Hover over multi-line tree node in EJ2 TypeScript TreeView control

28 Jan 202513 minutes to read

This section demonstrates how to hover and select a multi-line tree node. You can set the row height (element class: e-fullrow) to be the same as the row content (element class: e-text-content).

import { enableRipple } from '@syncfusion/ej2-base';
import { TreeView } from '@syncfusion/ej2-navigations';
enableRipple(true);

/**
 * Hovering multiple line TreeView sample
 */

// List data source for TreeView control
let hierarchicalData: { [key: string]: Object }[] = [
    {
        id: 1, name: 'Web Control sWeb ControlsWeb ControlsWeb ControlsWeb ControlsWeb ControlsWeb ControlsWeb Controls', expanded: true,
        child: [
            {
                id: 2, pid: 1, name: 'CalendarCalendarCalendarCalendarCalendarCalendarCalendarCalendarCalendarCalendarCalendarCalendarCalendar', checked: true, child: [
                    { id: 7, pid: 2, name: 'Constructors' },
                    { id: 8, pid: 2, name: 'Properties' },
                    { id: 9, pid: 2, name: 'Methods' },
                    { id: 10, pid: 2, name: 'Events' }
                ]
            },
            {
                id: 3, pid: 1, name: 'Data Grid', child: [
                    { id: 11, pid: 3, name: 'Constructors' },
                    { id: 12, pid: 3, name: 'Fields' },
                    { id: 13, pid: 3, name: 'Properties' },
                    { id: 14, pid: 3, name: 'Methods' },
                    { id: 15, pid: 3, name: 'Events' }
                ]
            },
            {
                id: 4, pid: 1, name: 'DropDownList', child: [
                    { id: 16, pid: 4, name: 'Constructors' },
                    { id: 17, pid: 4, name: 'Properties' },
                    { id: 18, pid: 4, name: 'Methods' }
                ]
            },
            {
                id: 5, pid: 1, name: 'Menu', child: [
                    { id: 19, pid: 5, name: 'Constructors' },
                    { id: 20, pid: 5, name: 'Fields' },
                    { id: 21, pid: 5, name: 'Properties' },
                    { id: 22, pid: 5, name: 'Methods' },
                    { id: 23, pid: 5, name: 'Events' }
                ]
            }
        ]
    },
    {
        id: 24, name: 'Web Controls',
        child: [
            {
                id: 25, pid: 24, name: 'Calendar', checked: true, child: [
                    { id: 26, pid: 25, name: 'Constructors' },
                    { id: 27, pid: 25, name: 'Properties' },
                    { id: 28, pid: 25, name: 'Methods' },
                    { id: 29, pid: 25, name: 'Events' }
                ]
            },
            {
                id: 30, pid: 24, name: 'Data Grid', child: [
                    { id: 31, pid: 30, name: 'Constructors' },
                    { id: 32, pid: 30, name: 'Fields' },
                    { id: 33, pid: 30, name: 'Properties' },
                    { id: 34, pid: 30, name: 'Methods' },
                    { id: 35, pid: 30, name: 'Events' }
                ]
            }
        ]
    }
];

// Render the TreeView by mapping its fields property with data source properties
let treeObj: TreeView = new TreeView({
    fields: { dataSource: hierarchicalData, id: 'id', text: 'name', child: 'child' },
    nodeSelecting: onselect,
    cssClass: ("customTree")
});
treeObj.appendTo('#tree');

// Triggers on mouse hover/keydown event
['mouseover', 'keydown'].forEach(evt =>
    (document.getElementById("tree") as HTMLElement).addEventListener(evt, (event) => { setHeight(event.target); }));

// Triggers on node selection
function onselect(arg) {
    setHeight(arg.node);
}

// Sets e-fullrow to be the same as e-text-content
function setHeight(element) {
    if (treeObj.fullRowSelect) {
        if (element.classList.contains("e-treeview")) {
            element = element.querySelector(".e-node-focus").querySelector(".e-fullrow");
        }
        else if (element.classList.contains("e-list-parent")) {
            element = element.querySelector(".e-fullrow");
        }
        else if (element.classList.value != ("e-fullrow") && element.closest(".e-list-item")) {
            element = element.closest(".e-list-item").querySelector(".e-fullrow");
        }
        if (element.nextElementSibling)
            element.style.height = element.nextElementSibling.offsetHeight + "px";
    }
}
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for TreeView </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for TreeView UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-navigations/styles/material.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='treeparent'>
            <div id="tree"></div>
        </div>
    </div>
    <style>
        #treeparent {
            display: block;
            max-width: 350px;
            max-height: 350px;
            margin: auto;
            overflow: auto;
            border: 1px solid #dddddd;
            border-radius: 3px;
        }

        .customTree li .e-list-text {
            white-space: normal;
            word-break: break-all;
        }
    </style>
</body>

</html>
#container {
  visibility: hidden;
}

#loader {
  color: #008cff;
  height: 40px;
  width: 30%;
  position: absolute;
  font-family: 'Helvetica Neue', 'calibiri';
  font-size: 14px;
  top: 45%;
  left: 45%;
}