We Keep Coding

Draw a textbox on canvas that contains an image and some drawing over it using fabric js

I am trying to draw a textbox on canvas that contains an image and some drawing over it. now I am trying to draw a textbox over it.
When I am trying to initialize canvas object using fabricJS it's making canvas empty first. like..
var canvas = new fabric.Canvas('mycanvas')
after this code, it makes canvas empty. but if I initialize this code in the very beginning just after canvas initialized and then I try to add a textbox to that canvas object like...
var text = new fabric.Textbox('A Computer Science Portal',
{
width: 450,
height: 10,
top: 100,
left: 100,
});
this.canvas.add(text);
Then the textbox is not visible. I think it went in the background of the image.
I have already written lots of code for drawing over the canvas not want to draw textbox on the canvas after with all existing drawing and image that is developed in javascript only.

On Fabric you have bringToFront use that to keep the text on top.
Here is the official documentation:
http://fabricjs.com/docs/fabric.Canvas.html#bringToFront
Sample code:
var image;
var canvas = new fabric.Canvas('canvas');
var url = "http://swagger-net-test.azurewebsites.net/api/SvgImage?"
var text = new fabric.Textbox('TEST', { width: 90, height: 10, top: 30, left: 50 });
this.canvas.add(text);
function loadSVG(url) {
fabric.loadSVGFromURL(url, function(objects, options) {
if (image) canvas.remove(image);
image = fabric.util.groupSVGElements(objects, options);
image.name = 'sticker';
canvas.add(image);
image.scaleToHeight(100);
image.center();
image.setCoords();
canvas.renderAll();
canvas.bringToFront(text)
});
}
loadSVG(url + "color=red")
setTimeout(function() {
loadSVG(url + "color=blue")
}, 3000);
<canvas id="canvas" width="200" height="200"></canvas>
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/2.3.4/fabric.min.js"></script>

