We Keep Coding

Background colour of line charts in chart.js

I would like to change the background colour of the line graph produced by chart.js. There doesn't appear to be an option for this, and the documentation doesn't help. Extensive searching on the interweb has yielded no results. Is this possible?
I must confess I don't really know much about the HTML5 canvas so I'm struggling a bit!

With v2.1 of Chart.js, you can write your own plugin to do this
Preview
Script
Chart.pluginService.register({
beforeDraw: function (chart, easing) {
if (chart.config.options.chartArea && chart.config.options.chartArea.backgroundColor) {
var helpers = Chart.helpers;
var ctx = chart.chart.ctx;
var chartArea = chart.chartArea;
ctx.save();
ctx.fillStyle = chart.config.options.chartArea.backgroundColor;
ctx.fillRect(chartArea.left, chartArea.top, chartArea.right - chartArea.left, chartArea.bottom - chartArea.top);
ctx.restore();
}
}
});
and then
...
options: {
chartArea: {
backgroundColor: 'rgba(251, 85, 85, 0.4)'
}
}
...
Fiddle - http://jsfiddle.net/rrcd60y0/

I'm not sure what you mean by "the background color of the main area of the graph that isn't occupied with the line chart", but you can set the background-color of the canvas via CSS:
#myChart {
background-color: #666;
}
Look at this fiddle to see how it affects the chart.
This will set the background for the whole canvas, if you only want to set it for the inner part, check out potatopeelings solution.

Just to help others who are thinking how to add multiple background colors:
I modified a little bit #potatopeelings answer. First I checked how many columns there are
var columnCount = chart.data.datasets[0].data.length;
var width = chartArea.right - chartArea.left;
var columnWidth = width/columnCount;
and then fill every other of them with background color
while (startPoint < chartArea.right) {
ctx.fillRect(startPoint, chartArea.top, columnWidth, height);
startPoint += columnWidth * 2;
}
For my chart this works better but for this the July column is for some reason only part of it. Doesn't know how to fix that but hopefully you can get idea from here.
http://jsfiddle.net/e7oy6yk6/2

Raphael JS: Changing circle into a another shape using a path

I currently have created a ball bouncing
var ball = paper.circle(700,275,25,25)
var a = 50;
ball.attr({
fill: "180-black-red"
});
In this function the ball bounces to the top. I then tried to make it change shape by doing ball.animate and the path. But this is not working.
function bounce_normal(){
ball.animate({cy: 220, cx: 275}, 500, 'ease-out' );
ball.animate({ path: "M190.5,320.5A20,20,0,1,1,190.1,320.5Z"});
}
I also tried to remove the cy and cx values however it still doesn't change shape. Is there a way to solve this?
Update
I now learnt I need to use a path for by ball.
var ball = paper.path("M190.5,320.5A20,20,0,1,1,190.1,320.5Z")
var a = 50;
ball.attr({
fill: "180-black-red"
});
Is there anyway of learning what that path means so i can animate the pathm ie: making it bounce ?

How to style images in highcharts flags?

In my chart, I show the user pictures for their comment date, so the users can read the comments in a tooltip using these icons. It seems like soundcloud charts. I did it using flags type and I set the shape variables as user picture url for each data item.
But I want to add also colorized border for each icons. I know, there is lineWidth and lineColor config in flags type but it doesn't work with images, it works only with default shapes flag, circlepin or squarepin.
I tried to use shape as flag and to add user images as background image, but It doesn't work.

In SVG you can not set border for the images, you need to create rect around the image: http://jsfiddle.net/xuL76rkL/1/
For example you can use load and redraw events to manage those rects, code:
var H = Highcharts;
function drawBorder() {
var chart = this;
H.each(chart.series[1].points, function(p) {
var bbox,
rect,
fontSize = 13, // it's used as default font size offet, even for the images
dim = 32; //width and height for the image
if(p.graphic) {
if(p.rectangle) {
p.rectangle.destroy();
}
bbox = p.graphic.getBBox();
rect = chart.renderer.rect(p.plotX - dim/2, p.plotY - dim/2 - fontSize, dim, dim).attr({
"stroke": "black",
"stroke-width": 2,
"fill": "transparent"
}).add(chart.series[1].markerGroup);
p.rectangle = rect;
}
});
}
$('#container').highcharts('StockChart', {
chart: {
events: {
load: drawBorder,
redraw: drawBorder
}
},
...
});

