<!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>
  </body>

</html>
/* Styles go here */

https://github.com/leye0/AngularSignatureComponent

# Angular Signature Component

Minimalist signature component for Angular

## Getting Started

Copy signature.component.ts in your project (and add it to the declaration of your module-s).
Tweak for your needs.

### Usage
```html
<!-- This is a place where the signature pad should be used. -->
<!-- The signature canvas will fill the whole space. In the example, full width and a height of 100px. -->
<!-- Notice how in the example the style reacts to the state of the component. -->
<div [ngStyle]="{'border': myAwesomeSignaturePad.isFocused ? '1px solid gray' : 'none'}" style="width: 100%; height: 100px;">

  <!-- When calling "save", the $event received from the component output is your image as a default data URL as PNG -->
  <app-signature (savedSignatureAsDataUrl)="someServiceThatHandlesTheData($event)" #myAwesomeSignaturePad></app-signature>
</div>

<!-- There are two functions: clear and save. -->
<button (click)="myAwesomeSignaturePad.clear()">Clear</button>
<button (click)="myAwesomeSignaturePad.save()">Save</button>
```

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

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',
    '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} from '@angular/core';
import {BrowserModule} from '@angular/platform-browser';
import {SignatureComponent} from './signature.component'

@Component({
  selector: 'my-app',
  template: `
    <div>
      <h1>Angular Signature Component</h1>
      <h2>https://github.com/leye0/AngularSignatureComponent</h2>
      
      <!-- This is a place where the signature pad should be used. -->
      <!-- The signature canvas will fill the whole space. In the example, full width and a height of 100px. -->
      <div style="border: 1px solid gray; width: 100%; height: 100px;">
        <!-- When calling "save", the $event received from the component output is your image as a default data URL as PNG -->
        
        
        <app-signature (savedSignatureAsDataUrl)="someFunctionThatHandlesTheData($event)" #myAwesomeSignaturePad></app-signature>
        
        
      </div>
      
      <!-- There are two functions: clear and save. -->
      <button (click)="myAwesomeSignaturePad.clear()">Clear</button>
      <button (click)="myAwesomeSignaturePad.save()">Save</button><br />
      <br/><br/>
      
      <h3>This is how your data looks like once saved</h3>
      <input style="width: 100%" id="text-signature" type="text" />
      <br/><br/>
      
      <h3>This is how your image will be saved</h3>
      <img id="img-signature" />
    </div>
  `,
})
export class App {
  name:string;
  constructor() {
    this.name = `Angular! v${VERSION.full}`
  }
  someFunctionThatHandlesTheData($event): void {
    console.log($event);
    document.querySelector('#text-signature').value = $event;
    document.querySelector('#img-signature').src = $event;
  }
}

@NgModule({
  imports: [ BrowserModule ],
  declarations: [ App, SignatureComponent ],
  bootstrap: [ App ]
})
export class AppModule {}
import { Component, OnInit, ViewChild, HostListener, EventEmitter, ElementRef, Output } from '@angular/core';

@Component({
  selector: 'app-signature',
  template: '<canvas #canvas></canvas>',
  styles: ['signature.component.scss']
})
export class SignatureComponent implements OnInit {

  @ViewChild('canvas') canvasElementRef: ElementRef;

  segments: Segment[] = [];
  @Output() savedSignatureAsDataUrl: EventEmitter<string> = new EventEmitter<string>();

  get canClear(): boolean { return this.segments.length >  0; }

  private get canvas(): HTMLCanvasElement { return this.canvasElementRef.nativeElement; }
  private get context(): CanvasRenderingContext2D { return this.canvas.getContext("2d"); }
  private isTouchingDown: boolean;
  private isTouchingInside: boolean;
  private previousUserSelectStyle: string;

  @HostListener("window:resize", ["$event"])
  onWindowResize = ($event: UIEvent) => this.resizeCanvas()

  @HostListener("document:mousedown", ["$event"])
  @HostListener("document:mousemove", ["$event"])
  @HostListener("document:touchstart", ["$event"])
  @HostListener("document:touchmove", ["$event"])
  touchOutside = ($event: MouseEvent) => this.handleTouchOutside($event, false)

