Adding tooltip

Add tooltip

Add tooltip property to the panel.

final chart = GChart(
    panels: [
      GPanel(
        valueViewPorts: ...
        valueAxes: ...
        pointAxes: ...
        graphs: ...
        // add the tooltip to the panel.
        tooltip: GTooltip(
          // set the tooltip x position to follow the mouse pointer.
          position: GTooltipPosition.followPointer,
          // set the tooltip y position to follow the value of the close price.
          followValueKey: "close",
          followValueViewPortId: "",
          // set the values to be displayed in the tooltip.
          dataKeys: [
            "open",
            "high",
            "low",
            "close",
            "volume",
          ],
        ),
      ),
    ],
);

The result

chart view

On the chart you can mouse hover the graph area to see the tooltip.