android gps 代码 分析(2)

android

Log.d(TAG,"provider enable");

}

public void onStatusChanged(String provider, int status, Bundle extras) {

// TODO Auto-generated method stub

Log.d(TAG,"status changed");

}

}

另外一部分就是hardware/libhardware_legacy/gps

部分的实现，这个主要就是实现一个gps.h里面的几个数据结构：

typedef struct {

gps_location_callback location_cb;

gps_status_callback status_cb;

gps_sv_status_callback sv_status_cb;

} GpsCallbacks;

typedef struct {

int (*init)( GpsCallbacks* callbacks );

int (*start)( void );

int (*stop)( void );

void (*set_fix_frequency)( int frequency );

void (*cleanup)( void );

int (*inject_time)(GpsUtcTime time, int64_t timeReference,

int uncertainty);

void (*delete_aiding_data)(GpsAidingData flags);

int (*set_position_mode)(GpsPositionMode mode, int fix_frequency);

const void* (*get_extension)(const char* name);

} GpsInterface;

typedef struct {

uint16_t flags;

double latitude;

double longitude;

double altitude;

float speed;

float bearing;

float accuracy;

GpsUtcTime timestamp;

} GpsLocation;

在GpsInterface->init()的时候要把上层的GpsCallbacks传进来，然后start后，从驱动那里poll获得gps raw data，并对raw data进行解析并填充GpsLocation数据结构，然后调用location_cb 上报location 数据。

//初始化的时候，得到GpsInterface，调用init,

static jboolean android_location_GpsLocationProvider_init(JNIEnv* env, jobject obj) {

if (!sGpsInterface)

sGpsInterface = gps_get_interface();

return (sGpsInterface && sGpsInterface->init(&sGpsCallbacks) == 0);

}

GpsCallbacks sGpsCallbacks = {