Hamilton County Draw Widget Measurements Page 2 of 11

Transcription

1 Hamilton County Draw Widget Measurements Larry Stout June 11, 2013 Introduction The Hamilton County Draw Widget is based on the Draw Widget from Version 2 of the Esri Flex Viewer. We have made several enhancements to the Esri Draw Widget. These include: Displaying coordinates for point graphics with the option of selecting the spatial reference for the coordinates. Showing a point graphic dynamically while the user is locating it on the map. Moving the configuration of length and area units and spatial references for point graphic coordinates from the Draw Widget configuration file to the main configuration file so other widgets can offer the same options for their measurement and coordinate display. Displaying dynamic and final measurements on the widget as well as on the map. Displaying additional dynamic measurements on the widget (e.g. width and height for extents and ellipses, radius and diameter for circles, segment length for polylines and polygons, and close length for polygons). Expanding the context menu choices for each drawn graphic. In addition to deleting the graphic, the context menu allows the user to update symbology, update measurements, remove measurements, and stop editing. Adding the ability to save graphics to a file and load graphics from a file (taken directly from Robert Scheitlin s Draw Widget). Adding the option of rotating text. A sample text string on the widget illustrates the font; font size; bold, italic, and underline settings; color, and rotation angle. Showing text dynamically while the user is locating it on the map. This document covers our enhancements to the measurements. For the sake of simplicity, when we refer to measurements, we are including coordinates on a point graphic in addition to length and area measurements on line and polygon graphics.

2 and Measurements measurements are measurements that display when a graphic is being drawn or edited. They change as the user moves the mouse, inserts a vertex, etc. measurements reflect the properties of a completed graphic. When the mouse hovers over a graphic, the final measurements are displayed on the widget whether they are displayed on the map or not. Measurement Configuration Spatial reference options for displaying point coordinates and options for displaying length units, and area units are configured in the main configuration file (e.g. config.xml) rather than the Draw Widget configuration file. By doing this, other widgets that show measurements (e.g. Identify Widget, Search Widget, and Clicktips Widget) can use the same configuration as the Draw Widget. Here is an example of the measurement tag section in the Hamilton County config.xml file: <measurementunits> <coordsys label="ine-83 State Plane" wkid="2965" abbr="ft" xlabel="x:" ylabel="y:" precision="0" dms="false"/> <coordsys label="nad83 UTM Zone 16N" wkid="26916" abbr="m" xlabel="x:" ylabel="y:" precision="1" dms="false"/> <coordsys label="gcs WGS 1984 (Deg Min Sec)" wkid="4326" abbr="" xlabel="lon:" ylabel="lat:" precision="0" dms="true" selected="true"/> <coordsys label="gcs WGS 1984 (Decimal Deg)" wkid="4326" abbr="deg" xlabel="lon:" ylabel="lat:" precision="6" dms="false"/> <lengthunit label="feet" abbr="ft" esriunit="9003" precision="0" cascade="true"/> <lengthunit label="miles" abbr="mi" esriunit="9093" precision="2" selected="true"/> <lengthunit label="meters" abbr="m" esriunit="9001" precision="1" cascade="true"/> <lengthunit label="kilometers" abbr="km" esriunit="9036" precision="2"/> <areaunit label="sq Feet" abbr="sq ft" esriunit="esrisquarefeet" precision="0" cascade="true"/> <areaunit label="acres" abbr="ac" esriunit="esriacres" precision="2" cascade="true"/> <areaunit label="sq Miles" abbr="sq mi" esriunit="esrisquaremiles" precision="2" selected="true"/> <areaunit label="sq Meters" abbr="sq m" esriunit="esrisquaremeters" precision="0" cascade="true"/> <areaunit label="hectares" abbr="ha" esriunit="esrihectares" precision="2" cascade="true"/> <areaunit label="sq km" abbr="sq km" esriunit="esrisquarekilometers" precision="2"/> </measurementunits> Hamilton County Draw Widget Measurements Page 2 of 11

3 Measurement Calculations Measurement calculations vary depending on the spatial reference of the map. Measurements are always calculated in or converted to meters and square meters. Coordinates for all Geographic spatial references are retrieved in decimal degrees. Coordinates for Web Mercator spatial references are converted to Geographic (4326) by the client. Measurements are then converted by the client and displayed in the selected units. Coordinates are converted to a different spatial reference with a call to the Geometry Service on the ArcGIS Server. Map Spatial Reference Coordinates Lengths Areas Geographic (4326) Latitude & Longitude Calculated by the client in meters Calculated by the client in square meters Web Mercator (102113, , 3857, or 3785) Latitude & Longitude (converted to 4326 by the client) Converted by the client to 4326 and calculated by the client in meters Converted by the client to 4326 and calculated by the client in square meters Projected (other than Web X & Y (in the spatial reference Mercator) units) Calculated by the client in meters Calculated by the client in square meters Geographic (other than 4326) Latitude & Longitude Calculated by the server in meters by a call to the Geometry Service Calculated by the server in meters by a call to the Geometry Service Measurement Units Measurement units for lengths and areas are very similar to the measurement units used by the Esri Draw Widget. Coordinates The coordinate system tag (<coordsys>) has been added to give the user the option of displaying point coordinates in different spatial references. For example, if the map spatial reference is in State Plane coordinates and the user wanted the Latitude and Longitude for calling in a helicopter, the spatial reference can be set to a geographic system. Hamilton County Draw Widget Measurements Page 3 of 11

