Grid display

The grid display is used in DELFT-FEWS for viewing grid time series. These grid time series can be dynamically animated against a map background (comparable to the main map display).

The Id of the grid display is identified in the DisplayInstanceDescriptors. When available on the file system, the name of the XML file for configuring the GridDisplay with an Id of FloodMapDisplay is for example:

FloodMapDisplay 1.00 default.xml

Figure 143 Example of a configuration of the Grid Display

Figure 144 Root elements of the gridDisplay configuration

title

Name of the Grid Display. When opened this will appear in the title bar of the window.

gridPlotGroup

Definition of a group in the grid display. Each group may have its own set of maps and time series to display. Defining groups creates a tree view in the left of the display (see example above). Multiple instances may exist.

Attributes;

• id : Id of the display group- this is used in the tree view.
• name : Optional name of the display group- used for reference purposes only
  

  description

  Optional description of the display group/grid plot. Used for reference purposes only
  

  gridPlot

  Definition of a grid plot within the display group. Each grid plot forms a node in the tree view. When a gridPlot is selected, the appropriate maps will be displayed and the time series data retrieved from the database.

Attributes;

• id : Id of the grid plot- this is used in the tree view.
• name : Optional name of the grid plot- used for reference purposes only
  

  timeSeriesSet

  Definition of the time series set to be displayed in the selected grid plot. This must obviously be a grid time series.
  

  classBreaks

  Definition of colours to use in displaying the dynamic grid. These are also shown in the legend on the left of the grid display (see example above).
  

  geoMap

  Definition of the maps used as a background to the dynamic grid displayed. The layout and zoom extent are also defined in this element.

Definition of class breaks

Figure 145 Elements of the configuration of class breaks

description

Optional description of the configuration. Used for reference purposes only.

lowerColor

Colour definition for the colour in the legend associated to the lowest value in the range.

upperColor

Colour definition for the colour in the legend associated to the highest value in the range.

lowerValue

Definition of the value at which the colour in the grid displayed changes. The legend will be a gradual change in colours from the lowest colour to the highest colour, with the number of increments determined by the number of lowerValue items entered. Multiple entries may exist

Definition of background maps

The background maps to be displayed are defined in the geoMap element. This is an XML implementation of the OpenMap configuration described also in Appendix C for configuring the main map display (in time this will also be done using the geoMap element).

Figure 146 Elements of the geoMap configuration

description

Optional description of the configuration. Used for reference purposes only.

extents

Root element for the definition of a zoom extent. The extents defined will appear in a drop down list in the grid display.

geoDatum

Coordinate system the extents are defined in. Enumeration of available coordinate systems is available in Appendix B.

defaultExtent

Definition of the default zoom extent.

Attributes;

• name : name of the default zoom extent (displayed in the drop-down list)
  

  extraExtent

  Definition of the additional zoom extents. Multiple entries may exist.

Attributes;

• name : name of the zoom extent (displayed in the drop-down list)
  

  left, right, top, bottom

  Coordinates of the zoom extent. Note that in displaying the maps for the extent defined, the map display will be scaled to fit the extent in the current display window.
  

  layer

  Definition of a GIS layer to be displayed.

Attributes;

• id : required id of the map layer- must be unique for the current geoMap element.
• name : optional name of the map layer defined
  

  description

  Optional description of the map layer. Used for reference purposes only.
  

  className

  Name of the class used in displaying the map layer. A different class is required for different types of GIS data.

NOTE: Defining a class name allows advanced users to add additional display functionality to the OpenMap utility, and this being used in map displays in DELFT-FEWS. See the OpenMap documentation for details on how to add additional display classes.

visible

Boolean flag indicating if layer is visible by default.

properties

Definition of properties associated with the map layer to be displayed. Properties that need to be defined depend on the class used. At least one property must be defined. This may be a dummy property. Multiple entries may exist.

string

Definition of a string property. An example is the definition of the geoDatum for displaying shape files using the geoDatumDisplay class.

key

Key to identify the property

Value

Value of the property defined.

Note: when displaying a shape file layer that does not use WGS 1984 as the coordinate system, a property must be defined that defines the geo datum. To do this set the key value as "geoDatum" and define the coordinate system using the enumeration in Appendix B.