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Display Absolute positioned images inside a div

i am trying to absolute position images at random positions inside a div. i'm not sure how to get the calculations right for 'top' and 'left' but the images on occasions display outside of the div. i want to also prevent the overlapping of the images.
Any ideas would help
(function() {
//array of links to the images
var images = ["http://via.placeholder.com/150/800",
"http://via.placeholder.com/150/080",
"http://via.placeholder.com/150/008",
"http://via.placeholder.com/150/880"
];
//function to calculate a random integer
var getRandomInt = function(min, max) {
return Math.floor(Math.random() * (max - min + 1)) + min;
}
//function to get a top and left value position for each image
var pos = function() {
var wrapWidth = document.getElementById("wrap");
wrapWidth = $("#wrap").width();
wrapHeight = $("#wrap").height();
// Image Position
var xPos = getRandomInt(0, wrapWidth - 150);
var yPos = getRandomInt(0, wrapHeight - 150);
return {
x: xPos + "px",
y: yPos + "px"
}
}
var displayImages = function(images) {
var elementArray = [];
for (var i = 0; i < images.length; i++) {
var src = images[i];
elementArray[i] = '<img class="imagePos" style="top:' + pos().x + '; left:' + pos().y + ' " src="' + src + ' "/>';
}
console.log(elementArray);
elementArray.forEach(function(element) {
console.log(element);
$("#wrap").append(element);
});
}
displayImages(images);
})();
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="IntTree">
<div id="header">
<h1>Interactive Tree</h1>
</div>
<div id="wrap">
</div>
</div>

I'm assuming that you have some css resembling this:
img {
position: absolute;
width:150;
height:150;
}
Regarding your first issue, you appear to have your x and y assignments backwards in the bit where you're adding the elems to the array. Also, you're making 2 times as many calls to pos() as needed.
That line should be:
let position = pos();
elementArray[i] = '<img class="imagePos" style="top:'+position.y+'; left:'+position.x+' " src="'+src+' "/>';
For the second issue, you need to check for each image whether any of the corners overlap a different image. The easy way to achieve this by adding an array to track the positions you've already used, and comparing against the items in the array for subsequent position calculations.
(function (){
//array of links to the images
var images = ["http://via.placeholder.com/150/800",
"http://via.placeholder.com/150/080",
"http://via.placeholder.com/150/008",
"http://via.placeholder.com/150/880"
];
//function to calculate a random integer
var getRandomInt = function (min, max) {
return Math.floor(Math.random() * (max - min + 1)) + min;
}
// array to track previous positions of images
var positions = [];
//function to get a top and left value position for each image
var pos = function (){
var wrapWidth = $("#wrap").width();
var wrapHeight = $("#wrap").height();
// Image Position
var xPos = getRandomInt(0, wrapWidth - 150);
var yPos = getRandomInt(0, wrapHeight - 150);
var overlapX = true;
var overlapY = true;
while(overlapX && overlapY) {
overlapX = false;
overlapY = false;
for(var i = 0; i < positions.length; i++) {
// check if x coord is inside previously placed image
if ( (xPos > positions[i].x && xPos < positions[i].x+150) ||
(xPos+150 > positions[i].x && (xPos+150) < positions[i].x+150) ){
overlapX = true;
}
// check if y coord is inside previously placed image
if( (yPos > positions[i].y && yPos < positions[i].y+150) ||
(yPos+150 > positions[i].y && yPos+150 < positions[i].y+150) ) {
overlapY = true;
}
}
if (overlapX) {
xPos = getRandomInt(0, wrapWidth - 150);
}
if (overlapY) {
yPos = getRandomInt(0, wrapHeight - 150);
}
}
positions.push({x:xPos,y:yPos});
return {
x: xPos + "px",
y: yPos + "px"
}
}
var displayImages = function(images){
var elementArray = [];
for (var i = 0; i < images.length; i++) {
var src = images[i];
let position = pos();
elementArray[i] = '<img class="imagePos" style="top:'+position.y+'; left:'+position.x+' " src="'+src+' "/>';
}
elementArray.forEach(function(element) {
$("#wrap").append(element);
});
}
displayImages(images);
})();

Prevent Fabric js Objects from scaling out of the canvas boundary

I have been trying to keep an object (constructed in fabric js over a canvas) inside the boundaries at all the times. It has been achieved at moving and rotating it. I took help from Move object within canvas boundary limit for achieving this. But when I start to scale the object, it simply keeps on going out of boundary. I do not understand what has to be done to keep it inside the boundary only, even while scaling. Please help me with a code to prevent this behavior. It would be great if you can attach a demo too.
<html>
<head>
<title>Basic usage</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.3/fabric.min.js"></script>
</head>
<body>
<canvas id="canvas" style= "border: 1px solid black" height= 480 width = 360></canvas>
<script>
var canvas = new fabric.Canvas('canvas');
canvas.add(new fabric.Circle({ radius: 30, fill: '#f55', top: 100, left: 100 }));
canvas.item(0).set({
borderColor: 'gray',
cornerColor: 'black',
cornerSize: 12,
transparentCorners: true
});
canvas.setActiveObject(canvas.item(0));
canvas.renderAll();
canvas.on('object:moving', function (e) {
var obj = e.target;
// if object is too big ignore
if(obj.currentHeight > obj.canvas.height || obj.currentWidth > obj.canvas.width){
return;
}
obj.setCoords();
// top-left corner
if(obj.getBoundingRect().top < 0 || obj.getBoundingRect().left < 0){
obj.top = Math.max(obj.top, obj.top-obj.getBoundingRect().top);
obj.left = Math.max(obj.left, obj.left-obj.getBoundingRect().left);
}
// bot-right corner
if(obj.getBoundingRect().top+obj.getBoundingRect().height > obj.canvas.height || obj.getBoundingRect().left+obj.getBoundingRect().width > obj.canvas.width){
obj.top = Math.min(obj.top, obj.canvas.height-obj.getBoundingRect().height+obj.top-obj.getBoundingRect().top);
obj.left = Math.min(obj.left, obj.canvas.width-obj.getBoundingRect().width+obj.left-obj.getBoundingRect().left);
}
});
</script>
</body>
</html>
My demo is attached here. :
https://jsfiddle.net/3v0cLaLk/

