Using a TextWatcher on a EditText to calculate the total and sum total in real time in android?

Question

Here i want to take the default value coming from my database and setText to that value and calculate the net rate and total or else if the user edits the rate or making charges i would like to calculate the net rate and total based on that value in real time.

This is my code for calculating and displaying the values.

    private void showItem(String json) {
    String itembarcode = "";
    String itemdesc = "";
    String weight = "";
    String rate = "";
    String making = "";

    double wt = 0.0d;
    double rt = 0.0d;
    double mk = 0.0d;

    try {
        JSONObject jsonObject = new JSONObject(json);
        JSONArray result = jsonObject.getJSONArray(ParseBarcode.JSON_ARRAY);
        JSONObject itemData = result.getJSONObject(0);
        itembarcode = itemData.getString(ParseBarcode.KEY_BARCODE);
        itemdesc = itemData.getString(ParseBarcode.KEY_DESC);
        weight = itemData.getString(ParseBarcode.KEY_WEIGHT);
        rate = itemData.getString(ParseBarcode.KEY_RATE);
        making = itemData.getString(ParseBarcode.KEY_MAKING);
    } catch (JSONException e) {
        e.printStackTrace();
    }

    //table started

    TableLayout.LayoutParams tableParams = new TableLayout.LayoutParams(TableLayout.LayoutParams.MATCH_PARENT, TableLayout.LayoutParams.WRAP_CONTENT);
    TableRow.LayoutParams rowParams = new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT, 1f);
    rowParams.setMargins(16, 0, 16, 0);

    TableLayout tableLayout = new TableLayout(AddInvEst.this);
    tableLayout.setLayoutParams(tableParams);

    TableRow newRow = new TableRow(AddInvEst.this);
    newRow.setLayoutParams(tableParams);

    TextView barCode = new TextView(AddInvEst.this);
    barCode.setLayoutParams(rowParams);
    barCode.setGravity(Gravity.CENTER);

    TextView itemDesc = new TextView(AddInvEst.this);
    itemDesc.setLayoutParams(rowParams);
    itemDesc.setGravity(Gravity.CENTER);

    TextView weightLine = new TextView(AddInvEst.this);
    weightLine.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT, 0.75f));
    weightLine.setGravity(Gravity.CENTER);

    EditText rateAmount = new EditText(AddInvEst.this);
    rateAmount.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT, 0.5f));
    rateAmount.setGravity(Gravity.CENTER);
   // String rtAmt = rateAmount.getText().toString().trim();

    EditText makingAmount = new EditText(AddInvEst.this);
    makingAmount.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT, 0.5f));
    makingAmount.setGravity(Gravity.CENTER);
    //String mkAmt = makingAmount.getText().toString().trim();

    TextView netRate = new TextView(AddInvEst.this);
    netRate.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT, 0.5f));
    netRate.setGravity(Gravity.CENTER);

    TextView itemtotal = new TextView(AddInvEst.this);
    itemtotal.setLayoutParams(rowParams);
    itemtotal.setGravity(Gravity.CENTER);

    wt = Double.parseDouble(weight);
    rt = Double.parseDouble(rate);
    mk = Double.parseDouble(making);

    double NetRate = rt + mk;
    double Total = (NetRate / 10) * wt;


    barCode.setText(itembarcode);
    itemDesc.setText(itemdesc);
    weightLine.setText(weight);
    rateAmount.setText(rate);
    makingAmount.setText(making);
    netRate.setText(NetRate + "");
    itemtotal.setText(Total + "");

    newRow.addView(barCode);
    newRow.addView(itemDesc);
    newRow.addView(weightLine);
    newRow.addView(rateAmount);
    newRow.addView(makingAmount);
    newRow.addView(netRate);
    newRow.addView(itemtotal);
    itemTable.addView(newRow);


}

Using this code I am able to calculate the net rate and total but i want to round the double value to 4 decimal points.Also how would i calculate the sum total of all the totals in real time.Any help is appreciated.Thanks in advance. This is my xml code.

@Krishnabhadra can you help me with this problem I have read your post on http://stackoverflow.com/questions/5645332/android-edittext-keyboard-textwatcher-problem?rq=1 I am trying to implement something similar. — AndroidNewBee, Nov 11 '15 at 07:32

score 4 · Answer 1 · answered Nov 11 '15 at 07:57

Below is not the complete code, but that will give an idea of the implementation. You have to create a new method for calculation and displaying the result -

private void calculateAndShow(long wt, long rt, long mk){
        double NetRate = rt + mk;
        double Total = (NetRate / 10) * wt;

        // Change the value here
        barCode.setText(itembarcode);
        itemDesc.setText(itemdesc);
        weightLine.setText(weight);
        rateAmount.setText(rate);
        makingAmount.setText(making);
        netRate.setText(NetRate + "");
        itemtotal.setText(Total + "");

    }

Now add these lines outside of your method -

 private TextWatcher rateTextWatcher = new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {

        }

        @Override
        public void afterTextChanged(Editable s) {
            String rate = rateAmount.getText().toString();
            newRate = Double.parseDouble(rate);
            calculateAndShow(wt, newRate, mk);
        }
    };

    private TextWatcher makingAmountTextWatcher = new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {

        }

        @Override
        public void afterTextChanged(Editable s) {
            String makingAmount = makingAmount.getText().toString();
            newMK = Double.parseDouble(makingAmount);
            calculateAndShow(wt, rt, newMK);
        }
    };

And these textwatcher to your edittext like this one -

EditText rateAmount = new EditText(AddInvEst.this);
        rateAmount.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT, 0.5f));
        rateAmount.setGravity(Gravity.CENTER);
        rateAmount.addTextChangedListener(rateTextWatcher);


 EditText makingAmount = new EditText(AddInvEst.this);
        makingAmount.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT, 0.5f));
        makingAmount.setGravity(Gravity.CENTER);
        makingAmount.addTextChangedListener(makingAmountTextWatcher);

Thanks @Rahul Chaurasia – AndroidNewBee Nov 11 '15 at 19:24 — AndroidNewBee, Nov 11 '15 at 19:24
Yes @Rahul Chaurasia this solved my problem thanks a lot! – AndroidNewBee Nov 13 '15 at 02:32 — AndroidNewBee, Nov 13 '15 at 02:32

Using a TextWatcher on a EditText to calculate the total and sum total in real time in android?

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