Question

I am trying to highlight cells with user preferred colors. A user will select a cell and drag mouse to select multiple cells that they want to color with the selected color. How can I trigger the javascript function that lives in a separate file (i know I have to include the file to html file, I have done that already) when user click and drag the mouse without using inline event handlers.

The code is there to drag and select but I would like to call this function when user click and drag cells. Before I was using google.setOnLoadCallBack to call this function, but that would call it only once. I would like user to have multiple selections. I hope I made sense.

HTML

<section id="importance">
   <label class="green">Green</label>
   <input type="radio" name="importance" value="green">

   <label class="yellow">Yellow</label>
   <input type="radio" name="importance" value="yellow">

   <label class="orange">Orange</label>
   <input type="radio" name="importance" value="orange">

   <label class="red">Red</label>
   <input type="radio" name="importance" value="red">
</section>

<table cellpadding="0" cellspacing="0" id="our_table">
  <tr>
   <td>a</td>
   <td>b</td>
   <td>c</td>
  </tr>
  <tr>
    <td>d</td>
    <td>e</td>
    <td>f</td>
  </tr>
  <tr>
    <td>g</td>
    <td>h</td>
    <td>i</td>
  </tr>
</table>

Javascript

function select_multiple() {
  var isMouseDown = false;
  // id for all the cells that were selected at the same time
  var colorGroupId = Math.floor(Math.random() * 1000);
  var highlight = find_importance_color();
  $("#our_table td")
    .mousedown(function () {
      isMouseDown = true;
      $(this).toggleClass(highlight);
      $(this).attr("data-highlightedId", colorGroupId);
      return false; // prevent text selection
  })
  .mouseover(function () {
    if (isMouseDown) {
      $(this).addClass(highlight);
    }
  });

  $("#our_table td")
    .mouseup(function (event) {
    isMouseDown = false;
    // time_importance(event);
  });
}

function find_importance_color() {
    return $('#importance input[name=importance]:checked').val();
}

CSS

.green {
  background-color: green;
}

.yellow {
  background-color: yellow;
}

.orange {
  background-color: orange;
}

.red {
  background-color: red;
}

table td {
  width:100px;
  height:100px;
  text-align:center;
  vertical-align:middle;
  background-color:#ccc;
  border:1px solid #fff;
}

Answer 1

Pass your initialization function to the jQuery ready handler:

$(document).ready(select_multiple);

jQuery will then call it when the document is loaded.