ngx-positioner

If You want to use smooth scroll top/bottom on DOM element or check if element is at the bottom of scrollable element? Keep on reading!

ngx-positioner is an Angular 9+ directive which allows to determin position of scrollable DOM element. So basicly the directive tells if scrollable element is scrolled top/bottom. Additionaly You can move to bottom/top element using smooth scroll or instant scroll.

Demo

Check the link

Usage

Install ngx-positioner

• npm: $ npm install @kubadospial/ngx-positioner
• yarn: $ yarn add @kubadospial/ngx-positioner

import NgxPositionerModule

import { NgxPositionerModule } from '@kubadospial/ngx-positioner';

@NgModule({
  imports: [
    NgxPositionerModule
  ]
})

Use NgxPositionerDirective

import { Settings } from '@kubadospial/ngx-positioner';


@Component(...)
export class SomeComponent {
  moveToTop$ = new Subject<any>();
  moveToBottom$ = new Subject<any>();

  positionerSettings: Settings = {
    smoothScroll: {
      moveToTop: true,
      moveToBottom: true
    }
  };

  onSettingsChanged(settings: Settings) {
    this.positionerSettings = settings;
  }

  onScrolledToTop(isTop: boolean) {
    this.isScrolledToTop = isTop;
  }

  onScrolledToBottom(isBottom: boolean) {
    this.isScrolledToBottom = isBottom;
  }

  moveToTop() {
    this.moveToTop$.next();
  }

  moveToBottom() {
    this.moveToBottom$.next();
  }
}

And

<div class="panel">
  ...
  <div (click)="moveToTop()">move to top</div>
  <div (click)="moveToBottom()">move to bottom</div>
</div>

<div
  class="parent"
  ngxPositioner
  // or [ngxPositioner]="'.child2'"
  [settings]="positionerSettings"
  [moveToTop$]="moveToTop$"
  [moveToBottom$]="moveToBottom$"
  (isScrolledToTop)="onScrolledToTop($event)"
  (isScrolledToBottom)="onScrolledToBottom($event)"
>
  <div class="child">// long content</div>
  <div class="child2"> .... </div>
</div>

Settings Model

offset: {
    isScrolledToBottom: number // default 0
    isScrolledToTop: number // default 0
    moveToBottom: number // default 0
    moveToTop: number // default 0
},
delay: {
    isScrolledToBottom: number // default 0
    isScrolledToTop: number // default 0
    moveToBottom: number // default 0
    moveToTop: number // default 0
},
debounceTime: {
    isScrolledToBottom: number // default 0
    isScrolledToTop: number // default 0
    moveToBottom: number // default 0
    moveToTop: number // default 0
},
smoothScroll: {
    moveToBottom: boolean, // default true
    moveToTop: boolean // default true
    moveToBottomSpeed: number // default 10
    moveToTopSpeed: number // default 10
}

Directive

Inputs:

• ngxPositioner: string;
• settings: Settings;
• moveToTop$: Subject;
• moveToBottom$: Subject;

ngxPositioner: optional input - that allows to pass string for querySelector if you want to assign other scrollable element than default. The default is host of the directive;
setting: optional input - passes settings object;
moveToTop$: scroll to the top of scrollable element;
moveToBottom$: scroll to the bottom of scrollable element;

Outputs:

• isScrolledToTop: boolean;
• isScrolledToBottom: boolean;

isScrolledToTop: EventEmitter that emits boolean is scrollable element is at top;
isScrolledToBottom: EventEmitter that emits boolean is scrollable element is at bottom;

Contributing

1. Fork repo.
2. npm install / yarn.
3. Make your changes.
4. Add your tests.
5. npm run test / yarn start test.
6. npm run build / yarn start build.
7. After all tests are passing.
8. Commit, push, PR.

License

Released under the terms of MIT License.