I was able to solve the problem as follows:
var canvas = new fabric.Canvas('canvas');
canvas.add(new fabric.Circle({ radius: 30, fill: '#f55', top: 100, left: 100 }));
canvas.item(0).set({
borderColor: 'gray',
cornerColor: 'black',
cornerSize: 12,
transparentCorners: true
});
canvas.setActiveObject(canvas.item(0));
canvas.renderAll();
canvas.on('object:moving', function (e) {
var obj = e.target;
// if object is too big ignore
if(obj.currentHeight > obj.canvas.height || obj.currentWidth > obj.canvas.width){
return;
}
obj.setCoords();
// top-left corner
if(obj.getBoundingRect().top < 0 || obj.getBoundingRect().left < 0){
obj.top = Math.max(obj.top, obj.top-obj.getBoundingRect().top);
obj.left = Math.max(obj.left, obj.left-obj.getBoundingRect().left);
}
// bot-right corner
if(obj.getBoundingRect().top+obj.getBoundingRect().height > obj.canvas.height || obj.getBoundingRect().left+obj.getBoundingRect().width > obj.canvas.width){
obj.top = Math.min(obj.top, obj.canvas.height-obj.getBoundingRect().height+obj.top-obj.getBoundingRect().top);
obj.left = Math.min(obj.left, obj.canvas.width-obj.getBoundingRect().width+obj.left-obj.getBoundingRect().left);
}
});
var left1 = 0;
var top1 = 0 ;
var scale1x = 0 ;
var scale1y = 0 ;
var width1 = 0 ;
var height1 = 0 ;
canvas.on('object:scaling', function (e){
var obj = e.target;
obj.setCoords();
var brNew = obj.getBoundingRect();
if (((brNew.width+brNew.left)>=obj.canvas.width) || ((brNew.height+brNew.top)>=obj.canvas.height) || ((brNew.left<0) || (brNew.top<0))) {
obj.left = left1;
obj.top=top1;
obj.scaleX=scale1x;
obj.scaleY=scale1y;
obj.width=width1;
obj.height=height1;
}
else{
left1 =obj.left;
top1 =obj.top;
scale1x = obj.scaleX;
scale1y=obj.scaleY;
width1=obj.width;
height1=obj.height;
}
});
<html>
<head>
<title>Basic usage</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.3/fabric.min.js"></script>
</head>
<body>
<canvas id="canvas" style= "border: 1px solid black" height= 480 width = 360></canvas>
</body>
</html>

You can set on object modified listener and check if object is out of bounds. If so, then restore it to its original state.
this.canvas.on('object:modified', function (options: any) {
let obj = options.target;
let boundingRect = obj.getBoundingRect(true);
if (boundingRect.left < 0
|| boundingRect.top < 0
|| boundingRect.left + boundingRect.width > scope.canvas.getWidth()
|| boundingRect.top + boundingRect.height > scope.canvas.getHeight()) {
obj.top = obj._stateProperties.top;
obj.left = obj._stateProperties.left;
obj.angle = obj._stateProperties.angle;
obj.scaleX = obj._stateProperties.scaleX;
obj.scaleY = obj._stateProperties.scaleY;
obj.setCoords();
obj.saveState();
}
});

If you want to perform a real time prevention, you should use object:scaling event, as object:modified is only triggered at the end of the transformation.
1) Add event handler to canvas:
this.canvas.on('object:scaling', (e) => this._handleScaling(e));
2) In the handler function, get the old and the new object's bounding rect:
_handleScaling(e) {
var obj = e.target;
var brOld = obj.getBoundingRect();
obj.setCoords();
var brNew = obj.getBoundingRect();
3) For each border, check if object has scaled beyond the canvas boundaries and compute its left, top and scale properties:
// left border
// 1. compute the scale that sets obj.left equal 0
// 2. compute height if the same scale is applied to Y (we do not allow non-uniform scaling)
// 3. compute obj.top based on new height
if(brOld.left >= 0 && brNew.left < 0) {
let scale = (brOld.width + brOld.left) / obj.width;
let height = obj.height * scale;
let top = ((brNew.top - brOld.top) / (brNew.height - brOld.height) *
(height - brOld.height)) + brOld.top;
this._setScalingProperties(0, top, scale);
}
4) Similar code for the other borders:
// top border
if(brOld.top >= 0 && brNew.top < 0) {
let scale = (brOld.height + brOld.top) / obj.height;
let width = obj.width * scale;
let left = ((brNew.left - brOld.left) / (brNew.width - brOld.width) *
(width - brOld.width)) + brOld.left;
this._setScalingProperties(left, 0, scale);
}
// right border
if(brOld.left + brOld.width <= obj.canvas.width
&& brNew.left + brNew.width > obj.canvas.width) {
let scale = (obj.canvas.width - brOld.left) / obj.width;
let height = obj.height * scale;
let top = ((brNew.top - brOld.top) / (brNew.height - brOld.height) *
(height - brOld.height)) + brOld.top;
this._setScalingProperties(brNew.left, top, scale);
}
// bottom border
if(brOld.top + brOld.height <= obj.canvas.height
&& brNew.top + brNew.height > obj.canvas.height) {
let scale = (obj.canvas.height - brOld.top) / obj.height;
let width = obj.width * scale;
let left = ((brNew.left - brOld.left) / (brNew.width - brOld.width) *
(width - brOld.width)) + brOld.left;
this._setScalingProperties(left, brNew.top, scale);
}
5) If object's BoundingRect has crossed canvas boundaries, fix its position and scale:
if(brNew.left < 0
|| brNew.top < 0
|| brNew.left + brNew.width > obj.canvas.width
|| brNew.top + brNew.height > obj.canvas.height) {
obj.left = this.scalingProperties['left'];
obj.top = this.scalingProperties['top'];
obj.scaleX = this.scalingProperties['scale'];
obj.scaleY = this.scalingProperties['scale'];
obj.setCoords();
} else {
this.scalingProperties = null;
}
}
6) Finally, when setting the scaling properties, we have to stick with the smallest scale in case the object has crossed more than one border:
_setScalingProperties(left, top, scale) {
if(this.scalingProperties == null
|| this.scalingProperties['scale'] > scale) {
this.scalingProperties = {
'left': left,
'top': top,
'scale': scale
};
}
}

