toSVG method not working on extended class with Fabric.js - javascript

I'm working on a project with Fabric.js.
Now I need to create a custom class and to export it to SVG.
I'm using Fabric.js tutorial to begin:
http://www.sitepoint.com/fabric-js-advanced/
Here is the javascript code:
var LabeledRect = fabric.util.createClass(fabric.Rect, {
type: 'labeledRect',
initialize: function(options) {
options || (options = { });
this.callSuper('initialize', options);
this.set('label', options.label || '');
},
toObject: function() {
return fabric.util.object.extend(this.callSuper('toObject'), {
label: this.get('label')
});
},
_render: function(ctx) {
this.callSuper('_render', ctx);
ctx.font = '20px Helvetica';
ctx.fillStyle = '#333';
ctx.fillText(this.label, -this.width/2, -this.height/2 + 20);
}
});
var canvas = new fabric.Canvas('container');
var labeledRect = new LabeledRect({
width: 100,
height: 50,
left: 100,
top: 100,
label: 'test',
fill: '#faa'
});
canvas.add(labeledRect);
document.getElementById('export-btn').onclick = function() {
canvas.deactivateAll().renderAll();
window.open('data:image/svg+xml;utf8,' + encodeURIComponent(canvas.toSVG()));
};
Here the HTML:
<canvas id="container" width="780" height="500"></canvas>
Export SVG
Here is my jsfiddle..
http://jsfiddle.net/QPDy5/
What I'm doing wrong?
Thanks in advance.

Every "class" in Fabric (rectangle, circle, image, path, etc.) knows how to output its SVG markup. The method responsible for it is toSVG. You can see toSVG of fabric.Rect, for example, or fabric.Text one.
Since you created subclass of fabric.Rect here and didn't specify toSVG, toSVG of the next object in prototype chain is used. The next "class" in the inheritance chain happens to be fabric.Rect, so you're seeing a result of fabric.Rect.prototype.toSVG.
The solution is simple: specify toSVG in your subclass. Theoretically, you would need to combine the code from fabric.Rect#toSVG and fabric.Text#toSVG, but to avoid repetition and keep things maintainable, we can utilize a bit of a hack:
toSVG: function() {
var label = new fabric.Text(this.label, {
originX: 'left',
originY: 'top',
left: this.left - this.width / 2,
top: this.top - this.height / 2,
fontSize: 20,
fill: '#333',
fontFamily: 'Helvetica'
});
return this.callSuper('toSVG') + label.toSVG();
}
The "fontSize", "fill", and "fontFamily" should ideally be moved to an instance-level property of course, to avoid repeating them there.
Here's a modified test — http://jsfiddle.net/fabricjs/QPDy5/1/
What #Sergiu Paraschiv suggested with a group is another just-as-viable solution.

Problem is there's no SVG equivalent to fillText so FabricJS seems to ignore it.
My workaround is to use a fabric.Group and build an inner Rect and Text
var LabeledRect = function(options) {
var rect = new fabric.Rect({
width: options.width,
height: options.height,
fill: options.fill
});
var label = new fabric.Text(options.label);
var group = new fabric.Group([rect, label]);
group.left = options.left;
group.top = options.top;
group.toSVG = function() {
var e=[];
for(var t = 0; t < this._objects.length; t++)
e.push(this._objects[t].toSVG());
return'<g transform="'+this.getSvgTransform()+'">'+e.join("")+"</g>"
};
return group;
};
The reason I overwrote toSVG is because the default implementation cycles through the children in reverse order (for(var t=this._objects.length;t--;)). I have no clue why it does that, but the text renders underneath the rectangle.

Related

How can I reload custom methods to a de-serialized FabricJS object?

