FabricJS SVG to canvas (using FileReader) - javascript

On my page, I have a button and a canvas with the following attributes -
<button onclick="openSVG()">Open</button>
<canvas></canvas>
On clicking the button, the openSVG() function is supposed to
Let the user select and open an SVG file from their local hard drive (previously created using FabricJS)
Read the contents of the SVG file using FileReader and storing it in a variable
Using that variable to populate the canvas using fabric.loadSVGFromString() method
Now clicking on Open button opens a file selection window but doesnt draw objects into canvas. Here's my openSVG() function -
function openSVG() {
// importing file
var input = $(document.createElement('input'));
input.attr("id", "mySVGFile")
input.attr("type", "file");
input.trigger('click');
//storing file contents in var using FileReader
var myInputFile = document.getElementById('mySVGFile');
var myFile = myInputFile.files[0];
var fr = new FileReader();
fr.onload = function(){
var canvasD = this.result;
//loading data from var to canvas
fabric.loadSVGFromString(canvasD, function(objects, options) {
var obj = fabric.util.groupSVGElements(objects, options);
canvas.add(obj).renderAll();
});
};
fr.readAsText(myFile); }
I'm new to FileReader. There's no errors in console so I can't even tell where I'm going wrong.
Does my approach not work? Is there a better way to achieve what I want.

Here is a much more easier and better approach using URL.createObjectURL() method ...
var canvas = new fabric.Canvas('c');
function openSVG(e) {
var url = URL.createObjectURL(e.target.files[0]);
fabric.loadSVGFromURL(url, function(objects, options) {
objects.forEach(function(svg) {
svg.set({
top: 90,
left: 90,
originX: 'center',
originY: 'center'
});
svg.scaleToWidth(50);
svg.scaleToHeight(50);
canvas.add(svg).renderAll();
});
});
}
canvas{margin-top:5px;border:1px solid #ccc}
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.11/fabric.min.js"></script>
<input type="file" onchange="openSVG(event)">
<canvas id="c" width="180" height="180"></canvas>

Related

Is there a way to import an image file using fabric.js?

I am currently working on importing png or svg files onto a canvas using the fabric.js library and an input file button. The code below works only if the image is in the root folder. I know that I don't have access to the file path, so I tried creating an element out of the file. There is no error in the console but nothing shows in the canvas. Is there a way to do make the importation work or is there a different library that could help me do this? I am using fabric.js in order to be able to scale and move the images within the canvas.
function upload(){
var canvas = new fabric.Canvas('canvas');
var file = document.getElementById('file').files[0].name;
fabric.Image.fromURL(file, function(img) {
canvas.add(img);
})
}
Yes!
There is a way to import an image / svg file using FabricJS, and that is as follows ...
var canvas = new fabric.Canvas('c');
function upload(e) {
var fileType = e.target.files[0].type;
var url = URL.createObjectURL(e.target.files[0]);
if (fileType === 'image/png') { //check if png
fabric.Image.fromURL(url, function(img) {
img.set({
width: 180,
height: 180
});
canvas.add(img);
});
} else if (fileType === 'image/svg+xml') { //check if svg
fabric.loadSVGFromURL(url, function(objects, options) {
var svg = fabric.util.groupSVGElements(objects, options);
svg.scaleToWidth(180);
svg.scaleToHeight(180);
canvas.add(svg);
});
}
}
canvas {
margin-top: 5px;
border: 1px solid #ccc
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.13/fabric.min.js"></script>
<input type="file" onchange="upload(event)">
<canvas id="c" width="180" height="180"></canvas>

where should i put controller code in a angularjs application

I have just started learning angularjs and nodejs.
I am trying to build an app using fabric.js to upload pictures and edit it. I have seen a link here, the second answer is really helpful.
However when I tried to implement it in my own application I have faced problem. I use the angular tutorial for the application. In my own application I know I should put the last part of the code from the question linked in index.html, and put the middle part of the code in style.css. However, I don't know where to put the first part of the code, from my previous experience in extJS I know it should be a controller.
I tried to create a new file called controller.js under the same directory of index.html, paste the code there and include the controller into the index.html in the script tag, but it didn't work.
Here is the js code I am trying to implement
var canvas = new fabric.Canvas('canvas');
document.getElementById('file').addEventListener("change", function (e) {
var file = e.target.files[0];
var reader = new FileReader();
reader.onload = function (f) {
var data = f.target.result;
fabric.Image.fromURL(data, function (img) {
var oImg = img.set({left: 0, top: 0, angle: 00,width:100, height:100}).scale(0.9);
canvas.add(oImg).renderAll();
var a = canvas.setActiveObject(oImg);
var dataURL = canvas.toDataURL({format: 'png', quality: 0.8});
});
};
reader.readAsDataURL(file);
});
You don't need the filereader, just have to call createObjectURL
var canvas = new fabric.Canvas('canvas');
document.getElementById('file').addEventListener("change", function (e) {
var file = e.target.files[0];
var url = URL.createObjectURL(file);
fabric.Image.fromURL(url, function (img) {
var oImg = img.set({left: 0, top: 0, angle: 00,width:100, height:100}).scale(0.9);
canvas.add(oImg).renderAll();
var a = canvas.setActiveObject(oImg);
var dataURL = canvas.toDataURL({format: 'png', quality: 0.8});
});
});
I find where I do wrong. There is nothing wrong with these backend code, it is in index.html, where I script the controller in the wrong place that caused the trouble. I have already solved that.

