I'm trying to implement a temperature sensor on a virtual Pixel 4a, Ambient Temp sensor is included according to list of sensors.
When I run the program, the textView continues to print "Hello world!" instead of what setText in the onSensorChanged method provides.
Here is my code, any help will be amazing:
public class MainActivity extends AppCompatActivity implements SensorEventListener {
private SensorManager sensorManager;
private TextView textView;
private Sensor tempSensor;
private Boolean tempSensorAvailable;
private int activityCode = 1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (ContextCompat.checkSelfPermission(MainActivity.this,
Manifest.permission.ACTIVITY_RECOGNITION)
!= PackageManager.PERMISSION_GRANTED) {
requestActivityPermission();
}
textView = findViewById(R.id.textView);
sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
if (sensorManager.getDefaultSensor(Sensor.TYPE_AMBIENT_TEMPERATURE) != null) {
tempSensor = sensorManager.getDefaultSensor(Sensor.TYPE_AMBIENT_TEMPERATURE);
tempSensorAvailable = true;
} else {
textView.setText("Temperature Sensor is not available.");
tempSensorAvailable = false;
}
}
#Override
public void onSensorChanged(SensorEvent sensorEvent) {
textView.setText(sensorEvent.values[0] + " Celsius");
}
#Override
public void onAccuracyChanged(Sensor sensor, int i) {
}
#Override
protected void onResume() {
super.onResume();
if (tempSensorAvailable) {
sensorManager.registerListener(this, tempSensor,
SensorManager.SENSOR_DELAY_NORMAL);
}
}
#Override
protected void onPause() {
super.onPause();
if (tempSensorAvailable) {
sensorManager.unregisterListener(this);
}
}
public void requestActivityPermission() {
if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.
ACTIVITY_RECOGNITION)) {
new AlertDialog.Builder(this)
.setTitle("Permission needed")
.setMessage("Permission is needed to run this app.")
.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
ActivityCompat.requestPermissions(MainActivity.this,
new String[]{Manifest.permission.ACTIVITY_RECOGNITION},
activityCode);
}
})
.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
dialogInterface.dismiss();
}
})
.create().show();
} else {
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.ACTIVITY_RECOGNITION},
activityCode);
}
}
You mus call SensroManager.registerListener():
https://developer.android.com/reference/android/hardware/SensorManager#registerListener(android.hardware.SensorEventListener,%20android.hardware.Sensor,%20int)
I am using Room Database with LiveData , but my Local Database is updating too fast as per our requirement and at the same time i have to reload my recycler view .instead of calling notifyDataSetChanged() to adapter , i am trying to use DiffUtil , but is crashing or not reloading properly , this is uncertain .
i am following this tutorial :
Tutorials Link here
MyAdapter :
public class SwitchGridAdapter extends RecyclerView.Adapter<SwitchGridAdapter.ViewHolder> {
private List<Object> allItemsList;
private LayoutInflater mInflater;
private OnItemClickListener mClickListener;
private Context context;
private Queue<List<Object>> pendingUpdates =
new ArrayDeque<>();
// data is passed into the constructor
public SwitchGridAdapter(Context context,List<Appliance> applianceList,List<ZmoteRemote> zmoteRemoteList) {
this.mInflater = LayoutInflater.from(context);
this.context = context;
allItemsList = new ArrayList<>();
if (applianceList!=null) allItemsList.addAll(applianceList);
if (zmoteRemoteList!=null)allItemsList.addAll(zmoteRemoteList);
}
// inflates the cell layout from xml when needed
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = mInflater.inflate(R .layout.switch_grid_item, parent, false);
return new ViewHolder(view);
}
// binds the data to the textview in each cell
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
// Doing some update with UI Elements
}
// total number of cells
#Override
public int getItemCount() {
return allItemsList.size();
}
// stores and recycles views as they are scrolled off screen
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener,View.OnLongClickListener {
TextView myTextView;
ImageView imgSwitch;
ViewHolder(View itemView) {
super(itemView);
myTextView = (TextView) itemView.findViewById(R.id.txtSwitchName);
imgSwitch = (ImageView) itemView.findViewById(R.id.imgSwitchStatus);
itemView.setOnClickListener(this);
itemView.setOnLongClickListener(this);
}
#Override
public void onClick(View view) {
// handling click
}
#Override
public boolean onLongClick(View view) {
return true;
}
// convenience method for getting data at click position
Object getItem(int id) {
return allItemsList.get(id);
}
// allows clicks events to be caught
public void setClickListener(OnItemClickListener itemClickListener) {
this.mClickListener = itemClickListener;
}
// parent activity will implement this method to respond to click events
public interface OnItemClickListener {
void onItemClick(View view, int position);
void onItemLongPressListner(View view, int position);
}
// ✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅
// From This Line Reloading with Diff Util is Done .
//✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅
public void setApplianceList( List<Appliance> applianceList,List<ZmoteRemote> zmoteRemoteList)
{
if (allItemsList == null)
allItemsList = new ArrayList<>();
List<Object> newAppliances = new ArrayList<>();
if (applianceList!=null) newAppliances.addAll(applianceList);
updateItems(newAppliances);
}
// when new data becomes available
public void updateItems(final List<Object> newItems) {
pendingUpdates.add(newItems);
if (pendingUpdates.size() > 1) {
return;
}
updateItemsInternal(newItems);
}
// This method does the heavy lifting of
// pushing the work to the background thread
void updateItemsInternal(final List<Object> newItems) {
final List<Object> oldItems = new ArrayList<>(this.allItemsList);
final Handler handler = new Handler();
new Thread(new Runnable() {
#Override
public void run() {
final DiffUtil.DiffResult diffResult =
DiffUtil.calculateDiff(new DiffUtilHelper(oldItems, newItems));
handler.post(new Runnable() {
#Override
public void run() {
applyDiffResult(newItems, diffResult);
}
});
}
}).start();
}
// This method is called when the background work is done
protected void applyDiffResult(List<Object> newItems,
DiffUtil.DiffResult diffResult) {
dispatchUpdates(newItems, diffResult);
}
// This method does the work of actually updating
// the backing data and notifying the adapter
protected void dispatchUpdates(List<Object> newItems,
DiffUtil.DiffResult diffResult) {
// ❌❌❌❌❌❌ Next Line is Crashing the app ❌❌❌❌❌
pendingUpdates.remove();
dispatchUpdates(newItems, diffResult);
if (pendingUpdates.size() > 0) {
updateItemsInternal(pendingUpdates.peek());
}
}
}
Observing LiveData
public void setUpAppliancesListLiveData()
{
if (applianceObserver!=null)
{
applianceObserver = null;
}
Log.e("Appliance Fetch","RoomName:"+this.roomName);
applianceObserver = new Observer<List<Appliance>>() {
#Override
public void onChanged(#Nullable List<Appliance> applianceEntities) {
// Log.e("Appliance Result","Appliance List \n\n:"+applianceEntities.toString());
new Thread(new Runnable() {
#Override
public void run() {
List<Appliance> applianceListTemp = applianceEntities;
zmoteRemoteList = new ArrayList<>(); //appDelegate.getDatabase().zmoteRemoteDao().getRemoteList(roomName);
// Sort according to name
Collections.sort(applianceListTemp, new Comparator<Appliance>() {
#Override
public int compare(Appliance item, Appliance t1) {
String s1 = item.getSwitchName();
String s2 = t1.getSwitchName();
return s1.compareToIgnoreCase(s2);
}
});
if(getActivity()!=null) {
getActivity().runOnUiThread(new Runnable() {
#Override
public void run() {
applianceList = applianceListTemp;
mRecyclerView.getRecycledViewPool().clear();
adapter.setApplianceList(applianceList,zmoteRemoteList);
}
});
}
}
}).start();
}
};
appDelegate.getDatabase().applianceDao().getApplinaceListByRoomName(this.roomName).observe(this, applianceObserver);
}
I am adding my two separate android activities in one application, one of my activity having volley library but it gives me an exception that appcontroller(volley library) its an application not an activity please help me out
Ya, you have mention in your manifest file appcontroller class as Application. This solves the exception.