I've been getting familiar w/ FabricJS on a project.
I have a custom class that extends fabric.Polyline. This custom class has many custom methods. My problem is : When I serialize the whole canvas and later on load it again with loadFromJSON(), the custom methods are not there anymore...
I noticed that the object before/after serialization are not exactly the same. Indeed, we can see that after serialization the method myCustomClassMethod() is not in the object's __proto__ anymore :
I know that loadFromJSON() has a reviver() method for re-adding event listeners, but how can I re-add methods? The tutorials say that I need to add a fromObject() method to save/restore objects, I tried playing with that but no luck.
It might also be that my de-serialized object is a "regular" object, and not a fabricjs object instance. But I haven't seen anywhere how to make it a fabric object again.
MRE down below. As you can see, method works if called before canvas reloading, but not if called afterwards.
// create a wrapper around native canvas element (with id="treeCanvas")
var canvas = new fabric.Canvas('treeCanvas', {
allowTouchScrolling: true,
});
// un-comment log below to inspect objects
canvas.on('mouse:up', function (e) {
if (e.target != null) {
//console.log(e.target);
}
});
// My TreeNode custom class
var TreeNode = fabric.util.createClass(fabric.Polyline, {
initialize: function (X, Y, armsArray, options) {
options || (options = {});
this.callSuper('initialize', options);
this.X = X;
this.Y = Y;
this.armsArray = armsArray;
this.set({ width: 160, height: 50, originX: 'center', originY: 'center' });
this.set({ left: this.X, top: this.Y, fill: 'rgba(255, 255, 255, 0)', stroke: 'black', selectable: true });
this.setCoords();
this.set({ pathOffset: { x: 0, y: 25 } });
for (point of this.armsArray) {
this.points.push({ x: point[0], y: point[1] });
this.points.push({ x: 0, y: 0 });
}
},
_render: function (ctx) {
this.callSuper('_render', ctx);
},
// this is the method that disappears after serializing
myCustomClassMethod: function () {
this.set({ stroke: 'green' });
canvas.renderAll();
}
});
// Adding an instance of my custom class to canvas
var node1 = new TreeNode(100, 100, [[-80, 50], [80, 50]], []);
canvas.add(node1);
canvas.renderAll();
// node1.myCustomClassMethod(); // method works before serializing + deserializing
var stringifiedCanvas = JSON.stringify(canvas);
canvas.loadFromJSON(stringifiedCanvas, canvas.renderAll.bind(canvas));
node1.myCustomClassMethod(); // method DOES NOT WORK anymore after deserializing
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/4.3.1/fabric.min.js"></script>
<div class="container">
<canvas id="treeCanvas" width="500" height="300"></canvas>
</div>
<script src="canvas.js"></script>
I am very far from being a fabricjs expert and I do things somewhat differently but you were missing a few important parts (marked with "** CHANGE" in the code below)
Hope this is of some help!
// create a wrapper around native canvas element (with id="treeCanvas")
var canvas = new fabric.Canvas('treeCanvas', {
allowTouchScrolling: true,
});
// un-comment log below to inspect objects
canvas.on('mouse:up', function(e) {
if (e.target != null) {
//console.log(e.target);
}
});
// ** CHANGE: define Treenode on the fabric instance
fabric.TreeNode = fabric.util.createClass(fabric.Polyline, {
// ** CHANGE: define the type
type: 'treeNode',
initialize: function(X, Y, armsArray, options) {
options || (options = {});
this.callSuper('initialize', options);
this.X = X;
this.Y = Y;
this.armsArray = armsArray;
this.set({
width: 160,
height: 50,
originX: 'center',
originY: 'center'
});
this.set({
left: this.X,
top: this.Y,
fill: null,
stroke: 'black',
selectable: true
});
this.setCoords();
this.set({
pathOffset: {
x: 0,
y: 25
}
});
for (point of this.armsArray) {
this.points.push({
x: point[0],
y: point[1]
});
this.points.push({
x: 0,
y: 0
});
}
},
_render: function(ctx) {
this.callSuper('_render', ctx);
},
// ** CHANGE: export the custom method when serializing
toObject: function() {
return fabric.util.object.extend(this.callSuper('toObject'), {
myCustomClassMethod: this.myCustomClassMethod
});
},
myCustomClassMethod: function(x, y, color) {
// console.log("myCustomClassMethod")
// console.log(this.myCustomClassMethod)
this.set({
left: x,
top: y,
stroke: color,
strokeWidth: 10
});
canvas.renderAll();
}
});
fabric.TreeNode.fromObject = function(object, callback) {
// console.log(object)
};
var node1 = new fabric.TreeNode(100, 100, [
[-80, 50],
[80, 50]
], []);
canvas.add(node1);
canvas.renderAll();
// DESERIALIZE
var stringifiedCanvas = JSON.stringify(canvas);
canvas.loadFromJSON(stringifiedCanvas, canvas.renderAll.bind(canvas));
// ** CHANGE: need to get a reference to the restored object
var restored = canvas.getObjects()[0]
///console.log(restored)
restored.myCustomClassMethod(200, 50, "red");
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/4.3.1/fabric.min.js"></script>
<div class="container">
<canvas id="treeCanvas" width="500" height="300"></canvas>
</div>
<script src="canvas.js"></script>

