I am having trouble flipping or mirroring the object horizontally when the object itself is clicked on the FabricJS canvas.
I came close but it was mirroring the object when it was being resized too, which I didn't want.
I would guess I need to add the 'flipX: true' attribute to object on the first click and on the next click remove that attribute and so on with each click. Or maybe that is over complicating it and it can be done much easier with a flipX function I do not know.
I did find a Fiddle that flipped the object, but it was onclick of a button not the object itself.
I am struggling to solve this :\
My Fiddle
HTML:
<canvas id="canvas" width="400" height="300"></canvas>
JS:
var canvas = this.__canvas = new fabric.Canvas('canvas');
canvas.on('object:selected', function() {
toggle('flipX');
});
// create a rectangle
var rect = new fabric.Rect({
left: 50,
top: 50,
width: 100,
height: 50,
angle: 20,
fill: 'red'
});
canvas.add(rect);
canvas.renderAll();
You could accomplish that in the following way ...
var canvas = this.__canvas = new fabric.Canvas('canvas');
// mouse event
canvas.on('mouse:down', function(e) {
if (e.target) {
if (!e.target.__corner) {
e.target.toggle('flipX');
canvas.renderAll();
}
e.target.__corner = null;
}
});
// create a rectangle
var rect = new fabric.Rect({
left: 50,
top: 50,
width: 100,
height: 50,
angle: 20,
});
// set gradient (for demonstration)
rect.setGradient('fill', {
type: 'linear',
x1: -rect.width / 2,
y1: 0,
x2: rect.width / 2,
y2: 0,
colorStops: {
0: '#ffe47b',
1: 'rgb(111,154,211)'
}
});
canvas.add(rect);
rect.set('flipX', true);
canvas.renderAll();
body{margin:10px 0 0 0;overflow:hidden}canvas{border:1px solid #ccc}
<script src="http://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.4.0/fabric.min.js"></script>
<canvas id="canvas" width="208" height="208"></canvas>
Same from above, different case.
Apply flip to background image
fabric.Image.fromURL('../' +ImageUrl, function (img02) {
Backcanvas.setBackgroundImage(img02, Backcanvas.renderAll.bind(Backcanvas), {
backgroundImageStretch: false,
top: 0,
left: 0,
originX: 'left',
originY: 'top',
flipY:'true'
});
Backcanvas.renderAll();
Backcanvas.backgroundImage.setCoords();
canvas.renderAll();
Backcanvas.renderAll();
}, { crossOrigin: 'anonymous' });
Related
I added a fabric Rect at (80, 80) and then called getImageData at that location. However, the data I get from that location doesn't match the Rect I placed there. Instead, I find the data around (60, 60).
var canvas = new fabric.Canvas('fabric-canvas');
canvas.setHeight(800);
canvas.setWidth(800);
var rect = new fabric.Rect({
left: 80,
top: 80,
fill: 'red',
width: 20,
height: 20
});
canvas.add(rect);
// This doesn't work
let data = canvas.getContext('2d').getImageData(80, 80, 20, 20);
canvas.getContext('2d').putImageData(data, 0, 0);
// This "works"
data = canvas.getContext('2d').getImageData(60, 60, 20, 20);
canvas.getContext('2d').putImageData(data, 100, 0);
Here's a fiddle demo: https://jsfiddle.net/2wxdb8ua/13/
How might this be possible?
The problem is certainly caused by some zooming, either due to your monitor being an high-res monitor (a.k.a retina), or browser/OS zoom being applied on the page.
You can either make the calculation yourself world_coord * window.devicePixelRatio:
var canvas = new fabric.Canvas('fabric-canvas');
canvas.setHeight(800);
canvas.setWidth(800);
var rect = new fabric.Rect({
left: 80,
top: 80,
fill: 'red',
width: 20,
height: 20
});
canvas.add(rect);
let ctx = canvas.getContext('2d').getImageData(...[80, 80, 20, 20].map(fixCoords));
canvas.getContext('2d').putImageData(ctx, ...[0, 0].map(fixCoords));
function fixCoords( coord ) {
return coord * window.devicePixelRatio;
}
canvas#fabric-canvas {
background: white;
border: 2px solid black;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.6.1/fabric.min.js"></script>
<canvas id='fabric-canvas'></canvas>
Or disable fabric's auto-scaling by using the enableRetinaScaling parameter of the initOptionObject:
var canvas = new fabric.Canvas('fabric-canvas', {
enableRetinaScaling: false
});
canvas.setHeight(800);
canvas.setWidth(800);
var rect = new fabric.Rect({
left: 80,
top: 80,
fill: 'red',
width: 20,
height: 20
});
canvas.add(rect);
let ctx = canvas.getContext('2d').getImageData(80, 80, 20, 20);
canvas.getContext('2d').putImageData(ctx, 0, 0);
canvas#fabric-canvas {
background: white;
border: 2px solid black;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.6.1/fabric.min.js"></script>
<canvas id='fabric-canvas'></canvas>
But note that with the latter solution, your canvas will certainly become blurry on high-res monitors.
