org.j4me.bluetoothgps
Class Criteria

java.lang.Object
  extended by org.j4me.bluetoothgps.Criteria

public class Criteria
extends java.lang.Object

The criteria used for the selection of the location provider is defined by the values in this class. It is up to the implementation to provide a LocationProvider that can obtain locations constrained by these values.

Instances of Criteria are used by the application to indicate criteria for choosing the location provider in the LocationProvider.getInstance method call. The implementation considers the different criteria fields to choose the location provider that best fits the defined criteria. The different criteria fields do not have any defined priority order but the implementation uses some implementation specific logic to choose the location provider that can typically best meet the defined criteria.

However, the cost criteria field is treated differently from others. If the application has set the cost field to indicate that the returned location provider is not allowed to incur financial cost to the end user, the implementation MUST guarantee that the returned location provider does not incur cost.

If there is no available location provider that is able to meet all the specified criteria, the implementation is allowed to make its own best effort selection of a location provider that is closest to the defined criteria (provided that the cost criteria is met). However, an implementation is not required to return a location provider if it does not have any available provider that is able to meet these criteria or be sufficiently close to meeting them, where the judgement of sufficiently close is an implementation dependent best effort choice. It is left up to the implementation to consider what is close enough to the specified requirements that it is worth providing the location provider to the application.

The default values for the criteria fields are specified below in the table. The default values are always the least restrictive option that will match all location providers. Default values:

Criteria field Default value
Horizontal accuracy NO_REQUIREMENT
Vertical accuracy NO_REQUIREMENT
Preferred response time NO_REQUIREMENT
Power consumption NO_REQUIREMENT
Cost allowed true (allowed to cost)
Speed and course required false (not required)
Altitude required false (not required)
Address info required false (not required)
Allow local LBS true (use the LBS on the device running this MIDlet if it meets the other criteria)
Remote LBS address null (only use the local LBS on the device running this MIDlet)

The implementation of this class only retains the values that are passed in using the set* methods. It does not try to validate the values of the parameters in any way. Applications may set any values it likes, even negative values, but the consequence may be that no matching LocationProvider can be created.


Field Summary
static int NO_REQUIREMENT
          Constant indicating no requirements for the parameter.
static int POWER_USAGE_HIGH
          Level indicating high power consumption allowed.
static int POWER_USAGE_LOW
          Level indicating only low power consumption allowed.
static int POWER_USAGE_MEDIUM
          Level indicating average power consumption allowed.
 
Constructor Summary
Criteria()
          Constructs a Criteria object.
 
Method Summary
 int getHorizontalAccuracy()
          Returns the horizontal accuracy value set in this Criteria.
 int getPreferredPowerConsumption()
          Returns the preferred power consumption.
 int getPreferredResponseTime()
          Returns the preferred maximum response time.
 java.lang.String getRemoteDeviceAddress()
          Returns the Bluetooth address of the remote GPS device to use if no local LBS matches the other criteria.
 int getVerticalAccuracy()
          Returns the vertical accuracy value set in this Criteria.
 boolean isAddressInfoRequired()
          Returns whether the location provider should be able to determine textual address information.
 boolean isAllowedToCost()
          Returns the preferred cost setting.
 boolean isAltitudeRequired()
          Returns whether the location provider should be able to determine altitude.
 boolean isLocalLBSAllowed()
          Returns if the LBS on this device should be used if it meets the other criteria.
 boolean isSpeedAndCourseRequired()
          Returns whether the location provider should be able to determine speed and course.
 void setAddressInfoRequired(boolean addressInfoRequired)
          Sets whether the location provider should be able to determine textual address information.
 void setAllowLocalLBS(boolean allowLocalLBS)
          Sets if the LBS on this device should be used if it meets the other criteria.
 void setAltitudeRequired(boolean altitudeRequired)
          Sets whether the location provider should be able to determine altitude.
 void setCostAllowed(boolean costAllowed)
          Sets the preferred cost setting.
 void setHorizontalAccuracy(int accuracy)
          Sets the desired horizontal accuracy preference.
 void setPreferredPowerConsumption(int level)
          Sets the preferred maximum level of power consumption.
 void setPreferredResponseTime(int time)
          Sets the desired maximum response time preference.
 void setRemoteDeviceAddress(java.lang.String address)
          Sets the Bluetooth address of the remote GPS device.
 void setSpeedAndCourseRequired(boolean speedAndCourseRequired)
          Sets whether the location provider should be able to determine speed and course.
 void setVerticalAccuracy(int accuracy)
          Sets the desired vertical accuracy preference.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

NO_REQUIREMENT

public static final int NO_REQUIREMENT
Constant indicating no requirements for the parameter.

