you need to take one variable globally and add the new entered value when button clicked
ex say
public String totalString = "";
final TextView singlevalue = (TextView) findViewById(R.id.priceInput);
one.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
final Button one = (Button) findViewById(R.id.one);
final String stringone = one.getText().toString();
totalString = totalString+""+stringone ;
singlevalue.setText(totalString);
}
});
two.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
final Button two = (Button) findViewById(R.id.two);
final String stringtwo = two.getText().toString();
totalString = totalString+""+stringtwo ;
singlevalue.setText(totalString);
}
});