Function createResizeObserver

src/platform/platform.dom.js:191–229

(chart, type, listener)

}

function createResizeObserver(chart, type, listener) {
  const canvas = chart.canvas;
  const container = canvas && _getParentNode(canvas);
  if (!container) {
    return;
  }
  const resize = throttled((width, height) => {
    const w = container.clientWidth;
    listener(width, height);
    if (w < container.clientWidth) {
      // If the container size shrank during chart resize, let's assume
      // scrollbar appeared. So we resize again with the scrollbar visible -
      // effectively making chart smaller and the scrollbar hidden again.
      // Because we are inside `throttled`, and currently `ticking`, scroll
      // events are ignored during this whole 2 resize process.
      // If we assumed wrong and something else happened, we are resizing
      // twice in a frame (potential performance issue)
      listener();
    }
  }, window);

  // @ts-ignore until https://github.com/microsoft/TypeScript/issues/37861 implemented
  const observer = new ResizeObserver(entries => {
    const entry = entries[0];
    const width = entry.contentRect.width;
    const height = entry.contentRect.height;
    // When its container's display is set to 'none' the callback will be called with a
    // size of (0, 0), which will cause the chart to lose its original height, so skip
    // resizing in such case.
    if (width === 0 && height === 0) {
      return;
    }
    resize(width, height);
  });
  observer.observe(container);
  listenDevicePixelRatioChanges(chart, resize);

  return observer;
}

function releaseObserver(chart, type, observer) {
  if (observer) {