/// <summary>
/// Calculates the dimensions of the Legend. This includes the maximum width
/// and height of a single entry, as well as the total width and height of
/// the Legend.
public void CalculateDimensions(Paint paint, ViewPortHandler viewPortHandler)
{
var maxEntrySize = GetMaximumEntrySize(paint);
float defaultFormSize = FormSize.DpToPixel();
float stackSpace = StackSpace.DpToPixel();
float formToTextSpace = FormToTextSpace.DpToPixel();
float xEntrySpace = XEntrySpace.DpToPixel();
float yEntrySpace = YEntrySpace.DpToPixel();
var wordWrapEnabled = WordWrapEnabled;
var entries = Entries;
int entryCount = entries.Count;
TextWidthMax = maxEntrySize.Width;
TextHeightMax = maxEntrySize.Height;
switch (Orientation)
{
case Orientation.Vertical:
{
float maxWidth = 0f, maxHeight = 0f, width = 0f;
float labelLineHeight = paint.LineHeight();
bool wasStacked = false;
for (int i = 0; i < entryCount; i++)
{
LegendEntry e = entries[i];
var drawingForm = e.Form != Form.None;
float formSize = float.IsNaN(e.FormSize)
? defaultFormSize
: e.FormSize.DpToPixel();
var label = e.Label;
if (!wasStacked)
{
width = 0.0f;
}
if (drawingForm)
{
if (wasStacked)
{
width += stackSpace;
}
width += formSize;
}
// grouped forms have null labels
if (label != null)
{
var size = paint.MeasureWidth(label);
// make a step to the left
if (drawingForm && !wasStacked)
{
width += formToTextSpace;
}
else if (wasStacked)
{
maxWidth = Math.Max(maxWidth, width);
maxHeight += labelLineHeight + yEntrySpace;
width = 0.0f;
wasStacked = false;
}
width += size;
maxHeight += labelLineHeight + yEntrySpace;
}
else
{
wasStacked = true;
width += formSize;
if (i < entryCount - 1)
{
width += stackSpace;
}
}
maxWidth = Math.Max(maxWidth, width);
}
NeededWidth = maxWidth;
NeededHeight = maxHeight;
break;
}
case Orientation.Horizontal:
{
float labelLineHeight = paint.LineHeight();
float labelLineSpacing = paint.LineSpacing() + yEntrySpace;
float contentWidth = viewPortHandler.ContentWidth * MaxSizePercent;
// Start calculating layout
float maxLineWidth = 0.0f;
float currentLineWidth = 0.0f;
float requiredWidth = 0.0f;
int stackedStartIndex = -1;
CalculatedLabelBreakPoints.Clear();
CalculatedLabelSizes.Clear();
CalculatedLineSizes.Clear();
for (int i = 0; i < entryCount; i++)
{
LegendEntry e = entries[i];
var drawingForm = e.Form != Form.None;
float formSize = float.IsNaN(e.FormSize)
? defaultFormSize
: e.FormSize.DpToPixel();
var label = e.Label;
CalculatedLabelBreakPoints.Add(false);
if (stackedStartIndex == -1)
{
// we are not stacking, so required width is for this label
// only
requiredWidth = 0.0f;
}
else
{
// add the spacing appropriate for stacked labels/forms
requiredWidth += stackSpace;
}
// grouped forms have null labels
if (label != null)
{
CalculatedLabelSizes.Add(paint.Measure(label));
requiredWidth += drawingForm ? formToTextSpace + formSize : 0.0f;
requiredWidth += CalculatedLabelSizes[i].Width;
}
else
{
CalculatedLabelSizes.Add(new ChartSize(0, 0));
requiredWidth += drawingForm ? formSize : 0.0f;
if (stackedStartIndex == -1)
{
// mark this index as we might want to break here later
stackedStartIndex = i;
}
}
if (label != null || i == entryCount - 1)
{
float requiredSpacing = currentLineWidth == 0.0f ? 0.0f : xEntrySpace;
if (!wordWrapEnabled // No word wrapping, it must fit.
// The line is empty, it must fit
|| currentLineWidth == 0.0f
// It simply fits
|| (contentWidth - currentLineWidth >=
requiredSpacing + requiredWidth))
{
// Expand current line
currentLineWidth += requiredSpacing + requiredWidth;
}
else
{ // It doesn't fit, we need to wrap a line
// Add current line size to array
CalculatedLineSizes.Add(new ChartSize(currentLineWidth, labelLineHeight));
maxLineWidth = Math.Max(maxLineWidth, currentLineWidth);
// Start a new line
CalculatedLabelBreakPoints.Insert(
stackedStartIndex > -1 ? stackedStartIndex
: i, true);
currentLineWidth = requiredWidth;
}
if (i == entryCount - 1)
{
// Add last line size to array
CalculatedLineSizes.Add(new ChartSize(currentLineWidth, labelLineHeight));
maxLineWidth = Math.Max(maxLineWidth, currentLineWidth);
}
}
stackedStartIndex = label != null ? -1 : stackedStartIndex;
}
NeededWidth = maxLineWidth;
NeededHeight = labelLineHeight
* (float)(CalculatedLineSizes.Count)
+ labelLineSpacing *
(float)(CalculatedLineSizes.Count == 0
? 0
: (CalculatedLineSizes.Count - 1));
break;
}
}
NeededHeight += YOffset;
NeededWidth += XOffset;
}
