tooltip.positioner

A callback function to place the tooltip in a custom position. The callback receives four parameters: labelWidth, labelHeight, point, and ctx, where point contains values for plotX and plotY telling where the reference point is in the plot area, and ctx is the tooltip context (so that arrow-functions can access the same context as a normal function using this). Add chart.plotLeft and chart.plotTop to get the full coordinates. Since v12.6.0, the callback receives ctx.

To find the actual hovered Point instance, use this.chart.hoverPoint. For shared or split tooltips, all the hover points are available in this.chart.hoverPoints.

Since v7, when tooltip.split option is enabled, positioner is called for each of the boxes separately, including xAxis header. xAxis header is not a point, instead point argument contains info: { plotX: Number, plotY: Number, isHeader: Boolean }

Since v12.2, the tooltip.fixed option combined with tooltip.position covers most of the use cases for custom tooltip positioning.

The return should be an object containing x and y values, for example { x: 100, y: 100 }.