internal static int CalculateYAxis(bool showYAxisText, bool showYAxisLines, IEnumerable <ChartEntry> entries, int yAxisMaxTicks, SKPaint yAxisTextPaint, Position yAxisPosition, int width, out float yAxisXShift, out List <float> yAxisIntervalLabels)
{
yAxisXShift = 0.0f;
yAxisIntervalLabels = new List <float>();
if (showYAxisText || showYAxisLines)
{
var yAxisWidth = width;
var enumerable = entries.ToList(); // to avoid double enumeration
var minValue = enumerable.Min(e => e.Value);
var maxValue = enumerable.Max(e => e.Value);
if (minValue == maxValue)
{
if (minValue >= 0)
{
maxValue += 100;
}
else
{
maxValue = 0;
}
}
NiceScale.Calculate(minValue, maxValue, yAxisMaxTicks, out var range, out var tickSpacing, out var niceMin, out var niceMax);
var ticks = (int)(range / tickSpacing);
yAxisIntervalLabels = Enumerable.Range(0, ticks)
.Select(i => (float)(niceMax - (i * tickSpacing)))
.ToList();
var longestYAxisLabel = yAxisIntervalLabels.Aggregate(string.Empty, (max, cur) => max.Length > cur.ToString().Length ? max : cur.ToString());
var longestYAxisLabelWidth = MeasureHelper.MeasureTexts(new string[] { longestYAxisLabel }, yAxisTextPaint).Select(b => b.Width).FirstOrDefault();
yAxisWidth = (int)(width - longestYAxisLabelWidth);
if (yAxisPosition == Position.Left)
{
yAxisXShift = longestYAxisLabelWidth;
}
// to reduce chart width
width = yAxisWidth;
}
return(width);
}
internal static void DrawYAxis(bool showYAxisText, bool showYAxisLines, Position yAxisPosition, SKPaint yAxisTextPaint, SKPaint yAxisLinesPaint, float margin, float animationProgress, float maxValue, float valueRange, SKCanvas canvas, int width, float yAxisXShift, List <float> yAxisIntervalLabels, float headerHeight, SKSize itemSize, float origin)
{
if (showYAxisText || showYAxisLines)
{
int cnt = 0;
var intervals = yAxisIntervalLabels
.Select(t => new ValueTuple <string, SKPoint>
(
t.ToString(),
new SKPoint(yAxisPosition == Position.Left ? yAxisXShift : width, MeasureHelper.CalculatePoint(margin, animationProgress, maxValue, valueRange, t, cnt++, itemSize, origin, headerHeight).Y)
))
.ToList();
if (showYAxisText)
{
DrawYAxisText(yAxisTextPaint, yAxisPosition, canvas, intervals);
}
if (showYAxisLines)
{
var lines = intervals.Select(tup =>
{
(_, SKPoint pt) = tup;
return(yAxisPosition == Position.Right ?
SKRect.Create(0, pt.Y, width, 0) :
SKRect.Create(yAxisXShift, pt.Y, width, 0));
});
DrawYAxisLines(margin, yAxisLinesPaint, canvas, lines);
}
}
}
