Develop Reference

RecyclerView of Button array - How to update the data?

This is my first Q on the site, I'll try to form it well.
I have a recyclerView, and the Item is an array of buttons.
Button click shows a popup menu that allows the user to change the color of the button.
I've managed to set that the onClick method will change the color, but I'm clueless about how to save the chosen color in the ButtonArrayList, that Holds the colors.
The problem is that when the button is pressed, I don't know how to understand programatically on which button, in which button array it was pressed.
Thanks!
Just to demonstrate the problem. when button is clicked, How to identify which button of which item was clicked?
1
The code of the fragment:
package com.examples.recyclerViewWithButtonArray;
import android.os.Build;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import java.util.LinkedList;
/**
* A simple {#link Fragment} subclass.
* Use the {#link Game#newInstance} factory method to
* create an instance of this fragment.
*/
public class Game extends Fragment {
// TODO: Rename parameter arguments, choose names that match
protected static int[] mButtonsColors;
private final LinkedList<ButtonArray> mButtonArrayList = new LinkedList<>();
RecyclerView mGuessLinesRecyclerView;
ButtonArrayListAdapter mButtonArrayListAdapter;
FloatingActionButton mFab;
// TODO: Rename and change types of parameters
public Game() {
// Required empty public constructor
}
public static Game newInstance(String param1, String param2) {
Game fragment = new Game();
return fragment;
}
private void initGameColors(){
mButtonsColors = new int[4];
int[] c = getContext().getResources().getIntArray(R.array.buttonColors);
//asign colors
for (int i = 0; i < 4; i++) {
this.mButtonsColors[i] = c[i];
}
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
initGameColors();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View vw = inflater.inflate(R.layout.fragment_game, container, false);
return vw;
}
#RequiresApi(api = Build.VERSION_CODES.M)
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
mGuessLinesRecyclerView = view.findViewById(R.id.recycler_view);
mFab = view.findViewById(R.id.fab);
//initialize recyclerView
// Create an adapter and supply the data to be displayed.
mButtonArrayListAdapter = new ButtonArrayListAdapter(getContext(), mButtonArrayList, this);
// Connect the adapter with the RecyclerView.
mGuessLinesRecyclerView.setAdapter(mButtonArrayListAdapter);
// Give the RecyclerView a default layout manager.
mGuessLinesRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
//initializeFAB
mFab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
mButtonArrayList.add(new ButtonArray(getContext(),mButtonsColors));
mGuessLinesRecyclerView.setAdapter(mButtonArrayListAdapter);
}
});
//add first array to the recycler view.
// Next guess lines will be added when clicking on movableFab
mButtonArrayList.add(new ButtonArray(getContext(), this.mButtonsColors));
}
}
The code of ButtonArrayListAdapter:
package com.examples.recyclerViewWithButtonArray;
import android.content.Context;
import android.graphics.drawable.ColorDrawable;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.PopupWindow;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
import java.util.List;
public class ButtonArrayListAdapter extends RecyclerView.Adapter<ButtonArrayListAdapter.ButtonArrayViewHolder> {
private final Context mContext;
private final List<ButtonArray> mData;
class ButtonArrayViewHolder extends RecyclerView.ViewHolder {
public ArrayList<Button> mButtons;
final ButtonArrayListAdapter mAdapter;
public ButtonArrayViewHolder(#NonNull View itemView, ButtonArrayListAdapter adapter) {
super(itemView);
this.mAdapter = adapter;
mButtons =new ArrayList<>();
if(4==4)
{
//create an array of button for binding
mButtons.add((Button)itemView.findViewById(R.id.button_Guess1));
mButtons.add((Button)itemView.findViewById(R.id.button_Guess2));
mButtons.add((Button)itemView.findViewById(R.id.button_Guess3));
mButtons.add((Button)itemView.findViewById(R.id.button_Guess4));
}
}
}
public ButtonArrayListAdapter(Context mContext, List<ButtonArray> mData, Game mGame) {
this.mContext = mContext;
this.mData = mData;
}
#NonNull
#Override
public ButtonArrayViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View layout;
layout = LayoutInflater.from(mContext).inflate(R.layout.guess_line,parent,false);
return new ButtonArrayViewHolder(layout,this);
}
#Override
public void onBindViewHolder(#NonNull final ButtonArrayViewHolder buttonArrayViewHolder, final int position) {
//bind data here
//initiate each guessLineButton
for (int i = 0; i < 4; i++) {
int c = mData.get(position).mAnswerButtonsColors[i];
final Button bt = buttonArrayViewHolder.mButtons.get(i);
//set initial button color
bt.setBackgroundColor(c);
//set button clik to open color chooser
bt.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int[] chooseColorButtons = new int[4];
// inflate the layout of the popup window
final View popupView = LayoutInflater.from(mContext).inflate(R.layout.choose_color_popup,null);
// create the popup window
int width = bt.getWidth();
int height = LinearLayout.LayoutParams.WRAP_CONTENT;
boolean focusable = true; // lets taps outside the popup also dismiss it
final PopupWindow popupWindow = new PopupWindow(popupView, width, height, focusable);
// show the popup window
// which view you pass in doesn't matter, it is only used for the window tolken
int[] loc = new int[]{0,0};
bt.getLocationOnScreen(loc);
popupWindow.showAtLocation(v, Gravity.TOP|Gravity.LEFT, loc[0], loc[1] + bt.getHeight());
// dismiss the popup window when touched
popupView.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
popupWindow.dismiss();
return true;
}
});
//initiate each color choose button
if(chooseColorButtons.length==4) {
chooseColorButtons[0] = R.id.buttonColor1;
chooseColorButtons[1] = R.id.buttonColor2;
chooseColorButtons[2] = R.id.buttonColor3;
chooseColorButtons[3] = R.id.buttonColor4;
}
for (int j = 0; j < 4 ; j++) {
Button colbt = (Button)(popupView.findViewById(chooseColorButtons[j]));
colbt.setBackgroundColor(Game.mButtonsColors[j]);
colbt.setTextColor(Game.mButtonsColors[j]);
colbt.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
bt.setBackgroundColor(((ColorDrawable)(((Button)v).getBackground())).getColor());
//WHAT SHOULD I DO HERE?
popupWindow.dismiss();
}
});
}
}
});
}
}
#Override
public int getItemCount() {
return mData.size();
}
}