4 Measurements Displayed on the Widget The Draw Widget displays final measurements on the widget when the mouse hovers over a graphic that was drawn with the Draw Widget. The measurements are in the units selected when the graphic was drawn unless the user sets different units and then selects Update Measurements from the context menu of the graphic. The Draw Widget displays dynamic measurements on the widget as a graphic is being drawn or edited if the measurements can be computed by the client without a call to the geometry service. This is only possible when the Measurement Spatial Reference is the same as the Map Spatial Reference and these spatial references are one of the following: Web Mercator (wkid = , , 3857, or 3785) Geographic (wkid = 4326) Non Geographic (e.g. State Plane, UTM, etc.) The Show Measurements checkbox label has changed to Show Measurements on Map in the Draw Widget configuration file since the measurements are always shown on the widget. Table 1 shows the conditions where dynamic and final measurements are shown on the widget and shown on the map if the Show Measurements on Map checkbox is checked. Hamilton County Draw Widget Measurements Page 4 of 11

5 Map Spatial Reference Table 1 Measurement Spatial Reference (from config.xml) Same as Map Spatial Reference Different from Map Spatial Reference Measurements Measurements Measurements Measurements Web Mercator (102113, , 3857, or 3785) * Geographic (4326) * Geographic (other than 4326) Non Geographic (e.g. State Plane, UTM, etc.) * *Note that dynamic measurements for point graphics are shown only if the coordinate system dropdown on the widget is also set to the same spatial reference as the Map Spatial Reference. Behavior of Measurement Display for Each Drawing Tool The Draw Widget supports eight different drawing tools. Different drawing tools have different measurements displayed on the Draw Widget. Table 2 is an index to the notes that describe the dynamic and final measurements that are displayed on the widget and on the map. Figure 1 illustrates the measurement locations on the widget. Table 2 Drawing Type Initial Draw Move Rotate Scale Move Vertex Add Vertex Delete Vertex Point 1 1 NA NA NA NA NA Polyline Freehand Polyline Extent 5 14 NA 5 NA NA NA Circle Ellipse Polygon Freehand Polygon Hamilton County Draw Widget Measurements Page 5 of 11

6 Figure 1 Notes See Table 2 for an index to the notes. 1. When a point is being drawn or moved, its map coordinates are shown as follows (subject to the conditions of Table 1): 1. X Coordinate (or Longitude) Y Coordinate (or Latitude) X Coordinate (or Longitude) Y Coordinate (or Latitude) 1. X Coordinate (or Longitude) Y Coordinate (or Latitude) X Coordinate (or Longitude) Y Coordinate (or Latitude) Hamilton County Draw Widget Measurements Page 6 of 11

7 When a Polyline is being drawn, the measurements are shown as follows (subject to the conditions of Table 1): 1. Length of the Polyline Length of the current segment Length of the Polyline 1. Length of the Polyline Length of the Polyline When a Polyline or a Freehand Polyline is being edited, the measurements are shown as follows (subject to the conditions of Table 1): 1. Length of the Polyline or Freehand Polyline Length of the Polyline or Freehand Polyline 1. Length of the Polyline or Freehand Polyline Length of the Polyline or Freehand Polyline Hamilton County Draw Widget Measurements Page 7 of 11

8 When a Freehand Polyline is being drawn, the measurements are shown as follows (subject to the conditions of Table 1): 1. Length of the Freehand Polyline Length of the Freehand Polyline 1. Length of the Freehand Polyline Length of the Freehand Polyline 5. When an Extent (rectangle) is being drawn, the measurements are shown as follows (subject to the conditions of Table 1): 1. area perimeter width Area and perimeter of the Extent height 1. area perimeter width height Area and perimeter of the Extent Hamilton County Draw Widget Measurements Page 8 of 11

9 6. When a Circle is being drawn, the measurements are shown as follows (subject to the conditions of Table 1): 1. area circumference radius Area and circumference of the Circle diameter 1. area circumference radius diameter Area and circumference of the Circle 7. When a Circle is scaled, it is demoted to an Ellipse (see Note 10 for its measurement display). 8. When a vertex of a Circle or an Ellipse is edited (moved, deleted, or added), the Circle or Ellipse is demoted to a Polygon (see Note 13 for its measurement display). 9. When an Ellipse is being drawn, the measurements are shown as follows (subject to the conditions of Table 1): Circumference Width Area and circumference of the Ellipse Height Circumference Width Height Area and circumference of the Ellipse Hamilton County Draw Widget Measurements Page 9 of 11

10 10. When an Ellipse is rotated, the height and width no longer display. The measurements are shown as follows (subject to the conditions of Table 1): Circumference Area and circumference of the Ellipse Circumference Area and circumference of the Ellipse 11. When an Ellipse is being scaled, the display of its measurements varies depending on whether it has been rotated in a previous edit. If the Ellipse has been rotated in a previous edit, the height and width are no longer displayed (see Note 10 for its measurement display). If the Ellipse has not been rotated in a previous edit, the measurements are the same as an Ellipse that is being drawn (see Note 9 for its measurement display). 1 When a Polygon or a Freehand Polygon is being drawn, the measurements are shown as follows (subject to the conditions of Table 1): Perimeter Area and perimeter of the Polygon or Length of segment being drawn Freehand Polygon Length to close the polygon Perimeter Length of segment being drawn Length to close the polygon Area and perimeter of the Polygon or Freehand Polygon Hamilton County Draw Widget Measurements Page 10 of 11

11 1 When a Polygon or a Freehand Polygon is being scaled or when a vertex is being edited (moved, deleted, or added), the measurements are shown as follows (subject to the conditions of Table 1): Perimeter Area and perimeter of the Polygon or Freehand Polygon Perimeter Area and perimeter of the Polygon or Freehand Polygon 1 Measurements don t change (very much) during this activity, but if they are displayed on the map, their location follows the location of the graphic. There may be minor changes in the measurements during a rotate edit if the spatial reference is Web Mercator or Geographic. Hamilton County Draw Widget Measurements Page 11 of 11