loadFromJSON doesn't including additional property in fabric js

I have this JSON: https://codepen.io/dhavalsisodiya/pen/RJNNXw
That json has additional property as textAnchor. Now the issue is when ever i am trying to load that json onto canvas, that textAnchor property doesn't get included on canvas object.
You can check the example here: https://codepen.io/dhavalsisodiya/pen/VdYLwo
As you can see on canavs textAnchor is not loaded on canvas.
So how to resolve this?
var json = '{"version":"2.2.2","objects":[{"type":"textbox","version":"2.2.2","originX":"left","originY":"top","left":12.5,"top":67.32,"width":382.12,"height":24.86,"fill":"rgb(0,0,0)","stroke":null,"strokeWidth":0,"strokeDashArray":null,"strokeLineCap":"butt","strokeLineJoin":"miter","strokeMiterLimit":10,"scaleX":1.51,"scaleY":1.87,"angle":0,"flipX":false,"flipY":false,"opacity":1,"shadow":null,"visible":true,"clipTo":null,"backgroundColor":"","fillRule":"nonzero","paintFirst":"fill","globalCompositeOperation":"source-over","transformMatrix":null,"skewX":0,"skewY":0,"text":"{First_Name} {Last_Name}","fontSize":22,"fontWeight":"normal","fontFamily":"Times New Roman","fontStyle":"normal","lineHeight":1.16,"underline":false,"overline":false,"linethrough":false,"textAlign":"center","textBackgroundColor":"","charSpacing":0,"minWidth":20,"styles":{},"textAnchor":"middle"},{"type":"textbox","version":"2.2.2","originX":"left","originY":"top","left":8.5,"top":150,"width":585,"height":24.86,"fill":"rgb(0,0,0)","stroke":null,"strokeWidth":0,"strokeDashArray":null,"strokeLineCap":"butt","strokeLineJoin":"miter","strokeMiterLimit":10,"scaleX":1,"scaleY":1,"angle":0,"flipX":false,"flipY":false,"opacity":1,"shadow":null,"visible":true,"clipTo":null,"backgroundColor":"","fillRule":"nonzero","paintFirst":"fill","globalCompositeOperation":"source-over","transformMatrix":null,"skewX":0,"skewY":0,"text":"{first_name} {last_name}","fontSize":22,"fontWeight":"normal","fontFamily":"Times New Roman","fontStyle":"normal","lineHeight":1.16,"underline":false,"overline":false,"linethrough":false,"textAlign":"center","textBackgroundColor":"","charSpacing":0,"minWidth":20,"styles":{},"textAnchor":"middle"},{"type":"textbox","version":"2.2.2","originX":"left","originY":"top","left":7.5,"top":187,"width":587,"height":24.86,"fill":"rgb(0,0,0)","stroke":null,"strokeWidth":0,"strokeDashArray":null,"strokeLineCap":"butt","strokeLineJoin":"miter","strokeMiterLimit":10,"scaleX":1,"scaleY":1,"angle":0,"flipX":false,"flipY":false,"opacity":1,"shadow":null,"visible":true,"clipTo":null,"backgroundColor":"","fillRule":"nonzero","paintFirst":"fill","globalCompositeOperation":"source-over","transformMatrix":null,"skewX":0,"skewY":0,"text":"{address_1}","fontSize":22,"fontWeight":"normal","fontFamily":"Times New Roman","fontStyle":"normal","lineHeight":1.16,"underline":false,"overline":false,"linethrough":false,"textAlign":"center","textBackgroundColor":"","charSpacing":0,"minWidth":20,"styles":{},"textAnchor":"middle"}]}';
var canvas1 = new fabric.Canvas('canvas1');
canvas1.loadFromJSON(json);
// re-render the canvas
canvas1.renderAll();
console.log(JSON.stringify(canvas1));
<script type="text/javascript" src="https://rawgit.com/kangax/fabric.js/master/dist/fabric.js"></script>
<body>
<canvas id="canvas1" style="border:1px solid black"></canvas>
Note: I have added textAnchor support using this question: How to use text-anchor : middle in fabric js
Also as per the doc: http://fabricjs.com/fabric-intro-part-3
We extended object's existing toObject method with additional property — "name", so that property is now part of toObject output, and as a result appears in canvas JSON representation. One more thing worth mentioning is that if you extend objects like this, you'll also want to make sure object's "class" (fabric.Rect in this case) has this property in "stateProperties" array, so that loading canvas from string representation would parse and add it to an object correctly.
So not sure which part of js i have to modify?

