How can i put a function regarding this one on java android fire-base. I am creating a chat app and i have a existing fire-base structure like this.let say i send a message "Hello".
Chat:
Author:"name"
Chat:"Hello"
I want to put push a function that it will count the number of message in every user. therefore it will be like this. let say i send a message saying hi? and Be right back
Chat:
Author:"name"
Chat:"hi?"
numMessages: 1
Chat:
Author:"name"
Chat:"Be right back"
numMessages: 2
I think it is if statement count++? but i try everything regarding this.ugh.
Java and Android masters hope you can give me some suggestions sir.
Global int variable: int counter = 0;
In your onClick add: counter++;
Set counter to 0 whenever you want, if not it will count on and on - and is only set to 0 when your activity is recreated.
If you want to send it to firebase, you'll need to add the counter there to, and simply send it with your messages,update your Message.class with an int named "counter" (similiar to the Strings "author" and "message",send it will be sent and shown in your Chat.
Does this answer your question?
Update:
First, go into Message.class and add:
int counter;
public int getCounter(){
return counter;
}
public void setCounter(int counter){
this.counter = counter;
}
If you want to show the counter in your View, you can simply add another TextView in your fragment_message.xml or you can add it programatically in your message, in your MessageAdapter.java add in populateView:
//if you added an extra TextView in your fragment_message.xml
TextView counter = (TextView) view.findViewById(R.id.yourcounterid);
counter.setText(message.getCounter());
//if you want to add the number in your messageView:
messageView.setText(message.getMessage() + " " + message.getCounter());
So to your MainActivity.java:
public class MainActivity extends AppCompatActivity{
private EditText editText;
private ListView listView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
counter = 0;
Firebase.setAndroidContext(this);
final Firebase firebase = new Firebase("https://samp-is.firebaseio.com/");
editText = (EditText) findViewById(R.id.editText);
listView = (ListView) findViewById(R.id.listView);
listView.setAdapter(new MessageAdapter(this, Message.class, R.layout.fragment_message, firebase.child("chat")));
Button button = (Button) findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
counter++;
Message message = new Message();
message.setMessage(editText.getText().toString());
editText.setText("");
message.setAuthor("Name");
message.setCounter(counter);
firebase.child("chat").push().setValue(message);
}
});
}
}
If I remember correctly, Firebase should add a Child "counter" to its database and update it with your counter value.
Does it work?
Related
I tried to get a array from an adapter from my code
here is the array that i wanted to get from my adapter, named MakananAdapter :
private int[] JumlahPesan = {0,0,0,0};
The array is changing constantly since user will be deciding the amount that they want, here is the onBindViewHolder code:
public void onBindViewHolder(#NonNull viewHolder holder, final int position) {
ImageView ivMakanan = holder.ivMakanan;
TextView tvNamaHarga = holder.tvNamaMakanan;
TextView tvKetersediaan = holder.tvKetersediaan;
TextView tvHarga = holder.tvHargaMakanan;
final TextView tvPesanan = holder.tvJumlahPesanan;
Button btnTambah = holder.btnTambah;
Button btnKurang = holder.btnKurang;
ivMakanan.setImageResource(makanans.get(position).getGambarMakanan());
tvNamaHarga.setText(makanans.get(position).getNamaMakanan());
tvKetersediaan.setText("Stok : " + makanans.get(position).getStatusMakanan());
tvHarga.setText("Harga : " + makanans.get(position).getHargaMakanan());
btnTambah.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
JumlahPesan[position]++;
tvPesanan.setText(String.valueOf(JumlahPesan[position]));
}
});
btnKurang.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
JumlahPesan[position]--;
tvPesanan.setText(String.valueOf(JumlahPesan[position]));
}
});
}
as you can see i make a button that increase and decrease the data of the array
and i tried to get the array data to my activity, but i still get error.
my activity named PilihMakananActivity.class
here is the array to save the data from the adapter
private int[] Pesanan = {0,0,0,0};
and i tried to get the data in onResume
protected void onResume() {
super.onResume();
com.example.iotforcanteen.adapter.MakananAdapter coba = null;
for (int i = 0; i<4 ; i++) {
Pesanan [i]= coba.AmbilJumlahPesanan(i);
}
}
and i tried to show it in a snackbar like this
btnKonfirmasi.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Snackbar.make(v, Pesanan[0] + Pesanan[1] + Pesanan[2] + Pesanan[3],Snackbar.LENGTH_SHORT).show();
}
});
Im so sorry if the code is so messy, because im new to android development.so is there any way to fix this error?
It has error because you set to your adapter null value in onResume .
