Angular Scroll Collapse

A simple lightweight library for Angular that detects scroll direction and adds a sn-scrolling-up or sn-scrolling-down class to the element. The library can also detect when the user has scrolled passed the element and apply a sn-affix class. Useful for make a element sticky when the user has scrolled beyond it. This library can will also apply sn-minimise class after the user has scrolled beyond the height of the element.

Appropriate events for the above classes are also emitted.

This is a simple library for Angular, implemented in the Angular Package Format v5.0.

Install

via NPM

npm i @thisissoon/{angular-scroll-collapse,angular-inviewport} --save

via Yarn

yarn add @thisissoon/angular-scroll-collapse @thisissoon/angular-inviewport

app.module.ts

import { InViewportModule } from '@thisissoon/angular-inviewport';
import { ScrollCollapseModule } from '@thisissoon/angular-scroll-collapse';

@NgModule({
  imports: [InViewportModule, ScrollCollapseModule],
})
export class AppModule {}

app.server.module.ts

import { InViewportModule } from '@thisissoon/angular-inviewport';
import { ScrollCollapseModule } from '@thisissoon/angular-scroll-collapse';

@NgModule({
  imports: [InViewportModule.forServer(), ScrollCollapseModule],
})
export class AppServerModule {}

Examples

A working example can be found inside here.

Scroll direction

<nav class="foo" snScrollCollapse (scrollDirectionChange)="scrollDirectionHandler($event)">
  ...
</nav>

.foo {
  height: 100px;
  left: 0;
  position: fixed;
  right: 0;
  top: 0;
  transition: all 0.35s ease-in-out;
}

.foo.sn-scrolling-down {
  transform: translateY(-100px);
}

.foo.sn-scrolling-up {
  transform: translateY(0);
}

Affix mode

In this scenario the nav element will have the class sn-affix added when the user scrolls past the header element and the nav is at the top of the viewport.

<header>...</header>
<nav class="foo" snScrollCollapse (affixChange)="affixHandler($event)">
  ...
</nav>

.foo.sn-affix {
  left: 0;
  position: fixed;
  right: 0;
  top: 0;
}

A [yOffset] can also be applied. Here sn-affix will be added when the top of the viewport is within 200 pixels of the top of the nav.

<header>...</header>
<nav class="foo" snScrollCollapse [yOffset]="200">
  ...
</nav>

Minimise mode

In this scenario the nav element will have the class sn-minimise added when the user scrolls 100px (the original height of the element) down the page.

<header class="foo" snScrollCollapse (minimiseChange)="minimiseHandler($event)">
  ...
</header>

.foo {
  height: 100px;
  left: 0;
  position: fixed;
  right: 0;
  top: 0;
}

.foo.sn-minimise {
  height: 50px;
}

Specify debounce time (default: 0ms)

<header class="foo" snScrollCollapse [debounce]="500">
  ...
</header>

Development server

Run ng serve for a dev server. Navigate to http://localhost:4200/. The app will automatically reload if you change any of the source files.

Code scaffolding

Run ng generate component component-name to generate a new component. You can also use ng generate directive|pipe|service|class|guard|interface|enum|module.

Build

Run ng build to build the project. The build artifacts will be stored in the dist/ directory. Use the -prod flag for a production build.

Running unit tests

Run ng test to execute the unit tests via Karma.

Running end-to-end tests

Run ng e2e to execute the end-to-end tests via Protractor.

Making Commits

This repo uses Commitizen CLI and Conventional Changelog to create commits and generate changelogs. Instead of running git commit run git cz and follow the prompts. Changelogs will then be generated when creating new releases by running npm run release.

Making Releases

Run npm run release to create a new release. This will use Standard Version to create a new release. Standard Version will generate / update the changelog based on commits generated using Commitizen CLI, update the version number following semantic versioning rules and then commit and tag the commit for the release. Simply run git push --follow-tags origin master.

Further help

To get more help on the Angular CLI use ng help or go check out the Angular CLI README.