ngx-virtual-dnd-list

A virtual scrolling list component that can be sorted by dragging

Live demo

Simple usage

npm i ngx-virtual-dnd-list

virutal-list.module.ts

...
import { VirtualDndListModule } from 'ngx-virtual-dnd-list';

@NgModule({
  declarations: [
    ...
  ],
  imports: [
    ...
    VirtualDndListModule
  ],
  providers: []
})
export class VirtualListModule { }

virutal-list.component.ts

import { Component } from '@angular/core';

@Component({
  selector: 'virutal-list',
  template: `
    <div #scroller>
      <virtual-dnd-list
        [scroller]="scroller"
        [dataKey]="'id'"
        [keeps]="30"
        [(ngModel)]="list"
        (ngModelChange)="onChange($event)"
      >
        <ng-template let-data let-index>
          <span>{{ data.index }}</span>
          <p>{{ data.id }}</p>
        </ng-template>
      </virtual-dnd-list>
    </div>
  `,
  styles: [],
})
export class AppComponent {
  public list = [
    { id: 'a', text: 'aaa' },
    { id: 'b', text: 'bbb' },
    { id: 'c', text: 'ccc' },
    ...
  ];

  onChange(data) {
    // the data changes after the dragging ends
  }
}

EventEmitters

| Event | Description | | ------------- | -------------------------------- | | onTop | scrolled to top | | onBottom | scrolled to bottom | | onDrag | the drag is started | | onDrop | the drag is completed | | rangeChange | triggered when the range changes |

Attributes

Required Attributes

| Prop | Type | Description | | ---------- | ------------------------- | --------------------------------------------------------------------- | | data-key | String | The unique identifier of each piece of data, in the form of 'a.b.c' | | scroller | HTMLElement \| Document | Virtual list scrolling element |

Optional Attributes

Commonly used

| Prop | Type | Default | Description | | -------------- | ------------------------ | ----------- | ----------------------------------------------------------------------------------------------------------------- | | keeps | Number | 30 | The number of lines rendered by the virtual scroll | | size | Number | - | The estimated height of each piece of data, you can choose to pass it or not, it will be automatically calculated | | handle | Function/String | - | Drag handle selector within list items | | group | Object/String | - | string: 'name' or object: { name: 'group', put: true/false, pull: true/false/'clone', revertDrag: true/false } | | keepOffset | Boolean | false | When scrolling up to load data, keep the same offset as the previous scroll | | direction | vertical \| horizontal | | scroll direction | | lockAxis | x \| y | - | Axis on which dragging will be locked | | debounceTime | Number | 0 | debounce time on scroll | | throttleTime | Number | 0 | throttle time on scroll |

Uncommonly used

| Prop | Type | Default | Description | | ------------------ | --------- | ----------- | ------------------------------------------------------------------------------------------------------------------------------ | | draggable | String | - | Specifies which items inside the element should be draggable. If does not set a value, the default list element can be dragged | | sortable | Boolean | true | Allow Sorting by Dragging | | disabled | Boolean | false | Disables the sortable if set to true | | animation | Number | 150 | Animation speed moving items when sorting | | autoScroll | Boolean | true | Automatic scrolling when moving to the edge of the container | | scrollThreshold | Number | 55 | Threshold to trigger autoscroll | | delay | Number | 0 | Time in milliseconds to define when the sorting should start | | delayOnTouchOnly | Boolean | false | Only delay on press if user is using touch | | fallbackOnBody | Boolean | false | Appends the ghost element into the document's body | | ghostClass | String | '' | The class of the mask element when dragging | | ghostStyle | Object | {} | The style of the mask element when dragging | | chosenClass | String | '' | The class of the selected element when dragging |

Public Methods

| Method | Description | | ------------------------ | ---------------------------------------------------------- | | getSize(key) | Get the size of the current item by unique key value | | getOffset() | Get the current scroll height | | getClientSize() | Get wrapper element client viewport size (width or height) | | getScrollSize() | Get all scroll size (scrollHeight or scrollWidth) | | scrollToTop() | Scroll to top of list | | scrollToBottom() | Scroll to bottom of list | | scrollToIndex(index) | Scroll to the specified index position | | scrollToOffset(offset) | Scroll to the specified offset |

Usage

import { Component, ViewChild } from '@angular/core';
import { VirtualDndListComponent } from 'ngx-virtual-dnd-list';

@Component({
  selector: 'virutal-list',
  template: `
    <div #scroller>
      <virtual-dnd-list
        #virtualList
        ...
      >
        ...
      </virtual-dnd-list>

      <button (click)="scrollToBottom()">scroll to bottom</button>
    </div>
  `,
  styles: [],
})
export class VirtualListComponent {
  @ViewChild('virtualList') virtualList: VirtualDndListComponent;

  scrollToBottom() {
    this.virtualList.scrollToBottom();
  }
}