But in general I assume you use RecyclerView in code so the steps for using RecyclerView is important, first you must set LayoutManager for RecyclerView. Then make an adapter and set it to RecyclerView and I recommend you to do this steps in onCreate not onResume.
Here is a little example
RecyclerView recyclerView = findViewById(R.id.rec);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
adapter = new MyRecyclerViewAdapter(this, list);
recyclerView.setAdapter(adapter);
Also make your array in adapter public or write getter for it. After calling setAdapter for RecyclerView, you can get your data in adapter. For example you can define a Button and in OnClickListener get the desired array(here is JumlahPesan) in adapter
you aren't initiating this adapter (null) and few lines below trying to access data from it, this is NullPointerException
com.example.iotforcanteen.adapter.MakananAdapter coba = null;
for (int i = 0; i<4 ; i++) {
Pesanan [i]= coba.AmbilJumlahPesanan(i);
}
make reference to already exitsting adapter atached to your ListView or RecyclerView, not freshly created and not initialised at all
note that onResume is called once at the beggining, thus your Pesanan won't have current data, only copy from start of Activity
maybe just get your values straightly when button pressed, without a copy of array in Activity:
btnKonfirmasi.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Snackbar.make(coordinatorLayout,
adapterAttachedToView.AmbilJumlahPesanan(0) + " " +
adapterAttachedToView.AmbilJumlahPesanan(1) + " " +
adapterAttachedToView.AmbilJumlahPesanan(2) + " " +
adapterAttachedToView.AmbilJumlahPesanan(3),
Snackbar.LENGTH_SHORT).show();
}
});
note that Snackbar.make( should take View, in which Snackbar will appear, not clicked Button (you are passing v to Snackbar.make)
i am new to development. i am creating an android calculator app with advanced functionality.The thing is i am using text view for taking and displaying inputs/outputs. My question is, how can i take Multiple inputs in multiple Textviews.
For example i have 3 text views,when user will enter 1st input in first textview(by default) and when user press the specific button it moves automatically to next textview . In some cases i want to take 2 inputs and in some cases i want to take 3 ,
How can i achieve this
Note: I dont want to use edit text , coz all buttons of already available in my app.Using Edit text will make softkeyboard to appear, and then for hiding the softkeyboard, i need to use hiding code lines in every class
You can do something like following:
private TextView[] textViews;
private TextView tvCurrentEditing;
private Button btnNext;
private Button btnPrev;
private Button btnSetText;
private int index = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
textViews = new TextView[3];
//Initialize all your textviews like textViews[0] = findViewById(<textview-id1>);
//textViews[1] = findViewById(<textview-id2>);
//textViews[2] = findViewById(<textview-id3>);
tvCurrentEditing = textViews[index];// I am assuming this is your first
//initialzie btnSettext
btnSettext.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
tvCurrentEditing.setText("<what ever you want");
}
});
//initialize next buton
btnNext.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(index < textViews.length) {
index++;
}
tvCurrentEditing = textViews[index];
}
});
//Initialize previous button
btnPrev.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(index > 0) {
index--;
}
tvCurrentEditing = textViews[index];
}
});
}
The names of the views could be different. The point is always use tvCurrentEditing whenever you want to change data of TextView. And update tvCurrentEditing whenever needed.
This question already has an answer here:
How to receive an int through an Intent
(1 answer)
Closed 4 years ago.
I'm trying to pass an Integer (from an edittext) to another activity through an intent.
When the user clicks a button, the text in the edittext will transform into a string and then into an int, then the int will be sent through an intent to another activity, but i have to use the int after that.
Here the activity sending the intent:
public class HomeActivityPro extends ActionBarActivity {
private InterstitialAd interstitial;
EditText conttext = (EditText) findViewById ( R.id.texthome );
Button buttone = (Button) findViewById(R.id.buttone);
String maxom = conttext.getText().toString();
int maxam = Integer.parseInt(maxom);
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.layout_home);
View.OnClickListener maxim = new View.OnClickListener() {
#Override
public void onClick (View view) {
Intent wall = new Intent(HomeActivityPro.this, GuessOne.class);
wall.putExtra("maxPressed", maxam);
startActivity(wall);
}
};
buttone.setOnClickListener(maxim);
Here the activity receiving it:
public class GuessOne extends ActionBarActivity {
int randone;
int contone;
int wall = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.layout_guess_one);
wall = getIntent().getIntExtra("maxPressed", -1);
randone = (int) (Math.random()*10+1);
contone = 0;
}
Here i'm using it:
public void guessone (View view){
contone++;
textcontone.setText(getString(R.string.attempts) + "" + contone);
if (contone >= wall ){
resultaone.setText("You Failed" + " " + wall);
Toast.makeText(this, "You Failed", Toast.LENGTH_LONG).show();
}
When i use the app, the value of the int is always -1. Where i am wrong.
