TPosition Class Reference

API published in: S60 2nd Ed FP 2

Link against: lbs.lib

Capability Information

Required Capabilities

Location

#include <lbsposition.h>

Inherits TLocality.

Detailed Description

This class is the standard data structure for retrieving location information.

It adds a time dimension to the inherited TLocality information. This enables the speed to be calculated from two TPosition instances.

The time reflects the system time (that is, the mobile terminal) of when the location fix was obtained. It does not indicate the time as obtained from the position technology (for example network or satellite time).

The time is contained in a TTime data structure that provides microsecond resolution. However, it should be noted that system clocks only provide a resolution of milliseconds or indeed hundredths of a second.


Public Member Functions
IMPORT_C�	TPosition ()
�	Default constructor for TCoordinate.
IMPORT_C�	TPosition (const TLocality &aLocality, TTime aTime)
�	Constructor for TPosition.
IMPORT_C void�	SetTime (TTime aTime)
�	Sets the time of this position data.
IMPORT_C void�	SetCurrentTime ()
�	Sets the time of this position data to the current universal time as indicated by the systems clock.
IMPORT_C TTime�	Time () const
�	Retrieves the time of this position data.
IMPORT_C TInt�	Speed (const TPosition &aPosition, TReal32 &aSpeed) const
�	This method calculates the horizontal speed between the current position and the supplied instance aPosition.
IMPORT_C TInt�	Speed (const TPosition &aPosition, TReal32 &aSpeed, TReal32 &aDelta) const
�	This method calculates the horizontal speed between the current position and the supplied instance aPosition.
Protected Attributes
TTime�	iTime
�	This is the system time when the position related member data was obtained.

Constructor & Destructor Documentation

IMPORT_C TPosition::TPosition

(�

�)�

�	Default constructor for TCoordinate. Sets the member data to default values (NaN for coordinates, 0 for time).

IMPORT_C TPosition::TPosition	(�	const TLocality &�	aLocality,
		TTime�	aTime
	)�

�

Constructor for TPosition.

Allows the client to set a locality and an associated time.

Parameters:

`[in]`�	aLocality�	specifies an initial value for the locality of the position.
	aTime�	specifies an initial value for the time of the position.

Member Function Documentation

IMPORT_C void TPosition::SetCurrentTime

(�

�)�

�	Sets the time of this position data to the current universal time as indicated by the systems clock.

IMPORT_C void TPosition::SetTime

Sets the time of this position data.

Parameters:

aTime�

is the new timing information.

IMPORT_C TInt TPosition::Speed	(�	const TPosition &�	aPosition,
		TReal32 &�	aSpeed,
		TReal32 &�	aDelta
	)�	const

�

This method calculates the horizontal speed between the current position and the supplied instance aPosition.

The speed is calculated based on the coordinates and time associated with each instance. An estimate of the accuracy of the result is also provided.

Parameters:

`[in]`�	aPosition�	is another position to use in the calculation.
`[out]`�	aSpeed�	upon successful completion, this is set to the speed indicated by being at this position at its recorded time, and at aPosition at its recorded time. Always positive, in metres per second.
`[out]`�	aDelta�	upon successful completion, this is set to an estimate of the accuracy of the calculation, in metres per second.

Returns:

a Symbian OS error code.

KErrArgument if any of iLatitude, iLongitude, aPosition.iLatitude or aPosition.iLongitude are set to NaN.

KErrArgument if any of iHorizontalAccuracy or aPosition.iHorizontalAccuracy are set to NaN.

KErrArgument if either of iTime or aPosition.iTime are set to zero.

KErrArgument if iTime and aPosition.iTime are the same.

IMPORT_C TInt TPosition::Speed	(�	const TPosition &�	aPosition,
		TReal32 &�	aSpeed
	)�	const

�

This method calculates the horizontal speed between the current position and the supplied instance aPosition.

The speed is calculated based on the coordinates and time associated with each instance.

Parameters:

`[in]`�	aPosition�	is another position to use in the calculation.
`[out]`�	aSpeed�	upon successful completion, this is set to the speed indicated by being at this position at its recorded time, and at aPosition at its recorded time. Always positive, in metres per second.

Returns:

a Symbian OS error code.

KErrArgument if any of iLatitude, iLongitude, aPosition.iLatitude or aPosition.iLongitude are set to NaN.

KErrArgument if either of iTime or aPosition.iTime are set to zero.

KErrArgument if iTime and aPosition.iTime are the same.

IMPORT_C TTime TPosition::Time

(�

�)�

const