Angular-Autogrow first commit

Author: Evyatar

angular-autogrow.js

@@ -0,0 +1,67 @@
+(function(){
+    'use strict';
+    angular.module('angular-autogrow', []).directive('autogrow', ['$window', function($window){
+        return {
+            link: function($scope, $element, $attrs){
+
+                /**
+                 * Default settings
+                 */
+                $scope.attrs = {
+                    rows: 1,
+                    maxLines: 999
+                };
+
+                /**
+                 * Merge defaults with user preferences
+                 */
+                for(var i in $scope.attrs){
+                    if($attrs[i]){
+                        $scope.attrs[i] = parseInt($attrs[i]);
+                    }
+                }
+
+                /**
+                 * Calculates the vertical padding of the element
+                 * @returns {number}
+                 */
+                $scope.getOffset = function(){
+                    var style = $window.getComputedStyle($element[0], null),
+                        props = ['paddingTop', 'paddingBottom'],
+                        offset = 0;
+
+                    for(var i=0; i<props.length; i++){
+                        offset += parseInt(style[props[i]]);
+                    }
+                    return offset;
+                };
+
+                /**
+                 * Sets textarea height as exact height of content
+                 * @returns {boolean}
+                 */
+                $scope.autogrowFn = function(){
+                    var newHeight = 0, hasGrown = false;
+                    if(($element[0].scrollHeight - $scope.offset) > $scope.maxAllowedHeight){
+                        $element[0].style.overflowY = 'scroll';
+                        newHeight = $scope.maxAllowedHeight;
+                    }
+                    else {
+                        $element[0].style.overflowY = 'hidden';
+                        $element[0].style.height = 'auto';
+                        newHeight = $element[0].scrollHeight - $scope.offset;
+                        hasGrown = true;
+                    }
+                    $element[0].style.height = newHeight + 'px';
+                    return hasGrown;
+                };
+
+                $scope.offset = $scope.getOffset();
+                $scope.lineHeight = ($element[0].scrollHeight / $scope.attrs.rows) - ($scope.offset / $scope.attrs.rows);
+                $scope.maxAllowedHeight = ($scope.lineHeight * $scope.attrs.maxLines) - $scope.offset;
+
+                $element[0].addEventListener('input', $scope.autogrowFn);
+            }
+        }
+    }]);
+})();