example:
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> To add support for private events with custom event handling to
another element.
</P
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> To add support for custom pad <CODE
CLASS="function"
>_query ()</CODE
>
or <CODE
CLASS="function"
>_convert ()</CODE
> handling to another element.
</P
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> To add custom data handling before or after another element's data
handler function (generally its <CODE
CLASS="function"
>_chain ()</CODE
>
function).
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> To embed an element, or a series of elements, into something that
looks and works like a simple element to the outside world.
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> Making a manager is about as simple as it gets. You can derive from a
<CODE
CLASS="classname"
>GstBin</CODE
>, and in most cases, you can embed the
required elements in the <CODE
CLASS="function"
>_init ()</CODE
> already, including
setup of ghostpads. If you need any custom data handlers, you can connect
signals or embed a second element which you control.
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