Below is the code for blocking the coordinates of any object outside the canvas area from all directions
canvas.on('object:modified', function (data) {
var currentObject = data.target;
var tempObject = angular.copy(data.target);
var canvasMaxWidth = canvas.width - 20,
canvasMaxHeight = canvas.height - 20;
var actualWidth = currentObject.getBoundingRect().width,
actualHeight = currentObject.getBoundingRect().height;
if (actualHeight > canvasMaxHeight) {
currentObject.scaleToHeight(canvasMaxHeight);
currentObject.setCoords();
canvas.renderAll();
if (tempObject.scaleX < currentObject.scaleX) {
currentObject.scaleX = tempObject.scaleX;
currentObject.setCoords();
canvas.renderAll();
}
if (tempObject.scaleY < currentObject.scaleY) {
currentObject.scaleY = tempObject.scaleY;
currentObject.setCoords();
canvas.renderAll();
}
if (currentObject.getBoundingRectHeight() < canvasMaxHeight - 50) {
currentObject.scaleX = (currentObject.scaleX * canvasMaxHeight) / (currentObject.scaleX * currentObject.width);
currentObject.setCoords();
canvas.renderAll();
}
}
if (actualWidth > canvasMaxWidth) {
currentObject.scaleToWidth(canvasMaxWidth);
obj.setCoords();
canvas.renderAll();
if (tempObject.scaleX < currentObject.scaleX) {
currentObject.scaleX = tempObject.scaleX;
currentObject.setCoords();
canvas.renderAll();
}
if (tempObject.scaleY < currentObject.scaleY) {
currentObject.scaleY = tempObject.scaleY;
currentObject.setCoords();
canvas.renderAll();
}
}
obj.setCoords();
canvas.renderAll();
});

I was able to block movement outside of boundaries using the Bounding box in the following way using the last version of Fabric ("fabric": "^4.6.0") & Typescript:
private boundingBox: fabric.Rect = null;
this.setBoundingBox(width, height);
private setBoundingBox(width: number, height: number) {
this.boundingBox = new fabric.Rect({
name: OBJECT_TYPE.BOUNDING_BOX,
fill: DEFINITIONS.BG_COLOR,
width: width,
height: height,
hasBorders: false,
hasControls: false,
lockMovementX: true,
lockMovementY: true,
selectable: false,
evented: false,
stroke: 'red',
});
this._canvas.add(this.boundingBox);
}
this._canvas.on('object:moving', (e) => {
console.log('object:moving');
this._avoidObjectMovingOutsideOfBoundaries(e);
});
private _avoidObjectMovingOutsideOfBoundaries(e: IEvent) {
let obj = e.target;
const top = obj.top;
const bottom = top + obj.height;
const left = obj.left;
const right = left + obj.width;
const topBound = this.boundingBox.top;
const bottomBound = topBound + this.boundingBox.height;
const leftBound = this.boundingBox.left;
const rightBound = leftBound + this.boundingBox.width;
obj.left = Math.min(Math.max(left, leftBound), rightBound - obj.width);
obj.top = Math.min(Math.max(top, topBound), bottomBound - obj.height);
return obj;
}
Any additional extensions for Scaling objects are welcome.

canvas.on('object:scaling', function (e) {
var obj = e.target;
obj.setCoords();
let top = obj.getBoundingRect().top;
let left = obj.getBoundingRect().left;
let height = obj.getBoundingRect().height;
let width = obj.getBoundingRect().width;
// restrict scaling below bottom of canvas
if (top + height > CANVAS_HEIGHT) {
obj.scaleY = 1;
obj.setCoords();
let h = obj.getScaledHeight();
obj.scaleY = (CANVAS_HEIGHT - top) / h;
obj.setCoords();
canvas.renderAll();
obj.lockScalingX = true;
obj.lockScalingY = true;
obj.lockMovementX = true;
obj.lockMovementY = true;
}
// restrict scaling above top of canvas
if (top < 0) {
obj.scaleY = 1;
obj.setCoords();
let h = obj.getScaledHeight();
obj.scaleY = (height + top) / h;
obj.top = 0;
obj.setCoords();
canvas.renderAll();
obj.lockScalingX = true;
obj.lockScalingY = true;
obj.lockMovementX = true;
obj.lockMovementY = true;
}
// restrict scaling over right of canvas
if (left + width > CANVAS_WIDTH) {
obj.scaleX = 1;
obj.setCoords();
let w = obj.getScaledWidth();
obj.scaleX = (CANVAS_WIDTH - left) / w;
obj.setCoords();
canvas.renderAll();
obj.lockScalingX = true;
obj.lockScalingY = true;
obj.lockMovementX = true;
obj.lockMovementY = true;
}
// restrict scaling over left of canvas
if (left < 0) {
obj.scaleX = 1;
obj.setCoords();
let w = obj.getScaledWidth();
obj.scaleX = (width + left) / w;
obj.left = 0;
obj.setCoords();
canvas.renderAll();
obj.lockScalingX = true;
obj.lockScalingY = true;
obj.lockMovementX = true;
obj.lockMovementY = true;
}
});
canvas.on('object:modified', function (event) {
// after text object is done with modifing e.g. resizing or moving
if (!!event.target) {
event.target.lockScalingX = false;
event.target.lockScalingY = false;
event.target.lockMovementX = false;
event.target.lockMovementY = false;
}
})

