/// <inheritdoc cref="HoverArea.SuggestTooltipPlacement(TooltipPlacementContext)"/>
public override void SuggestTooltipPlacement(TooltipPlacementContext context)
{
var angle = (StartAngle + EndAngle) / 2d;
context.PieX = CenterX + (float)Math.Cos(angle * (Math.PI / 180)) * Radius;
context.PieY = CenterY + (float)Math.Sin(angle * (Math.PI / 180)) * Radius;
}
/// <summary>
/// Returns the left, top coordinate of the tooltip based on the found points, the position and the tooltip size.
/// </summary>
/// <param name="foundPoints"></param>
/// <param name="position"></param>
/// <param name="tooltipSize"></param>
/// <param name="chartSize"></param>
/// <returns></returns>
public static LvcPoint?GetCartesianTooltipLocation(
this IEnumerable <ChartPoint> foundPoints, TooltipPosition position, LvcSize tooltipSize, LvcSize chartSize)
{
var count = 0f;
var placementContext = new TooltipPlacementContext();
foreach (var point in foundPoints)
{
if (point.Context.HoverArea is null)
{
continue;
}
point.Context.HoverArea.SuggestTooltipPlacement(placementContext);
count++;
}
if (count == 0)
{
return(null);
}
if (placementContext.MostBottom > chartSize.Height - tooltipSize.Height)
{
placementContext.MostBottom = chartSize.Height - tooltipSize.Height;
}
if (placementContext.MostTop < 0)
{
placementContext.MostTop = 0;
}
var avrgX = (placementContext.MostRight + placementContext.MostLeft) / 2f - tooltipSize.Width * 0.5f;
var avrgY = (placementContext.MostTop + placementContext.MostBottom) / 2f - tooltipSize.Height * 0.5f;
return(position switch
{
TooltipPosition.Top => new LvcPoint(avrgX, placementContext.MostTop - tooltipSize.Height),
TooltipPosition.Bottom => new LvcPoint(avrgX, placementContext.MostBottom),
TooltipPosition.Left => new LvcPoint(placementContext.MostLeft - tooltipSize.Width, avrgY),
TooltipPosition.Right => new LvcPoint(placementContext.MostRight, avrgY),
TooltipPosition.Center => new LvcPoint(avrgX, avrgY),
TooltipPosition.Hidden => new LvcPoint(),
_ => new LvcPoint(),
});
/// <summary> /// Suggests the tooltip placement. /// </summary> /// <param name="context">The context.</param> public abstract void SuggestTooltipPlacement(TooltipPlacementContext context);