As in tutorial it's mentioned you can override toobject method to include your custom properties.
fabric.Textbox.prototype.toObject = (function(toObject) {
return function() {
return fabric.util.object.extend(toObject.call(this), {
textAnchor: this.textAnchor
});
};
})(fabric.Textbox.prototype.toObject);
DEMO
var json = '{"version":"2.2.2","objects":[{"type":"textbox","version":"2.2.2","originX":"left","originY":"top","left":12.5,"top":67.32,"width":382.12,"height":24.86,"fill":"rgb(0,0,0)","stroke":null,"strokeWidth":0,"strokeDashArray":null,"strokeLineCap":"butt","strokeLineJoin":"miter","strokeMiterLimit":10,"scaleX":1.51,"scaleY":1.87,"angle":0,"flipX":false,"flipY":false,"opacity":1,"shadow":null,"visible":true,"clipTo":null,"backgroundColor":"","fillRule":"nonzero","paintFirst":"fill","globalCompositeOperation":"source-over","transformMatrix":null,"skewX":0,"skewY":0,"text":"{First_Name} {Last_Name}","fontSize":22,"fontWeight":"normal","fontFamily":"Times New Roman","fontStyle":"normal","lineHeight":1.16,"underline":false,"overline":false,"linethrough":false,"textAlign":"center","textBackgroundColor":"","charSpacing":0,"minWidth":20,"styles":{},"textAnchor":"middle"},{"type":"textbox","version":"2.2.2","originX":"left","originY":"top","left":8.5,"top":150,"width":585,"height":24.86,"fill":"rgb(0,0,0)","stroke":null,"strokeWidth":0,"strokeDashArray":null,"strokeLineCap":"butt","strokeLineJoin":"miter","strokeMiterLimit":10,"scaleX":1,"scaleY":1,"angle":0,"flipX":false,"flipY":false,"opacity":1,"shadow":null,"visible":true,"clipTo":null,"backgroundColor":"","fillRule":"nonzero","paintFirst":"fill","globalCompositeOperation":"source-over","transformMatrix":null,"skewX":0,"skewY":0,"text":"{first_name} {last_name}","fontSize":22,"fontWeight":"normal","fontFamily":"Times New Roman","fontStyle":"normal","lineHeight":1.16,"underline":false,"overline":false,"linethrough":false,"textAlign":"center","textBackgroundColor":"","charSpacing":0,"minWidth":20,"styles":{},"textAnchor":"middle"},{"type":"textbox","version":"2.2.2","originX":"left","originY":"top","left":7.5,"top":187,"width":587,"height":24.86,"fill":"rgb(0,0,0)","stroke":null,"strokeWidth":0,"strokeDashArray":null,"strokeLineCap":"butt","strokeLineJoin":"miter","strokeMiterLimit":10,"scaleX":1,"scaleY":1,"angle":0,"flipX":false,"flipY":false,"opacity":1,"shadow":null,"visible":true,"clipTo":null,"backgroundColor":"","fillRule":"nonzero","paintFirst":"fill","globalCompositeOperation":"source-over","transformMatrix":null,"skewX":0,"skewY":0,"text":"{address_1}","fontSize":22,"fontWeight":"normal","fontFamily":"Times New Roman","fontStyle":"normal","lineHeight":1.16,"underline":false,"overline":false,"linethrough":false,"textAlign":"center","textBackgroundColor":"","charSpacing":0,"minWidth":20,"styles":{},"textAnchor":"middle"}]}';
var canvas1 = new fabric.Canvas('canvas1');
fabric.Textbox.prototype.toObject = (function(toObject) {
return function() {
return fabric.util.object.extend(toObject.call(this), {
textAnchor: this.textAnchor
});
};
})(fabric.Textbox.prototype.toObject);
canvas1.loadFromJSON(json,function(){
// re-render the canvas
canvas1.renderAll();
console.log(JSON.stringify(canvas1));
});
<script type="text/javascript" src="https://rawgit.com/kangax/fabric.js/master/dist/fabric.js"></script>
<body>
<canvas id="canvas1" style="border:1px solid black"></canvas>

I am using 2.4.6 and solve the things.
canvas.loadFromJSON(Json, function ()
{
debugger;
canvas.renderAll();
console.log(JSON.stringify(canvas));
var json = canvas.toJSON(['selectable', 'name', 'ownType', 'ddlValue', 'lockScalingX']);
console.log(JSON.stringify(json))
});

After ImportJson Path is not editable in paper.js

Here is the below code for export and import of paper js layouts.
$('#btnSave').click(function () {
var json = paper.project.activeLayer.exportJSON();
localStorage.setItem('oncjson', json);
alert('Data has been save successfully;');
});
$('#btnGet').click(function () {
var json = localStorage.getItem('oncjson');
paper.project.activeLayer.importJSON(json);
paper.project.view.update();
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/paper.js/0.11.5/paper-full.js"></script>
It is loading data as per expectations but once the import has done, I am not able to alter or drag segments from the path. it is like hardcode design rendered on the canvas.
Any help highly appreciated.