FabricJS v.2 and AngularJS – set canvas background image dynamically

I am using this function to define my fabricJS canvas background image:
$scope.bgImage = function () {
const {
ipcRenderer
} = require('electron')
ipcRenderer.send('openFile', () => {
})
ipcRenderer.once('fileData', (event, filepath) => {
fabric.Image.fromURL(filepath, function (image) {
var hCent = canvas.getHeight / 2;
var wCent = canvas.getWidth / 2;
canvas.setBackgroundColor({
source: filepath,
top: hCent,
left: wCent,
originX: 'center',
originY: 'middle',
repeat: 'no-repeat',
scaleX: 10,
scaleY: 10
}, canvas.renderAll.bind(canvas));
})
})
};
All the parameters shoulkd be change on the fly with some html inputs. Setting the repeat is working fine and i can change it dynamically.
But I am simply not able to change the scale of my background image. Using the above function I would expect that my background image would be:
would be not repeated (ok. is working)
positioned in the middle/center of my canvas (it is not)
would be scaled by a factor of 10 (it is not)
I am making again a newbish mistake? Or ist this realted to some changes in image handling in FabricJS v.2
canvas.setBackgroundImage() Use this function to add Image as a background.
To get Height/Width of canvas use canvas.getHeight()/canvas.getWidth(),these are functions. Or else you can use the properties > canvas.height/canvas.width respectively.
DEMO
// initialize fabric canvas and assign to global windows object for debug
var canvas = window._canvas = new fabric.Canvas('c');
var hCent = canvas.getHeight() / 2;
var wCent = canvas.getWidth() / 2;
canvas.setBackgroundImage('http://fabricjs.com/assets/jail_cell_bars.png', canvas.renderAll.bind(canvas), {
originX: 'center',
originY: 'center',
left: wCent,
top: hCent,
scaleX: 1,
scaleY: 1
});
fabric.util.addListener(document.getElementById('toggle-scaleX'), 'click', function () {
if (!canvas.backgroundImage) return;
canvas.backgroundImage.scaleX = canvas.backgroundImage.scaleX < 1 ? 1 : fabric.util.toFixed(Math.random(), 2);
canvas.renderAll();
});
fabric.util.addListener(document.getElementById('toggle-scaleY'), 'click', function () {
if (!canvas.backgroundImage) return;
canvas.backgroundImage.scaleY = canvas.backgroundImage.scaleY < 1 ? 1 : fabric.util.toFixed(Math.random(), 2);
canvas.renderAll();
});
canvas {
border: 1px solid #999;
}
button {
margin-top: 20px;
}
<script src="https://rawgithub.com/kangax/fabric.js/master/dist/fabric.js"></script>
<canvas id="c" width="600" height="600"></canvas>
<button id="toggle-scaleX">Toggle scaleX</button>
<button id="toggle-scaleY">Toggle scaleY</button>

Drag, drop and delete objects on FabricJS canvas

I am having issues getting drag, drop and delete to work on a FabricJS using JQuery.
Select an object and click delete is working with no issues.
Here's a demo of my code Fiddle
I can get drag, drop and delete to work outside of FabricJS (Just dragging unrelated elements to delete) but I'm having difficulty combing the two.
Maybe I need to incorporate the delete button inside the canvas in order for the 'drop' to work? When I try this the #delete element disappears.
JS
var canvas = new fabric.Canvas('canvas');
$("#delete").click(function() {
deleteObjects();
});
//Test objects on the canvas
//Circle
var circle = new fabric.Circle({
left: 200,
top: 150,
radius: 30,
fill: "#ff0072"
});
circle.hasRotatingPoint = true;
canvas.add(circle);
// adding triangle
var triangle = new fabric.Triangle({
left: 130,
top: 150,
strokeWidth: 1,
width: 70,
height: 60,
fill: '#00b4ff',
selectable: true,
originX: 'center'
});
triangle.hasRotatingPoint = true;
canvas.add(triangle);
//Select all objects
function deleteObjects() {
var activeObject = canvas.getActiveObject(),
activeGroup = canvas.getActiveGroup();
if (activeObject) {
canvas.remove(activeObject);
}
}
//Drag and drop delete
$(function() {
$('#delete').droppable({
drop: function(event, ui) {
deleteObjects();
}
});
});
HTML
<section class="canvas__container">
<canvas id="canvas" width="400" height="400"></canvas>
<div id="delete">♻</div>
</section>
(I didn't paste my CSS as that's not particularly relevant)
This should get you close:
var bin;
var selectedObject;
fabric.Image.fromURL('data:image/png;base64,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', function(img) {
img.set({
left: 174,
top: 329,
selectable: false
});
bin = img;
canvas.add(img, circle, triangle);
});
canvas.on('object:selected', function(evn) {
selectedObject = evn.target;
})
canvas.on('mouse:up', function(evn) {
var x = evn.e.offsetX;
var y = evn.e.offsetY;
if (x > bin.left && x < (bin.left + bin.width) &&
y > bin.top && y < (bin.top + bin.height)) {
canvas.remove(selectedObject);
}
});
Here's your JSFiddle updated, https://jsfiddle.net/rekrah/jgruwse0/.
Let me know if you have any further questions.

