Hclsvg

Light and easy to use graphic library for Angular :

• line, rectangle, circle, arc, polyline, polygon, text, path, image
• translate, rotate, scale, remove all shapes
• make shapes draggable or clickable, including callbacks
• export complete SVG code or corresponding PNG image

Author : [email protected]

Installation

npm install hclsvg

Documentation

Setup

Typical use in xxxx.component.ts

import { Component, OnInit } from '@angular/core';
import { Hclsvg } from 'hclsvg';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent implements OnInit {

  ngOnInit() {

    const draw = new Hclsvg('mysvg')
    draw.setCanvasSize({width: 400, height: 300})
    draw.rect({
	  x: 50,
	  y: 30,
	  width: 250,
	  height: 80,
      stroke: '#c00',
      strokeWidth: 3,
      fill: '#008',
      fillOpacity: 0.3
    });
    
  }
}

The component's HTML template shall include this code somewhere:

<svg id="mysvg"></svg>

Methods

Common parameters

Each shape drawn in SVG has a common set of parameters, as the style of the stroke for instance. Therefore each Hclsvg method that generates a shape can receive one or many of the following parameters. They are not mandatory, if one of them is not present, a default value will be used :

stroke:          string  //either 'none', 'rgb(...)', '#...', 'rgba(...)'
strokeWidth:     number  //in pixels
strokeOpacity:   string  //from 0 transparent to 1 opaque
strokeLinecap:   string  //SVG syntax for the stroke-linecap ('butt', 'round', 'square')
strokeDasharray: string  //SVG syntax for the stroke-dasharray, e.g. '20,10,5,5,5,10'
transform:       string  //svg transform string, e.g. 'rotate(45, 200,100)'
fill:            string  //either 'none', 'rgb(...)', '#...', 'rgba(...)'
fillOpacity:     number  //from 0 transparent to 1 opaque

In addition to this, each SVG element requires some dedicated parameters. These last are described in the following list of methods. They are not mandatory, if one of them is not present, a default value will be used.

setCanvasSize()

draw.setCanvasSize() ({ 
	width: number, //in pixels
	height:number  //in pixels
})

line()

draw.line({
	x1: number,          //left position of start point in pixels
	y1: number,          //top position of the start point in pixels
	x2: number,          //left position of end point in pixels
	y2: number,          //top position of the end point in pixels
	[common parameters]
})

polyline()

draw.polyline({
	points: array, //Array of arrays of pixels [ [x0,y0], [x1,y1], ...]
	[common parameters]
})

polygon()

draw.polygon({
	points: array, //Array of arrays of pixels [ [x0,y0], [x1,y1], ...]
	[common parameters]
})

rect()

draw.rect({
	x: number,            //left position in pixels
	y: number,            //top position in pixels
	width: number,        //in pixels
	height: number,       //in pixels
	[common parameters]
})

circle()

draw.circle({
	cx: number,            //left position of the center in pixels
	cy: number,            //top position of the center in pixels
	r: number,             //radius in pixels
	[common parameters]
})

arc()

draw.arc({
	cx: number,            //left position of the center in pixels
	cy: number,            //top position of the center in pixels
	r: number,             //radius in pixels
	startAngle: number,    //from -360 to 360
	endAngle: number,      //from -360 to 360
	[common parameters]
})

path()

draw.path({
	path: string,          //value of the attribute d of a path SVG tag
	[common parameters]
})

text()

draw.text({
	x: number,             //left position in pixels
	y: number,             //top position in pixels
	textAnchor: string     //'start', 'middle' or 'end'
	fontSize: number       //in pixels
	fontFamily: string     //the name of the HTML fonts
	text:                  //the text to be displayed
	[common parameters]
})

image()

Because the image is loaded over an asynchronous process, it can be accessed after the return of a promise (use of .then(...)). All imported images are translated into a base64 url image. You will be able to exports an imported image only if the provider of the image allows your cross origin.

draw.image({
	x: number,        //left position in pixels
	y: number,        //top position in pixels
	width: number,    //in pixels
	height: number,   //in pixels
	src: string       //the src attribute of the image (url, data/image, ...)
	[common parameters]
}).then( (image) => {
	const myimage = image;
});

translate()

let myrect = draw.rect({...});

draw.translate(myrect, {
	dx: number,            //x shift in pixels
	dy: number,            //y shift in pixels
})

rotate()

let myrect = draw.rect({...});

//To rotate around the center of the chape
draw.rotate(myrect, {angle: 45});

//To rotate from a different axis
draw.rotate(myrect, {
	angle: number   //rotation angle from -360 to 360
	cx: number,     //x coordonate of the center of rotation in pixels
	cy: number,     //y coordonate of the center of rotation in pixels
})

scale()

let myrect = draw.rect({...});

draw.scale(myrect, {
	x: number,  //scale factor on x axis
	y: number,  //scale factor on y axis, equal to x scale factor if omitted
})

remove()

let myrect = draw.rect({...});

draw.remove(myrect);

makeClickable()

let myrect = draw.rect({...});

//if you provide a callback
draw.makeClickable(myrect, {
   onclick: this.onClick,  //callback on click
})

//The parameter bbox passed to the callback 
//is the getBoundingClientRect of myrect
onClick(bbox) {
   console.log(bbox)
   //do whatever you want here ...
}

disableClickable()

draw.disableClickable(myrect);

makeDraggable()

let myrect = draw.rect({...});

//if you do not provide any callback
draw.makeDraggable(myrect) 

//if you provide callbacks
draw.makeDraggable(myrect, {
   dragstart: this.dragStart,  //callback on drag start, optional
   ondrag: this.onDrag,        //callback when dragging, optional
   dragend: this.dragEnd       //callback on drag end, optional
})

//The parameter bbox passed to the callbacks 
//is the getBoundingClientRect of myrect
dragStart(bbox) {
   console.log(bbox)
   //do whatever you want here ...
}
onDrag(bbox) {
   console.log(bbox)
   //do whatever you want here ...
}
dragEnd(bbox) {
   console.log(bbox)
   //do whatever you want here ...
}

disableDraggable()

let myrect = draw.rect({...});

//Set draggable
draw.makeDraggable(myrect, {
   dragstart: this.dragStart,  //callback on drag start
   ondrag: this.onDrag,        //callback when dragging
   dragend: this.dragEnd       //callback on drag end
})

...

//Unset draggable
draw.disableDraggable(myrect);

exportSvg()

const svg_code = draw.exportSvg();

exportPng()

//Require to install the npm module "file-saver"
import { saveAs } from 'file-saver';

...

//The function exportPng returns a promise containing 
//the PNG image as a Base64 URL format
draw.exportPng().then( (image) => {
	
	//image can be used as the src of an <img> tag,
	//eg. <img [attr.src]="imgSrc" />,
	//referenced in the component's HTML template
	this.imgSrc = image;
	
	//image can be dowloaded
	saveAs(image, 'myimage.png');
});

Dev infos

This library was generated with Angular CLI version 7.2.0.

Code scaffolding

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

Note: Don't forget to add --project hclsvg or else it will be added to the default project in your angular.json file.

Build

Run ng build hclsvg to build the project. The build artifacts will be stored in the dist/ directory.

Publishing

After building your library with ng build hclsvg, go to the dist folder cd dist/hclsvg and run npm publish.

Running unit tests

Run ng test hclsvg to execute the unit tests via Karma.

Further help

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