WVR_RegisterTrackerInfoCallback¶
-
WVR_EXPORT WVR_Result WVR_RegisterTrackerInfoCallback(WVR_TrackerInfoNotify_t * notify)
Function to register an info notify of tracker.
- Version
- API Level 9
- Parameters
notify
: which contains an info callback function. This callback function will be called if a tracker info notify has been triggered by tracker device. (Refer to WVR_TrackerInfoNotify.)
- Return Value
WVR_Success
: start the tracker feature successfully.others
: means failure. (Refer to WVR_Result.)
Warning
- This function only works at API level 9 or later.
How to use¶
Here is an example for the function:
- Header & global variable.
#include <wvr/wvr.h> // for enum WVR_SupportedFeature
#include <wvr/wvr_tracker.h>
#include <wvr/wvr_types.h>
bool gRunningTR = false;
- Start tracker feature first if it has not been started yet. (See also WVR Supported Features)
if (WVR_GetSupportedFeatures() & WVR_SupportedFeature_Tracker) { // the tracker feature is supported or not
WVR_Result res = WVR_StartTracker();
if (res == WVR_Success) gRunningTR = true;
}
- Implement the callback function. (See also WVR_TrackerInfoCallback.)
void CustomizedTrackerInfoCallback(WVR_TrackerId trackerId, const char *cbInfo, uint64_t *cbTimestamp);
void CustomizedTrackerInfoCallback(WVR_TrackerId trackerId, const char *cbInfo, uint64_t *cbTimestamp) {
LOGD("CustomizedTrackerInfoCallback, WVR_TrackerId(%d), cbInfo(%s), cbTs(%" PRId64 ")", trackerId, cbInfo, *cbTimestamp);
// TODO: The developer might want to do something corresponding to this function call.
}
- Use function WVR_RegisterTrackerInfoCallback to register callback function.
if (gRunningTR) {
WVR_TrackerInfoNotify_t mTrackerInfoNotify;
mTrackerInfoNotify.callback = CustomizedTrackerInfoCallback;
WVR_Result ret = WVR_RegisterTrackerInfoCallback(&mTrackerInfoNotify);
}
- Passively waiting for the callback function CustomizedTrackerInfoCallback to be called from Wave runtime (triggered by tracker device). The tracker info (cbInfo, cbTimestamp) will be updated.
Note
- See also WVR_UnregisterTrackerInfoCallback.
- See also Tracker Info Notification.