How to focus cursor in between two brackets (parentheses) with Jquery?

Question

I have a calculator that works with buttons to assign values. The main idea is to generate formulas. The values are added seamlessly into an "input". All the brackets when entering your respective button, I need to happen is to continue entering values in the parenthesis

Jquery

    $(document).ready(function () {
    $("input:button").click(function () {
        valor = $(this).val();
        actual = $("#ContentPlaceHolder1_formula").val();
        if (valor == "C") {
            $("#ContentPlaceHolder1_formula").val("");
        } else {
            if (valor == "=") {
                $("#ContentPlaceHolder1_formula").val(eval(actual));
            } else {
                $("#ContentPlaceHolder1_formula").val(actual + valor);
            }
        }
    });
});

Html

                    <div class="form-group">
                    <input class="btn" type="button" value="()" id="parentesis" />
                    <input class="btn" type="button" value="1" id="1" />
                    <input class="btn" type="button" value="2" id="2" />
                    <input class="btn" type="button" value="3" id="3" />
                    <input class="btn" type="button" value="+" id="sumar" /><br />
                    <input class="btn" type="button" value="4" id="4" />
                    <input class="btn" type="button" value="5" id="5" />
                    <input class="btn" type="button" value="6" id="6" />
                    <input class="btn" type="button" value="-" id="restar" /><br />
                    <input class="btn" type="button" value="7" id="7" />
                    <input class="btn" type="button" value="8" id="8" />
                    <input class="btn" type="button" value="9" id="9" />
                    <input class="btn" type="button" value="*" id="multiplicar" /><br />
                    <input class="btn" type="button" value="0" id="0" />
                    <input class="btn" type="button" value="=" id="igual" />
                    <input class="btn" type="button" value="C" id="C" />
                    <input class="btn" type="button" value="/" id="dividir" />
                    <asp:Button ID="btn_login" OnClick="docreateformula" CssClass="btn btn-primary btn-lg center-block" Text="Guardar" runat="server"/>
                </div>    

With that code this happen: 5+()3*()+5+3 and I need: 5+(3*(5+3))

How can I do that?

Answer 1

You use the following code to make it work

function occurrences(string, subString, allowOverlapping) {

    string+=""; subString+="";
    if(subString.length<=0) return string.length+1;

    var n=0, pos=0;
    var step=(allowOverlapping)?(1):(subString.length);

    while(true){
        pos=string.indexOf(subString,pos);
        if(pos>=0){ n++; pos+=step; } else break;
    }
    return(n);
}

$("input:button").click(function () {
    valor = $(this).val();
    actual = $("#ContentPlaceHolder1_formula").val();
    if (valor == "C") {
        $("#ContentPlaceHolder1_formula").val("");
    }
    else if(valor=="()")
    {
   var count1= occurrences(actual,'(',false);
   var count2= occurrences(actual,')',false);
        var count=count1+count2;
        if(count%2==0)  { $("#ContentPlaceHolder1_formula").val(actual+"("); 
                        } 
        else {
       $("#ContentPlaceHolder1_formula").val(actual+")"); 
        }
                }
    else {
        if (valor == "=") {
            $("#ContentPlaceHolder1_formula").val(eval(actual));
        } else {
            $("#ContentPlaceHolder1_formula").val(actual + valor);
        }
    }
});

demo link : http://jsfiddle.net/asimshahiddIT/6hje7nvh/

Answer 2

You can do 2 ways.

Can separate the '(' button from ')' or you can try this:

if(valor=="()"){
  for(i=0;i<actual.lenght;i++){
  var aux = actual.IndexOf("(",i);
  if(aux){
    var aux2 = actual.IndexOf(")");
    if(aux2){
      i=aux2-1;
    }else{
      valor=")";
    }else{
      valor="(";
    }
$("#ContentPlaceHolder1_formula").val(actual + valor);

Answer 3

Create two buttons instead of one, one for ( and one for ) and you will have no problem.