jquery - Retrieving last known geolocation - Phonegap -

the following code

navigator.geolocation.getcurrentposition(getgeo_success, getgeo_fail, {     enablehighaccuracy : true,     maximumage : infinity,     timeout : 15000 }); 

retrieves current gps position - but - there must valid gps signal (and ofcourse, device's gps feature should turned on).

if @ other applications (say, maps on android devices) - knows how retrieve last known position - if didn't use application updates geolocation before opening maps - shows position on map, if i'm inside building no gps signal @ all.

just clarify: i'm not interested in last geolocation application retrieved, on next time i`ll start it, geolocation irrelevant.

question is: how can achieve html5/phonegap? seems navigator.geolocation knows retrieve current position, though, maximumage set infinity (which means, age of last cached position irrelevant, hit okay (or, should be!))

android solution (iphone solution follows):

this neat:

i've made use of android's native locationmanager, provides getlastknownlocation function - name says all

here's relevant code

1) add following java class application

package your.package.app.app;  import org.apache.cordova.droidgap;  import android.content.context; import android.location.*; import android.os.bundle; import android.webkit.webview;  public class getnativelocation implements locationlistener {     private webview mappview;     private droidgap mgap;     private location mostrecentlocation;      public getnativelocation(droidgap gap, webview view) {         mappview = view;         mgap = gap;     }      public void onlocationchanged(location location) {         // todo auto-generated method stub         getlocation();     }      public void getlocation() {         locationmanager lm =                          (locationmanager)mgap.                                         getsystemservice(context.location_service);         criteria criteria = new criteria();         criteria.setaccuracy(criteria.accuracy_fine);         string provider = lm.getbestprovider(criteria, true);          lm.requestlocationupdates(provider, 1000, 500, this);         mostrecentlocation = lm                 .getlastknownlocation(locationmanager.gps_provider);     }      public void doinit(){         getlocation();     }      public double getlat(){ return mostrecentlocation.getlatitude();}     public double getlong() { return mostrecentlocation.getlongitude(); }     public void onproviderdisabled(string arg0) {         // todo auto-generated method stub       }      public void onproviderenabled(string provider) {         // todo auto-generated method stub       }      public void onstatuschanged(string provider, int status, bundle extras) {         // todo auto-generated method stub     } } 

2) make sure main class looks follows:

public class app extends droidgap {      // hold private member of class calls locationmanager     private getnativelocation glocation;      /** called when activity first created. */     @override     public void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         // line important, system services not available         // prior initialization         super.init();          glocation = new getnativelocation(this, appview);          // add interface can invoke java functions our .js          appview.addjavascriptinterface(glocation, "nativelocation");          try {             super.loadurl("file:///android_asset/www/index.html");         } catch (exception e) {             // todo: handle exception             e.printstacktrace();         }     }      @override     public void ondestroy() {         // todo auto-generated method stub         super.ondestroy();     }      @override     protected void onstop() {         // todo auto-generated method stub         super.onstop();     } } 

3) on js code, call native java using:

window.nativelocation.doinit(); alert(window.nativelocation.getlat()); alert(window.nativelocation.getlong()); 

thats folks! :-)

edit: iphone solution:

i wrote tiny phonegap plugin creates interface custom class making use of ios's native cllocationmanager

1) phonegap plugin (js)

var nativelocation = {     doinit: function(types, success, fail) {         return cordova.exec(success, fail, "nativelocation", "doinit", types);     },      getlongitude: function(types, success, fail){         return cordova.exec(success, fail, "nativelocation", "getlongitude", types);     },      getlatitude: function(types, success, fail){         return cordova.exec(success, fail, "nativelocation", "getlatitude", types);     } } 

2) objective-c class enables invoke 'cclocationmanager's functions *nativelocation.h*

