TransformPicker Class

Inherits from

GEOCALCPBW_NAMESPACE::GeoBase

Description

The TransformPicker is a user interface dialog for selecting transformations between various horizontal and vertical coordinate reference systems. This selection process is guided by parameters provided during the creation of the TransformPicker class. There are also several member methods and properties that allow for more complete control during the selection procedure. Once the dialog has been created and displayed, the user will be presented with a complete list of transforms based on their specified requirements. In order to visually aide the user in their selection process, the polygon AreaOfUse for a given transformation is displayed in map window contained inside of the dialog. It is important to note that this dialog is used for both horizontal and vertical transformation selection. In a workflow where a transformation is vertical in both, the dialog will present options for selecting horizontal transformation, followed but a second selection process for the vertical.

The list of coordinate transforms displayed in the dialog are sorted into two major categories: Datasource Transformations, and Generated Transformations. These are clearly identified in the left pane of the TransformPicker dialog. Datasource Transformations are items that are defined in the GeoCalc datasource object. They are organized in the display based on the viewfile that is attached to the current datasource. These transforms can be either a single transformation, or a series of transformations grouped together. In GeoCalc nomenclature, this is referred to as a ConcatenatedTransform. Generated Transformations are constructed using component parts from the GeoCalc datasource. They will always be represented as a ConcatenatedTransformation, and will always have hub, or intermediate geodetic coordinate system. There is a third category for Time Dependent transformation that is displayed when using epochs with HTDP and Time dependent Helmert operations. For more details on all of these return types, please refer to Lesson 6 in the Getting Started Guide.

On the right side of the TransformPicker dialog there are two additional areas of the dialog. The main information pane on the top right portion of the interface provides the name, accuracy, type, and EPSG code (if available) for each individual transformation. For additional details you can right click on a given object and gain access to any parameters stored in the GeoCalc database. Below the details pane is a map interface that will display the AreaOfUse polygon for the currently selected transformation. All of these data can be used to select the most appropriate transformation for the user.

Public Constructors

Public Methods