  @HostListener("document:click", ["$event"])
  @HostListener("document:mouseup", ["$event"])
  @HostListener("document:touchend", ["$event"])
  touchUpOutside = ($event: MouseEvent) => this.handleTouchOutside($event, true)

  @HostListener("document:scroll", ["$event"]) onDocumentScroll =
    ($event: MouseEvent) => {
      if (this.isTouchingInside) {
        $event.preventDefault();
      }
    }

  @HostListener("document:wheel", ["$event"]) onDocumentWheel =
    ($event: MouseWheelEvent) => {
      if (this.isTouchingInside) {
        $event.preventDefault();
      }
    }

  @HostListener("touchstart", ["$event"])
  ontouchstart = ($event: TouchEvent) => this.drawDown($event, true)

  @HostListener("touchmove", ["$event"])
  ontouchmove = ($event: TouchEvent) => this.drawMove($event, true)

  @HostListener("touchend", ["$event"])
  ontoucheend = ($event: TouchEvent) => this.drawEnd()

  @HostListener("mousedown", ["$event"])
  onmousedown = ($event: MouseEvent) => this.drawDown($event, false)

  @HostListener("mousemove", ["$event"])
  onmousemove = ($event: MouseEvent) => this.drawMove($event, false)

  @HostListener("mouseup", ["$event"])
  onmouseup = ($event: MouseEvent) => this.drawEnd()

  constructor(private element: ElementRef) {}

  ngOnInit(): void {
    this.previousUserSelectStyle = (document.body as HTMLElement).style.userSelect;
    this.resizeCanvas();
    this.clear();
    this.element.nativeElement.style.background = 'white';
  }

  private resizeCanvas(): void {
    this.canvas.style.width = '100%';
    this.canvas.style.height = '100%';
    this.canvas.width = this.canvas.offsetWidth;
    this.canvas.height = this.canvas.offsetHeight;
    this.refreshCanvas();
  }

  private drawDown($event: any, isTouch: boolean): void {
    const touchLocationEvent: TouchLocationEvent = isTouch ? $event.touches[0] : $event;
    const point: Point = this.getTouchLocation(touchLocationEvent);
    (document.body as HTMLElement).style.userSelect = 'none';
    this.isTouchingDown = true;
    this.segments.push({ points: [point] });
    this.refreshCanvas();
  }

  private drawMove($event: any, isTouch: boolean): void {
    if (!this.isTouchingDown) { return; }
    const touchLocationEvent: TouchLocationEvent = isTouch ? $event.touches[0] : $event;
    const point: Point = this.getTouchLocation(touchLocationEvent);
    this.segments[this.segments.length - 1].points.push(point);
    this.refreshCanvas();
  }

  private drawEnd(): void {
    this.isTouchingDown = false;
    (document.body as HTMLElement).style.userSelect = this.previousUserSelectStyle;
  }

  private handleTouchOutside($event: any, up: boolean): boolean {
    const focused: boolean = this.canvas.contains($event.target as Node);
     this.isTouchingInside = focused;
     if (!focused && up) {
       this.drawEnd();
     }
     return !focused;
  }

  save(): void {
    this.savedSignatureAsDataUrl.emit(this.canvas.toDataURL());
  }

  clear(): void {
    this.segments = [];
    this.context.clearRect(0, 0, this.canvas.width, this.canvas.height);
  }

  private refreshCanvas(): void {
    this.context.clearRect(0, 0, this.canvas.width, this.canvas.height);
    this.context.beginPath();
    this.segments.filter(s => s.points.length).forEach(s => {
      this.context.moveTo(s.points[0].x, s.points[0].y);
      s.points.forEach(p => this.context.lineTo(p.x, p.y));
    });
    this.context.stroke();
  }

  private getTouchLocation(touchLocation: TouchLocationEvent): Point {
    const rect: ClientRect = this.canvas.getBoundingClientRect();
    return {
      x: touchLocation.clientX - rect.left,
      y: touchLocation.clientY - rect.top
    };
  }
}

export interface TouchLocationEvent {
  clientX: number;
  clientY: number;
}

export interface Point {
  x: number;
  y: number;
}

export interface Segment {
  points: Point[];
}