Chart.js canvas resize

Question

In (Android WebView HTML5 canvas error) i posted a question regarding plotting graphs using Graph.js library. The problem i have now is that if i call the function to plot t

Answer 1

I had a similar problem and found your answer.. I eventually came to a solution.

It looks like the source of Chart.js has the following(presumably because it is not supposed to re-render and entirely different graph in the same canvas):

    //High pixel density displays - multiply the size of the canvas height/width by the device pixel ratio, then scale.
if (window.devicePixelRatio) {
    context.canvas.style.width = width + "px";
    context.canvas.style.height = height + "px";
    context.canvas.height = height * window.devicePixelRatio;
    context.canvas.width = width * window.devicePixelRatio;
    context.scale(window.devicePixelRatio, window.devicePixelRatio);
}

This is fine if it is called once, but when you redraw multiple times you end up changing the size of the canvas DOM element multiple times causing re-size.

Hope that helps!