User Interaction
An end user can scroll the List with a swipe gesture and with the scrollbar. Although by default the swipe gesture is active for mobile devices and the scrollbar is active for desktops, you can force any or both of them to be used on all platforms. For this purpose, set the scrollByContent or scrollByThumb property to true.
jQuery
$(function() { $("#listContainer").dxList({ // ... scrollByContent: true, // the swipe gesture on all platforms scrollByThumb: true // the scrollbar on all platforms }); });
Angular
<dx-list ... [scrollByContent]="true" <!-- the swipe gesture on all platforms --> [scrollByThumb]="true"> <!-- the scrollbar on all platforms --> </dx-list>
import { DxListModule } from "devextreme-angular"; // ... export class AppComponent { // ... } @NgModule({ imports: [ // ... DxListModule ], // ... })
The List employs native scrolling on most platforms, except non-Mac desktops and devices based on Android older than version 4. To employ native scrolling on all platforms without exception, assign true to the useNativeScrolling property. Note that if you assign false to this property, the List will simulate scrolling on all platforms.
jQuery
$(function() { $("#listContainer").dxList({ // ... useNativeScrolling: true }); });
Angular
<dx-list ... [useNativeScrolling]="true"> </dx-list>
import { DxListModule } from "devextreme-angular"; // ... export class AppComponent { // ... } @NgModule({ imports: [ // ... DxListModule ], // ... })
If simulated scrolling is used, you can specify when to show the scrollbar. For this purpose, use the showScrollbar property.
jQuery
$(function() { $("#listContainer").dxList({ // ... useNativeScrolling: false, showScrollbar: 'always' // or 'onScroll' | 'onHover' | 'never' }); });
Angular
<dx-list ... [useNativeScrolling]="false" showScrollbar="always"> <!-- or "onScroll" | "onHover" | "never" --> </dx-list>
import { DxListModule } from "devextreme-angular"; // ... export class AppComponent { // ... } @NgModule({ imports: [ // ... DxListModule ], // ... })
On mobile devices, the user can pull the List to scroll it slightly further than its top or bottom boundary. Once the user releases the List, it bounces back to the boundary position. You can disable this effect using the bounceEnabled property.
jQuery
$(function() { $("#listContainer").dxList({ // ... bounceEnabled: false }); });
Angular
<dx-list ... [bounceEnabled]="false"> </dx-list>
import { DxListModule } from "devextreme-angular"; // ... export class AppComponent { // ... } @NgModule({ imports: [ // ... DxListModule ], // ... })
If you want to disable scrolling completely, assign false to the scrollingEnabled property.
jQuery
$(function() { $("#listContainer").dxList({ // ... scrollingEnabled: false }); });
Angular
<dx-list ... [scrollingEnabled]="false"> </dx-list>
import { DxListModule } from "devextreme-angular"; // ... export class AppComponent { // ... } @NgModule({ imports: [ // ... DxListModule ], // ... })
See Also
- Configure a Widget: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
API
The following table gives an overview of scrolling-related methods exposed by the List.
Method | Description |
---|---|
scrollHeight() | Returns the height of the scrollable content in pixels. |
scrollToItem(itemIndex) | Scrolls the List to the item with a specific index. |
scrollToItem(itemElement) | Scrolls the List to a specific DOM node. |
scrollTo(location) | Scrolls the List to a location specified in pixels. |
scrollBy(distance) | Scrolls the List from the current location by a distance specified in pixels. |
scrollTop() | Returns a pixel-measured value that shows how far the List is scrolled from the top. |
The following examples shows how to call these methods.
