按下返回按钮清除editText的内容

Question

I want to clear the contents of editText. When back button is pressed while typing it should minimize the keyboard and take me back to the starting listview....Now doing so it directly exists the app.. And the keyboard appears on the screen once the app is started....instead i want it to appear when the user clicks on the editText.....

Here's my code:

package com.example.acer.aartisangrah;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;

import java.util.ArrayList;

public class first extends AppCompatActivity {
EditText editText;
private ListView listView;

private String[] names = {"प्रार्थना", "सुखकर्ता दु:खहर्ता", "गजानना श्रीगणराया", "येई हो विठ्ठले", "लवथवती विक्राळा", "दुर्गे दुर्घट भारी", "आरती ज्ञानराजा",
        "हे भोळ्या शंकरा", "ओवाळू", "मंगेशा महारूद्रा", "आला गणराया", "शेंदुर लाल चढायो", "एकदंता", "कर्पूर गौरा", "हे गजवधना", "प्रथमेश्वरा", "जयदेवा हे  साईनाथा",
        "श्री सत्यनारायणाची आरती", "श्री महालक्ष्मीची आरती", "ॐ जय लक्ष्मी माता", "आरती संतोषी माता की", "धन्य धन्य हो प्रदक्षिणा", "सुखंकर्ता की दु:खहर्ता",
        "ॐ जय जगदीश", "हे गौरी गजानन", "घालीन लोटांगण"};
private int imageid[] = {R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji,
        R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji,
        R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji,
        R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji, R.drawable.ganeshaji};
int textlength = 0;
ArrayList<String> text_sort = new ArrayList<String>();

ArrayList<Integer> image_sort = new ArrayList<Integer>();

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_first);
    listView = (ListView) findViewById(R.id.listView);
    editText = (EditText) findViewById(R.id.inputSearch);
    listView.setAdapter(new MyCustomAdapter(names, imageid));
    editText.addTextChangedListener(new TextWatcher()

    {
        public void afterTextChanged(Editable s) {
        }

        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        }

        public void onTextChanged(CharSequence s, int start, int before, int count) {
            textlength = editText.getText().length();
            text_sort.clear();
            image_sort.clear();
            for (int i = 0; i < names.length; i++) {
                if (textlength <= names[i].length()) {
                    if (editText.getText().toString().equalsIgnoreCase((String) names[i].subSequence(0, textlength))) {
                        text_sort.add(names[i]);
                        image_sort.add(imageid[i]);
                    }
                }
            }
            listView.setAdapter(new MyCustomAdapter(text_sort, image_sort));
        }

    });

    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

            TextView tv = (TextView) view.findViewById(R.id.textViewName);
            String strSelectedString = tv.getText().toString();
            for (int selectedPosition = 0; selectedPosition < names.length; selectedPosition++) {
                if (names[selectedPosition].equalsIgnoreCase(strSelectedString)) {
                    moveToNextActivity(selectedPosition);
                    break;
                }
            }

        }
    });
}


public void moveToNextActivity(int position) {
    if (position == 0) {
        Intent myIntent = new Intent(getApplicationContext(), akalp.class);
        startActivityForResult(myIntent, 0);
    }

    if (position == 1) {
        Intent myIntent = new Intent(getApplicationContext(), Sukharta.class);
        startActivityForResult(myIntent, 0);
    }