#import <foundation/foundation.h> #import <cordova/cdvplugin.h> #import <corelocation/corelocation.h>  @protocol nativelocationdelegate @required - (void)locationupdate:(cllocation *)location; - (void)locationerror:(nserror *)error;  @end  @interface nativelocation : cdvplugin <cllocationmanagerdelegate> {     id delegate;     nsstring* callbackid;     cllocationmanager *lm;     boolean benabled;     double nlat;     double nlon; }  @property (nonatomic, copy) nsstring* callbackid; @property (nonatomic, retain) cllocationmanager *lm; @property (nonatomic, readonly) boolean benabled; @property (nonatomic, assign) id delegate;  - (void) doinit:(nsmutablearray*)arguments                                  withdict:(nsmutabledictionary*)options; - (void) getlatitude:(nsmutablearray*)arguments                                   withdict:(nsmutabledictionary *)options; - (void) getlongitude:(nsmutablearray*)arguments                                   withdict:(nsmutabledictionary *)options;  @end 

nativelocation.m

#import "nativelocation.h"  @implementation nativelocation  @synthesize callbackid; @synthesize lm; @synthesize benabled; @synthesize delegate;  - (void)doinit:(nsmutablearray *)arguments                                   withdict:(nsmutabledictionary *)options{     if (self != nil){         self.lm = [[[cllocationmanager alloc] init] autorelease];         self.lm.delegate = self;         if (self.lm.locationservicesenabled == no)             benabled = false;         else benabled = true;     }      nlat = 0.0;     nlon = 0.0;      if (benabled == true)         [self.lm startupdatinglocation];      cdvpluginresult* pluginresult = [cdvpluginresult                                      resultwithstatus:cdvcommandstatus_ok                                      messageasstring[@"ok"                                     stringbyaddingpercentescapesusingencoding:nsutf8stringencoding]];      if (benabled == true){         [self writejavascript: [pluginresult                                 tosuccesscallbackstring:self.callbackid]];     } else {         [self writejavascript: [pluginresult                                 toerrorcallbackstring:self.callbackid]];     } }  - (void)locationmanager:(cllocationmanager *)manager                          didupdatetolocation:(cllocation *)newlocation                          fromlocation:(cllocation *)oldlocation {     if ([self.delegate conformstoprotocol:@protocol(nativelocationdelegate)])         [self.delegate locationupdate:newlocation ]; }  - (void)locationmanager:(cllocationmanager *)manager didfailwitherror:(nserror *)error {     if ([self.delegate conformstoprotocol:@protocol(nativelocationdelegate)])         [self.delegate locationerror:error]; }  - (void)dealloc {     [self.lm release];     [super dealloc]; }  - (void)locationupdate:(cllocation *)location {     cllocationcoordinate2d ccoord = [location coordinate];     nlat = ccoord.latitude;     nlon = ccoord.longitude;  }  - (void)getlatitude:(nsmutablearray *)arguments                                        withdict:(nsmutabledictionary *)options{      self.callbackid = [arguments pop];      nlat = lm.location.coordinate.latitude;     nlon = lm.location.coordinate.longitude;      cdvpluginresult* pluginresult = [cdvpluginresult                                      resultwithstatus:cdvcommandstatus_ok                                      messageasdouble:nlat];      [self writejavascript: [pluginresult tosuccesscallbackstring:self.callbackid]];  } - (void)getlongitude:(nsmutablearray *)arguments                                         withdict:(nsmutabledictionary *)options{      self.callbackid = [arguments pop];      nlat = lm.location.coordinate.latitude;     nlon = lm.location.coordinate.longitude;      cdvpluginresult* pluginresult = [cdvpluginresult                       resultwithstatus:cdvcommandstatus_ok messageasdouble:nlon];      [self writejavascript: [pluginresult tosuccesscallbackstring:self.callbackid]];  }  @end 

3) , finally, invoking main .js

function getlongitudesuccess(result){     glongitude = result; }  function getlatitudesuccess(result){     glatitude = result; }  function rungpstimer(){     var stmp = "gps";      thetime = settimeout('rungpstimer()', 1000);      nativelocation.getlongitude(                                 ["getlongitude"],                                 getlongitudesuccess,                                 function(error){ alert("error: " + error); }                                 );      nativelocation.getlatitude(                                ["getlatitude"],                                getlatitudesuccess,                                function(error){ alert("error: " + error); }                                );