You can set an image with the shape option:
Example: shape: "url(/assets/my_image.svg)"
Documentation available here: https://api.highcharts.com/highstock/series.flags.shape

Generating onclick text at the bottom of my SVG, modifying 'selected' colour

With the aid of a tutorial, I've built a map of five regions of England in SVG. I've used Raphael to work with it a little. Most of it seems to be turning out alright so far:
http://codepen.io/msummers40/pen/EjExeO
I'm trying to add two more features and am just not sure how to do it. Are you able to help, please?
I'd like to: Set up the effect of the regions turning red upon clicking so that only the most recently clicked region is coloured. Can you help explain what I'm supposed to do to make this shift from region to region? At the moment, a region gets clicked and stays highlighted.
I'd like to figure out how to add more text to the bottom of the canvas. It may mean adding more information to my JSON but I'm hoping that I can add the text - about two paragraphs with a hyperlink - as a string.
Can you please let me know if you have thoughts about ways that I can do the two things outlined above?
Thank you,
Matt
The full code is on Codepen. What I've added below is a representative sample of the code.
var regions = [
{'title':"northeast_england", 'path' : "M219.02,6.876l-0.079,0.05l-0.482,0.371L218.23,7.47l-0.858,0.346h-0.008l-0.307,0.26l-0.779,0.666 l-0.104,0.278l-0.005,0.019l0.056,0.481l0.116,0.846l0.048,0.395l-0.344,1.05l-0.052-0.007v0.007l-0.635-0.081l-0.375,0.167 l-0.148,0.061v0.006l-0.1,0.328l0.178,0.338l-0.104,0.353h-0.006l-0.32,0.179l-0.056,0.031l-0.161,0.729h-0.006v0.012l-0.271,0.117 l-0.08,0.031l-0.031-0.019l-0.043,0.019l-0.327-0.167l-0.147-0.079l-0.117-0.007h-0.021l-0.216-0.006l-0.419,0.252l-0.009,0.007 l-0.004,0.302v0.605l-0.117,0.292l-0.037,0.11h-0.006v0.006h-0.025l-0.37,0.056l-0.536,0.079l-0.562,0.372l0.017,0.165l0.033,0.187 l0.481,0.788l0.023,0.038l0.008,0.013l-0.988,0.425l-0.594,0.637l-0.011,0.03l-0.187,0.637l-0.068,0.062l-0.801,0.747l-0.409,0.617 l0.062,0.414l0.068,0.414l-0.012,0.012l-0.203,0.228h-0.008l-0.123,0.05l-0.006,0.005l-0.377,0.136l-0.073,0.074l-0.13,0.143 l-0.401,0.426l-0.081,0.08l-0.055,0.055l-0.116,0.136l-0.05,0.364l0.646,0.191l0.025,0.119l0.05,0.153l-0.265,0.148l-0.26,0.155 l-0.155-0.006l-0.005,0.006l-0.309-0.006l-0.648-0.365l-0.624,0.142l-0.363,0.087l-......LOTS MORE COORDINATES...."},
THERE ARE SEVERAL OTHER SVG REGIONS/SHAPES IN THE CODEPEN LINK
var MAP_WIDTH = 600;
var MAP_HEIGHT = 600;
var mapContainer = document.getElementById("map");
var map = new Raphael(mapContainer, MAP_WIDTH, MAP_HEIGHT);
var group = map.set();
var style = {
fill: "#ddd",
stroke: "#aaa",
"stroke-width": 1,
"stroke-linejoin": "round",
cursor: "pointer"
};
regions.forEach(function(region){
group.push(
map.path(region.path).attr('title', region.title)
);
});
group.attr(style);
group.click(function(){
var slug = this.attr('title');
var title;
var fill = this.attr('fill') == 'red' ? '#1f1f1f' : 'red';
// format the title
title = slug.split('-')
.map(function(subString){
return subString[0].toUpperCase() + subString.substr(1);
})
.join(' ')
.trim();
// add some color
this.attr('fill', fill);
// do something useful
document.getElementById('title').textContent = title;
});

For the highlight thing, what I would do is have your click function as follows (pseudocode)::
on-region-clicked {
remove class "highlight" from all regions
add class "highlight" to clicked region
}
Where class "highlight" is:
.highlight {
fill: red;
}
I'll leave the actual Raphael code up to you.

kinetic.js change fill type of object after instantiation, after added to layer and scene, and in animation loop