Main Acitivity:
public class MainActivity extends FragmentActivity implements OnTabChangeListener, OnPageChangeListener {
MyPageAdapter pageAdapter;
private ViewPager mViewPager;
private TabHost mTabHost;
private Button btn;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mViewPager = (ViewPager) findViewById(R.id.viewpager);
// Tab Initialization
initialiseTabHost();
// Fragments and ViewPager Initialization
List<Fragment> fragments = getFragments();
pageAdapter = new MyPageAdapter(getSupportFragmentManager(), fragments);
mViewPager.setAdapter(pageAdapter);
mViewPager.setOnPageChangeListener(MainActivity.this);
}
// Method to add a TabHost
private static void AddTab(MainActivity activity, TabHost tabHost, TabHost.TabSpec tabSpec,String message,int picture,Context x)
{
tabSpec.setContent(new MyTabFactory(activity));
View tabIndicator = LayoutInflater.from(x).inflate(R.layout.tab_indicator, tabHost.getTabWidget(), false);
TextView title = (TextView) tabIndicator.findViewById(R.id.title);
title.setText(message);
ImageView icon = (ImageView) tabIndicator.findViewById(R.id.icon);
icon.setBackgroundDrawable(x.getResources().getDrawable(picture));
icon.setScaleType(ImageView.ScaleType.FIT_CENTER);
tabSpec.setIndicator(tabIndicator);
tabHost.addTab(tabSpec);
}
// Manages the Tab changes, synchronizing it with Pages
public void onTabChanged(String tag) {
int pos = this.mTabHost.getCurrentTab();
this.mViewPager.setCurrentItem(pos);
for(int i=0;i<mTabHost.getTabWidget().getChildCount();i++)
{
mTabHost.getTabWidget().getChildAt(i).setBackgroundColor(Color.BLUE);
//mTabHost.getTabWidget().setDividerDrawable(R.Color.transperant);
}
mTabHost.getTabWidget().getChildAt(mTabHost.getCurrentTab()).setBackgroundColor(Color.CYAN);// selected
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
public void destroyItem(View collection, int position, Object view){
((ViewPager) collection).removeView((ImageView) view);
}
// Manages the Page changes, synchronizing it with Tabs
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
int pos = this.mViewPager.getCurrentItem();
this.mTabHost.setCurrentTab(pos);
}
#Override
public void onPageSelected(int arg0) {
}
private List<Fragment> getFragments(){
List<Fragment> fList = new ArrayList<Fragment>();
// TODO Put here your Fragments
NewSampleFragment f1 = NewSampleFragment.newInstance(getApplicationContext(),R.layout.newfragment_a);
MySampleFragment f2 = MySampleFragment.newInstance("Sample Fragment 2");
MySampleFragment f3 = MySampleFragment.newInstance("Sample Fragment 3");
MySampleFragment f4 = MySampleFragment.newInstance("Sample Fragment 4");
MySampleFragment f5 = MySampleFragment.newInstance("Sample Fragment 5");
fList.add(f1);
fList.add(f2);
fList.add(f3);
fList.add(f4);
fList.add(f5);
return fList;
}
// Tabs Creation
private void initialiseTabHost() {
mTabHost = (TabHost) findViewById(android.R.id.tabhost);
mTabHost.setup();
// TODO Put here your Tabs
MainActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab1").setIndicator("Tab1"),"Grocery",R.drawable.movies,getApplicationContext());
MainActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab2").setIndicator("Tab2"),"Crockery",R.drawable.artist,getApplicationContext());
MainActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab3").setIndicator("Tab3"),"Foods",R.drawable.song,getApplicationContext());
MainActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab3").setIndicator("Tab4"),"Drinks",R.drawable.shopping,getApplicationContext());
MainActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab3").setIndicator("Tab5"),"Toys",R.drawable.play,getApplicationContext());
mTabHost.setOnTabChangedListener(this);
}
}
OfferActivity (This should be open when button pressed)
public class OfferActivity extends Activity
{
private static final String TAG = MainActivity.class.getSimpleName();
private ListView listView;
private FeedListAdapter listAdapter;
private List<FeedItem> feedItems;
private ProgressDialog pDialog;
private String URL_FEED = "http://nusdtech.com/public_html/checking2.php";
#SuppressLint("NewApi")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main1);
listView = (ListView) findViewById(R.id.list);
feedItems = new ArrayList<FeedItem>();
listAdapter = new FeedListAdapter(this, feedItems);
listView.setAdapter(listAdapter);
pDialog = new ProgressDialog(this);
// Showing progress dialog before making http request
pDialog.setMessage("Loading...");
pDialog.show();
// These two lines not needed,
// just to get the look of facebook (changing background color & hiding the icon)
getActionBar().setBackgroundDrawable(new ColorDrawable(Color.parseColor("#3b5998")));
//getActionBar().setIcon(
// new ColorDrawable(getResources().getColor(android.R.color.transparent)));