From what you are describing, I think the problem is that you are expecting that event handlers will be imported along with the serialized data.
Unfortunately, that is not the case because custom callbacks are hardly serializable (see this issue for more details).
Here is an example simulating export/import in 2 separated canvas.
You can see that, after importing, we need to attach event handlers manually.
// create one scope per canvas
var scope1 = new paper.PaperScope();
scope1.setup(document.getElementById('canvas1'));
var scope2 = new paper.PaperScope();
scope2.setup(document.getElementById('canvas2'));
// draw a circle in canvas 1
new paper.Path.Circle({
center: scope1.view.center,
radius: 50,
fillColor: 'orange',
parent: scope1.project.activeLayer,
// name it so we can easily find it in hierarchy
name: 'circle'
});
// draw instructions
new paper.PointText({
content: 'Drag the circle around',
justification: 'center',
point: scope1.view.center.subtract(0, 80),
parent: scope1.project.activeLayer
});
// bind custom drag handler to circle (using its name to find it)
scope1.project.activeLayer.children['circle'].onMouseDrag = customDragHandler;
// export canvas 1 content
var json = scope1.project.exportJSON();
// import it into canvas 2
scope2.project.importJSON(json);
// we need to manually attach event handler for canvas 2 as it wasn't serialized
scope2.project.activeLayer.children['circle'].onMouseDrag = customDragHandler;
// this position the item under the mouse pointer when it is dragged
function customDragHandler(event) {
this.position = event.point;
}
html,
body {
margin: 0;
overflow: hidden;
height: 100%;
}
main {
display: flex;
height: 100vh;
}
canvas {
flex: 1;
border: 1px solid;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/paper.js/0.11.5/paper-core.min.js"></script>
<main>
<canvas id="canvas1" resize></canvas>
<canvas id="canvas2" resize></canvas>
</main>

Adding canvas inside another canvas: obj.setCoords is not a function( fabric js)

Started using fabric.js and trying to add a canvas inside another canvas, so that the top canvas stays constant and I'll add objects to inner canvas.
Here is the snippet of adding a canvas to another canvas.
canvas = new fabric.Canvas('artcanvas');
innerCanvas = new fabric.Canvas("innerCanvas");
canvas.add(innerCanvas);
and my html looks like this
<canvas id="artcanvas" width="500" height="500"></canvas>
<canvas id="innerCanvas" width="200" height="200" ></canvas>
Once adding these successfully, what I am going to do is , add the coordinates to the inner canvas, so that it looks like one on another to the end user.
However, ran into the below error for the tried code
Uncaught TypeError: obj.setCoords is not a function
at klass._onObjectAdded (fabric.js:6894)
at klass.add (fabric.js:231)
at main.js:60
at fabric.js:19435
at HTMLImageElement.fabric.util.loadImage.img.onload (fabric.js:754)
_onObjectAdded # fabric.js:6894
add # fabric.js:231
(anonymous) # main.js:60
(anonymous) # fabric.js:19435
fabric.util.loadImage.img.onload # fabric.js:754
Looking at the error message, just went to the line of error and here is what I found in chrome console
Can someone point the mistake in my codes ?

After going through no.of discussions and internet solutions, for time being I am using Fabric Rectangle as a clipper and setting it's boundaries so user can be able to drop/play with in that particular clipper.
Dotted red(image below) is my clipper and now I can bound the dropping and below is the code to add an image with a clipper.
function addImageToCanvas(imgSrc) {
fabric.Object.prototype.transparentCorners = false;
fabric.Image.fromURL(imgSrc, function(myImg) {
var img1 = myImg.set({
left: 20,
top: 20,
width: 460,
height: 460
});
img1.selectable = false;
canvas.add(img1);
var clipRectangle = new fabric.Rect({
originX: 'left',
originY: 'top',
left: 150,
top: 150,
width: 200,
height: 200,
fill: 'transparent',
/* use transparent for no fill */
strokeDashArray: [10, 10],
stroke: 'red',
selectable: false
});
clipRectangle.set({
clipFor: 'layer'
});
canvas.add(clipRectangle);
});
}
Now while appending any image/layer to the canvas, I bind that image/layer/text to the clipper I created.
function addLayerToCanvas(laImg) {
var height = $(laImg).height();
var width = $(laImg).width();
var clickedImage = new Image();
clickedImage.onload = function(img) {
var pug = new fabric.Image(clickedImage, {
width: width,
height: height,
left: 150,
top: 150,
clipName: 'layer',
clipTo: function(ctx) {
return _.bind(clipByName, pug)(ctx)
}
});
canvas.add(pug);
};
clickedImage.src = $(laImg).attr("src");
}
And the looks like, after restriction of bounds,
Here is the fiddle I have created with some static image url.
https://jsfiddle.net/sureshatta/yxuoav39/
So I am staying with this solution for now and I really feel like this is hacky and dirty. Looking for some other clean solutions.