After reading your question what I get is you want to save the color against every button so next time when that button click the same color should load if yes then you can consider these tw0 suggestions
1- if the number of buttons is static and you are not adding them dynamically then you can hardcode the color against each button by adding them in the list and assign them manually against each button.
2- you can use key-value pair(hash map), these are the best solution for any case either you're are manually adding the button or dynamically, just store the color against each key. In this case, buttons should be your keys and colors will be value.
Thanku

How can set my button a random color to the background. Android

Sorry for my bad English I'm a beginner of android and now I'm stuck.
Now my Question is how can I set the random colors to the background with the OnClickListener. Can you maybe help my with this problem?
I have one class (Kleurenpalet.java)
package com.example.pstek.randomcolor;
import android.graphics.Color;
import java.util.Random;
public class Kleurenpalet{
private static String[] kleur = {
"#39add1", // light blue
"#3079ab", // dark blue
"#3FD52D", // green
"FFFF0000", // red
""};
public int getRandomColor() {
Random rand = new Random();
int color = rand.nextInt(kleur.length);
return Color.parseColor(kleur[color]);
}
}
And I have my main class :
package com.example.pstek.tegeltjeswijsheid;
import android.support.constraint.ConstraintLayout;
import android.support.constraint.solver.widgets.ConstraintWidget;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Layout;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import java.util.Random;
public class MainActivity extends AppCompatActivity {
private ConstraintLayout layout;
private Button randombutton;
int randomColor = new Kleurenpalet().getRandomColor();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
layout = findViewById(R.id.layout);
randombutton = findViewById(R.id.button);
randombutton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
layout.setBackgroundColor(ContextCompat.getColor(getApplicationContext(), ;
}
});
}
}

