com.esri.arcgis.networkanalyst
Interface INACompactStreetDirection

All Superinterfaces:

Serializable

All Known Subinterfaces:

INACompactStreetDirection2

All Known Implementing Classes:

INACompactStreetDirection2Proxy, INACompactStreetDirectionProxy

public interface INACompactStreetDirection
extends Serializable

Provides access to a compact street direction item.

Remarks

The INACompactStreetDirection interface provides access to each direction element. The NACompactStreetDirection object this interface accesses is significantly smaller than the NAStreetDirection object accessed via the INAStreetDirection interface. In particular, there is less information stored about the direction, and the geometry representing the traversed streets is highly compressed. Due to their smaller size, these directions are better suited for passing across low bandwidth connections in server applications.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Method Summary

String	getCompressedGeometry() The compressed geometry for the driving direction.
Date	getETA() The estimated time of arrival.
double	getLength() The cumulative driving length (in directions length units).
int	getManeuverType() The maneuver type.
String	getText() The driving direction text.
double	getTime() The time spent.

Method Detail

getLength

double getLength()
                 throws IOException,
                        AutomationException

The cumulative driving length (in directions length units).

Remarks

Length returns the length of the particular direction element.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Returns:

The length

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getTime

double getTime()
               throws IOException,
                      AutomationException

The time spent.

Remarks

Time returns the travel time of the particular direction element.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Returns:

The time

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getText

String getText()
               throws IOException,
                      AutomationException

The driving direction text.

Remarks

Text returns the text of the particular direction element.

The following lines are examples of what Text might return:

• Start at Stop 1
• Go east on Quintara St toward 32nd Ave
• Turn right onto 28th St
• Take roundabout and proceed northeast on 28th St
• Finish at Stop 2, on the right

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Returns:

The strText

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getCompressedGeometry

String getCompressedGeometry()
                             throws IOException,
                                    AutomationException

The compressed geometry for the driving direction.

Remarks

CompressedGeometry returns a compressed line geometry representing the direction. By compressing the geometry, the overall size of the direction item is significantly reduced.

The direction's line geometry is compressed by the directions agent. It compresses it by converting the line geometry into a string that holds the relative offsets of the points in the line as integers stored in 32-based notation.

Here is a description of the compression algorithm that is used:

Input to compression: 

  dirPoints - Direction's line geometry as a collection of points

  coefficient - Integer to multiply each x and y double by when converting to integer

Output: 

  compressedGeometry - String representing geometry

1. Convert coefficient to string and add to the start of the compressedGeometry string

2. set pointPrev = (0,0)

3. For each point in dirPoints

   a. int xDifference = Round(coefficient  * (point.x - pointPrev.x))

   b. Int yDifference = Round(coefficient  * (point.y - pointPrev.y))

   c. Convert xDifference to string using 32-based scale and add to compressedGeometry string

   d. Convert yDifference to string using 32-based scale and add to compressedGeometry string

   e. pointPrev = point;

4. return compressedGeometry string

To extract the points for the line geometry from the CompressedGeometry string, the reverse of the above must be done. It is necessary to get the first integer from the string and convert it to an integer to be used as the coefficient. Then, pop off each remaining substring and convert it back into a double.

Here is a description of the uncompression algorithm:

Input to decompression: 

  compressedGeometry - String representing geometry

Output:

  dirPoints - Direction's line geometry as a collection of points 

1. get first token from compressedGeometry string and convert to integer to use as the coefficient

2. xDiffPrev = 0, yDiffPrev = 0

3. For each point in dirPoints

   a. xDiff = get token from compressedGeometry string and convert from 32-based scale to integer

   b. yDiff = get token from compressedGeometry string and convert from 32-based scale to integer

   c. point.x = (xDiff + xDiffPrev) / coefficient

   e. point.y = (yDiff + yDiffPrev) / coeffiecint

   f. add point to dirPoints

   g. xDiffPrev = xDiff, yDiffPrev = yDiff

4. return dirPoints

Thus, with the following input data:
dirPoints:
-118.356654545455, 34.1146
-118.356436363636, 34.1143272727273
-118.356418181818, 34.1142363636364
-118.356490909091, 34.1137636363636
coefficient:
55000 - represents 2 meter resolution

It would be compressed into the following string:
"+1lmo-66l1f+1p8af+c-f+1-5-4-q"

When uncompressed, the resulting points would be the following (slightly different due to lossy compression):
-118.356636363636, 34.1146
-118.356418181818, 34.1143272727273
-118.3564, 34.1142363636364
-118.356472727273, 34.1137636363636

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Returns:

The strGeometry

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getETA

Date getETA()
            throws IOException,
                   AutomationException

The estimated time of arrival.

Remarks

ETA returns the estimated time of arrival at the direction element.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Returns:

The value

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getManeuverType

int getManeuverType()
                    throws IOException,
                           AutomationException

The maneuver type.

Remarks

ManeuverType returns the type of maneuver that the direction represents.

The esriDirectionsManeuverType enumeration has the following values:

• esriDMTUnknown - This indicates an unknown type of maneuver.
• esriDMTStop - This indicates a direction at a stop.
• esriDMTStraight - Go straight.
• esriDMTBearLeft - Bear left.
• esriDMTBearRight - Bear right.
• esriDMTTurnLeft - Turn left.
• esriDMTTurnRight - Turn right.
• esriDMTSharpLeft - Make a sharp left turn.
• esriDMTSharpRight - Make a sharp right turn.
• esriDMTUTurn - Make a U-turn.
• esriDMTFerry - Arrive at a ferry.
• esriDMTRoundabout - Enter a traffic circle.
• esriDMTHighwayMerge - Merge onto a highway.
• esriDMTHighwayExit - Exit a highway.
• esriDMTHighwayChange - The highway changes name.
• esriDMTForkCenter - Go through the center fork.
• esriDMTForkLeft - Fork left.
• esriDMTForkRight - Fork right.
• esriDMTDepart - Depart a stop.
• esriDMTTripItem - Trip item.
• esriDMTEndOfFerry - Depart a ferry.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Returns:

A com.esri.arcgis.networkanalyst.esriDirectionsManeuverType constant

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.