fix: prevent scrolling to a placeholder on open

vaadin · Sep 4, 2021 · f5c53c2 · f5c53c2
1 parent 33be450
commit f5c53c2
Show file tree

Hide file tree

Showing 3 changed files with 19 additions and 4 deletions.
diff --git a/packages/vaadin-combo-box/src/vaadin-combo-box-dropdown-wrapper.js b/packages/vaadin-combo-box/src/vaadin-combo-box-dropdown-wrapper.js
@@ -265,7 +265,7 @@ class ComboBoxDropdownWrapperElement extends PolymerElement {
   }
 
   _setOverlayHeight() {
-    if (!this.opened || !this.positionTarget) {
+    if (!this.__virtualizer || !this.opened || !this.positionTarget) {
       return;
     }
 
@@ -374,7 +374,7 @@ class ComboBoxDropdownWrapperElement extends PolymerElement {
   }
 
   _scrollIntoView(index) {
-    if (!(this.opened && index >= 0)) {
+    if (!this.__virtualizer || !(this.opened && index >= 0)) {
       return;
     }
     const visibleItemsCount = this._visibleItemsCount();

diff --git a/packages/vaadin-combo-box/src/vaadin-combo-box-mixin.js b/packages/vaadin-combo-box/src/vaadin-combo-box-mixin.js
@@ -933,7 +933,7 @@ export const ComboBoxMixin = (subclass) =>
     _indexOfValue(value, items) {
       if (items && this._isValidValue(value)) {
         for (let i = 0; i < items.length; i++) {
-          if (this._getItemValue(items[i]) === value) {
+          if (items[i] !== this.__placeHolder && this._getItemValue(items[i]) === value) {
             return i;
           }
         }

diff --git a/packages/vaadin-combo-box/test/lazy-loading.test.js b/packages/vaadin-combo-box/test/lazy-loading.test.js
@@ -1,6 +1,6 @@
 import { expect } from '@esm-bundle/chai';
 import sinon from 'sinon';
-import { fixtureSync, nextFrame, enterKeyDown, fire } from '@vaadin/testing-helpers';
+import { fixtureSync, nextFrame, aTimeout, enterKeyDown, fire } from '@vaadin/testing-helpers';
 import { flush } from '@polymer/polymer/lib/utils/flush.js';
 import '@polymer/iron-input/iron-input.js';
 import { ComboBoxPlaceholder } from '../src/vaadin-combo-box-placeholder.js';
@@ -827,6 +827,21 @@ describe('lazy loading', () => {
           comboBox.opened = true;
         });
 
+        it('should be scrolled to start on reopen', async () => {
+          comboBox.dataProvider = spyAsyncDataProvider;
+          comboBox.size = SIZE;
+          comboBox.opened = false;
+
+          // Wait for the async data provider to respond
+          await aTimeout(0);
+
+          // Reopen
+          comboBox.open();
+          await nextFrame();
+
+          expect(getViewportItems(comboBox)[0].index).to.eql(0);
+        });
+
         it('should replace filteredItems with placeholders', () => {
           comboBox.dataProvider = spyAsyncDataProvider;
           comboBox.size = SIZE;