in the MainActivity code this :
public class MainActivity extends AppCompatActivity {
private ConstraintLayout layout;
private Button randombutton;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
layout = findViewById(R.id.layout);
randombutton = findViewById(R.id.button);
randombutton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int randomColor = new Kleurenpalet().getRandomColor();
layout.setBackgroundColor(randomColor);
}
});
}
}

Perhaps call setBackgroundColor with the initialized color:
layout.setBackgroundColor(randomColor);
Or a different one each time:
layout.setBackgroundColor(new Kleurenpalet().getRandomColor());

I do not understand what you try to do here:
layout.setBackgroundColor(ContextCompat.getColor(getApplicationContext(), ;
Why did you leave empty space there? Moreover, if you parse color in your Kleurenpalet, you must use without ContextCompat. Just set your color like this:
layout.setBackgroundColor(randomColor);
ContextCompat is for parsing color from resources file, for instance:
layout.setBackgroundColor(
ContextCompat.getColor(
getApplicationContext(),
R.color.colorPrimary
)
);

You must put "Random Num" and "layout set Color" in button click event :
randombutton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int randomColor = new Kleurenpalet().getRandomColor();
layout.setBackgroundColor(randomColor);
}
});

Test if a user has selected an item from AutoCompleteTextView

My problem is that my code does not react accordingly whenever an user selects an item from an AutoCompleteTextView.
flag is a variable which is set to a value whenever one item from each AutoCompleteTextView has been selected. If it's set to 1, then it means it's right and it should proceed to main activity. Otherwise, a toast is displayed on click of button whose onClick calls the method callMainActivity.
There are no errors. Gradle build is successful, but clicking on that button (mentioned above) does nothing at all.
Code:
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
import android.widget.ListView;
import android.widget.Spinner;
import android.widget.Toast;
import java.util.Arrays;
import java.util.List;
public class Location extends AppCompatActivity {
private static int flag=0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_location);
int city = android.R.layout.simple_dropdown_item_1line;
int area = android.R.layout.simple_dropdown_item_1line;
int store = android.R.layout.simple_dropdown_item_1line;
String []city_array = getResources().getStringArray(R.array.City);
String []area_array= getResources().getStringArray(R.array.Area);
String []store_array= getResources().getStringArray(R.array.Store);
List<String> city_list= Arrays.asList(city_array);
List<String> area_list= Arrays.asList(area_array);
List<String> store_list= Arrays.asList(store_array);
ArrayAdapter<String> adapter_city = new ArrayAdapter(this,city, city_list);
ArrayAdapter<String> adapter_area = new ArrayAdapter(this, area, area_list);
ArrayAdapter<String> adapter_store = new ArrayAdapter(this, store, store_list);
final AutoCompleteTextView autocompleteView_city =
(AutoCompleteTextView) findViewById(R.id.City);
final AutoCompleteTextView autocompleteView_area =
(AutoCompleteTextView) findViewById(R.id.Area);
final AutoCompleteTextView autocompleteView_store =
(AutoCompleteTextView) findViewById(R.id.Store);
autocompleteView_area.setAdapter(adapter_area);
autocompleteView_city.setAdapter(adapter_city);
autocompleteView_store.setAdapter(adapter_store);
autocompleteView_area.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(final View arg0) {
autocompleteView_area.showDropDown();
if(autocompleteView_area.getListSelection()!= ListView.INVALID_POSITION)
flag=1;
else
flag=0;
}
});
autocompleteView_city.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(final View arg0) {
autocompleteView_city.showDropDown();
if(autocompleteView_area.getListSelection()!= ListView.INVALID_POSITION)
flag=1;
else
flag=0;
}
});
autocompleteView_store.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(final View arg0) {
autocompleteView_store.showDropDown();
if(autocompleteView_area.getListSelection()!= ListView.INVALID_POSITION)
flag=1;
else
flag=0;
}
});
//This is the newly updated part
autocompleteView_area.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick (AdapterView<?> parent, View view, int position, long id) {
//... your stuff
if(autocompleteView_area.getListSelection()>0) {
flag = 1;
System.out.println(flag + "flag at area");
}else
flag=0;
}
});
}
public void callMainActivity(View view){
if(flag==1) {
Intent in = new Intent(getBaseContext(), MainActivity.class);
startActivity(in);
}
else
Toast.makeText(getBaseContext(),"Please select all fields properly",Toast.LENGTH_LONG);
}
}

