# Titanium.Geolocation.Android
Module for Android-specific geolocation functionality.
# Overview
This module is used for manually configuring geolocation settings on Android.
Manual configuration is recommended for applications that have more demanding geolocation needs (for example, driving directions). However, for basic geolocation information, simple mode geolocation may be sufficient. For information on simple mode, see Titanium.Geolocation.
Manual configuration involves managing providers and rules:
Location providers, such as GPS, provide location updates.
Location rules filter the results returned by location providers.
Configuring geolocation manually involves three steps:
Enabling manual mode.
Enabling location providers.
Adding location rules (optional).
As with the other modes, you register for location updates using the main
Titanium.Geolocation module. Location updates are generated as long as
an event listener is registered for the location
event. When you are not
using location updates, you should remove any registered event listeners.
In manual mode, the application is responsible for dynamically updating the settings to acheive its required accuracy while limiting battery usage. For example, an application might do any of the following:
If the application isn't getting updates frequently enough, it can adjust its provider settings to provide more updates, or relax its location rules to allow less accurate updates through.
If the application isn't receiving accurate enough updates from one provider, it can add another provider to try to improve results.
If the application is getting sufficiently accurate results from the network provider, it can disable the GPS provider to save power.
# Enabling Manual Configuration Mode
To enable manual configuration mode, set the Titanium.Geolocation.Android.manualMode
property to true
. In manual configuration mode, the location providers and location
rules set through this module control the generation of location updates.
When manualMode
is true
, the following configuration settings in the
Titanium.Geolocation module are ignored:
When manualMode
is false
, the accuracy
, frequency
and preferredProvider
settings from Titanium.Geolocation are used to configure location updates.
Any location providers and location rules set in Titanium.Geolocation.Android
are retained, but they have no effect.
# Location Providers
Android supports three kinds of location providers: GPS, network, and the "passive" location provider, which provides only cached information.
Each location provider represents a different tradeoff between accuracy and battery power. For most accurate results, you can use a combination of location providers. Your application can also dynamically change providers to optimize battery life (for example, if the network provider is providing good enough location updates, you can disable the GPS provider).
Location providers are represented by the Titanium.Geolocation.Android.LocationProvider object. To specify a location provider, create a new provider object, then register it with Titanium.Geolocation.Android.createLocationProvider:
var gpsProvider = Ti.Geolocation.Android.createLocationProvider({
name: Ti.Geolocation.Android.PROVIDER_GPS,
minUpdateTime: 60,
minUpdateDistance: 100
});
Ti.Geolocation.Android.addLocationProvider(gpsProvider);
As shown above, when you create a location provider, you can specify two properties to limit update frequency:
minUpdateTime
. Limits the frequency of location updates to no more than one perminUpdateTime
seconds.minUpdateDistance
. Don't send location updates until the location changes at leastminUpdateDistance
meters.
Only one provider of each type (GPS, network, passive) can be registered at a
time. Adding a new location provider with the same name
value replaces any
existing provider with the same name
.
Once a location provider is added, changes made to the location provider object itself
(such as changing its minUpdateTime
value) change the active configuration of the
location system.
# Location Rules
Location Rules filter the results returned by location providers. You use location rules to reduce the number of location update events, and ensure that the events you do receive are as accurate and recent as your application requires.
You are not required to set any location rules. However, by reducing the number of location events that are passed from the native code to the JavaScript layer, location rules can improve both performance and battery life.