See Also:
Constant Field Values

POWER_USAGE_LOW

public static final int POWER_USAGE_LOW
Level indicating only low power consumption allowed.

See Also:
Constant Field Values

POWER_USAGE_MEDIUM

public static final int POWER_USAGE_MEDIUM
Level indicating average power consumption allowed.

See Also:
Constant Field Values

POWER_USAGE_HIGH

public static final int POWER_USAGE_HIGH
Level indicating high power consumption allowed.

See Also:
Constant Field Values
Constructor Detail

Criteria

public Criteria()
Constructs a Criteria object. All the fields are set to the default values that are specified below in the specification of the set* methods for the parameters.

Method Detail

getPreferredPowerConsumption

public int getPreferredPowerConsumption()
Returns the preferred power consumption.

Returns:
the power consumption level, should be one of NO_REQUIREMENT, POWER_USAGE_LOW, POWER_USAGE_MEDIUM, POWER_USAGE_HIGH.
See Also:
setPreferredPowerConsumption(int)

isAllowedToCost

public boolean isAllowedToCost()
Returns the preferred cost setting.

Returns:
the preferred cost setting. true if allowed to cost, false if it must be free of charge.
See Also:
setCostAllowed(boolean)

getVerticalAccuracy

public int getVerticalAccuracy()
Returns the vertical accuracy value set in this Criteria.

Returns:
the accuracy in meters.
See Also:
setVerticalAccuracy(int)

getHorizontalAccuracy

public int getHorizontalAccuracy()
Returns the horizontal accuracy value set in this Criteria.

Returns:
the horizontal accuracy in meters.
See Also:
setHorizontalAccuracy(int)

getPreferredResponseTime

public int getPreferredResponseTime()
Returns the preferred maximum response time.

Returns:
the maximum response time in milliseconds.
See Also:
setPreferredResponseTime(int)

isSpeedAndCourseRequired

public boolean isSpeedAndCourseRequired()
Returns whether the location provider should be able to determine speed and course.

Returns:
whether the location provider should be able to determine speed and course. true means that it should be able, false means that this is not required.
See Also:
setSpeedAndCourseRequired(boolean)

isAltitudeRequired

public boolean isAltitudeRequired()
Returns whether the location provider should be able to determine altitude.

Returns:
whether the location provider should be able to determine altitude. true means that it should be able, false means that this is not required.
See Also:
setAltitudeRequired(boolean)

isAddressInfoRequired

public boolean isAddressInfoRequired()
Returns whether the location provider should be able to determine textual address information.

Returns:
whether the location provider should be able to normally provide textual address information. true means that it should be able, false means that this is not required.
See Also:
setAddressInfoRequired(boolean)

isLocalLBSAllowed

public boolean isLocalLBSAllowed()
Returns if the LBS on this device should be used if it meets the other criteria. Local LBS gets preference over any remote LBS specified by in remoteDeviceAddress.

If false only the remote LBS at setRemoteDeviceAddress can be used.

Returns:
true if local LBS can be used; false if remote LBS must be used.

getRemoteDeviceAddress

public java.lang.String getRemoteDeviceAddress()
Returns the Bluetooth address of the remote GPS device to use if no local LBS matches the other criteria. If this is null than only local LBS can be used.

Returns:
the URL of a remote LBS device. Typically this is a Bluetooth URL obtained from the LocationProvider.discoverBluetoothDevices method. If this is null than only local LBS will be used.
See Also:
setRemoteDeviceAddress(String)

setHorizontalAccuracy

public void setHorizontalAccuracy(int accuracy)
Sets the desired horizontal accuracy preference. Accuracy is measured in meters. The preference indicates maximum allowed typical 1-sigma standard deviation for the location method. Default is NO_REQUIREMENT, meaning no preference on horizontal accuracy.