You can't use findViewById without setting the xml to the activity. That means you need to use findViewById method only after you have called setContentView.
Also you need to read the EditText text value once you click on the button otherwise it always will be null/empty.
Do this
public class HomeActivityPro extends ActionBarActivity {
private InterstitialAd interstitial;
EditText conttext;
Button buttone;
String maxom;
int maxam = -1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.layout_home);
conttext = (EditText) findViewById ( R.id.texthome );
buttone = (Button) findViewById(R.id.buttone);
View.OnClickListener maxim = new View.OnClickListener() {
#Override
public void onClick (View view) {
maxom = conttext.getText().toString();
maxam = Integer.parseInt(maxom);
Intent wall = new Intent(HomeActivityPro.this, GuessOne.class);
wall.putExtra("maxPressed", maxam);
startActivity(wall);
}
};
buttone.setOnClickListener(maxim);
Problem 1
Put this in the on click listener instead:
String maxom = conttext.getText().toString();
int maxam = Integer.parseInt(maxom);
You want the values to be read at the time you click the button not when you open the activity, correct?
Problem 2
The following needs to be after setContentView in onCreate:
conttext = (EditText) findViewById ( R.id.texthome );
buttone = (Button) findViewById(R.id.buttone);
Keep the declarations where they are. Just the declarations:
EditText conttext;
Button buttone;
Note
Follow the same pattern in all your activities. Declare views as field variables, assign them in onCreate after setContentLayout. Get the values at the time they're needed.
public int getIntExtra (String name, int defaultValue)
Added in API level 1 Retrieve extended data from the intent.
Parameters name The name of the desired item. defaultValue the value
to be returned if no value of the desired type is stored with the
given name. Returns the value of an item that previously added with
putExtra() or the default value if none was found. See Also
putExtra(String, int)
This means that no int was found when you called getIntExtra(valueName, defaultValue); so the default value was chosen.
You should check to see what your maxam value is before you call the new activity.
In the activity you receive it:
wall = getIntent().getIntExtra("maxPressed");
SOLVED: by getInt and String.valueOf
private static final String IMGID = "ImgID";
if (getIntent().getExtras().containsKey(IMGID)) {
//Picasso.with(this).load(getIntent().getExtras().getString(IMG)).into(mImg);
Picasso.with(this).load(getIntent().getExtras().getInt(String.valueOf(IMGID))).into(mImg);
}
I have this code :
private ImageView d1;
private ArrayList<Integer> listaImagenes = new ArrayList<Integer>();
private ArrayList<String> listaFrases = new ArrayList<String>();
private Button button;
private Integer contador = 0;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.rellenarImagenes();
setContentView(R.layout.imagentonas);
d1 = (ImageView) findViewById(R.id.imagenes01);
while (contador < listaImagenes.size()) {
d1.setImageResource(listaImagenes.get(contador));
button = (Button) findViewById(R.id.botoncillo);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
contador++;
}
});
}
}
private void rellenarImagenes() {
listaImagenes.add(R.drawable.a01);
listaImagenes.add(R.drawable.a02);
listaImagenes.add(R.drawable.a03)
}
I am trying do a loop that when I press the button , increment contador and d1 change image.
but it is not working, application background remains black and not working.
remove while loop and setimage in onclick method.
You are expecting that modifying the value of the variable contador would result in the array item to change.
Keep in mind that in the code line d1.setImageResource(listaImagenes.get(contador));, the get function receives an int. So at the time where it's called it receives a value, not a reference to an Integer. When you change the value of contador, the value that was used to obtain the index in the array is not changed.
And even if the value did change, d1 would still be using the same resource.
What you need to do in the onClickListener is add the code to set the image. Something along the lines of
public void onClick(View v) {
++contador;
if (contador >= listaImagenes.size())
{
contador=0;
}
//you'll probably need to modify the next line to be able to access the button variable.
//one way to do it is to use a final variable in the onCreate method that creates this OnClickListener
button.setImageResource(listaImagenes.get(contador));
}
The while loop is not needed. What your code is doing is setting the image to the 3 items of the array, one after the other, and adding a new click listener 3 times.
I will try to answer and point some of the flaws you have in the code.
wat if there were 100 drawable like R01 ,R02...? Instead you can use getting drawable using string.
why are you using while loop ? since you have the counter you can directly use that.
