/// <summary>
/// Layout all legned items.
/// </summary>
public virtual void MeasureSize(DrawingContext dc, Rectangle parentClientRect)
{
var ds = Chart.DataSource;
if (ds == null)
{
return;
}
int count = SymbolCount;
Children.Clear();
RGFloat maxSymbolWidth = 0, maxSymbolHeight = 0, maxLabelWidth = 0, maxLabelHeight = 0;
// Suppress the legend when it has no labels or just repeats the chart title
if (count == 1 && string.IsNullOrEmpty(Chart.Title) && GetSymbolText(0) == Chart.GetDisplayTitle())
{
return;
}
#region Measure Sizes
for (int index = 0; index < count; index++)
{
string label = GetSymbolText(index);
if (string.IsNullOrEmpty(label))
{
continue;
}
var symbolSize = GetSymbolSize(index);
if (maxSymbolWidth < symbolSize.Width)
{
maxSymbolWidth = symbolSize.Width;
}
if (maxSymbolHeight < symbolSize.Height)
{
maxSymbolHeight = symbolSize.Height;
}
var legendItem = new ChartLegendItem(Chart.DataSerialStyles[index], label)
{
FontName = FontName,
FontSize = FontSize,
FontStyles = FontStyles,
SymbolBounds = new Rectangle(new Point(0, 0), symbolSize),
};
var labelSize = PlatformUtility.MeasureText(dc, label, legendItem.FontName, legendItem.FontSize, legendItem.FontStyles);
if (maxLabelWidth < labelSize.Width)
{
maxLabelWidth = labelSize.Width;
}
if (maxLabelHeight < labelSize.Height)
{
maxLabelHeight = labelSize.Height;
}
legendItem.LabelBounds = new Rectangle(new Point(0, 0), labelSize);
Children.Add(legendItem);
}
#endregion // Measure Sizes
#region Layout
const RGFloat symbolLabelSpacing = 4;
var itemWidth = maxSymbolWidth + symbolLabelSpacing + maxLabelWidth;
var itemHeight = Math.Max(maxSymbolHeight, maxLabelHeight);
var clientRect = parentClientRect;
RGFloat x = 0, y = 0, right = 0, bottom = 0, overflow = 0;
if (LegendPosition == LegendPosition.Top || LegendPosition == LegendPosition.Bottom)
{
overflow = clientRect.Width - itemWidth;
}
foreach (var item in Children)
{
if (item is ChartLegendItem legendItem)
{
legendItem.SetSymbolLocation(0, (itemHeight - legendItem.SymbolBounds.Height) / 2);
legendItem.SetLabelLocation(maxSymbolWidth + symbolLabelSpacing, (itemHeight - legendItem.LabelBounds.Height) / 2);
legendItem.Bounds = new Rectangle(x, y, itemWidth, itemHeight);
if (right < legendItem.Right)
{
right = legendItem.Right;
}
if (bottom < legendItem.Bottom)
{
bottom = legendItem.Bottom;
}
}
const RGFloat itemSpacing = 10;
x += itemWidth + itemSpacing;
if (x > overflow)
{
x = 0;
y += itemHeight + itemSpacing;
}
}
#endregion // Layout
layoutedSize = new Size(right + 10, bottom);
}