Hover over multi-line tree node in EJ2 JavaScript 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).

index.js

/**
* Hovering multiline tree sample
*/

// Hierarchical data source for TreeView control
var hierarchicalData = [
    {
        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' }
                ]
            }
        ]
    }
];
var tree1 = new ej.navigations.TreeView({
    fields: { dataSource: hierarchicalData, id: 'id', text: 'name', child: 'child' },
    nodeSelecting: onselect,
    cssClass: "customTree"
});
tree1.appendTo('#tree');

// Triggers on mouse hover/keydown event
['mouseover', 'keydown'].forEach(evt =>
    document.getElementById("tree").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 (tree1.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";
    }
}

index.html

<!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://cdn.syncfusion.com/ej2/29.1.33/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
  <div id="container">
    <div id="treeparent">
      <div id="tree"></div>
    </div>
  </div>

  <script>
    var ele = document.getElementById('container');
    if (ele) {
      ele.style.visibility = "visible";
    }   
  </script>
  <script src="index.js" type="text/javascript"></script>
  <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>

index.css

#container {
  visibility: hidden;
}

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