:right-sidebar: True

TagMergeMode
===================================================================

.. currentmodule:: gi.repository.Gst





.. class:: TagMergeMode
   :no-contents-entry:






The different tag merging modes are basically replace, overwrite and append,
but they can be seen from two directions. Given two taglists: (A) the tags
already in the element and (B) the ones that are supplied to the element (
e.g. via :func:`~gi.repository.Gst.TagSetter.merge_tags` / :func:`~gi.repository.Gst.TagSetter.add_tags` or a
:const:`~gi.repository.Gst.EventType.TAG`), how are these tags merged?
In the table below this is shown for the cases that a tag exists in the list
(A) or does not exists (!A) and combinations thereof.

+-------------+-------+--------+--------+---------+
| merge mode  | A + B | A + !B | !A + B | !A + !B |
+-------------+-------+--------+--------+---------+
| ----------- | ----- | ------ | ------ | ------- |
+-------------+-------+--------+--------+---------+
| REPLACE_ALL | B     | ø      | B      | ø       |
+-------------+-------+--------+--------+---------+
| REPLACE     | B     | A      | B      | ø       |
+-------------+-------+--------+--------+---------+
| APPEND      | A, B  | A      | B      | ø       |
+-------------+-------+--------+--------+---------+
| PREPEND     | B, A  | A      | B      | ø       |
+-------------+-------+--------+--------+---------+
| KEEP        | A     | A      | B      | ø       |
+-------------+-------+--------+--------+---------+
| KEEP_ALL    | A     | A      | ø      | ø       |
+-------------+-------+--------+--------+---------+














Fields
------

.. rst-class:: interim-class

.. class:: TagMergeMode
   :no-index:
   

   .. attribute:: APPEND

      Append tags







   .. attribute:: COUNT

      The number of merge modes







   .. attribute:: KEEP

      Keep existing tags







   .. attribute:: KEEP_ALL

      Keep all existing tags







   .. attribute:: PREPEND

      Prepend tags







   .. attribute:: REPLACE

      Replace tags







   .. attribute:: REPLACE_ALL

      Replace all tags (clear list and append)







   .. attribute:: UNDEFINED

      Undefined merge mode