    if (position == 2) {
        Intent myIntent = new Intent(getApplicationContext(), gajananashriganraya.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 3) {
        Intent myIntent = new Intent(getApplicationContext(), yehihovittale.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 4) {
        Intent myIntent = new Intent(getApplicationContext(), lavathavthi.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 5) {
        Intent myIntent = new Intent(getApplicationContext(), durgedurgat.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 6) {
        Intent myIntent = new Intent(getApplicationContext(), nyanraja.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 7) {
        Intent myIntent = new Intent(getApplicationContext(), bolya.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 8) {
        Intent myIntent = new Intent(getApplicationContext(), vovalo.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 9) {
        Intent myIntent = new Intent(getApplicationContext(), mangesha.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 10) {
        Intent myIntent = new Intent(getApplicationContext(), alaganraya.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 11) {
        Intent myIntent = new Intent(getApplicationContext(), shendorlal.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 12) {
        Intent myIntent = new Intent(getApplicationContext(), ekdanta.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 13) {
        Intent myIntent = new Intent(getApplicationContext(), karpurgaura.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 14) {
        Intent myIntent = new Intent(getApplicationContext(), heygajavadana.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 15) {
        Intent myIntent = new Intent(getApplicationContext(), prathmeshvara.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 16) {
        Intent myIntent = new Intent(getApplicationContext(), sainatha.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 17) {
        Intent myIntent = new Intent(getApplicationContext(), satyanarayan.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 18) {
        Intent myIntent = new Intent(getApplicationContext(), jaidevijaidevi.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 19) {
        Intent myIntent = new Intent(getApplicationContext(), omjaimahalakshmi.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 20) {
        Intent myIntent = new Intent(getApplicationContext(), maitohaarti.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 21) {
        Intent myIntent = new Intent(getApplicationContext(), danyadanyaho.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 22) {
        Intent myIntent = new Intent(getApplicationContext(), sukhartakidukharta.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 23) {
        Intent myIntent = new Intent(getApplicationContext(), omjaijagdish.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 24) {
        Intent myIntent = new Intent(getApplicationContext(), heygaurigajanana.class);
        startActivityForResult(myIntent, 0);
    }
    if (position == 25) {
        Intent myIntent = new Intent(getApplicationContext(), ghalinlotangan.class);
        startActivityForResult(myIntent, 0);
    }
}

class MyCustomAdapter extends BaseAdapter {
    String[] data_text;
    int[] data_image;

    MyCustomAdapter() {

    }

    MyCustomAdapter(String[] names, int[] imageid) {
        data_text = names;
        data_image = imageid;
    }

    MyCustomAdapter(ArrayList<String> names, ArrayList<Integer> imageid) {
        data_text = new String[names.size()];
        data_image = new int[imageid.size()];
        for (int i = 0; i < names.size(); i++) {
            data_text[i] = names.get(i);
            data_image[i] = imageid.get(i);
        }
    }

    public int getCount() {
        return data_text.length;
    }

    public String getItem(int position) {
        return null;
    }

    public long getItemId(int position) {
        return position;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        LayoutInflater inflater = getLayoutInflater();
        View row;
        row = inflater.inflate(R.layout.list_layout, parent, false);
        TextView textview = (TextView) row.findViewById(R.id.textViewName);
        ImageView imageview = (ImageView) row.findViewById(R.id.imageView);
        textview.setText(data_text[position]);
        imageview.setImageResource(data_image[position]);
        return (row);
    }
}
}

Answer 1

You will need to override your onBackPressed() method in your actiivty so that it does not finish

@Override
public void onBackPressed(){
    edittext.setText("");
    listView.setSelection(0);
    //or
    listView.smoothScrollToPosition(0);
}

The above will set the edittext to an empty string and then move your listview back to index 0 when you click the back button.

https://developer.android.com/reference/android/app/Activity.html#onBackPressed()

EDIT

So in order to still close the application if you are at the top of the listview, you will need to add some logic to keep track of where you are in your listview. The easiest way would be to create a boolean that you alter in a listview scroll listener.

public class first extends AppCompatActivity {
EditText editText;
private ListView listView;
boolean atTop; --> add this variable here. This will monitor our top status.
...// rest of logic

Then we need to apply a scrollListener to your listview in your onCreate.

listView.setOnScrollListener(new AbsListView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(AbsListView absListView, int i) {

            }

            @Override
            public void onScroll(AbsListView absListView, int i, int i1, int i2) {
                if(i == 0){
                    View v = myListView.getChildAt(0);
                    int offset = (v == null) ? 0 : v.getTop();
                    if (offset == 0) {
                        atTop = true;
                        return;
                    }
                }else{
                    atTop = false;
                }
            }
});

In the onscroll essentially we are checking if we are at the top or somewhere else. We aren't checking for the bottom so this should work almost anywhere. Then in your onBackPressed you would jsut do:

@Override
public void onBackPressed(){
     if(atTop){
          super.onBackPressed();
     }else {
          edittext.setText("");
          listView.setSelection(0);
          //or
          listView.smoothScrollToPosition(0);
      }
}

So now if we are at the top we want the onBackPressed to run the same as it normally would. If we aren't clear the edit text and scroll to the top.