NgxSignaturePad
Angular 9 library for drawing smooth signatures, based on
signaturepad.
Usage:
Install package
npm i @o.krucheniuk/ngx-signature-pad -D
Import NgxSignaturePadModule into app.module.ts
`import {NgxSignaturePadModule} from '@o.krucheniuk/ngx-signature-pad';
imports:
SharedModule,
BrowserModule,
NgxSignaturePadModule
,`
Use component:
Add into app.component.html :
<ngx-signature-pad [config]="config" #testPad></ngx-signature-pad>
Add into app.component.ts:
@ViewChild('testPad', {static: true}) signaturePadElement: NgxSignaturePadComponent;
`config: SignaturePadOptions = {
minWidth: 1,
maxWidth: 10,
penColor: 'blue'
};`
Stackblitz example
https://stackblitz.com/edit/ngx-signature-pad
API
API is accessable via this.signaturePadElement
Returns signature image as data URL (see https://mdn.io/todataurl for the list of possible parameters)
toDataURL(); // save image as PNG
toDataURL("image/jpeg"); // save image as JPEG
toDataURL("image/svg+xml"); // save image as SVG
// Draws signature image from data URL.
// NOTE: This method does not populate internal data structure that represents drawn signature. Thus, after using #fromDataURL, #toData won't work properly.
fromDataURL("data:image/png;base64,iVBORw0K...");
// Returns signature image as an array of point groups
toData();
// Draws signature image from an array of point groups
fromData(data);
// Clears the canvas
clear();
// Returns true if canvas is empty, otherwise returns false
isEmpty();
// Unbinds all event handlers
off();
// Rebinds all event handlers
on();
// Force re-render of the signature canvas. Method also clears canvas
forceUpdate();
Config options
dotSize : (float or function) Radius of a single dot.
minWidth: (float) Minimum width of a line. Defaults to 0.5.
maxWidth: (float) Maximum width of a line. Defaults to 2.5.
throttle: (integer) Draw the next point at most once per every x milliseconds. Set it to 0 to turn off throttling. Defaults to 16.
minDistance: (integer) Add the next point only if the previous one is farther than x pixels. Defaults to 5.
backgroundColor: (string) Color used to clear the background. Can be any color format accepted by context.fillStyle. Defaults to "rgba(0,0,0,0)" (transparent black). Use a non-transparent color e.g. "rgb(255,255,255)" (opaque white) if you'd like to save signatures as JPEG images.
penColor: (string) Color used to draw the lines. Can be any color format accepted by context.fillStyle. Defaults to "black".
velocityFilterWeight: (float) Weight used to modify new velocity based on the previous velocity. Defaults to 0.7.
Notes:
Canvas used for drawing is responsive. To limit it size add static dimensions for parent element of ngx-signature-pad