As far as I know you can't add a canvas to another canvas - you're getting that error as it tries to call setCoords() on the object you've added, but in this case it's another canvas and fabric.Canvas doesn't contain that method (see docs). I think a better approach would be to have two canvases and position them relatively using CSS - see this simple fiddle
HTML
<div class="parent">
<div class="artcanvas">
<canvas id="artcanvas" width="500" height="500"></canvas>
</div>
<div class="innerCanvas">
<canvas id="innerCanvas" width="200" height="200" ></canvas>
</div>
</div>
CSS
.parent {
position: relative;
background: black;
}
.artcanvas {
position: absolute;
left: 0;
top: 0;
}
.innerCanvas {
position: absolute;
left: 150px;
top: 150px;
}
JS
$(document).ready(function() {
canvas = new fabric.Canvas('artcanvas');
innerCanvas = new fabric.Canvas("innerCanvas");
var rect = new fabric.Rect({
fill: 'grey',
width: 500,
height: 500
});
canvas.add(rect);
var rect2 = new fabric.Rect({
fill: 'green',
width: 200,
height: 200
});
innerCanvas.add(rect2);
})
To handle the object serialization, you can do something like this:
var innerObjs = innerCanvas.toObject();
console.dir(innerObjs);
var outerObjs = canvas.toObject();
innerObjs.objects.forEach(function (obj) {
obj.left += leftOffset; // offset of inner canvas
obj.top += topOffset;
outerObjs.objects.push(obj);
});
var json = JSON.stringify(outerObjs);
This will then give you the JSON for all objects on both canvases

I have no understanding why you want to do this thing, but to put a canvas inside another canvas, you have one simple way:
canvas = new fabric.Canvas('artcanvas');
innerCanvas = new fabric.Canvas("innerCanvas");
imageContainer = new fabric.Image(innerCanvas.lowerCanvasEl);
canvas.add(imageContainer);
Then depending what you want to do, you may need additional tweaks, but this should work out of the box.

