.. include:: ../../../vars.rst
.. _section-administration-data-type-view:


DDS Data Type View
==================

The DDS Data Type View has two tabs: 

.. figure:: ../../../_static/administration/ddsDataTypeView_typeTree.png
    :alt: DDS Data Type view type tree
    :name: DDS Data Type view type tree
    :align: center
    :figWidth: 100%

.. figure:: ../../../_static/administration/ddsDataTypeView_equivalentIdl.png
    :alt: DDS Data Type View Equivalent IDL
    :name: DDS Data Type View Equivalent IDL
    :align: left
    :figWidth: 100%


========
Overview
========

.. |ICON_KEY| image:: ../../../_static/administration/branding/icons/key.png

The DDS Data Type View presents hierarchical and textual (IDL)
views of a data type used by a DataWriter or DataReader.

* **Name** - The name of the type or field represented by this row. If the row is a field and the field is part of the type's key, then it will have the key icon |ICON_KEY| as well as having the text "(key)" following the name.

* **Type / Ordinal** - The field's type or enumerate's ordinal.

* **Extensibility** - Indicates the field's extensibility status. Note that not every row will have this indication, for example, enumerates inside an enumeration will have no indication here.

* **Optional?** - Indicates if the field is optional (true), not optional (false) or blank if this concept is not applicable for the row.

* **Min Sample Size** - The minimum size that samples of this type can be when serialized for distribution. Note that this size does not account for protocol overhead.

* **Max Sample Size** - The maximum size that samples of this type can be when serialized for distribution. Not that this size does not account for protocol overhead.

* **TypeCode Size** - The serialized size of the TypeCode. Note that this is not the size for samples, those are explained above in the Min/Max Sample Sizes. Rather, this is the size needed to transfer information about the data type itself.

* **TypeObject Size** - The serialized size of the TypeObject. Note that this is not the size for samples, those are explained above in the Min/Max Sample Sizes. Rather, this is the size needed to transfer information about the data type itself.

* **Union Labels** - If the field is part of a union, then the associated labels will be shown here.

The equivalent IDL view is a read-only textual representation of the data type.
The text in this view can be exported to a file or selected and copied to the
clipboard through the standard OS shortcuts or through the right-click menu.

.. Note::
    The min and max sample serialized size columns are provided as a guide to
    show representative sizes. The actual sizes may vary somewhat from the
    calculated values due to byte alignments as a sample is serialized. Also,
    row 1 is calculated to include encapsulation whereas other rows are not
    (since only the top level type includes encapsulation). As a result of
    this, the sum of rows 2 and greater may not be equal to the value displayed
    in row 1.

=======
Toolbar
=======

.. |ICON_EXPORT_TO_FILE| image:: ../../../_static/administration/exportToFile.png
.. |ICON_EXPAND_ALL| image:: ../../../_static/administration/branding/icons/tree_expand_all.gif
.. |ICON_COLLAPSE_ALL| image:: ../../../_static/administration/branding/icons/tree_collapse_all.gif
.. |ICON_CONNECTED| image:: ../../../_static/administration/connected.png


The toolbar in this view contains controls to:

* CDR and CDR2 buttons choose how the min and max sample serialized sizes are calculated.

* |ICON_EXPORT_TO_FILE| Export IDL to a file.
* |ICON_EXPAND_ALL| Expand all tree nodes.
* |ICON_COLLAPSE_ALL| Collapse all tree nodes.
* |ICON_CONNECTED| Link with selection - Toggling this button will link/unlink this view to/from displaying information about the current selection. One way to use this feature is to select something and then unlink this view from the selection. Then, a new instance of this view can be created and a populated with a new selection. Data can then be compared between the first and second selection.
* Minimize and maximize the view.