android format edittext to display spaces after every 4 characters

Question

Android - I want to get a number input from the user into an EditText - it needs to be separated by spaces - every 4 characters. Example: 123456781234 -> 1234 5678 1234

Answer 1

change the live text while typing is some what difficult. we should handle the following issues.

a. cursor position b. we should allow the user delete the entered text.

The following code handle both the issues.

1. Add TextWatcher to EditText, and get the text from "afterTextchanged()" and write your logic

   String str=""; int strOldlen=0;

       @Override
               public void afterTextChanged(Editable s) {
   
      str = edtAadharNumber.getText().toString();
                   int strLen = str.length();
   
   
                   if(strOldlen 0) {
                           if (strLen == 4 || strLen == 9) {
   
                               str=str+" ";
   
                               edtAadharNumber.setText(str);
                               edtAadharNumber.setSelection(edtAadharNumber.getText().length());
   
                           }else{
   
                               if(strLen==5){
                                   if(!str.contains(" ")){
                                    String tempStr=str.substring(0,strLen-1);
                                       tempStr +=" "+str.substring(strLen-1,strLen);
                                       edtAadharNumber.setText(tempStr);
                                       edtAadharNumber.setSelection(edtAadharNumber.getText().length());
                                   }
                               }
                               if(strLen==10){
                                   if(str.lastIndexOf(" ")!=9){
                                       String tempStr=str.substring(0,strLen-1);
                                       tempStr +=" "+str.substring(strLen-1,strLen);
                                       edtAadharNumber.setText(tempStr);
                                       edtAadharNumber.setSelection(edtAadharNumber.getText().length());
                                   }
                               }
                               strOldlen = strLen;
                           }
                       }else{
                           return;
                       }
   
                   }else{
                       strOldlen = strLen;
   
   
                       Log.i("MainActivity ","keyDel is Pressed ::: strLen : "+strLen+"\n old Str Len : "+strOldlen);
                   }
   
               }
   }
   

2. Here I am trying to add space for every four characters. After adding first space, then the length of the text is 5. so next space is after 9 characters like that.

   if (strLen== 4||strLen==9)

   3. Here another problem is cursor position, once you modify the text of the edittext, the cursor move to first place. so we need to set the cursor manually.

   edtAadharNumber.setSelection(edtAadharNumber.getText().length());

   4. My text length is only 12 characters. So I am doing manual calculations, if your text is dynamic then you write dynamic logic.