I have a canvas on one page that is built using fabricjs
can i send that canvas to another page so that it retains all its objects as it is with all their properties and attributes to be same aswell.
Sure you can, just export your canvas to JSON
var canvas = new fabric.Canvas('c');
data = JSON.stringify(canvas)
Now you can send that data using a post request or store it in a database or whatever you want.
canvas.loadFromJSON(data, canvas.renderAll.bind(canvas));
Example: http://jsfiddle.net/P9cEf/3/
The example uses two canvases one page, but the concept is the same.
Edit:
To download the image client side
var canvas1 = document.getElementById("c");
var image = canvas1.toDataURL("image/png").replace("image/png", "image/octet-stream");
window.location.href = image;
Related
I am using ESRI basemaps with Mapbox-GL-JS. I am trying to capture a screenshot of the map using the following code:
this.map.getCanvas().toBlob(function (blob) {
canvasContext.strokeStyle = '#CCCCCC';
canvasContext.strokeRect(leftPosition, topPosition, width, height);
var img = new Image();
img.setAttribute("crossOrigin", "anonymous");
var srcURL = URL.createObjectURL(blob);
img.onload = function () {
canvasContext.drawImage(img, leftPosition, topPosition, width, height);
URL.revokeObjectURL(srcURL);
};
img.src = srcURL;
});
I am not able to figure out why the attribution on the Map is not getting captured in the screenshot. I understand that here I am just trying to get the canvas of the map. I even tried adding text elements to the map canvas and that doesn't work either. I have markers & routes, which get in the image correctly. I also tried using the Mapbox basemap and try the same, but faced the same issue.
Any help is highly appreciated!
map.getCanvas() will only return the Map's canvas not any of the HTML Elements which sit over the map like the controls, Mapbox logo or attribution text. Sam Murphy has been working on an example showing how to capture the Map including the Logo and Attribution text to an image which you can see at https://github.com/mapbox/mapbox-gl-js/pull/6518/files.
Since we can't easily capture an HTML Element to an image in JavaScript the attribution text is re-created in a canvas drawn into the Image.
I am trying to get shadow Image of Text object without affecting the output of fabric.
Code
var clonedText = jQuery.extend({}, obj);
clonedText.fill = "rgba(50,50,50,0.5)";
imageURL = clonedText.toDataURL({format:'png'});
Result
Default:
AfterRun:
How can it be fixed?
I mean how can I copy object so that cant affect default image?
UPDATE:
I also tried this and this.
canvas._objects.forEach(function(obj, index){
var clonedText = fabric.util.object.clone(obj);
clonedText.fill = "rgba(50,50,50,0.5)";
imageURL = clonedText.toDataURL({format:'png'});
});
This has same result.
So you should not really clone instances like you would clone javascript objects.
Fabric objects can have references to canvas elements, image elements, deep structures, and every clone logic works on its own.
on fabricjs docs is specified that fabric.util.object.extende/clone does not clones fabricJS objects:
http://fabricjs.com/docs/fabric.util.object.html
Also in the docs is specified the clone method:
So you have to run
myText.clone(function(cloned) {
// do something with cloned....
});
If you are in need of a full syncronous process, and you are not using patterns or image sources for text you can also do:
var objectForm = myText.toObject();
var clonedText = new fabric.Text(objectForm.text, objectForm);
I would like to two show a Chart and also present an url with a link to a bigger Chart. The small preview-image looks and works fine:
<canvas id="image"></canvas>
var ct1 = document.getElementById("image").getContext("2d");
ct1.canvas.width = document.getElementById("image").offsetWidth;
ct1.canvas.height = document.getElementById("image").offsetHeight;
var Chart1 = new Chart(ct1).Line(lineChartData1,options);
The canvas is wrapped in a div, that's why offsetWidth and offsetHeight (to fill this additional div-element). Cause of the responsive-design there is no fixed image. Anyway, this works perfectly. For the URL to the "bigger" image I want to have the URL. I know the toDataURL() will help.
var url = document.getElementById("image").toDataURL();
document.write(url);
There are two disturbing problems with it:
The URL with this way exisists and, but the image has no content.
I also want to give the canvas-image a new size, like I managed with ct1.canvas.width and ct1.canvas.height, but it seems I cannot add this to the toDataURL.
What's wrong with the code?
Okay, I think I got it. Chart.js is animating the charts, so the toDataURL() I mentioned in my first question rendered only an empty image. We have to initiate the toDataURL, not before the animation is done. We handle that with the options:
var options = {
onAnimationComplete: done
}
and a tiny function:
function done() {
console.log('done');
var url=document.getElementById("canvas").toDataURL();
document.getElementById("canvas_link").href=url;
}
I think that's all.
i want to load image from remote url and synchronicity and change it width and height.
i am using the folowwing code, but it want let me change the width and highet, i think i needto convert the loader to a Bitmap object.
how can i do that, thank you very much.
var imageURLRequest:URLRequest = new URLRequest(pic);
var myImageLoader:Loader = new Loader();
myImageLoader.load(imageURLRequest);
var urlRequest:URLRequest = new URLRequest(pic);
var loader:Loader = new Loader();
loader.load(urlRequest);
trace(loader.width); // return 0
loader.width =100; //dosent work
allMC[i].img.addChild(loader);
To access what the loader loaded, use loader.content reference. If you are loading an image, you can retrieve its raw data via (loader.content as Bitmap).bitmapData, of course first check if it's so via if (loader.content is Bitmap). Also, you need to do all of this after your loader will finish loading, it'll send an event indicating this.
...
loader.load(urlRequest);
loader.contentLoaderInfo.addEventListener(Event.COMPLETE, loaderComplete);
...
private function loaderComplete(e:Event):void {
// now your image is fully loaded
trace(loader.content.width);
// etc etc, whatever you need to do with your image prior to
// addressing it from elsewhere.
}
I got this web service that gives me a (jpeg) image. What I want is take this image, convert it into a Data URI and display it on an HTML5 canvas, like that:
obj = {};
obj.xmlDoc = new window.XMLHttpRequest();
obj.xmlDoc.open("GET", "/cgi-bin/mjpegcgi.cgi?x=1",false, "admin", "admin");
obj.xmlDoc.send("");
obj.oCanvas = document.getElementById("canvas-processor");
obj.canvasProcessorContext = obj.oCanvas.getContext("2d");
obj.base64Img = window.btoa(unescape(encodeURIComponent( obj.xmlDoc.responseText )));
obj.img = new Image();
obj.src = 'data:image/jpeg;base64,' + obj.base64Img;
obj.img.src = obj.src
obj.canvasProcessorContext.drawImage(obj.img,0,0);
Unfortunately, this piece of code doesn't work; the image is not painted on the canvas at all (plus it seems to have width and height = 0, could it be not decoded correctly? I get no exceptions). img.src looks like data:image/jpeg;base64,77+977+977+977+9ABBKRklG....
Resolved: turns out I should have overridden the mime type with:
req.overrideMimeType('text/plain; charset=x-user-defined');
and set the response type with:
req.responseType = 'arraybuffer';
(see this. You should make an asynchronous request if you change the response type, too).
First you need to create an img element (which is hidden)
Then you do exactly what you have done except that you listen to your onload event on your img element.
When this event is launched you are able to get the width and height of your pictures so you can set your canvas to the same size.
The you can draw your image as you did in last line.