Parameters:
accuracy - - the preferred horizontal accuracy in meters
See Also:
getHorizontalAccuracy()

setVerticalAccuracy

public void setVerticalAccuracy(int accuracy)
Sets the desired vertical accuracy preference. Accuracy is measured in meters. The preference indicates maximum allowed typical 1-sigma standard deviation for the location method. Default is NO_REQUIREMENT, meaning no preference on vertical accuracy.

Parameters:
accuracy - - the preferred vertical accuracy in meters
See Also:
getVerticalAccuracy()

setPreferredResponseTime

public void setPreferredResponseTime(int time)
Sets the desired maximum response time preference. This value is typically used by the implementation to determine a location method that typically is able to produce the location information within the defined time. Default is NO_REQUIREMENT, meaning no response time constraint.

Parameters:
time - - the preferred time constraint and timeout value in milliseconds
See Also:
getPreferredResponseTime()

setPreferredPowerConsumption

public void setPreferredPowerConsumption(int level)
Sets the preferred maximum level of power consumption.

These levels are inherently indeterminable and depend on many factors. It is the judgement of the implementation that defines a positioning method as consuming low power or high power. Default is NO_REQUIREMENT, meaning power consumption is not a quality parameter.

Parameters:
level - - the preferred maximum level of power consumption. Should be one of NO_REQUIREMENT, POWER_USAGE_LOW, POWER_USAGE_MEDIUM, POWER_USAGE_HIGH.
See Also:
getPreferredPowerConsumption()

setCostAllowed

public void setCostAllowed(boolean costAllowed)
Sets the preferred cost setting.

Sets whether the requests for location determination is allowed to incur any financial cost to the user of the terminal.

The default is true, i.e. the method is allowed to cost.

Note that the platform implementation may not always be able to know if a location method implies cost to the end user or not. If the implementation doesn't know, it MUST assume that it may cost. When this criteria is set to false, the implementation may only return a LocationProvider of which it is certain that using it for determining the location does not cause a per usage cost to the end user.

Parameters:
costAllowed - - false if location determination is not allowed to cost, true if it is allowed to cost
See Also:
isAllowedToCost()

setSpeedAndCourseRequired

public void setSpeedAndCourseRequired(boolean speedAndCourseRequired)
Sets whether the location provider should be able to determine speed and course. Default is false.

Parameters:
speedAndCourseRequired - - if set to true, the LocationProvider is required to be able to normally determine the speed and course. if set the false, the speed and course are not required.
See Also:
isSpeedAndCourseRequired()

setAltitudeRequired

public void setAltitudeRequired(boolean altitudeRequired)
Sets whether the location provider should be able to determine altitude.

Default is false.

Parameters:
altitudeRequired - - if set to true, the LocationProvider is required to be able to normally determine the altitude if set the false, the altitude is not required.
See Also:
isAltitudeRequired()

setAddressInfoRequired

public void setAddressInfoRequired(boolean addressInfoRequired)
Sets whether the location provider should be able to determine textual address information. Setting this criteria to true implies that a location provider should be selected that is capable of providing the textual address information. This does not mean that every returned location instance necessarily will have all the address information filled in, though.

Default is false.

Parameters:
addressInfoRequired - - if set to true, the LocationProvider is required to be able to normally determine the textual address information. If set the false, the textual address information is not required.
See Also:
isAddressInfoRequired()

setAllowLocalLBS

public void setAllowLocalLBS(boolean allowLocalLBS)
Sets if the LBS on this device should be used if it meets the other criteria. Local LBS gets preference over any remote LBS specified by in remoteDeviceAddress.

To force remote LBS to be used set this value to false and provide a remote address to setRemoteDeviceAddress.

Default is true.

Parameters:
allowLocalLBS - when true uses LBS on the current device if it meets the other criteria; when false forces remote LBS to be used.

setRemoteDeviceAddress

public void setRemoteDeviceAddress(java.lang.String address)
Sets the Bluetooth address of the remote GPS device. This address can be obtained from the LocationProvider.discoverBluetoothDevices method. Once the address is known, it should be stored using the Record Management System (RMS) for the next time the MIDlet is run. If this value is set to null, the default, than only LBS providers built into the device running the MIDlet will be used.

Parameters:
address - - the Bluetooth address of the remote GPS device or null if only local LBS can be used.
See Also:
getRemoteDeviceAddress()