The reason you are not seeing the Toast or changing activities, is because you are never calling callMainActivity(View view) in your code. Add this line to the end of all your OnClickListeners: callMainActivity(arg0) -- if this does not work, put some log statements in your OnClickListeners to check if they are triggering or not.
Also, if you want to trigger the call when an item from your AutoCompleteTextView result list is selected, you should use an AdapterView.OnItemClickedListener instead. This will notify you when an item is selected from the AutoCompleteTextView list, or when nothing is selected and then you can react accordingly.

Change the value of EditText with onClick Button?

In main.xml I made a row containing a TextView, an EditText and a "+" and "-" button.
Underneath that I made an "Add" button that will help you create a new row When you click the add button, you get an EditText and a Submit and Cancel button.
On "Submit" it outputs the EditText value to the TextView and creates the same row as the first one.
The numeric value "NewValueBox" should +1 when the "+" button is pressed.
But because I call it in another function it is not recognized by createNewAddButton() function in which the button is set up.
So in short:
"How do I change the value of NewValueBox when I click NewAddButton?"
Here's the code:
package com.lars.MyApp;
import com.google.ads.*;
import com.lars.MyApp.R;
import android.app.Activity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TableLayout;
import android.widget.TableRow;
import android.widget.TextView;
import android.text.InputType;
import android.view.View;
import android.view.View.OnClickListener;
public class DrinkRecOrderActivity extends Activity {
int currentValue1 = 0;
int currentValueNew = 0;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final EditText firstValue = (EditText) findViewById(R.id.firstValue);
Button valuePlus = (Button) findViewById(R.id.valuePlus);
Button valueMinus = (Button) findViewById(R.id.valueMinus);
final Button addValue = (Button) findViewById(R.id.add);
final TableLayout tableLayout1 = (TableLayout) findViewById(R.id.tableLayout1);
final LinearLayout addValueRow = (LinearLayout) findViewById(R.id.addValueRow);
final EditText addNewValue = (EditText) findViewById(R.id.addNewValue);
final Button submitNewValue = (Button) findViewById(R.id.submitNewValue);
final Button cancelNewValue = (Button) findViewById(R.id.cancelNewValue);
// BEGIN ONCLICKLISTENERS
valuePlus.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
plusValue();
firstValue.setText("" + currentValue1);
}
});
valueMinus.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
minValue();
firstValue.setText("" + currentValue1);
}
});
addValue.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
addValueRow.setVisibility(View.VISIBLE);
addValue.setVisibility(View.GONE);
}
});
cancelNewValue.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
addValueRow.setVisibility(View.GONE);
addValue.setVisibility(View.VISIBLE);
}
});
submitNewValue.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
tableLayout1.addView(createnewRow());
addValueRow.setVisibility(View.GONE);
addValue.setVisibility(View.VISIBLE);
addNewValue.setText("");
}
});
// END ONCLICKLISTENERS
// Look up the AdView as a resource and load a request.
AdView adView = (AdView) this.findViewById(R.id.adView);
adView.loadAd(new AdRequest());
}
public TableRow createNewRow() {
final TableRow newRow = new TableRow(this);
final EditText addNewValue = (EditText) findViewById(R.id.addNewValue);
newRow.addView(createNewTextView(addNewValue.getText().toString()));
newRow.addView(createNewValueBox());
newRow.addView(createNewAddButton());
newRow.addView(createNewMinusButton());
return newRow;
}
public TextView createNewTextView(String text) {
final TextView textView = new TextView(this);
textView.setText(text);
return textView;
}
public EditText createNewValueBox() {
EditText NewValueBox = new EditText(this);
NewValueBox.setHint("0");
NewValueBox.setInputType(InputType.TYPE_CLASS_NUMBER);
return NewValueBox;
}
public Button createNewAddButton() {
final Button NewAddButton = new Button(this);
NewAddButton.setText("+");
NewAddButton.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
plusNew();
//NewValueBox.setText("" + currentValueNew);
}
});
return NewAddButton;
}
public Button createNewMinusButton() {
final Button NewMinusButton = new Button(this);
NewMinusButton.setText("-");
return NewMinusButton;
}
// BEGIN PLUS AND MIN FUNCTIONS
public void plusNew() {
if (currentValueNew <= 999) {
currentValueNew = currentValueNew + 1;
}
}
public void plusValue() {
if (currentValue1 <= 999) {
currentValue1 = currentValue1 + 1;
}
}
public void minValue() {
if (currentValue1 >= 1) {
currentValue1 = currentValue1 - 1;
}
}
// END PLUS AND MIN FUNCTIONS
}