How to target a single div with JS

I'm trying to create 'snow' on the background of a single div. The code is below but you can see it here: http://www.getwiththebrand.com/makeabrew_copy/
I want to put the effect on the div with the red border only (number 4).
Can anyone tell me what I'm missing?
<!-- language: lang-js -->
var width = getWidth();
var height = getHeight();
var flakeCount = 50;
var gravity = 0.7;
var windSpeed = 20;
var flakes = [];
function getWidth() {
var x = 0;
if (self.innerHeight) {
x = self.innerWidth;
}
else if (document.documentElement && document.documentElement.clientHeight) {
x = document.documentElement.clientWidth;
}
else if (document.body) {
x = document.body.clientWidth;
}
return x;
}
function getHeight() {
var y = 0;
if (self.innerHeight) {
y = self.innerHeight;
}
else if (document.documentElement && document.documentElement.clientHeight) {
y = document.documentElement.clientHeight;
}
else if (document.body) {
y = document.body.clientHeight;
}
return y;
}
function getRandom(min, max) {
return Math.floor(Math.random() * (max - min + 1)) + min;
}
var currentFlake = 0;
var snowglobe = document.getElementById("snowglobe");
while (currentFlake < flakeCount) {
var flake = document.createElement("div");
flake.className = 'flake';
flake.style.fontSize = getRandom(12, 24) + 'px';
flake.style.top = getRandom(0, height) + 'px';
flake.style.left = getRandom(0, width) + 'px';
flake.innerHTML = "•";
newFlake = snowglobe.appendChild(flake);
newFlake.speed = getRandom(1, 100);
flakes.push(newFlake);
currentFlake++;
}
function doAnimation() {
for (var i = 0; i < flakes.length; i++) {
newX = false;
newY = false;
// Calculate Y position
newY = parseFloat(flakes[i].style.top) + (flakes[i].speed / 100) * gravity;
if (newY > height) {
newY = 0 - parseInt(flakes[i].style.fontSize);
// If Y is at bottom, randomize X
newX = getRandom(0, width);
}
// Calculate X position if it hasn't been set randomly
if (!newX) newX = parseFloat(flakes[i].style.left) + Math.sin(newY / windSpeed);
if (newX < -20) newX = width + 20;
if (newX > width + 20) newX = -20;
// Set new position
flakes[i].style.top = newY + 'px';
flakes[i].style.left = newX + 'px';
}
}
setInterval(doAnimation, 10);
window.onresize = function(event) {
width = getWidth();
height = getHeight();
}​
<!-- language: lang-css -->
#snowglobe .flake {
position: absolute;
width: 1px;
height: 1px;
color: rgba(255,255,255,0);
text-shadow: 0 0 3px rgba(255,255,255,1);
}​
<!-- language: lang-html -->
<div class="ui-full-width">
<div class="container even" id="snowglobe">
<h3><span class="num">4</span>Add freshly boiled water to the pot</h3>
<p>Give it a stir and secure the lid. Wrap your pot in a tea-cosy if it's nippy outside!</p>
</div>
</div>
<!-- end snippet -->
<div class="ui-full-width">
<div class="container even" id="snowglobe">
<h3><span class="num">4</span>Add freshly boiled water to the pot</h3>
<p>Give it a stir and secure the lid. Wrap your pot in a tea-cosy if it's nippy outside!</p>
</div>
</div>

Your myjs.js has an extra character at the end of the file when it's loaded in my browser and it triggers a rightful
SCRIPT1014: Invalid character
myjs.js (116,2)
The script part:
window.onresize = function(event) {
width = getWidth();
height = getHeight();
}â // << here
Also, I don't know what browser you're using but try hitting F12, you'll get the console and you'll see javascript erros and other useful informations.
Edit: it's even worse, you have multiple characters at the end of your script:
window.onresize = function(event) {
width = getWidth();
height = getHeight();
}​ // ??
Did you mess around with some file encoding options?

thanks for looking. I commented out the code so that's what the extra characters were. I haven't done anything to the file encoding options.
I checked the console and there were some elements undefined. Looks like I missed a whole chunk:
var width = getWidth();
var height = getHeight();
var flakeCount = 50;
var gravity = 0.7;
var windSpeed = 20;
var flakes = [];
All good now!