I am attempting to change the fill style of a KineticJS Rect object after it has been instantiated, after being added to the layer and scene, and in the animation loop.
I am trying to toggle the fill type between a single color type to a linear gradient type based on a user button control in my main app file that renders the canvas.
I instantiate the object in a different file which is a class I wrote that instantiates a KineticJS Rect with a linear gradient fill initially in it's constructor like so:
function MyBackground(width,height,c1,c2,mode) {
this.width = width;
this.height = height;
this.color1 = c1;
this.color2 = c2;
this.mode = mode;
this.background = new Kinetic.Rect({
x: 0,
y: 0,
width: this.width,
height: this.height,
fillLinearGradientStartPoint: [0, 0],
fillLinearGradientEndPoint: [this.width, this.height],
fillLinearGradientColorStops: [0, this.color1, 1, this.color2]
});
this.getMode = function() { return this.mode; }; }
I then create an instance of this in the main file:
var myBack= new MyBackground(stageWidth,stageHeight,getRandomHexColor(),getRandomHexColor(),'dualColorLinearGradientStatic');
var background = myBack.getBackground();
myBack.setMode('singleColor');
I then add the background Rect to the layer, and the layer to the stage:
layer.add(background);
stage.add(layer);
I then start the animation loop code and after that the event handler that catches the button press to change the fill trying this inside:
myBack.setMode(bgmodeselected);
background = myBack.getBackground();
The app page loads fine showing the initial linear gradient fill. If I select that same mode of linear gradient and press the button control, it changes the colors as I desire maintaining the fill type of linear gradient. If I then switch the mode to single color fill and click the control button, that works too, changing the rect to a single color.
Here is what I have inside my class function to change the mode that makes that specifically work:
this.background.setFill(this.color1);
Inside that same function based on a conditional it should change the fill to linear gradient (and does this as long as its not changed to single color fill as above first)
this.background.setAttrs({
fillLinearGradientStartPoint: [0, 0],
fillLinearGradientEndPoint: [960, 600],
fillLinearGradientColorStops: [0, this.color1, 1, this.color2]
});
I've also tried within that same block:
this.background.setFillLinearGradientStartPoint(0, 0);
this.background.setFillLinearGradientEndPoint(960, 600);
this.background.setFillLinearGradientColorStops([0, this.color1, 1, this.color2]);
I know that the proper variables and values are being passed to the function and that the conditionals are working because it will change the fill mode type from its (as initially instantiated) linear gradient fill to a single color fill (which will continue working even as a different single color).
The problem is when I try to switch BACK to linear gradient fill it will not do so, or repaint/refresh at least despite it's calling this same function with the proper values. So, I suppose that my specific question is how can I change the fill style of a KineticJS Rect multiple times, from a single color fill back to a linear gradient fill after it has been already been added to the layer and stage and has an animation loop implemented?
This is my first question post so I hope that I am doing so properly; please inform me if I should be doing anything differently. Thanks.

Welcome to stackoverflow!
When you’re re-applying your gradient, be sure to clear out the solid color fill:
// clear the solid fill
this.setFill('');
// then apply the gradient fill
this.setFillLinearGradientStartPoint(-50);
this.setFillLinearGradientEndPoint(50);
this.setFillLinearGradientColorStops([0, 'green', 1, 'yellow']);
Here is code and a Fiddle: http://jsfiddle.net/m1erickson/dmMF2/
<!DOCTYPE HTML>
<html>
<head>
<style>
body {
margin: 0px;
padding: 0px;
}
</style>
</head>
<body>
<div id="container"></div>
<script src="http://www.html5canvastutorials.com/libraries/kinetic-v4.3.0-beta2.js"></script>
<script>
function draw(images) {
var stage = new Kinetic.Stage({
container: 'container',
width: 578,
height: 200
});
var layer = new Kinetic.Layer();
var linearGradPentagon = new Kinetic.Rect({
x: 100,
y: 30,
width: 75,
height: 50,
fill:"red",
stroke: 'black',
strokeWidth: 4,
draggable: true
});
linearGradPentagon.on('mouseover touchstart', function() {
this.setFill('');
this.setFillLinearGradientStartPoint(-50);
this.setFillLinearGradientEndPoint(50);
this.setFillLinearGradientColorStops([0, 'green', 1, 'yellow']);
layer.draw();
});
linearGradPentagon.on('mouseout touchend', function() {
this.setFill('red');
layer.draw();
});
layer.add(linearGradPentagon);
stage.add(layer);
}
draw();
</script>
</body>
</html>