Uploading an image from computer to Fabric.JS Canvas

Are there any Fabric.JS Wizards out there?
I've done my fair research and I can't seem to find much of an explanation on how to add an image to the fabric.JS canvas.
User Journey:
a) User uploads an image from an input file type button.
b) As soon as they have selected an image from their computer I want to place it into the users canvas.
So far I've got to storing the image into an expression, this is my code below:
scope.setFile = function(element) {
scope.currentFile = element.files[0];
var reader = new FileReader();
/**
*
*/
reader.onload = function(event) {
// This stores the image to scope
scope.imageSource = event.target.result;
scope.$apply();
};
// when the file is read it triggers the onload event above.
reader.readAsDataURL(element.files[0]);
};
My HTML/Angular:
<label class="app-file-input button">
<i class="icon-enter"></i>
<input type="file"
id="trigger"
onchange="angular.element(this).scope().setFile(this)"
accept="image/*">
</label>
If you haven't guessed yet I am using a MEAN stack. Mongoose, Express, Angular and Node.
The scope imageSource is what the image is store in. I've read this SO
and it talks about pushing the image to the Image object with my result, and then pass it to the fabric.Image object. Has anyone done a similar thing that they can help me with?
Thanks in advance
**** UPDATE ****
Directive defines the canvas variable:
var canvas = new fabric.Canvas(attrs.id, {
isDrawingMode: true
});
Upload image from computer with Fabric js.
var canvas = new fabric.Canvas('canvas');
document.getElementById('file').addEventListener("change", function (e) {
var file = e.target.files[0];
var reader = new FileReader();
reader.onload = function (f) {
var data = f.target.result;
fabric.Image.fromURL(data, function (img) {
var oImg = img.set({left: 0, top: 0, angle: 00,width:100, height:100}).scale(0.9);
canvas.add(oImg).renderAll();
var a = canvas.setActiveObject(oImg);
var dataURL = canvas.toDataURL({format: 'png', quality: 0.8});
});
};
reader.readAsDataURL(file);
});
canvas{
border: 1px solid black;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://rawgit.com/kangax/fabric.js/master/dist/fabric.min.js"></script>
<input type="file" id="file"><br />
<canvas id="canvas" width="450" height="450"></canvas>
once you have a dataURL done, you can do either:
reader.onload = function(event) {
// This stores the image to scope
fabric.Image.fromURL(event.target.result, function(img) {
canvas.add(img);
});
scope.$apply();
};
Or you put on your image tag an onload event where you do:
var img = new fabric.Image(your_img_element);
canvas.add(img);
This is for drag and drop from desktop using the dataTransfer interface.
canvas.on('drop', function(event) {
// prevent the file to open in new tab
event.e.stopPropagation();
event.e.stopImmediatePropagation();
event.e.preventDefault();
// Use DataTransfer interface to access the file(s)
if(event.e.dataTransfer.files.length > 0){
var files = event.e.dataTransfer.files;
for (var i = 0, f; f = files[i]; i++) {
// Only process image files.
if (f.type.match('image.*')) {
// Read the File objects in this FileList.
var reader = new FileReader();
// listener for the onload event
reader.onload = function(evt) {
// put image on canvas
fabric.Image.fromURL(evt.target.result, function(obj) {
obj.scaleToHeight(canvas.height);
obj.set('strokeWidth',0);
canvas.add(obj);
});
};
// Read in the image file as a data URL.
reader.readAsDataURL(f);
}
}
}
});
Resources
https://developer.mozilla.org/en-US/docs/Web/API/HTML_Drag_and_Drop_API/File_drag_and_drop