Let me try to write the code
int contador=1;
#Override
public void onCreate (Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.imagentonas);
context=this;
d1=(ImageView)findViewById(R.id.imagenes01);
button=(Button)findViewById(R.id.botoncillo);
button=(Button)findViewById(R.id.botoncillo);
button.setOnClickListener( new View . OnClickListener () {
public void onClick ( View v ) {
int id = context.getResources().getIdentifier("a"+contador,
"drawable", context.getPackageName());
d1.setImageResource(id);
contador++;
}
});
}
Notice : int id = context.getResources().getIdentifier("a"+contador,"drawable", context.getPackageName()); Here using the string you can access the drawable this solves the issue for any number of consecutive drawables.
Hope you get the concept...
Thanks
This is kind of hard to explain. Basically it's kind of like a simple game. I want the people to input their names (currently the submit button is not working correctly) hit submit for each name and when all names are in they hit play. It then opens up the next class. It needs to get the string array from the prior class as well as the number of players. It then needs to select each persons name in order and give them a task to do (which it randomly generates). Then it allows the other people to click a button scoring how they did. (I am not sure how to set up the score system. Not sure if there is a way to assign a score number to a particular array string) I would then like it after 5 rounds to display the winner. If you have any input or could help me out I would be extremely grateful. Thanks for taking the time... here are the two classes i have.
Class 1
public class Class1 extends Activity
{
int players=0;
String names[];
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.class1);
final EditText input = (EditText) findViewById(R.id.nameinput);
Button submitButton = (Button) findViewById(R.id.submit_btn);
submitButton.setOnClickListener(new View.OnClickListener()
{
public void onClick(View submit1)
{
players++;
for(int i=0; i < players; i++)
{
names[i] = input.getText().toString();
input.setText("");
}
}
});
Button doneButton = (Button) findViewById(R.id.done_btn);
doneButton.setOnClickListener(new View.OnClickListener()
{
public void onClick(View done1)
{
Intent done = new Intent(Class1.this, Class2.class);
done.putExtra("players", players);
done.putExtra("names", names[players]);
startActivity(done);
}
});
}
Class 2
public class Class2 extends Activity
{
int players, counter, score, ptasks,rindex;
String[] names, tasks;
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.class2);
Intent game = getIntent();
players = game.getIntExtra("players", 1);
names = game.getStringArrayExtra("names");
Random generator = new Random();
tasks[0]= "task1";
tasks[1]= "task2";
tasks[2]= "task3";
tasks[3]= "task4";
tasks[4]= "task5";
tasks[5]= "task6";
tasks[6]= "task7";
tasks[7]= "task8";
tasks[8]= "task9";
tasks[9]= "task10";
while (counter <5)
{
for (int i = 0; i < players; i++)
{
TextView name1 = (TextView) findViewById(R.id.pname);
name1.setText( names[i]+":");
ptasks = 10;
rindex = generator.nextInt(ptasks);
TextView task = (TextView) findViewById(R.id.task);
task.setText( tasks[rindex]);
}
Button failButton = (Button) findViewById(R.id.fail_btn);
failButton.setOnClickListener(new View.OnClickListener()
{
public void onClick(View failed)
{
//not sure what to put here to get the scores set up
}
});
Button notButton = (Button) findViewById(R.id.notbad_btn);
notButton.setOnClickListener(new View.OnClickListener()
{
public void onClick(View notbad)
{
//not sure what to put here to get the scores set up
}
});
Button champButton = (Button) findViewById(R.id.champ_btn);
champButton.setOnClickListener(new View.OnClickListener()
{
public void onClick(View champp)
{
//not sure what to put here
}
});
counter++;
}
}
I'm sure this thing is riddled with errors. And I'm sorry if it is I'm not that well experienced a programmer. Thanks again
You can pass a string array from one activity to another using a Bundle.
Bundle bundle = new Bundle();
bundle.putStringArray("arrayKey", stringArray);
You can then access this stringArray from the next activity as follows:
Bundle bundle = this.getIntent().getExtras();
String[] stringArray = bundle.getStringArray("arrayKey");
I'm not sure if this is the only thing you intend to do. I hope it helps. Also, to assign a score to a particular string array, assuming your scores are int's you could use a HashMap as follows,
HashMap<String[],int> imageData = new HashMap<String[],int>();
But I'm not sure how you would pass this Map to another activity if you intend to do so.
http://developer.android.com/reference/android/content/Intent.html#putExtra(java.lang.String,%20java.lang.String[])
Use this cheat:
In Class2, convert you array string (tasks) to string (strSavedTask)by adding "|" separator. After that, pass your strSavedTask into Bundle and start to Class1.
When return to Class1, read strSavedTask from Bundle, split it by "|".
That's my cheat to pass array between 2 activity ^^
Hope this way can help you!