image-cutter v0.0.3

image-cutter

React.js component to cut an image and generate a square image from it. Useful to edit profile images before saving

Install

npm i image-cutter

https://www.npmjs.com/package/image-cutter

Usage

On your component import:

import  ImageCutter  from  "image-cutter";

Call de component:

<ImageCutter
    image_src = { image_source }
    side = "400"
    callback = { callback_funtion }
    close = { close_function }
    width = "400"
/>

note: image_src must be a local source to avoid cross origin constraint. If you want to get the cut from external image first you can get the data through Fetch and take the base64 result then pass it to ImageCutter

Example

   import  React  from  "react";
   import  ImageCutter  from  "image-cutter";
    
   export  default  class  App  extends  React.Component {
       constructor(props) {
	   super(props);
	   this.callback  =  this.callback.bind(this);
	   this.click  =  this.click.bind(this);
	   this.state  = {
		    img_src:"data:image/jpeg;base64,/9j/.....",
		    img_rslt: "",
			image_cutter:  false
	   };
   }
    callback(rslt) {
	    console.log(rslt);
	    this.setState({ img_rslt:  rslt.base64 });
    }
    click() {
	    this.setState({ image_cutter:  !this.state.image_cutter });
    }
    render() {
	    return (
		    <div  className="App">
				<img
				    src={this.state.img_src}
				    onClick={this.click}
			    />
			    <p>click/tap on image, select and see the result below.</p>
			    {(() => {
				    if (this.state.image_cutter) {
					    return (
						    <ImageCutter
							    image_src={this.state.img_src}
							    side="400"
							    callback={this.callback}
							    close={this.click}
							    width="400"
						    />
					    );
				    }
				    return  null;
				})()}
				<img  src={this.state.img_rslt} alt=""  />
		    </div>
	    );
    }
}

watch it working on sandbox: https://codesandbox.io/s/image-cutter-0v2he?file=/src/App.js:0-41414

How it work?

In depth is the html5 Canvas API that does the job. The source image to cut is instantiated in a javacript Image object after a Canvas api is instantiated with the image object before created and the square image is drawn on the canvas, at the end, the result is returned using the api function Canvas to get base64 and blob.

html, css and javascript main idea: https://codepen.io/ivanot/pen/GRpYVxm

Style

this are the css class, feel free to overwrite. "ic" is for image cutter

.ic-scroll{
  ...
}
.ic-scroll > canvas{
  ...
}
.ic-scroll::-webkit-scrollbar {
  ...
}
.ic-scroll::-webkit-scrollbar-button {
  ...
}
.ic-scroll::-webkit-scrollbar-thumb {
  ...
}
.ic-scroll::-webkit-scrollbar-track {
 ...
}

.ic-scroll::-webkit-scrollbar-corner {
  ...
}
.ic-button{
  ...
}
.ic-buttons{
  ...
}
.ic-background{
 ...
}