Angular + Typescript Updating an elements position dynamically via CSS transform

<!DOCTYPE html>
<html>

  <head>
    <base href="." />
    <script type="text/javascript" charset="utf-8">
      window.AngularVersionForThisPlunker = 'latest'
    </script>
    <title>angular playground</title>
    <link rel="stylesheet" href="style.css" />
    <script src="https://unpkg.com/core-js@2.4.1/client/shim.min.js"></script>
    <script src="https://unpkg.com/zone.js/dist/zone.js"></script>
    <script src="https://unpkg.com/zone.js/dist/long-stack-trace-zone.js"></script>
    <script src="https://unpkg.com/reflect-metadata@0.1.3/Reflect.js"></script>
    <script src="https://unpkg.com/systemjs@0.19.31/dist/system.js"></script>
    <script src="config.js"></script>
    <script>
    System.import('app')
      .catch(console.error.bind(console));
  </script>
  </head>

  <body>
    <my-app>
    loading...
  </my-app>
      <div id="draggable">Almost ready...</div>
  </body>

</html>

/* Styles go here */
html, body {
  width: 100%;
  height: 100%;
}


#draggable {
  
  width: 200px;
  height: 200px;
  background-color: red;
  color: #000;
  z-index: 100;
  position: absolute;
  /*opacity: 0.5;*/
  user-select: none;
  transition: transform 100ms linear;
  will-change: transform;
}

### Angular Starter Plunker - Typescript

var angularVersion;
if(window.AngularVersionForThisPlunker === 'latest'){
  angularVersion = ''; //picks up latest
}
else {
  angularVersion = '@' + window.AngularVersionForThisPlunker;
}

angularVersion = '@5.2.6';

System.config({
  //use typescript for compilation
  transpiler: 'typescript',
  //typescript compiler options
  typescriptOptions: {
    emitDecoratorMetadata: true
  },
  paths: {
    'npm:': 'https://unpkg.com/'
  },
  //map tells the System loader where to look for things
  map: {
    
    'app': './src',
    '@angular/core': 'npm:@angular/core'+ angularVersion + '/bundles/core.umd.js',
    '@angular/common': 'npm:@angular/common' + angularVersion + '/bundles/common.umd.js',
    '@angular/common/http': 'npm:@angular/common' + angularVersion + '/bundles/common-http.umd.js',
    '@angular/compiler': 'npm:@angular/compiler' + angularVersion  + '/bundles/compiler.umd.js',
    '@angular/platform-browser': 'npm:@angular/platform-browser' + angularVersion + '/bundles/platform-browser.umd.js',
    '@angular/platform-browser-dynamic': 'npm:@angular/platform-browser-dynamic' + angularVersion + '/bundles/platform-browser-dynamic.umd.js',
    '@angular/http': 'npm:@angular/http' + angularVersion + '/bundles/http.umd.js',
    '@angular/router': 'npm:@angular/router' + angularVersion +'/bundles/router.umd.js',
    '@angular/forms': 'npm:@angular/forms' + angularVersion + '/bundles/forms.umd.js',
    '@angular/animations': 'npm:@angular/animations' + angularVersion + '/bundles/animations.umd.js',
    '@angular/platform-browser/animations': 'npm:@angular/platform-browser' + angularVersion + '/bundles/platform-browser-animations.umd.js',
    '@angular/animations/browser': 'npm:@angular/animations' + angularVersion + '/bundles/animations-browser.umd.js',
    
