[TNL-6027] Fix bug where user could select multiple items.

drag_and_drop_v2/public/js/drag_and_drop.js

@@ -1015,16 +1015,18 @@ function DragAndDropBlock(runtime, element, configuration) {
         return false;
     };
 
-    var placeItem = function($zone, $item) {
-        var item_id;
-        if ($item !== undefined) {
-            item_id = $item.data('value');
-        } else {
-            item_id = $selectedItem.data('value');
-        }
-
+    var placeGrabbedItem = function($zone) {
         var zone = String($zone.data('uid'));
         var zone_align = $zone.data('zone_align');
+        var items = configuration.items;
+
+        var item_id;
+        for (var i = 0; i < items.length; i++) {
+            if (items[i].grabbed) {
+                item_id = items[i].id;
+                break;
+            }
+        }
 
         var items_in_zone_count = countItemsInZone(zone, [item_id.toString()]);
         if (configuration.max_items_per_zone && configuration.max_items_per_zone <= items_in_zone_count) {
@@ -1070,18 +1072,17 @@ function DragAndDropBlock(runtime, element, configuration) {
                     } else if (isCancelKey(evt)) {
                         evt.preventDefault();
                         state.keyboard_placement_mode = false;
-                        releaseItem($selectedItem);
+                        releaseGrabbedItems();
                     } else if (isActionKey(evt)) {
                         evt.preventDefault();
                         evt.stopPropagation();
                         state.keyboard_placement_mode = false;
-                        releaseItem($selectedItem);
                         if ($zone.is('.item-bank')) {
                             delete state.items[$selectedItem.data('value')];
-                            applyState();
                         } else {
-                            placeItem($zone);
+                            placeGrabbedItem($zone);
                         }
+                        releaseGrabbedItems();
                     }
                 } else if (isTabKey(evt) && !evt.shiftKey) {
                     // If the user just dropped an item to this zone, next TAB keypress
@@ -1108,8 +1109,7 @@ function DragAndDropBlock(runtime, element, configuration) {
             tolerance: 'pointer',
             drop: function(evt, ui) {
                 var $zone = $(this);
-                var $item = ui.helper;
-                placeItem($zone, $item);
+                placeGrabbedItem($zone);
             }
         });
 
@@ -1121,7 +1121,7 @@ function DragAndDropBlock(runtime, element, configuration) {
                 drop: function(evt, ui) {
                     var $item = ui.helper;
                     var item_id = $item.data('value');
-                    releaseItem($item);
+                    releaseGrabbedItems();
                     delete state.items[item_id];
                     applyState();
                 }
@@ -1174,7 +1174,7 @@ function DragAndDropBlock(runtime, element, configuration) {
                     stop: function(evt, ui) {
                         // Revert to original position.
                         $item.css($item.data('initial-position'));
-                        releaseItem($(this));
+                        releaseGrabbedItems();
                     }
                 });
             } catch (e) {
@@ -1186,31 +1186,27 @@ function DragAndDropBlock(runtime, element, configuration) {
 
     var grabItem = function($item, interaction_type) {
         var item_id = $item.data('value');
-        setGrabbedState(item_id, true, interaction_type);
-        closePopup(false);
-        // applyState(true) skips destroying and initializing draggable
-        applyState(true);
-    };
-
-    var releaseItem = function($item) {
-        var item_id = $item.data('value');
-        setGrabbedState(item_id, false);
-        // applyState(true) skips destroying and initializing draggable
-        applyState(true);
-    };
-
-    var setGrabbedState = function(item_id, grabbed, interaction_type) {
         configuration.items.forEach(function(item) {
             if (item.id === item_id) {
-                if (grabbed) {
                 item.grabbed = true;
                 item.grabbed_with = interaction_type;
             } else {
                 item.grabbed = false;
                 delete item.grabbed_with;
             }
-            }
         });
+        closePopup(false);
+        // applyState(true) skips destroying and initializing draggable
+        applyState(true);
+    };
+
+    var releaseGrabbedItems = function() {
+        configuration.items.forEach(function(item) {
+            item.grabbed = false;
+            delete item.grabbed_with;
+        });
+        // applyState(true) skips destroying and initializing draggable
+        applyState(true);
     };
 
     var destroyDraggable = function() {

tests/integration/test_base.py

@@ -403,7 +403,7 @@ class InteractionTestBase(object):
         item.send_keys("")
         item.send_keys(action_key)
         # Focus is on first *zone* now
-        self.assert_grabbed_item(item)
+        self.assert_item_grabbed(item)
         # Get desired zone and figure out how many times we have to press Tab to focus the zone.
         if zone_id is None:  # moving back to the bank
             zone = self._get_item_bank()
@@ -420,9 +420,12 @@ class InteractionTestBase(object):
             ActionChains(self.browser).send_keys(Keys.TAB).perform()
         zone.send_keys(action_key)
 
-    def assert_grabbed_item(self, item):
+    def assert_item_grabbed(self, item):
         self.assertEqual(item.get_attribute('aria-grabbed'), 'true')
 
+    def assert_item_not_grabbed(self, item):
+        self.assertEqual(item.get_attribute('aria-grabbed'), 'false')
+
     def assert_placed_item(self, item_value, zone_title, assessment_mode=False):
         item = self._get_placed_item_by_value(item_value)
         self.wait_until_visible(item)

tests/integration/test_interaction.py

@@ -382,6 +382,22 @@ class StandardInteractionTest(DefaultDataTestMixin, InteractionTestBase, Paramet
         # After placing all items, we get the full score.
         self.assertEqual(progress.text, '1/1 point (ungraded)')
 
+    @data(*ITEM_DRAG_KEYBOARD_KEYS)
+    def test_cannot_select_multiple_items(self, action_key):
+        all_item_ids = self.items_map.keys()
+        # Go through all items and select them all using the keyboard action key.
+        for item_id in all_item_ids:
+            item = self._get_item_by_value(item_id)
+            item.send_keys('')
+            item.send_keys(action_key)
+            # Item should be grabbed.
+            self.assert_item_grabbed(item)
+            # Other items should NOT be grabbed.
+            for other_item_id in all_item_ids:
+                if other_item_id != item_id:
+                    other_item = self._get_item_by_value(other_item_id)
+                    self.assert_item_not_grabbed(other_item)
+
 
 class MultipleValidOptionsInteractionTest(DefaultDataTestMixin, InteractionTestBase, BaseIntegrationTest):