Location rules are represented by the Titanium.Geolocation.Android.LocationProvider object. To specify a location rule, create a new rule object, then register it with Titanium.Geolocation.Android.createLocationProvider:
var gpsRule = Ti.Geolocation.Android.createLocationRule({
provider: Ti.Geolocation.PROVIDER_GPS,
// Updates should be accurate to 100m
accuracy: 100,
// Updates should be no older than 5m
maxAge: 300000
// But no more frequent than once per 10 seconds
minAge: 10000
});
Ti.Geolocation.Android.addLocationRule(gpsRule);
Each rule can specify any combination of the following criteria:
provider
. If specified, this rule only applies to updates generated by the specified provider. If not specified, this rule applies to all updates.accuracy
. Minimum accuracy required for a location update. Accuracy is expressed as the maximum allowable error, in meters. Updates with reported accuracy values greater than this are filtered out.minAge
. Controls the frequency of location updates. Do not forward an update unless at leastminAge
milliseconds have passed since the last good location update.maxAge
. Controls the freshness of location updates. Do not forward an update unless it is newer thanmaxAge
milliseconds.
You can specify as many location rules as you like. The order in which location rules
are added is not significant. For a location
event to be generated, the location
update must pass all of the active rules.
Note that some combinations of rules may make it very difficult to get location
updates. In particular, very low values for either accuracy
or maxAge
may prevent
results from getting through.
# Properties
# manualMode
Set to true
to enable manual configuration of location updates through this module.
If true
, location updates are controlled by the location providers and location rules
configured in this module.
If false
, location updates are configured using the accuracy,
frequency and preferredProvider
properties in the Titanium.Geolocation module.
Default: false
# Methods
# addLocationProvider
Adds and enables the specified location provider, possibly replacing an existing one.
If another location provider with the same name
value is already active, the
new location provider replaces the exiting one.
Parameters
Name | Type | Description |
---|---|---|
provider | Titanium.Geolocation.Android.LocationProvider | The location provider to add. |
Returns
- Type
- void
# addLocationRule
Adds and enables the specified location rule.
Only location updates that pass all of the active rules are passed on to the application.
Parameters
Name | Type | Description |
---|---|---|
rule | Titanium.Geolocation.Android.LocationRule | The location rule to add. |
Returns
- Type
- void
# createLocationProvider
Creates and returns an instance of Titanium.Geolocation.Android.LocationProvider.
Parameters
Name | Type | Description |
---|---|---|
parameters | Dictionary<Titanium.Geolocation.Android.LocationProvider> | Properties to set on a new object, including any defined by Titanium.Geolocation.Android.LocationProvider except those marked not-creation or read-only. |
Returns
# createLocationRule
Creates and returns an instance of Titanium.Geolocation.Android.LocationRule.
Parameters
Name | Type | Description |
---|---|---|
parameters | Dictionary<Titanium.Geolocation.Android.LocationRule> | Properties to set on a new object, including any defined by Titanium.Geolocation.Android.LocationRule except those marked not-creation or read-only. |
Returns
# removeLocationProvider
Disables and removes the specified location provider.
Parameters
Name | Type | Description |
---|---|---|
provider | Titanium.Geolocation.Android.LocationProvider | The location provider to remove. |
Returns
- Type
- void
# removeLocationRule
Disables and removes the specified location rule.
Parameters
Name | Type | Description |
---|---|---|
rule | Titanium.Geolocation.Android.LocationRule | The location rule to remove. |
Returns
- Type
- void
# Constants
# PROVIDER_GPS
Specifies the GPS location provider.
Used with Titanium.Geolocation.Android.LocationProvider, Titanium.Geolocation.Android.LocationRule. In general, the GPS provider has the highest power consumption and the highest accuracy, but this may vary. In some circumstances, the network provider may be more reliable.
# PROVIDER_NETWORK
Specifies the network location provider.
Used with Titanium.Geolocation.Android.LocationProvider, Titanium.Geolocation.Android.LocationRule. Generally requires less power than the GPS provider and provides less accurate results, but may produce very accurate results in densely-populated areas with many cell towers and WiFi networks.
# PROVIDER_PASSIVE
Specifies the passive location provider.
Used with Titanium.Geolocation.Android.LocationProvider, Titanium.Geolocation.Android.LocationRule. This provider only uses cached location information, so it does not use any power, but makes no guarantee that the location results are recent.