JsonArrayRequest movieReq = new JsonArrayRequest(URL_FEED,
new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
Log.d(TAG, response.toString());
hidePDialog();
// Parsing json
for (int i = 0; i < response.length(); i++) {
try {
JSONObject obj = response.getJSONObject(i);
FeedItem movie = new FeedItem();
movie.setId(obj.getInt("id"));
movie.setName(obj.getString("name"));
// Image might be null sometimes
String image = obj.isNull("image") ? null : obj
.getString("image");
movie.setImge(image);
movie.setStatus(obj.getString("status"));
movie.setProfilePic(obj.getString("profilePic"));
//movie.setTimeStamp(obj.getString("price"));
movie.setPrice(obj.getString("price"));
movie.setDate(obj.getString("dates"));
feedItems.add(movie);
} catch (JSONException e) {
e.printStackTrace();
}
}
// notifying list adapter about data changes
// so that it renders the list view with updated data
listAdapter.notifyDataSetChanged();
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
hidePDialog();
}
});
// Adding request to request queue
AppController.getInstance().addToRequestQueue(movieReq);
}
#Override
public void onDestroy() {
super.onDestroy();
hidePDialog();
}
private void hidePDialog() {
if (pDialog != null) {
pDialog.dismiss();
pDialog = null;
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
AppController:
public class AppController extends Application {
public static final String TAG = AppController.class.getSimpleName();
private RequestQueue mRequestQueue;
private ImageLoader mImageLoader;
LruBitmapCache mLruBitmapCache;
private static AppController mInstance;
#Override
public void onCreate() {
super.onCreate();
mInstance = this;
}
public static synchronized AppController getInstance() {
return mInstance;
}
public RequestQueue getRequestQueue() {
if (mRequestQueue == null) {
mRequestQueue = Volley.newRequestQueue(getApplicationContext());
}
return mRequestQueue;
}
public ImageLoader getImageLoader() {
getRequestQueue();
if (mImageLoader == null) {
getLruBitmapCache();
mImageLoader = new ImageLoader(this.mRequestQueue, mLruBitmapCache);
}
return this.mImageLoader;
}
public LruBitmapCache getLruBitmapCache() {
if (mLruBitmapCache == null)
mLruBitmapCache = new LruBitmapCache();
return this.mLruBitmapCache;
}
public <T> void addToRequestQueue(Request<T> req, String tag) {
req.setTag(TextUtils.isEmpty(tag) ? TAG : tag);
getRequestQueue().add(req);
}
public <T> void addToRequestQueue(Request<T> req) {
req.setTag(TAG);
getRequestQueue().add(req);
}
public void cancelPendingRequests(Object tag) {
if (mRequestQueue != null) {
mRequestQueue.cancelAll(tag);
}
}
}
Activity that contain fragment buttons
public class NewSampleFragment extends Fragment {
private static View mView;
private Context con;
public static final NewSampleFragment newInstance(Context con,int layout) {
NewSampleFragment f = new NewSampleFragment();
con=con;
Bundle b = new Bundle();
b.putInt("mylayout",layout);
f.setArguments(b);
return f;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
int layout = getArguments().getInt("mylayout");
mView = inflater.inflate(R.layout.newfragment_a, container, false);
Button button = (Button) mView.findViewById(R.id.bactivity);
Button offer=(Button) mView.findViewById(R.id.aactivity);
button.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
Intent myIntent = new Intent(getActivity(), ListViewDemo.class);
//Optional parameters
getActivity().startActivity(myIntent);
Log.e("Error","Kashif");
}
});
offer.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
startApplication("uzair.sabir.app.OfferActivity");
}
});
return mView;
}
public void startApplication(String application_name){
try{
Intent intent = new Intent("android.intent.action.MAIN");
intent.addCategory("android.intent.category.LAUNCHER");
intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
List<ResolveInfo> resolveinfo_list = getActivity().getPackageManager().queryIntentActivities(intent, 0);
for(ResolveInfo info:resolveinfo_list){
if(info.activityInfo.packageName.equalsIgnoreCase(application_name)){
launchComponent("uzair.sabir.app", "OfferActivity");
break;
}
}
}
catch (ActivityNotFoundException e) {
Toast.makeText(getActivity(), "There was a problem loading the application: "+application_name,Toast.LENGTH_SHORT).show();
Log.e("Error",e.getMessage());
}
}
private void launchComponent(String packageName, String name){
Intent launch_intent = new Intent("android.intent.action.MAIN");
launch_intent.addCategory("android.intent.category.LAUNCHER");
launch_intent.setComponent(new ComponentName(packageName, name));
launch_intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
getActivity().startActivity(launch_intent);
}
}
The ImagePagerActivity show the page 1 (In scrollview) when i rotate the device. How to solve it? Thanks.