jQuery
const list = $("#listContainer").dxList("instance"); const listItems = list.option("items"); // Scrolls the List to the last item list.scrollToItem(listItems.length-1); // Scrolls a grouped List to the first item of the last group list.scrollToItem({ group: listItems.length-1, item: 0 });
// Finds the DOM nodes of all items and scrolls the List to the last node const listItemNodes = $("#listContainer").find(".dx-list-item"); list.scrollToItem(listItemNodes[listItemNodes.length-1]); // Finds the DOM nodes of all groups and scrolls the List to the last node const listGroupNodes = $("#listContainer").find(".dx-list-group"); list.scrollToItem(listGroupNodes[listGroupNodes.length-1]);
const contentHeight = list.scrollHeight(); const scrolledFromTopBy = list.scrollTop(); list.scrollTo(200); list.scrollBy(100);
Angular
import { ..., ViewChild } from "@angular/core"; import { DxListModule, DxListComponent } from "devextreme-angular"; // ... export class AppComponent { @ViewChild(DxListComponent, { static: false }) list: DxListComponent; // Prior to Angular 8 // @ViewChild(DxListComponent) list: DxListComponent; scrollToLastItem () { let listItems = this.list.instance.option("items"); this.list.instance.scrollToItem(listItems.length-1); } scrollToLastGroup () { let listItems = this.list.instance.option("items"); this.list.instance.scrollToItem({ group: listItems.length-1, item: 0 }); } } @NgModule({ imports: [ // ... DxListModule ], // ... })
import { ..., ViewChild } from "@angular/core"; import { DxListModule, DxListComponent } from "devextreme-angular"; // ... export class AppComponent { @ViewChild(DxListComponent, { static: false }) list: DxListComponent; // Prior to Angular 8 // @ViewChild(DxListComponent) list: DxListComponent; scrollToLastItem () { // Finds the DOM nodes of all items and scrolls the List to the last node let listItemNodes = document.getElementsByClassName("dx-list-item"); this.list.instance.scrollToItem(listItemNodes[listItemNodes.length-1]); } scrollToLastGroup () { // Finds the DOM nodes of all groups and scrolls the List to the last node let listGroupNodes = document.getElementsByClassName("dx-list-group"); this.list.instance.scrollToItem(listGroupNodes[listGroupNodes.length-1]); } } @NgModule({ imports: [ // ... DxListModule ], // ... })
import { ..., ViewChild } from "@angular/core"; import { DxListModule, DxListComponent } from "devextreme-angular"; // ... export class AppComponent { @ViewChild(DxListComponent, { static: false }) list: DxListComponent; // Prior to Angular 8 // @ViewChild(DxListComponent) list: DxListComponent; getListHeight() { return this.list.instance.scrollHeight(); } getScrolledDistanceFromTop () { return this.list.instance.scrollTop(); } scrollTo () { this.list.instance.scrollTo(200); } scrollBy () { this.list.instance.scrollBy(100); } } @NgModule({ imports: [ // ... DxListModule ], // ... })
See Also
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
- List Demos
- List API Reference
Events
To execute certain commands when the List is scrolled, handle the scroll event. If the event handling function is not going to be changed during the lifetime of the UI component, assign it to the onScroll property when you configure the UI component.
jQuery
$(function () { $("#listContainer").dxList({ // ... onScroll: function(e) { const scrollOffset = e.scrollOffset.top; const scrolledToTop = e.reachedTop; const scrolledToBottom = e.reachedBottom; // Handler of the "scroll" event } }); });
Angular
<dx-list ... (onScroll)="onScroll($event)"> </dx-list>
import { DxListModule } from "devextreme-angular"; // ... export class AppComponent { onScroll (e) { const scrollOffset = e.scrollOffset.top; const scrolledToTop = e.reachedTop; const scrolledToBottom = e.reachedBottom; // Handler of the "scroll" event } } @NgModule({ imports: [ // ... DxListModule ], // ... })
If you are going to change the scroll event handler at runtime, or if you need to attach several handlers to this event, subscribe to it using the on(eventName, eventHandler) method. This approach is more typical of jQuery.
const scrollEventHandler1 = function(e) { // First handler of the "scroll" event }; const scrollEventHandler2 = function(e) { // Second handler of the "scroll" event }; $("#listContainer").dxList("instance") .on("scroll", scrollEventHandler1) .on("scroll", scrollEventHandler2);
See Also
- Handle Events: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
- List Demos
- List API Reference
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