2.4.10.6. DDS Data Type View

The DDS Data Type View presents hierarchical and textual views of a data type used by a DataWriter or DataReader. This view includes two tabs:

  • The Type tree tab presents the data type as a hierarchy.

    DDS Data Type view type tree

  • The Equivalent IDL tab presents the same information in IDL.

    DDS Data Type view idl

2.4.10.6.1. Overview

The Type tree tab in DDS Data Type View includes the following columns:

  • 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 tab displays 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.

Note

The TypeCode Size and TypeObject Size columns provide size estimates and not exact values. The actual sizes may vary due to padding, alignment, and other factors. Also, the values in a single column may not sum up to the total size for the top-level type because of these variations.

2.4.10.6.2. Toolbar

The toolbar ICON_DATATYPE_TOOLBAR in this view contains controls to:

  • Choose how the min and max sample serialized sizes are calculated, using the XCDR and XCDR2 buttons.

  • ICON_EXPORT_TO_FILE Export IDL to a file.

  • ICON_EXPORT_TO_FILE Export type tree contents to a CSV 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.