I created an arrow using Fabric.js group functionality by grouping Rectangle and Triangle.
Unfortunately I am not able to delete it as a group.
I figured out that getActiveObject() for a single object works fine. Instead, while debugging getActiveGroup() gives error.
var canvas = new fabric.Canvas('canvas');
canvas.setHeight(window.innerHeight * 0.75);
canvas.setWidth(window.innerWidth * 0.75);
//-------------------------Group - Rectangle and Triangle----------------------------------------------
window.addArrow = function() {
var rect = new fabric.Rect({
left: 0,
top: 0,
stroke: 'red',
fill: 'red',
width: 1,
height: 50,
});
rect.hasRotatingPoint = true;
canvas.add(rect);
var triangle = new fabric.Triangle({
width: 10,
height: 10,
fill: 'red',
left: -4,
top: -10
});
var group = new fabric.Group([rect, triangle], {
left: 150,
top: 100,
angle: 90
});
canvas.add(group);
}
//-------------------------Group Delete----------------------------------------------
window.deleteObject = function() {
return canvas.getActiveObject() == null ? canvas.getActiveGroup() : canvas.getActiveObject();
}
function getActiveGroup() {
canvas.getActiveGroup().forEachObject(function(o) {
canvas.remove(o)
});
}
function getActiveObject() {
canvas.remove(canvas.getActiveObject());
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/2.3.6/fabric.min.js"></script>
<canvas id="canvas" width="800" height="600" style="border:1px solid red;"></canvas>
<button onClick="addArrow()">Arrow</button>
<button onClick="deleteObject()">Delete</button>
Because you didn't set any active object you cannot use getActiveObject.
In this case you may use getObjects:
canvas.getObjects('group') // in order to get the group
canvas.getObjects('rect') // in order to get the rectangle
var canvas = new fabric.Canvas('canvas');
canvas.setHeight(window.innerHeight * 0.75);
canvas.setWidth(window.innerWidth * 0.75);
//-------------------------Group - Rectangle and Triangle----------------------------------------------
window.addArrow = function() {
var rect = new fabric.Rect({
left: 0,
top: 0,
stroke: 'red',
fill: 'red',
width: 1,
height: 50,
});
rect.hasRotatingPoint = true;
canvas.add(rect);
var triangle = new fabric.Triangle({
width: 10,
height: 10,
fill: 'red',
left: -4,
top: -10
});
var group = new fabric.Group([rect, triangle], {
left: 150,
top: 100,
angle: 90
});
canvas.add(group);
}
//-------------------------Group Delete----------------------------------------------
window.deleteObject = function() {
// remove group....
canvas.getObjects('group').forEach(function(ele,idx) {
canvas.remove(ele);
});
canvas.getObjects('rect').forEach(function(ele,idx) {
canvas.remove(ele);
});
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/2.3.6/fabric.min.js"></script>
<canvas id="canvas" width="800" height="600" style="border:1px solid red;"></canvas>
<button onClick="addArrow()">Arrow</button>
<button onClick="deleteObject()">Delete</button>
use sub classing in fabric.js for creating arrow object so that single object is only needed. So handling will be easier.
[http://fabricjs.com/fabric-intro-part-3#subclassing][1]
I could select the background image from inside rectangle, but not able to move.
To move the image, i should go outside of the rectangle.
I know that the rectangle is created over the image, I'm looking for any option to move the image as it is selectable from inside rectangle.
My canvas screenshot
This is how i set the image and rectangle.
changeImage(innercanvasHeight, innercanvasWidth) {
const base_image = new Image();
base_image.crossOrigin = 'Anonymous';
base_image.src = 'assets/images/1wal.jpg';
fabric.Image.fromURL(base_image.src, (myImg) => {
const img1 = myImg.set({left: 160, top: 80, width: 600, height:
400, id: 'wallpaper'});
this.FabriCanvas.add(img1).setActiveObject(img1);
const hiddenImg = document.createElement('img');
hiddenImg.src = this.FabriCanvas.getActiveObject().toDataURL();
hiddenImg.id = 'target';
hiddenImg.style.display = 'none';
document.body.appendChild(hiddenImg);
this.innerCanvas(innercanvasHeight, innercanvasWidth);
});
innerCanvas(height, width) {
this.innercanvas = this.FabriCanvas.add(new fabric.Rect({
left: 160,
top: 80,
id: 'innerCan',
fill: 'transparent',
stroke: '#fff',
strokeWidth: 1,
width: width,
height: height,
selectable: false
}));
this.FabriCanvas.renderAll();
}
Use preserveObjectStacking so it wont come up while dragging, and use perPixelTargetFind to click through the object if it is transparent.