Add IDs for your Views so you can later reference them. Make 3 private static int field in your activity(the ID for NewValueBox, NewAddButton and NewMinusButton):
private static int edt = 1;
private static int add = 1001;
private static int minus = 2001;
Then in your createNewValueBox() method set the ID:
NewValueBox.setId(edt);
edt++;
Do the same for the NewAddButton and the NewMinusButton:
NewAddButton.setId(add);
add++;
NewMinusButton.setId(minus);
minus++;
Then in your listener for the buttons find out exactly which add button has been clicked and set the text in the corresponding EditText:
NewAddButton.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
plusNew();
int tmp = v.getId();
EditText temp = (EditText) findViewById(1 + (tmp - 1001));
temp.setText("" + currentValueNew);
}
Kind of hackish method.

AlertDialog crashes application

Can someone explain to me why this AlertDialog crashes?
package com.clicker;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class Clicker extends Activity
{
public int clickerNumber = 0;
private TextView clickerText;
private Button clickerButton;
private Button resetButton;
// Called when the activity is first created.
#SuppressWarnings("null")
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Declare each of the layout objects
clickerText = (TextView)findViewById(R.id.clickerText);
clickerButton = (Button)findViewById(R.id.clickerButton);
resetButton = (Button)findViewById(R.id.resetButton);
clickerText.setText("0");
final AlertDialog.Builder resetQuestion = null;
resetQuestion.setTitle("Reset?");
resetQuestion.setMessage("Are you sure you want to reset the counter?");
resetQuestion.setPositiveButton("Yes", new OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
clickerNumber = 0;
clickerText.setText("0");
}
});
resetQuestion.setNegativeButton("No", new OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
dialog.dismiss();
}
});
clickerButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
clickerNumber++;
clickerText.setText(Integer.toString(clickerNumber));
}
});
resetButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
resetQuestion.show();
}
});
};
};

This is a great fail:
final AlertDialog.Builder resetQuestion = null;
resetQuestion.setTitle("Reset?");
You are trying to use a null object, and that (of course) will throw a NullPointerException
This is how I create dialogs (and I think it's the best way to do it):
LayoutInflater factory = LayoutInflater.from(this);
final View textEntryView = factory.inflate(R.layout.dialogo_layout, null);
final AlertDialog.Builder resetQuestion = new AlertDialog.Builder(YourActivity.this)
// do whatever you want with the resetQuestion AlertDialog
Here, R.layout.dialogo_layout represent a file called dialogo_layout.xml in the res/layout dir that contains the dialog layout.