Uncaught ReferenceError. Phaser.io

Okay, I am building a game and after implementing a level selection I nearly got my project working. However, there is a error(probably easy to fix) that has caught my eye.
In my create function I create the variable "pages", but when I want to use it in an other function I get the ReferenceError: Uncaught ReferenceError: pages is not defined. I am fairly new to javascript and I also tried to pass the variable in the paramater, the error will go away, but the code won't work as I want to.
I define the pages in the create function and I want to use it in the arrowClicked function
UshanGame.Selection = function(game){};
var thumbRows = 2;
var thumbCols = 3;
var thumbWidth = 128;
var thumbHeight = 128;
var thumbSpacing = 3;
var levelThumbsGroup;
var currentPage = 0;
var leftArrow;
var rightArrow;
UshanGame.Selection.prototype = {
create: function(){
console.log("%c ✔✔ Level Selection Ready! ✔✔", "color:red;");
// array with finished levels and stars collected.
var starsArray = [1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2];
// how many pages are needed to show all levels?
var pages = starsArray.length /(thumbRows * thumbCols);
leftArrow = this.add.button(50, 420, "level_arrows", this.arrowClicked);
leftArrow.anchor.setTo(0.5);
leftArrow.frame = 0;
leftArrow.alpha = 0.3;
rightArrow = this.add.button(270, 420, "level_arrows", this.arrowClicked);
rightArrow.anchor.setTo(0.5);
rightArrow.frame = 1;
// creation of the thumbails group
levelThumbsGroup = this.add.group();
// determining level thumbnails width and height for each page
var levelLength = thumbWidth * thumbCols + thumbSpacing * (thumbCols - 1);
var levelHeight = thumbWidth * thumbRows + thumbSpacing * (thumbRows - 1);
// looping through each page
for(var l = 0; l < pages; l++){
// horizontal offset to have level thumbnails horizontally centered in the page
var offsetX = (this.width-levelLength)/ 2 + game.width * l;
// I am not interested in having level thumbnails vertically centered in the page, but
// if you are, simple replace my "20" with
// (game.height-levelHeight)/2
var offsetY = 20;
// looping through each level thumbnails
for(var i = 0; i < thumbRows; i ++){
for(var j = 0; j < thumbCols; j ++){
var levelNumber = i * thumbCols + j + l *(thumbRows * thumbCols);
var levelThumb = this.add.button(offsetX + j * (thumbWidth + thumbSpacing), offsetY + i * (thumbHeight + thumbSpacing), "levels", this.thumbClicked, this);
levelThumb.frame=starsArray[levelNumber];
levelThumb.levelNumber = levelNumber + 1;
levelThumbsGroup.add(levelThumb);
// if the level is playable, also write level number
if(starsArray[levelNumber] < 4){
var style = {
font: "18px Arial",
fill: "#ffffff"
};
var levelText = this.add.text(levelThumb.x + 5, levelThumb.y + 5, levelNumber + 1,style);
levelText.setShadow(2, 2, 'rgba(0,0,0,0.5)', 1);
levelThumbsGroup.add(levelText);
}
}
}
}
},
thumbClicked: function(button){
// the level is playable, then play the level!!
if(button.frame < 4){
alert("playing level " + button.levelNumber);
} else {
var buttonTween = this.add.tween(button)
buttonTween.to({
x: button.x + thumbWidth / 15
}, 20, Phaser.Easing.Cubic.None);
buttonTween.to({
x: button.x - thumbWidth / 15
}, 20, Phaser.Easing.Cubic.None);
buttonTween.to({
x: button.x + thumbWidth / 15
}, 20, Phaser.Easing.Cubic.None);
buttonTween.to({
x: button.x - thumbWidth / 15
}, 20, Phaser.Easing.Cubic.None);
buttonTween.to({
x: button.x
}, 20, Phaser.Easing.Cubic.None);
buttonTween.start();
}
},
arrowClicked: function(button){
if(button.frame == 1 && currentPage < pages - 1){
leftArrow.alpha = 1;
currentPage++;
if(currentPage == pages - 1){
button.alpha = 0.3;
}
var buttonsTween = this.add.tween(levelThumbsGroup);
buttonsTween.to({
x: currentPage * game.width * -1
}, 500, Phaser.Easing.Cubic.None);
buttonsTween.start();
}
if(button.frame==0 && currentPage>0){
rightArrow.alpha = 1;
currentPage--;
if(currentPage == 0){
button.alpha = 0.3;
}
var buttonsTween = game.add.tween(levelThumbsGroup);
buttonsTween.to({
x: currentPage * game.width * -1
}, 400, Phaser.Easing.Cubic.None);
buttonsTween.start();
}
}
};

You're getting the error because pages is defined within your create function but isn't defined anywhere else. pages doesn't exist in your arrowClicked function.
To fix this, make pages a global variable by adding it alongside your var declarations at the top:
...
var leftArrow;
var rightArrow;
var pages;
Then modify your create function to instead reference this variable (by dropping the var keyword):
// array with finished levels and stars collected.
var starsArray = [1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2];
// how many pages are needed to show all levels?
pages = starsArray.length /(thumbRows * thumbCols);

Snap edges of objects to each other and prevent overlap

My goal is to prevent overlapping of two or more rectangles inside my FabricJS canvas.
Imagine two rectangles having info on position and size and you can drag and drop any rectangle inside the canvas.
If rectangle A gets close enough to rectangle B, the position of rectangle A should snap to the edge of rectangle B. This should work for any edge of rectangle B. The vertices do not have to match, cause the sizes of the rectangles are variable.
I have a working example for this snapping on one dimension (x-axes).
My best jsfiddle attempt
See jsfiddle.
But I need it to work around the rectangle on both dimensions. I am quite sure, that my code is not well enough to manage this.
Code-snippets which might help:
object.oCoords.tl.x //top-left corner x position. similar goes for top-right (tr), bottom-left (bl), bottom-right (br) and .y for y-position
mouse_pos = canvas.getPointer(e.e);
mouse_pos.x //pointer x.position
mouse_pos.y //pointer y.position
object.intersectsWithObject(targ) // object = dragged rectangle, targ = targeted rectangle
The snapping should work for an unlimited amount of objects (not only for two rectangles).

I solved the problem on my own.
See jsfiddle: http://jsfiddle.net/gcollect/FD53A/
This is the code:
this.canvas.on('object:moving', function (e) {
var obj = e.target;
obj.setCoords(); //Sets corner position coordinates based on current angle, width and height
canvas.forEachObject(function (targ) {
var objects = this.canvas.getObjects(),
i = objects.length;
activeObject = canvas.getActiveObject();
if (targ === activeObject) return;
if (Math.abs(activeObject.oCoords.tr.x - targ.oCoords.tl.x) < edgedetection) {
activeObject.left = targ.left - activeObject.currentWidth;
}
if (Math.abs(activeObject.oCoords.tl.x - targ.oCoords.tr.x) < edgedetection) {
activeObject.left = targ.left + targ.currentWidth;
}
if (Math.abs(activeObject.oCoords.br.y - targ.oCoords.tr.y) < edgedetection) {
activeObject.top = targ.top - activeObject.currentHeight;
}
if (Math.abs(targ.oCoords.br.y - activeObject.oCoords.tr.y) < edgedetection) {
activeObject.top = targ.top + targ.currentHeight;
}
if (activeObject.intersectsWithObject(targ) && targ.intersectsWithObject(activeObject)) {
targ.strokeWidth = 10;
targ.stroke = 'red';
} else {
targ.strokeWidth = 0;
targ.stroke = false;
}
if (!activeObject.intersectsWithObject(targ)) {
activeObject.strokeWidth = 0;
activeObject.stroke = false;
}
});
Works pretty legit! Cheers!

