CODEWITHSUNDEEP
javaandroidandroid-recyclerview
VinayakPurohit
VinayakPurohit

Reputation: 45

How to change the color of an element of a recyclerview?

I want to change color of my cardview in Recyclerview if a string matches a string from QR code. I am able to display a toast if string matches, but I also want to change color of that particular element in Recyclerview.

here is the code of selecting an item for scanning

recyclerView.addOnItemTouchListener(new RecyclerItemClickListener(getApplicationContext(), new RecyclerItemClickListener.OnItemClickListener() {
                @Override
                public void onItemClick(View view, int position) {
                   tempString = passengerDataModelList.get(position).getPnr();
                   tempClickPosi = position;
                    Intent intent = new Intent("com.google.zxing.client.android.SCAN");
                    startActivityForResult(intent, 0);

                }
            }));

Now on ActivityResult I will get the result: 

    public void onActivityResult(int requestCode, int resultCode, Intent intent) {
            if (requestCode == 0) {
                if (resultCode == RESULT_OK) {
                    String contents = intent.getStringExtra("SCAN_RESULT");
                    String format = intent.getStringExtra("SCAN_RESULT_FORMAT");


                    if(contents.equalsIgnoreCase(tempString)){
                        Toast.makeText(this, "String MATCHED", Toast.LENGTH_SHORT).show();
///// Here I want to change the color of that item in recycler view
                    }else if(!contents.equalsIgnoreCase(tempString)){
                        Toast.makeText(this, "String NOT MATCHED", Toast.LENGTH_SHORT).show();
                    }else {
                        Toast.makeText(this, "Error in scanning", Toast.LENGTH_SHORT).show();
                    }


                }
            }

        }

So please help me to change the color of that particular item from activity. If need more info kindly comment. Thank You

Upvotes: 0

Views: 844

Answers (3)

Rajan Kali
Rajan Kali

Reputation: 12953

For suppose you have a model 

public class PassengerData{

  //add this property
  private boolean isMatched = false;

  void setMatched(boolean matched){
        this.isMatched = matched;
  }

  boolean isMatched(){
       return isMatched;
  }

}

Then in recyclerview's bindview just verify the boolean,

boolean matched = passengerDataModelList.get(position).isMatched();
cardview.setBackgroundColor(matched ? R.color.matched_color : R.color.unmatched_color);

Then in Activity

    if(contents.equalsIgnoreCase(tempString)){
                            Toast.makeText(this, "String MATCHED", Toast.LENGTH_SHORT).show();
    ///// Here I want to change the color of that item in recycler view
              // modify `isMatched` value for that item and call `notifyDataSetChanged`();
     }

Upvotes: 1

coder_baba
coder_baba

Reputation: 402

According to my understanding, I guess You want to make background colorful if String is match. In RecyclerView you are inflating rows so your rows must have a Layout which You can use like below if your string is matched. The below code is only for understanding purpose. Customize it accordingly. Here I am changing color of Recycler Item, based on condition so i wrote this condition. You can modify it

@Override
public void onBindViewHolder(ViewHolder holder, int position) {
if(position==0){
    holder.itemView.setBackgroundColor(Color.BLACK);
}else{
    holder.itemView.setBackgroundColor(Color.GREY);
}
holder.mTextView.setText(mDataArray.get(position));

}

Upvotes: 0

yogesh lokhande
yogesh lokhande

Reputation: 1275

Create separate flag for color and then once string is matched update flag for particular item and then notify your adapter

Upvotes: 0

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