Build dropdown module

dist/semantic.js

@@ -6536,6 +6536,12 @@ $.fn.dropdown = function(parameters) {
               else {
                 module.set.upward($menu);
               }
+              if(module.is.fitWidth($menu)) {
+                module.remove.leftward($menu);
+              }
+              else {
+                module.set.leftward($menu);
+              }
             }
             else if(settings.direction == 'upward') {
               module.set.upward($menu);
@@ -6545,6 +6551,14 @@ $.fn.dropdown = function(parameters) {
             var $element = $menu || $module;
             $element.addClass(className.upward);
           },
+          leftward: function($menu) {
+            var $element = $menu || $module;
+            var parentMenu = $element.parent().closest(selector.menu);
+            if (parentMenu.hasClass('transition')) {
+              $element = parentMenu;
+            }
+            $element.addClass(className.leftward);
+          },
           value: function(value, text, $selected) {
             var
               escapedValue = module.escape.value(value),
@@ -6897,6 +6911,14 @@ $.fn.dropdown = function(parameters) {
             var $element = $menu || $module;
             $element.removeClass(className.upward);
           },
+          leftward: function($menu) {
+            var $element = $menu || $module;
+            var parentMenu = $element.parent().closest(selector.menu);
+            if (parentMenu.hasClass('transition')) {
+              $element = parentMenu;
+            }
+            $element.removeClass(className.leftward);
+          },
           visible: function() {
             $module.removeClass(className.visible);
           },
@@ -7253,6 +7275,34 @@ $.fn.dropdown = function(parameters) {
             $currentMenu.removeClass(className.loading);
             return canOpenDownward;
           },
+          fitWidth: function($subMenu) {
+            var
+                $currentMenu   = $subMenu || $menu,
+                canOpenRightward = true,
+                isOutsideScreen = false,
+                calculations
+                ;
+            $currentMenu.addClass(className.loading);
+            calculations = {
+              childrenWidth: 0,
+              contextWidth: $context.outerWidth(),
+              menuOffset  : $currentMenu.offset().left,
+              menuWidth   : $currentMenu.outerWidth()
+            };
+            $currentMenu.find(selector.menu).each(function() {
+              var child = $(this);
+              child.show();
+              calculations.childrenWidth += child[0].offsetWidth;
+            });
+            isOutsideScreen = ((calculations.contextWidth < calculations.menuOffset + calculations.menuWidth + calculations.childrenWidth) || (calculations.menuOffset - $menu.offset().left < 0));
+
+            if(isOutsideScreen) {
+              module.verbose('Dropdown cannot fit in context rightward', isOutsideScreen);
+              canOpenRightward = false;
+            }
+            $currentMenu.removeClass(className.loading);
+            return canOpenRightward;
+          },
           inObject: function(needle, object) {
             var
               found = false
@@ -7422,7 +7472,12 @@ $.fn.dropdown = function(parameters) {
                     onStart    : start,
                     onComplete : function() {
                       if(settings.direction == 'auto') {
-                        module.remove.upward($subMenu);
+                        if ($currentMenu.hasClass(className.leftward)) {
+                          module.remove.leftward($subMenu);
+                        }
+                        else {
+                          module.remove.upward($subMenu);
+                        }
                       }
                       callback.call(element);
                     }
@@ -7850,6 +7905,7 @@ $.fn.dropdown.settings = {
     selected    : 'selected',
     selection   : 'selection',
     upward      : 'upward',
+    leftward    : 'left',
     visible     : 'visible'
   }