This is based on gco's answer, updated to work with FabricJS 1.5.0, with the following improvements:
Shapes don't overlap.
Snapping is more responsive.
Shapes are contained within the canvas.
JS Fiddle: https://jsfiddle.net/aphillips8/31qbr0vn/1/
var canvas = new fabric.Canvas('canvas'),
canvasWidth = document.getElementById('canvas').width,
canvasHeight = document.getElementById('canvas').height,
counter = 0,
rectLeft = 0,
snap = 20; //Pixels to snap
canvas.selection = false;
plusrect();
plusrect();
plusrect();
function plusrect(top, left, width, height, fill) {
var rect = new fabric.Rect({
top: 300,
name: 'rectangle ' + counter,
left: 0 + rectLeft,
width: 100,
height: 100,
fill: 'rgba(' + (Math.floor(Math.random() * 256)) + ',' + (Math.floor(Math.random() * 256)) + ',' + (Math.floor(Math.random() * 256)) + ', 0.75)',
lockRotation: true,
originX: 'left',
originY: 'top',
cornerSize: 15,
hasRotatingPoint: false,
perPixelTargetFind: true,
minScaleLimit: 1,
maxWidth: canvasWidth,
maxHeight: canvasHeight
});
rect.custom = {};
rect.custom.counter = counter;
canvas.add(rect);
counter++;
rectLeft += 200;
}
function findNewPos(distX, distY, target, obj) {
// See whether to focus on X or Y axis
if(Math.abs(distX) > Math.abs(distY)) {
if (distX > 0) {
target.setLeft(obj.getLeft() - target.getWidth());
} else {
target.setLeft(obj.getLeft() + obj.getWidth());
}
} else {
if (distY > 0) {
target.setTop(obj.getTop() - target.getHeight());
} else {
target.setTop(obj.getTop() + obj.getHeight());
}
}
}
canvas.on('object:moving', function (options) {
// Sets corner position coordinates based on current angle, width and height
options.target.setCoords();
// Don't allow objects off the canvas
if(options.target.getLeft() < snap) {
options.target.setLeft(0);
}
if(options.target.getTop() < snap) {
options.target.setTop(0);
}
if((options.target.getWidth() + options.target.getLeft()) > (canvasWidth - snap)) {
options.target.setLeft(canvasWidth - options.target.getWidth());
}
if((options.target.getHeight() + options.target.getTop()) > (canvasHeight - snap)) {
options.target.setTop(canvasHeight - options.target.getHeight());
}
// Loop through objects
canvas.forEachObject(function (obj) {
if (obj === options.target) return;
// If objects intersect
if (options.target.isContainedWithinObject(obj) || options.target.intersectsWithObject(obj) || obj.isContainedWithinObject(options.target)) {
var distX = ((obj.getLeft() + obj.getWidth()) / 2) - ((options.target.getLeft() + options.target.getWidth()) / 2);
var distY = ((obj.getTop() + obj.getHeight()) / 2) - ((options.target.getTop() + options.target.getHeight()) / 2);
// Set new position
findNewPos(distX, distY, options.target, obj);
}
// Snap objects to each other horizontally
// If bottom points are on same Y axis
if(Math.abs((options.target.getTop() + options.target.getHeight()) - (obj.getTop() + obj.getHeight())) < snap) {
// Snap target BL to object BR
if(Math.abs(options.target.getLeft() - (obj.getLeft() + obj.getWidth())) < snap) {
options.target.setLeft(obj.getLeft() + obj.getWidth());
options.target.setTop(obj.getTop() + obj.getHeight() - options.target.getHeight());
}
// Snap target BR to object BL
if(Math.abs((options.target.getLeft() + options.target.getWidth()) - obj.getLeft()) < snap) {
options.target.setLeft(obj.getLeft() - options.target.getWidth());
options.target.setTop(obj.getTop() + obj.getHeight() - options.target.getHeight());
}
}
// If top points are on same Y axis
if(Math.abs(options.target.getTop() - obj.getTop()) < snap) {
// Snap target TL to object TR
if(Math.abs(options.target.getLeft() - (obj.getLeft() + obj.getWidth())) < snap) {
options.target.setLeft(obj.getLeft() + obj.getWidth());
options.target.setTop(obj.getTop());
}
// Snap target TR to object TL
if(Math.abs((options.target.getLeft() + options.target.getWidth()) - obj.getLeft()) < snap) {
options.target.setLeft(obj.getLeft() - options.target.getWidth());
options.target.setTop(obj.getTop());
}
}
// Snap objects to each other vertically
// If right points are on same X axis
if(Math.abs((options.target.getLeft() + options.target.getWidth()) - (obj.getLeft() + obj.getWidth())) < snap) {
// Snap target TR to object BR
if(Math.abs(options.target.getTop() - (obj.getTop() + obj.getHeight())) < snap) {
options.target.setLeft(obj.getLeft() + obj.getWidth() - options.target.getWidth());
options.target.setTop(obj.getTop() + obj.getHeight());
}
// Snap target BR to object TR
if(Math.abs((options.target.getTop() + options.target.getHeight()) - obj.getTop()) < snap) {
options.target.setLeft(obj.getLeft() + obj.getWidth() - options.target.getWidth());
options.target.setTop(obj.getTop() - options.target.getHeight());
}
}
// If left points are on same X axis
if(Math.abs(options.target.getLeft() - obj.getLeft()) < snap) {
// Snap target TL to object BL
if(Math.abs(options.target.getTop() - (obj.getTop() + obj.getHeight())) < snap) {
options.target.setLeft(obj.getLeft());
options.target.setTop(obj.getTop() + obj.getHeight());
}
// Snap target BL to object TL
if(Math.abs((options.target.getTop() + options.target.getHeight()) - obj.getTop()) < snap) {
options.target.setLeft(obj.getLeft());
options.target.setTop(obj.getTop() - options.target.getHeight());
}
}
});
options.target.setCoords();
// If objects still overlap
var outerAreaLeft = null,
outerAreaTop = null,
outerAreaRight = null,
outerAreaBottom = null;
canvas.forEachObject(function (obj) {
if (obj === options.target) return;
if (options.target.isContainedWithinObject(obj) || options.target.intersectsWithObject(obj) || obj.isContainedWithinObject(options.target)) {
var intersectLeft = null,
intersectTop = null,
intersectWidth = null,
intersectHeight = null,
intersectSize = null,
targetLeft = options.target.getLeft(),
targetRight = targetLeft + options.target.getWidth(),
targetTop = options.target.getTop(),
targetBottom = targetTop + options.target.getHeight(),
objectLeft = obj.getLeft(),
objectRight = objectLeft + obj.getWidth(),
objectTop = obj.getTop(),
objectBottom = objectTop + obj.getHeight();
// Find intersect information for X axis
if(targetLeft >= objectLeft && targetLeft <= objectRight) {
intersectLeft = targetLeft;
intersectWidth = obj.getWidth() - (intersectLeft - objectLeft);
} else if(objectLeft >= targetLeft && objectLeft <= targetRight) {
intersectLeft = objectLeft;
intersectWidth = options.target.getWidth() - (intersectLeft - targetLeft);
}
// Find intersect information for Y axis
if(targetTop >= objectTop && targetTop <= objectBottom) {
intersectTop = targetTop;
intersectHeight = obj.getHeight() - (intersectTop - objectTop);
} else if(objectTop >= targetTop && objectTop <= targetBottom) {
intersectTop = objectTop;
intersectHeight = options.target.getHeight() - (intersectTop - targetTop);
}
// Find intersect size (this will be 0 if objects are touching but not overlapping)
if(intersectWidth > 0 && intersectHeight > 0) {
intersectSize = intersectWidth * intersectHeight;
}
// Set outer snapping area
if(obj.getLeft() < outerAreaLeft || outerAreaLeft == null) {
outerAreaLeft = obj.getLeft();
}
if(obj.getTop() < outerAreaTop || outerAreaTop == null) {
outerAreaTop = obj.getTop();
}
if((obj.getLeft() + obj.getWidth()) > outerAreaRight || outerAreaRight == null) {
outerAreaRight = obj.getLeft() + obj.getWidth();
}
if((obj.getTop() + obj.getHeight()) > outerAreaBottom || outerAreaBottom == null) {
outerAreaBottom = obj.getTop() + obj.getHeight();
}
// If objects are intersecting, reposition outside all shapes which touch
if(intersectSize) {
var distX = (outerAreaRight / 2) - ((options.target.getLeft() + options.target.getWidth()) / 2);
var distY = (outerAreaBottom / 2) - ((options.target.getTop() + options.target.getHeight()) / 2);
// Set new position
findNewPos(distX, distY, options.target, obj);
}
}
});
});