Using FabricJS loadSVGFromURL within a subclass

I have a custom subclass in FabricJS that is based on a FabricJS group:
var canvasObject = fabric.util.createClass(fabric.Group, {
type: 'canvasObject',
initialize: function(options) {
options || (options = { });
this.callSuper('initialize', options);
var rectBase = new fabric.Rect({
fill : 'red',
originX: 'left',
originY: 'top',
left: options.margin.l,
top: options.margin.t,
width : (options.width-options.margin.l-options.margin.r),
height :(options.height-options.margin.t-options.margin.b),
});
var labeledRect = new LabeledRect({
width: options.width,
height: options.height,
'idname': options.idname,
background: 'transparent',
labelFont: '14px Helvetica',
});
this.callSuper('initialize', [labeledRect, rectBase], options);
},
toObject: function() {
return fabric.util.object.extend(this.callSuper('toObject'), {
idname: this.get('idname')
});
},
_render: function(ctx) {
this.callSuper('_render', ctx);
}
});
How do I include an SVG within this custom group. I'd like to be able to load an SVG from a URL similar to this:
fabric.loadSVGFromURL('example.svg', function(objects, options) {
var shape = fabric.util.groupSVGElements(objects, options);
canvas.add(shape.scale(1));
canvas.renderAll();
});
But have it add to the canvas within my custom group - so that each canvasObject added can have an SVG attached.
I've tried adding the SVG to a PathGroup object - but I'm not sure the asynchronous load is working with it.
I'd also like to be able to update the SVG images within each group. How can I update an SVG path content similar to updating an objects properties?

How to reference a Raphael canvas created dynamically?

I'm creating a jQuery plugin that creates Raphael objects on the fly, let's say you do...
$("div").draw({
type: 'circle',
radius: '10',
color: '#000'
})
And the plugin code (just as an example):
$.fn.draw = function( options ) {
//settings/options stuff
var width = $(this).width();
var height = $(this).height();
var widget = Raphael($(this)[0], width, height);
var c = widget.circle(...).attr({...})
//saving the raphael reference in the element itself
$(this).data('raphael', {
circle : c
})
}
But then I'd like to be able to update elements like this:
$("div").draw({
type: 'update',
radius: '20',
color: '#fff'
});
I can "rescue" the object doing $(this).data().raphael.circle, but then it refuses to animate, I know it's a raphael object because it even has the animate proto , but it yields a Uncaught TypeError: Cannot read property '0' of undefined).
I tried out your code, made some modifications, and $(this).data().raphael.circle does animate. This is what I did (I know it's not exactly the same as yours, but gives the gist)
$.fn.draw = function( options ) {
//settings/options stuff
if(options.type === 'draw') {
var width = $(this).width();
var height = $(this).height();
var widget = Raphael($(this)[0], width, height);
var c = widget.circle(100, 100, 50);
//saving the raphael reference in the element itself
$(this).data('raphael', {
circle : c
});
//$(this).data().raphael.circle.animate() does not work here
}
else if(options.type === 'update') {
$(this).data().raphael.circle.animate({cx: 200, cy: 200});
//But this works here
}
}
In this case, referencing the element with $(this).data().raphael.circle does work, but only in the else if. I'm not sure why.

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