chartjs / chartjs-plugin-datalabels

Chart.js plugin to display labels on data elements
https://chartjs-plugin-datalabels.netlify.app
MIT License
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When using with zoom plugin, `clip: true` affect the labels on the edge #398

Open helloint opened 8 months ago

helloint commented 8 months ago

See this demo: https://codesandbox.io/s/chart-js-data-labels-plugin-clip-issue-mqkrgd?file=/src/App.tsx It use zoom and datalabels

When using with zoom, you have to set clip: true on datalabels, otherwise the label will overlap with the yAxis

image

But if did this, the first and the last bar label get cut.

image

Because it is beyond the chart area.

image

The document tells me the clip is calling CanvasRenderingContext2D.clip(), so I then took a look at the source code here:

    if (model.clip) {
      area = model.area;
      ctx.beginPath();
      ctx.rect(
        area.left,
        area.top,
        area.right - area.left,
        area.bottom - area.top);
      ctx.clip();
    }

I guess maybe we can allow a paddingOffset to slightly extend the rect area, to let customer to adjust? like:

    var paddingOffset = modal.paddingOffset;
    if (model.clip) {
        area = model.area;
        ctx.beginPath();
        ctx.rect(
            area.left - paddingOffset,
            area.top - paddingOffset,
            area.right + paddingOffset * 2 - area.left,
            area.bottom + paddingOffset * 2 - area.top);
        ctx.clip();
    }