I based this fiddle off #Anna Phillips' and #gco's examples. It includes:
Corner snapping
Edge snapping
Objects can overlap
Objects are fully contained within the canvas
Objects cannot have a size larger than the canvas area
Here is the code:
window.canvas = new fabric.Canvas('fabriccanvas');
window.counter = 0;
var newleft = 0,
edgedetection = 20, //pixels to snap
canvasWidth = document.getElementById('fabriccanvas').width,
canvasHeight = document.getElementById('fabriccanvas').height;
canvas.selection = false;
plusrect();
plusrect();
plusrect();
function plusrect(top, left, width, height, fill) {
window.canvas.add(new fabric.Rect({
top: 300,
name: 'rectangle ' + window.counter,
left: 0 + newleft,
width: 100,
height: 100,
fill: 'rgba(' + (Math.floor(Math.random() * 256)) + ',' + (Math.floor(Math.random() * 256)) + ',' + (Math.floor(Math.random() * 256)) + ', 0.75)',
lockRotation: true,
originX: 'left',
originY: 'top',
cornerSize: 15,
hasRotatingPoint: false,
perPixelTargetFind: true,
minScaleLimit: 1,
maxHeight: document.getElementById("fabriccanvas").height,
maxWidth: document.getElementById("fabriccanvas").width,
}));
window.counter++;
newleft += 200;
}
this.canvas.on('object:moving', function (e) {
var obj = e.target;
obj.setCoords(); //Sets corner position coordinates based on current angle, width and height
if(obj.getLeft() < edgedetection) {
obj.setLeft(0);
}
if(obj.getTop() < edgedetection) {
obj.setTop(0);
}
if((obj.getWidth() + obj.getLeft()) > (canvasWidth - edgedetection)) {
obj.setLeft(canvasWidth - obj.getWidth());
}
if((obj.getHeight() + obj.getTop()) > (canvasHeight - edgedetection)) {
obj.setTop(canvasHeight - obj.getHeight());
}
canvas.forEachObject(function (targ) {
activeObject = canvas.getActiveObject();
if (targ === activeObject) return;
if (Math.abs(activeObject.oCoords.tr.x - targ.oCoords.tl.x) < edgedetection) {
activeObject.left = targ.left - activeObject.currentWidth;
}
if (Math.abs(activeObject.oCoords.tl.x - targ.oCoords.tr.x) < edgedetection) {
activeObject.left = targ.left + targ.currentWidth;
}
if (Math.abs(activeObject.oCoords.br.y - targ.oCoords.tr.y) < edgedetection) {
activeObject.top = targ.top - activeObject.currentHeight;
}
if (Math.abs(targ.oCoords.br.y - activeObject.oCoords.tr.y) < edgedetection) {
activeObject.top = targ.top + targ.currentHeight;
}
if (activeObject.intersectsWithObject(targ) && targ.intersectsWithObject(activeObject)) {
targ.strokeWidth = 10;
targ.stroke = 'red';
} else {
targ.strokeWidth = 0;
targ.stroke = false;
}
if (!activeObject.intersectsWithObject(targ)) {
activeObject.strokeWidth = 0;
activeObject.stroke = false;
}
});
});
What I'd like to know is if it's possible to extend this to add the following features:
Dynamic snapping. Continuing to drag an object after the initial snap will temporarily disable snapping until the object stops moving. For example, if I drag one box next to another, they will snap together once they are within range. However if I continue moving the first box, I can "drop" it in a position where it is within the snapping range but not aligned to the other box.
Show guide lines when selected object is within range of another object. Currently we add a border around the target object, but it would be better to show guidelines that extend outwards (possibly to the edge of the canvas) to more easily visualize the bounds of the target object.
Parallel snapping. When moving an object that is already snapped to the target object, the selected object should snap to the target object in such a way that the tops, bottoms, or sides of both objects are parallel. For example, assume that the selected square is snapped to the left of the target square and that the top of the selected square is below the top of the target square. Moving the selected square up should cause its top to snap into alignment with the top of the target once in range. The same logic should apply when moving it down, or if the selected object is above/below the target and being moves horizontally.

