/**
* Thread that handles accelerometer events and
* sends relevant information to a dialog.
*
* @param p Unused.
*/
static void *
accel_main (void *p) {
bool run = true;
bps_event_t *event;
float force_x, force_y, force_z;
bps_initialize();
/*
* Each thread that calls bps_initialize() will have its
* own unique channel ID. Protect it inside a mutex and
* condition variable to avoid race condition where main
* thread tries to use it before we assign it.
*/
pthread_mutex_lock(&chidMutex);
accel_chid = bps_channel_get_active();
pthread_cond_signal(&chidCond);
pthread_mutex_unlock(&chidMutex);
/*
* Create and display a dialog that will show the data.
*/
create_bottom_dialog();
show_bottom_dialog_message("\n\nThis is the Accelerometer Dialog");
if (BPS_SUCCESS != sensor_request_events(SENSOR_TYPE_ACCELEROMETER)) {
fprintf(stderr, "Error requesting sensor's accelerometer events: %s", strerror(errno));
bps_shutdown();
return NULL;
}
sensor_set_rate(SENSOR_TYPE_ACCELEROMETER, ACCELEROMETER_RATE);
sensor_set_skip_duplicates(SENSOR_TYPE_ACCELEROMETER, true);
while (run) {
/*
* Block, at the very least we'll get the "STOP" event
*/
bps_get_event(&event, -1);
if (bps_event_get_domain(event) == local_event_domain) {
if (bps_event_get_code(event) == STOP_REQUEST) {
run = false;
}
}
if (bps_event_get_domain(event) == sensor_get_domain()) {
if (SENSOR_ACCELEROMETER_READING == bps_event_get_code(event)) {
sensor_event_get_xyz(event, &force_x, &force_y, &force_z);
display_accelerometer_reading(force_x, force_y, force_z);
}
}
}
sensor_stop_events(0);
destroy_bottom_dialog();
bps_shutdown();
fprintf(stderr, "Exiting accelerometer thread\n");
return NULL;
}
/**
* A sample application demonstrates the BlackBerry Native APIs for accelerometer.
* The sample initializes and reads the accelerometer periodically until a
* NAVIGATOR_EXIT event is received.
* The application also listens for window state changes from the navigator so that
* it can stop reading the accelerometer when the application is no longer visible.
*/
int
main(int argc, char *argv[])
{
if (setup_screen() != EXIT_SUCCESS) {
printf("Unable to set up the screen. Exiting.");
return 0;
}
/*
* The accelerometer forces
*/
double force_x, force_y, force_z;
/*
* Before we can listen for events from the BlackBerry Tablet OS platform
* services, we need to initialize the BPS infrastructure
*/
bps_initialize();
/*
* Once the BPS infrastructure has been initialized we can register for
* events from the various BlackBerry Tablet OS platform services. The
* Navigator service manages and delivers application life cycle and
* visibility events.
* For this sample, we request Navigator events so we can track when
* the system is terminating the application (NAVIGATOR_EXIT event). This allows
* us to clean up application resources.
*/
navigator_request_events(0);
/*
* Before initializing the accelerometer service we must ensure the device
* supports it
*/
if (!accelerometer_is_supported()) {
/*
* If the device does not support accelerometer then notify the user,
* clean up and exit
*/
printf("Accelerometer not supported by device!");
bps_shutdown();
return EXIT_FAILURE;
}
/*
* Initialize the accelerometer by setting the rates at which the
* accelerometer values will be updated from hardware
*/
accelerometer_set_update_frequency(FREQ_40_HZ);
/*
* Process Navigator events and take accelerometer readings periodically
* until we receive a NAVIGATOR_EXIT event.
*/
int exit_application = 0;
int paused = 0;
while (!exit_application) {
/*
* By setting the bps_get_event timeout to ACCELEROMETER_MAX_POLL_INTERVAL,
* we assign the maximum time (in millis) that we will wait before
* unblocking so we can take an accelerometer reading.
*/
bps_event_t *event = NULL;
bps_get_event(&event, ACCELEROMETER_MAX_POLL_INTERVAL);
if (event) {
if (bps_event_get_domain(event) == navigator_get_domain()) {
/*
* If it is a NAVIGATOR_EXIT event then set the
* exit_application flag so the application will stop
* processing events, clean up and exit.
*
* If it is a NAVIGATOR_WINDOW_STATE event, and the window
* state is NAVIGATOR_WINDOW_INVISIBLE, set paused to true so
* that we stop collecting accelerometer data. Otherwise, if
* we're currently paused, then set paused back to false to
* resume collecting accelerometer data.
*/
unsigned int event_code = bps_event_get_code(event);
if (NAVIGATOR_EXIT == event_code) {
exit_application = 1;
} else if (NAVIGATOR_WINDOW_STATE == event_code) {
if (navigator_event_get_window_state(event) == NAVIGATOR_WINDOW_FULLSCREEN) {
/*
* The application is now full screen.
* Resume reading the accelerometer.
*/
paused = 0;
printf("Resuming accelerometer reads.\n");
} else if (!paused){
/*
* The application has become thumbnailed or invisible.
* If it is not already paused, then pause it.
* Otherwise, ignore the window state change.
*/
paused = 1;
printf("Resuming accelerometer reads.\n");
}
}
}
/*
* Remember to destroy any delivered events as we need to trigger
* the release of any event resources when we are done processing
* it.
*/
bps_event_destroy(event);
} else {
/*
* We've woken up. See if we are in the paused state. If not,
* take an accelerometer reading
*/
if (!paused) {
accelerometer_read_forces(&force_x, &force_y, &force_z);
display_accelerometer_reading(
ACCELEROMETER_CALCULATE_PITCH(force_x, force_y, force_z),
ACCELEROMETER_CALCULATE_ROLL(force_x, force_y, force_z));
}
}
}
/*
* Clean up screen resources
*/
screen_destroy_window(screen_win);
screen_destroy_context(screen_ctx);
/*
* Clean up the BPS infrastructure and exit
*/
bps_shutdown();
return 0;
}