    '@angular/core/testing': 'npm:@angular/core' + angularVersion + '/bundles/core-testing.umd.js',
    '@angular/common/testing': 'npm:@angular/common' + angularVersion + '/bundles/common-testing.umd.js',
    '@angular/common/http/testing': 'npm:@angular/common' + angularVersion + '/bundles/common-http-testing.umd.js',
    '@angular/compiler/testing': 'npm:@angular/compiler' + angularVersion + '/bundles/compiler-testing.umd.js',
    '@angular/platform-browser/testing': 'npm:@angular/platform-browser' + angularVersion + '/bundles/platform-browser-testing.umd.js',
    '@angular/platform-browser-dynamic/testing': 'npm:@angular/platform-browser-dynamic' + angularVersion + '/bundles/platform-browser-dynamic-testing.umd.js',
    '@angular/http/testing': 'npm:@angular/http' + angularVersion + '/bundles/http-testing.umd.js',
    '@angular/router/testing': 'npm:@angular/router' + angularVersion + '/bundles/router-testing.umd.js',
    'tslib': 'npm:tslib@1.6.1',
    'rxjs': 'npm:rxjs@5.5.5',
    'typescript': 'npm:typescript@2.2.1/lib/typescript.js'
  },
  //packages defines our app package
  packages: {
    app: {
      main: './main.ts',
      defaultExtension: 'ts'
    },
    rxjs: {
      defaultExtension: 'js'
    }
  }
});

//main entry point
import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
import {AppModule} from './app';

platformBrowserDynamic().bootstrapModule(AppModule)

//our root app component
import { Component, NgModule, VERSION, OnInit, OnDestroy, ElementRef } from '@angular/core'
import { BrowserModule} from '@angular/platform-browser';
import { Observable } from "rxjs/Observable";
import { AsyncSubject } from "rxjs/AsyncSubject";
import { Subscription } from "rxjs/Subscription";
import { fromEvent } from 'rxjs/observable/fromEvent';
import { takeUntil } from 'rxjs/operators/takeUntil';
import { tap } from 'rxjs/operators/tap';
import { filter } from 'rxjs/operators/filter';

@Component({
  selector: 'my-app',
  template: `
    <div>
      
    </div>
  `,
})
export class App implements OnInit, OnDestroy {
  name:string;
  
  $isAlive = new AsyncSubject();
  down$: Observable<PointerEvent>;
  move$: Observable<PointerEvent>;
  up$: Observable<PointerEvent>;
  el: ElementRef;
  
  isPointerDown: false;
  
  constructor() {
    this.name = `Angular! v${VERSION.full}`
  }
  
  updatePosition($ev: PointerEvent){
    this.el.nativeElement.style.transform = `translate(${$ev.clientX + 10}px, ${$ev.clientY + 10}px)`;
  }
  
  ngOnInit(){ 
    
    let down = "mousedown", up = "mouseup", move = "mousemove", out = "mouseleave";

    if ((window as any).PointerEvent) {
        down = "pointerdown";
        move = "pointermove";
        up = "pointerup";
        out = "pointerleave";
    } else if ((('ontouchstart' in window) || (window as any).DocumentTouch && document instanceof DocumentTouch)) {
        down = "touchstart";
        move = "touchmove";
        up = "touchend";
        out = "touchend";
    }
    
    this.el = new ElementRef(document.getElementById("draggable"));
    this.down$ = fromEvent(this.el.nativeElement, down);
    this.move$ = fromEvent(document.body, move);
    this.up$ = fromEvent(document.body, up);
    
    this.el.nativeElement.style.top = "0";
    this.el.nativeElement.style.left = "0";
    this.el.nativeElement.innerText = "Drag me around";
    
    this.down$.pipe(
      takeUntil(this.$isAlive),
      tap(() => this.isPointerDown = true),
      tap(($ev: PointerEvent) => this.updatePosition($ev)),
      tap(($ev) => $ev.preventDefault()), //prevent text selection
      tap(($ev) => $ev.stopPropagation())
    ).subscribe();
    
    this.move$.pipe(
      takeUntil(this.$isAlive),
      filter(() => this.isPointerDown),
      //.throttleTime(20)
      tap(($ev: PointerEvent) => this.updatePosition($ev))
    ).subscribe();
    
    this.up$.pipe(
      takeUntil(this.$isAlive),
      tap(() => this.isPointerDown = false)
    ).subscribe();
  }
  
  ngOnDestroy(){
    this.$isAlive.next();
    this.$isAlive.complete();
  }
}

@NgModule({
  imports: [ BrowserModule ],
  declarations: [ App ],
  bootstrap: [ App ]
})
export class AppModule {}