Add image to HTML5 canvas on file upload issue

Allright, this is going to be quite hard to explain but I will try to explain my problem as clear as possible.
I currently have a HTML5 Canvas with a couple of preloaded shapes which I changed to images. I am using a modified version of this example. On the canvas I have now I can drag, drop and select the shapes which are preloaded.
I have implemented an option to upload a new image to the canvas using this:
var imageLoader = document.getElementById('uploader');
imageLoader.addEventListener('change', handleImage, false);
var canvas = document.getElementById('canvas1');
var ctx = canvas.getContext('2d');
function handleImage(e){
var reader = new FileReader();
reader.onload = function(event){
var imgNew = new Image();
imgNew.onload = function(){
ctx.drawImage(imgNew, 0, 0);
}
imgNew.src = event.target.result;
}
reader.readAsDataURL(e.target.files[0]);
}
This will now just put an image in the top-left corner of the canvas and when I select another shape this image will disappear. All shapes that are already in the canvas are in an array called 'shapes'. In the example there is an option to add a new shape when you dubbelclick on the canvas, this is the code:
// double click for making new shapes
canvas.addEventListener('dblclick', function(e) {
var mouse = myState.getMouse(e);
myState.addShape(new Shape(mouse.x - 10, mouse.y - 10, 20, 20, 'rgba(0,255,0,.6)'));
}, true);
This is the addShape part which is called when double clicking:
CanvasState.prototype.addShape = function(shape) {
this.shapes.push(shape);
this.valid = false;
}
What I am trying to do is when I upload an image using the file upload the image should be added to the 'shapes' array so I can also drag,drop and select the uploaded image. (basically I need to do the same with the uploaded image as I can do with the preloaded ones) My guess is that it should be done something like the doubleclick method and addShape but I can't get this to work.
A working version of my current version can be found here:
http://codepen.io/anon/pen/qLuCy/
If anyone knows how I can get this to work it would be great!
first the result, here : http://codepen.io/anon/pen/qBmnC/
Your shape object can only draw one single hard-coded image, so change this and have shape be either a color or an image. In fact for this you just have to change shape.draw since the 'type' of the fill does not matter in the constructor.
So just test the fill and draw accordingly :
// Tekent de Shape
Shape.prototype.draw = function(ctx) {
var locx = this.x;
var locy = this.y;
var fill = this.fill ;
if (typeof fill == 'string' )
{
ctx.fillStyle = fill;
ctx.fillRect(locx, locy, this.w, this.h);
}
else
{
ctx.drawImage(fill, locx, locy, this.w, this.h);
}
}
then on image load i just add a shape that has this image as fill :
function handleImage(e){
var reader = new FileReader();
reader.onload = function(event){
var imgNew = new Image();
imgNew.onload = function(){
s.addShape(new Shape(60,60,imgNew.width,imgNew.height,imgNew));
}
imgNew.src = event.target.result;
}
reader.readAsDataURL(e.target.files[0]);
}
I had to put the shape collection, s, as a global var.
You can also see that i used the same scheme in init() to
add an image once it's loaded.

CamanJS - Mobile - Blank Canvas

I am having problems running the CamanJS script on mobile devices, i.e. iPad and iPhone's Safari / Chrome, and I've been trying to resolve it for days.
The test script is very simple:
1) Accepts browser file selection of image
2) Gets the image source using FileData, then drawing it into a canvas, then instantiate a Caman("#sample") object
3) Run some filter (either within onLoad of that image, or manually by clicking a button)
It works perfectly fine on all desktop browsers and the filters are also successfully applied, but when I try it on mobile devices like iOS Safari, the moment I try to instantiate the Caman object, my existing canvas #sample goes blank and reverts to the original canvas default background color, with no image loaded at all. I've tried instantiating the Caman object before image is drawn on canvas, image onLoad, or on demand after the canvas image is successfully drawn, but the end result is still the same - the canvas goes blank.
Below is my sample code, can someone please advise? Thank you for your kind assistance.
<script>
var caman = null;
function handleUpload(evt) {
var target = (evt.target) ? evt.target : evt.srcElement;
var files = target.files; // FileList object
var field = target.id;
var curCount = target.id.replace(/\D+/, "");
for (var i = 0, f; f = files[i]; i++) {
var reader = new FileReader();
reader.onload = (function(theFile) {
return function(e) {
renderImage(e.target.result);
};
})(f);
reader.readAsDataURL(f);
}
}
function renderImage(imagedata) {
var canvas = document.getElementById("sample");
var ctx = canvas.getContext("2d");
// Render Preview
var previewImage = new Image();
previewImage.src = imagedata;
previewImage.onload = function() {
ctx.drawImage(previewImage, 0, 0, previewImage.width, previewImage.height);
caman = Caman("#sample", function () { this.sunrise().render(); });
};
}
function testProcess() {
//caman = Caman("#sample", function () { this.sunrise().render(); });
if (caman) {
caman.sunrise().render();
}
}
</script>
<form>
<input id="photo" name="photo" value="" type=file size="30" maxlength="50">
</form>
<canvas id="sample" width=300 height=300 style="background-color: #aaaaaa;"></canvas>
<br><br>Test Process<br><br>
<script>
document.getElementById('photo').addEventListener('change', handleUpload, false);
</script>
I had the same problem: worked on Chrome and Safari on my Mac, but did not work on Chrome or Safari on the iPhone 5s running iOS7. I solved by adding the data-caman-hidpi-disabled attribute to my canvas tag.
Try this:
<canvas id="sample" width=300 height=300 style="background-color: #aaaaaa;" data-caman-hidpi-disabled="true"></canvas>
According to the CamanJS website:
If a HiDPI display is detected, CamanJS will automatically switch to
the HiDPI version if available unless you force disable it with the
data-caman-hidpi-disabled attribute.
http://camanjs.com/guides/#BasicUsage

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