Don't create a canvas
Most objects in fabric (from my limited experience) are at some point converted to a canvas. Creating an additional fabric canvas to manage a group of objects is kind of pointless as you are just adding overhead and mimicking fabrics built in groups object.
Fabric objects are basically DOM canvases wrappers.
The following example shows how fabric uses a canvas to store the content of a group. The demo creates a group and adds it to the fabric canvas, then gets the groups canvas and adds it to the DOM. Clicking on the group's canvas will add a circle. Note how it grows to accommodate the new circles.
const radius = 50;
const fill = "#0F0";
var pos = 60;
const canvas = new fabric.Canvas('fCanvas');
// create a fabric group and add two circles
const group = new fabric.Group([
new fabric.Circle({radius, top : 5, fill, left : 20 }),
new fabric.Circle({radius, top : 5, fill, left : 120 })
], { left: 0, top: 0 });
// add group to the fabric canvas;
canvas.add(group);
// get the groups canvas and add it to the DOM
document.body.appendChild(group._cacheContext.canvas);
// add event listener to add circles to the group
group._cacheContext.canvas.addEventListener("click",(e)=>{
group.addWithUpdate(
new fabric.Circle({radius, top : pos, fill : "blue", left : 60 })
);
canvas.renderAll();
pos += 60;
});
canvas {
border : 2px solid black;
}
div {
margin : 10px;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.13/fabric.min.js"></script>
<div>Fabric's canvas "canvas = new fabric.Canvas('fCanvas');"</div>
<canvas id="fCanvas" width="256" height="140"></canvas>
<div>Fabric group canvas below. Click on it to add a circle.</div>
Use a group rather than a new instance of a fabric canvas.
As you can see a canvas is generated for you. Adding another fabric canvas (Note that a fabric canvas is not the same as a DOM canvas) will only add more work for fabric to do, which already has a lot of work to do.
You are best of to use a group and have that hold the content of the other fabric object you wish to shadow. That would also contain its content in a group.
Just an image
And just a side not, a DOM canvas is an image and can be used by fabric just as any other image. It is sometimes better to do the rendering directly to the canvas rather than via fabric so you can avoid rendering overheads that fabric needs to operate.
To add a DOM canvas to fabric just add it as an image. The border and text are not fabric object, and apart from the code to render them take up no memory, and no additional CPU overhead that would be incurred if you used a fabric canvas and objects.
const canvas = new fabric.Canvas('fCanvas');
// create a standard DOM canvas
const myImage = document.createElement("canvas");
// size it add borders and text
myImage.width = myImage.height = 256;
const ctx = myImage.getContext("2d");
ctx.fillRect(0,0,256,256);
ctx.fillStyle = "white";
ctx.fillRect(4,4,248,248);
ctx.fillStyle = "black";
ctx.font = "32px arial";
ctx.textAlign = "center";
ctx.textBaseline = "middle";
ctx.fillText("The DOM canvas!",128,128);
// use the canvas to create a fabric image and add it to fabrics canvas.
canvas.add( new fabric.Image(myImage, {
left: (400 - 256) / 2,
top: (400 - 256) / 2,
}));
canvas {
border : 2px solid black;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.13/fabric.min.js"></script>
<canvas id="fCanvas" width="400" height="400"></canvas>

innerCanvas.setCoords(); ìs a function, but you need it only after you set the coordinates. Or more precise, set these four elements:
innerCanvas.scaleX = 1;
innerCanvas.scaleY = 1;
innerCanvas.left = 150;
innerCanvas.top = 150;
innerCanvas.setCoords();
canvas.renderAll();

How to add image to fabric canvas?

I want to add images/icons to my fabric canvas. The code given on the Fabric demo is not working.
fabric.Image.fromURL('my_image.png', function(oImg) {
canvas.add(oImg);
});
This just makes my entire canvas blank.
I want to add icons as clickable elements which respond to events.

I have done a jsfiddle that loads a jpg image on the canvas, by using the
fabric.Image.fromURL() function and the 'mouse:down' event. Inside the mouse:down i check if the user clicks on an object or just on the canvas.
here is a snippet of the javascript:
var canvas = new fabric.Canvas('c');
canvas.backgroundColor = 'yellow';
fabric.Image.fromURL('http://fabricjs.com/assets/pug_small.jpg', function(myImg) {
//i create an extra var for to change some image properties
var img1 = myImg.set({ left: 0, top: 0 ,width:150,height:150});
canvas.add(img1);
});
canvas.on('mouse:down',function(event){
if(canvas.getActiveObject()){
alert(event.target);
}
})
but my example also works ok ,if i dont use the extra variable:
fabric.Image.fromURL('http://fabricjs.com/assets/pug_small.jpg', function(myImg) {
canvas.add(myImg);
});
if you need more fabric events you can take a look here : http://fabricjs.com/events/
jsfiddle : https://jsfiddle.net/tornado1979/5nrmwtxu/
Hope helps , good luck.

This code is working properly but you need to use fabric.js file.
You also need to use fabric.js CDN file in your header.
Fabric.js CDN->
var canvas = new fabric.Canvas('drawarea');
var imgElement = document.getElementById('my-image');
var imgInstance = new fabric.Image(imgElement, {
left: 100,
top: 100,
angle: 0,
opacity: 0.75,
width:300,
height:300
});
canvas.add(imgInstance);
#my-image{display:none;}
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.22/fabric.min.js"></script>
<canvas width="800" height="800" id="drawarea" style="border: 1px solid red;float: right"> </canvas>
<img src="https://via.placeholder.com/300.png" id="my-image" width="500px" height="500px">