public class ImagePagerActivity extends BaseActivity {
private static final String STATE_POSITION = "STATE_POSITION";
ViewPager pager;
public void onCreate(Bundle savedInstanceState) {
// ...
if (savedInstanceState != null) {
pagerPosition = savedInstanceState.getInt(STATE_POSITION);
}
// ...
pager.setCurrentItem(pagerPosition);
}
public void onSaveInstanceState(Bundle outState) {
outState.putInt(STATE_POSITION, pager.getCurrentItem());
}
...
}
How to display an image on a UiApplication?
I have a code that displays a button and when clicked it goes to a MainScreen, but I'd like to display an image below that button. I found a way to insert a zoomable image but not a static one.
Here's my code so far:
public class HelloWorldDemo extends UiApplication {
private MainScreen _screen;
private ButtonField _nextScreen;
public static void main(String[] args) {
HelloWorldDemo instance = new HelloWorldDemo();
instance.enterEventDispatcher();
}
public HelloWorldDemo() {
EncodedImage myImg = EncodedImage.getEncodedImageResource("k.jpg");
ZoomScreen zoomableImg = new ZoomScreen(myImg);
_screen = new MainScreen();
_nextScreen = new ButtonField("Go to Next Screen",ButtonField.FIELD_HCENTER | ButtonField.CONSUME_CLICK);
_nextScreen.setChangeListener(new FieldChangeListener() {
public void fieldChanged(Field field,int context) {
pushScreen(new NextScreen());
}
});
_screen.setTitle(new LabelField("Hello World Demo",LabelField.USE_ALL_WIDTH));
_screen.add(new RichTextField("Hello to the BlackBerry World!",Field.NON_FOCUSABLE));
_screen.add(_nextScreen);
pushScreen(_screen);
pushScreen(zoomableImg);
}
}
//I'm confused about your question. But still I'm posting ans here hope it will help you.
public final class ZoomScreenDemo extends UiApplication
{
public static void main(final String[] args)
{
UiApplication app = new ZoomScreenDemo();
app.enterEventDispatcher();
}
public ZoomScreenDemo()
{
pushScreen(new ZoomScreenDemoScreen());
}
public final static class ZoomScreenDemoScreen extends MainScreen
{
private EncodedImage _image;
private ButtonField _nextScreen;
public ZoomScreenDemoScreen()
{
setTitle("Zoom Screen Demo");
_nextScreen = new ButtonField("Go to next screen ",ButtonField.CONSUME_CLICK);
_nextScreen.setChangeListener(new FieldChangeListener() {
public void fieldChanged(Field field, int context) {
UiApplication.getUiApplication().pushScreen(new DemoZoomScreen(_image));
}
});
add( _nextScreen );
_image = EncodedImage.getEncodedImageResource("img/building.jpg");
BitmapField bitmapField = new BitmapField(_image.getBitmap(), FIELD_HCENTER | FOCUSABLE);
add(bitmapField);
}
}
static class DemoZoomScreen extends ZoomScreen
{
DemoZoomScreen(EncodedImage image)
{
super(image);
}
public void zoomedOutNearToFit()
{
close();
}
}
}