HTML5 Canvas is not responsive - html

Question

I have a main div, inside it are two div's each having a canvass. My problem is the canvass is not responsive, it overlaps when I resize the browser. please see below image.
Here is my HTML code:
<div id="mainContainer">
<div id="leftcolumn">
<h2>
Canvass Graph1
</h2>
<canvas id="Canvass_One"></canvas>
</div>
<div id="rightcolumn">
<h2>Canvass Graph2</h2>
<canvas id="Canvass_Two"></canvas>
</div>
</div>
CSS Code:
#mainContainer
{
width:100%;
height: 100%;
}
#leftcolumn
{
float:left;
display:inline-block;
width: -moz-calc(100% - 50%);
width: -webkit-calc(100% - 50%);
width: calc(100% - 50%);
height: 100%;
background: blue;
}
#rightcolumn {
float:left;
display:inline-block;
width: -moz-calc(100% - 50%);
width: -webkit-calc(100% - 50%);
width: calc(100% - 50%);
height: 100%;
background-color : red;
}
JS to set height and width of Canvass
var ctx2 = $("#Canvass_One").get(0).getContext('2d');
ctx2.canvas.height = 300; // setting height of canvas
ctx2.canvas.width = 560; // setting width of canvas
var ctx1 = $("#Canvass_Two").get(0).getContext('2d');
ctx1.canvas.height = 300; // setting height of canvas
ctx1.canvas.width = 560; // setting width of canvas
Canvas:
Again, my problem is when I minimized/resize the browser window , the canvass overlaps. thank you for any help. My case is that I'm not using image within my div, it's just a pure canvass with chart js framework to create a graph.
Sample data:
var barData = {
labels: ['CityA', 'CityB', 'CityC', 'CityD', 'CityF', 'CityG'],
datasets: [
{
label: '2010 customers #',
fillColor: '#382765',
data: [2500, 1902, 1041, 610, 1245, 952]
},
{
label: '2014 customers #',
fillColor: '#7BC225',
data: [3104, 1689, 1318, 589, 1199, 1436]
}
]
};

Answer 1

The trick is to set the style width/height in combination with the attribute width/height, as the style controls display and attribute controls image.
#Canvass_One, #Canvass_Two
{
width: 100%;
height: 100%;
}
Note: Chart.js appears to have its own setting do deal with responsiveness like this, Chart.defaults.global.responsive = true;, so one might need to combine the two.
Here is a sample to show how it works.
Chart.defaults.global.responsive = true;
var barData = {
labels: ['CityA', 'CityB', 'CityC', 'CityD', 'CityF', 'CityG'],
datasets: [
{
label: '2010 customers #',
fillColor: '#382765',
data: [2500, 1902, 1041, 610, 1245, 952]
},
{
label: '2014 customers #',
fillColor: '#7BC225',
data: [3104, 1689, 1318, 589, 1199, 1436]
}
]
};
var ctx2 = $("#Canvass_One").get(0).getContext('2d');
ctx2.canvas.height = 300; // setting height of canvas
ctx2.canvas.width = 560; // setting width of canvas
//ctx2.fillStyle = "#FF0000";
//ctx2.fillRect(10,0,450,75);
var clientsChart = new Chart(ctx2).Bar(barData);
var ctx1 = $("#Canvass_Two").get(0).getContext('2d');
ctx1.canvas.height = 300; // setting height of canvas
ctx1.canvas.width = 560; // setting width of canvas
ctx1.fillStyle = "#0000FF";
ctx1.fillRect(10,0,450,75);
#mainContainer
{
width:100%;
height: 100%;
}
#leftcolumn
{
float:left;
display:inline-block;
width: 50%;
height: 100%;
background: blue;
}
#rightcolumn
{
float:left;
display:inline-block;
width: 50%;
height: 100%;
background-color : red;
}
#Canvass_One, #Canvass_Two
{
width: 100%;
height: 100%;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/1.0.2/Chart.min.js"></script>
<div id="mainContainer">
<div id="leftcolumn">
<h2>Canvass Graph1</h2>
<canvas id="Canvass_One"></canvas>
</div>
<div id="rightcolumn">
<h2>Canvass Graph2</h2>
<canvas id="Canvass_Two"></canvas>
</div>
</div>