AngularJS Example:

HTML

<link rel="stylesheet" href="http://twitter.github.com/bootstrap/assets/css/bootstrap.css">
<div ng-app>
  <div ng-controller="todoctrl"> 
      <div>
      {{ some }}
      </div>
      <div ng-repeat="i in items" ng-mousedown="mousedown(i);" ng-mouseup="mouseup($event);" onselectstart="return false">
          <div ng-mousemove="mousemove($event,$index)" ng-class="getClass($index);">{{ i.content }}22</div>
      </div>
  </div>
</div>

CSS

.selected {
  background-color:green;
}

JavaScript

function todoctrl($scope) {
    $scope.selected = {};
    $scope.items = [{content:'abc'},{content:'def'},{content:'ghi'}];
    $scope.getClass = function(index){
        if($scope.selected[index]){
            return 'selected';
        }else{
            return '';
        }
    };
    var mouseIsDown = false;
    var changed = {};
    $scope.mousedown = function(objectt){
       $scope.some = objectt.content;
    };
    $scope.mouseup = function($event){
      mouseIsDown = false;
    };
    $scope.mousemove = function($event,$index){
        alert($index);
        if(mouseIsDown && !changed[$index]){
            $scope.selected[$index] = $scope.selected[$index] || false;
            $scope.selected[$index] = !$scope.selected[$index];
            changed[$index] = true;
        }
    };
}