Interested in taking over this project?

I haven't had time to maintain this project, and have all but stopped working on Angular projects, so if someone would like to take this over, I'm happy to transfer it over. Please contact me if interested.

ngx-animate-on-scroll

A very simple Angular directive with no dependencies that allows you to add CSS animations on elements, once that element has been reached via scrolling the page. Works with whatever CSS animation you choose, including Animate.css as shown in examples.

Installation

To install the directive in your project, run:

$ npm install ngx-animate-on-scroll --save

Using the directive

Modify the following in your app module:

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { AppComponent } from './app.component';

// import third-party module
import { AnimateOnScrollModule } from 'ngx-animate-on-scroll';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,

    // import module here
    AnimateOnScrollModule.forRoot()
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

Use the directive in your component template:

<div animateOnScroll animationName="animation-class-name"></div>

animationName attribute

Required. The animationName attribute is for the name(s) of the CSS class(es) to be added at the time the element appears. Here is a real-world example if you were using the Animate.css library in your project:

<div class="container">

  long scrolling content..

  <div class="animated" animateOnScroll animationName="fadeIn">
    animated content upon appearing in the viewport..
  </div>

</div>

or

<div class="container">

  long scrolling content..

  <div animateOnScroll animationName="animated fadeIn">
    animated content upon appearing in the viewport..
  </div>

</div>

Animate.css Peculiarity

If you're using Animate.css with this component and you're trying to animate an element IN to view (fadeIn, slideInLeft etc), you may experience "flashing" when the element scrolls into the viewport (i.e. the element will be shown, then be hidden, then animate into view). This can be mitigated by overriding Animate.css's .animated class, then applying visibility: hidden; to the element you want to hide:

.animated {
    visibility: visible !important;
}
.hide-on-init {
    visibility: hidden;
}

<div class="container">

  long scrolling content..

  <div class="hide-on-init" animateOnScroll animationName="animated fadeIn">
    animated content upon appearing in the viewport..
  </div>

</div>

offset attribute

You can also optionally add an offset attribute (thanks siegerx3) to specify the number of pixels you would need to scroll to below the top of the element for the animation to activate. The default is 80 pixels and the value given can be positive or negative.

  <div animateOnScroll animationName="animated slideDown" offset="120">
    content with different pixel offset specified
  </div>

Demo

An example of usage of the directory can be found at: https://github.com/abhazelton/animate-on-scroll-test

License

MIT © Aaron Hazelton