DEMO
var canvas = new fabric.Canvas('canvas',{
preserveObjectStacking: true
});
var image = new fabric.Image('');
var rect = new fabric.Rect({
left: 160,
top: 80,
id: 'innerCan',
fill: 'transparent',
stroke: '#fff',
strokeWidth: 1,
width: 100,
height: 100,
selectable: false,
perPixelTargetFind : true
});
canvas.add(image,rect);
image.setSrc('//fabricjs.com/assets/pug.jpg',function(img){
img.set({ scaleX:canvas.width/img.width,scaleY: canvas.height/img.height});
img.setCoords();
canvas.renderAll();
})
canvas{
border: 2px solid #000;
}
<script src="https://rawgit.com/kangax/fabric.js/master/dist/fabric.js"></script>
<canvas id='canvas' width=300 height=300></canvas>
I am using Fabric.JS to create a layout builder. However once the object is displayed on canvas I cannot update the rx and ry property of the object like rectangle. I have a used a slider field where the user uses a slider for updating value of rx and ry on the object.
Further when I view the object it has been updated but the canvas is not updated with the new value of rx and ry.
Following is the code snippet I use :
$('#slider').slider()
.on('slideStop', function (ev) {
var val = $('#slider').slider('getValue').val();
var activeObject = canvas.getActiveObject();
if (activeObject) {
console.log('Inside active object');
activeObject.set({'rx': val, 'ry': val});
canvas.renderAll();
}
});
DEMO
var canvas = new fabric.Canvas('canvas');
$("#slider").slider({
orientation: "horizontal",
range: "min",
max: 50,
slide: refreshSwatch,
change: refreshSwatch
});
canvas.add(new fabric.Rect({
left: 25,
top: 50,
width: 150,
height: 150
}));
canvas.add(new fabric.Rect({
left: 225,
top: 50,
width: 150,
height: 150,
fill: 'rgba(100,100,200,0.5)'
}));
canvas.renderAll();
canvas.on('object:selected',function(){
$("#slider").slider('value',canvas.getActiveObject().rx);
})
function refreshSwatch() {
var val = $("#slider").slider("value");
var activeObject = canvas.getActiveObject();
if (activeObject) {
activeObject.set({
'rx': val,
'ry': val
});
canvas.renderAll();
}
}
canvas {
border: 2px dotted blue;
}
<link href="https://code.jquery.com/ui/1.12.1/themes/base/jquery-ui.css" rel="stylesheet"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.16/fabric.min.js"></script>
<script src="https://code.jquery.com/jquery-1.12.4.min.js"></script>
<script src="https://code.jquery.com/ui/1.12.1/jquery-ui.min.js"></script>
<div id="slider"></div><br>
<canvas id="canvas" width="400" height="400"></canvas>
Probably I am not getting what is your actual issue, but I added a demo and from jQuery slider value, its updating rect rx,ry value.
I draw multiple objects on a canvas, but the top one has transparency. So you can see images behind it. It is unselectable. I want to be able to click on that image and then programatically select an image behind it and when I drag the mouse, move that one (not the front, trasnparent image).
I tried this code but it doesn't work:
function onSelect(event)
{
var activeObject = canvas.getActiveObject();
var newActive = canvas.getObjects()[ 0 ];
//Do nothing
if ( activeObject === newActive ) return;
//Switch
canvas.setActiveObject( newActive );
}
//Add listener
canvas.on( "object:selected", onSelect );
This appears to select the right object, but it won't drag it.
have you tried just setting the selectable and evented property to false? here is an example with a blue square over two other squares. you can only interact with the 2 objects below the blue square and not the blue square at all.
var canvas = new fabric.Canvas("c", { preserveObjectStacking: true });
canvas
.add(new fabric.Rect({
top: 0,
left: 0,
width: 100,
height: 100,
fill: "green"
}))
.add(new fabric.Rect({
top: 50,
left: 50,
width: 100,
height: 100,
fill: "red"
}))
.add(new fabric.Rect({
top: 0,
left: 0,
width: 400,
height: 300,
opacity: 0.5,
fill: "blue",
selectable: false,
evented: false,
}))
.renderAll();
canvas { border: 1px solid black; }
<canvas id="c" width="400" height="300"></canvas>
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.6.3/fabric.min.js"></script>