I needed snapping of unequal sized areas. jsfiddle
var canvas = new fabric.Canvas('c');
canvas.setDimensions({width:window.innerWidth});
var edge_detection_external = 21;
var corner_detection = 5;
canvas.selection = false;
canvas.on('object:moving', function (e) {
var obj = e.target;
obj.setCoords();
function update_position(obj){
return function(targ){
if(targ === obj) return;
// Check overlap case https://www.geeksforgeeks.org/find-two-rectangles-overlap/
if(!(function(targ,obj){
if(obj.aCoords.tl.x > targ.aCoords.br.x || targ.aCoords.tl.x > obj.aCoords.br.x)
return false;
if(targ.aCoords.tl.y > obj.aCoords.br.y || obj.aCoords.tl.y > targ.aCoords.br.y)
return false;
return true;
})(targ,obj)){
// is on RIGHT or LEFT?
if((obj.top > targ.top && obj.top < targ.top + targ.height)
|| (targ.top > obj.top && targ.top < obj.top + obj.height)){
// Object is to the RIGHT and Edge detection
if(obj.aCoords.tl.x > targ.aCoords.br.x
&& obj.aCoords.tl.x - targ.aCoords.br.x < edge_detection_external){
obj.set({left:targ.aCoords.br.x});
// Corner detection
obj.setCoords();
if(Math.abs(targ.aCoords.tr.y - obj.aCoords.tl.y) < corner_detection)
obj.set({top:targ.top});
else if(Math.abs(targ.aCoords.br.y - obj.aCoords.bl.y) < corner_detection)
obj.set({top:targ.top + targ.height - obj.height});
}
// LEFT
if(targ.aCoords.tl.x > obj.aCoords.br.x
&& targ.aCoords.tl.x - obj.aCoords.br.x < edge_detection_external){
obj.set({left:targ.aCoords.tl.x - obj.width});
obj.setCoords();
if(Math.abs(targ.aCoords.tl.y - obj.aCoords.tr.y) < corner_detection)
obj.set({top:targ.top});
else if(Math.abs(targ.aCoords.bl.y - obj.aCoords.br.y) < corner_detection)
obj.set({top:targ.top + targ.height - obj.height});
}
}
// is on TOP or BOTTOM?
if((obj.left > targ.left && obj.left < targ.left + targ.width)
|| (targ.left > obj.left && targ.left < obj.left + obj.width)){
// TOP
if(targ.aCoords.tl.y > obj.aCoords.br.y
&& targ.aCoords.tl.y - obj.aCoords.br.y < edge_detection_external){
obj.set({top:targ.aCoords.tl.y - obj.height});
obj.setCoords();
if(Math.abs(targ.aCoords.tl.x - obj.aCoords.bl.x) < corner_detection)
obj.set({left:targ.left});
else if(Math.abs(targ.aCoords.tr.x - obj.aCoords.br.x) < corner_detection)
obj.set({left:targ.left + targ.width - obj.width});
}
// BOTTOM
if(obj.aCoords.tl.y > targ.aCoords.br.y
&& obj.aCoords.tl.y - targ.aCoords.br.y < edge_detection_external){
obj.set({top:targ.aCoords.br.y});
obj.setCoords();
if(Math.abs(targ.aCoords.bl.x - obj.aCoords.tl.x) < corner_detection)
obj.set({left:targ.left});
else if(Math.abs(targ.aCoords.br.x - obj.aCoords.tr.x) < corner_detection)
obj.set({left:targ.left + targ.width - obj.width});
}
}
}
}
}
canvas.getObjects('group').some(update_position(obj));
});
String.prototype.to_inches = function(){
return this.split('-').map(function(value,index){
value = Number(value);
if(index == 0)
return value * 12
else
return value
}).reduce(function(total,current){
return total + current;
});
}
Array.prototype.to_object_list = function(){
const preserved = [...this];
var header = this.splice(0,1)[0];
for(var i = 0;i < this.length; i++){
var obj = {};
for(var j = 0;j < header.length; j++){
obj[header[j].toLowerCase()] = this[i][j];
}
this[i] = obj;
}
return preserved;
}
function draw_areas(){
var offset = 0;
return function(area_params,index){
if(area_params.area.indexOf('>') === -1){
var area = new fabric.Rect({
fill: 'red',
width:area_params.width.to_inches(),
height:area_params.length.to_inches(),
});
var text = new fabric.Text(area_params.area + '\n' + area_params.width + ' x ' + area_params.length,{
fontSize:12,
fill:"white"
});
if(text.width - area.width > 0){
text.set('width',area.width);
}
if(text.height - area.height > 0){
text.set('height',area.height);
}
var group_name = 'group_' + area_params.area.split(' ').join('-');
var group = new fabric.Group([area,text],{
name: group_name,
left: 5,
top: 5*(index++) + offset,
});
canvas.add(group);
offset = area_params.length.to_inches() + offset;
canvas.setDimensions({height:5*(index++) + offset});
}
}
}
function handler_get_data(data){
data = JSON.parse(data);
data.to_object_list();
data.forEach(draw_areas());
}
var d = '[["Area","Width","Length"],["Bedroom 1","19-5.5","14"],["Kitchen","14","16-3"],["Bedroom 2","13-6","12-9"]]';
handler_get_data(d);