private TableRectangle getTableFromText(List <TableLine> lines, List <TextEdge> relevantEdges, int relevantEdgeCount, List <Ruling> horizontalRulings)
{
TableRectangle table = new TableRectangle();
TableLine prevRow = null;
TableLine firstTableRow = null;
TableLine lastTableRow = null;
int tableSpaceCount = 0;
double totalRowSpacing = 0;
// go through the lines and find the ones that have the correct count of the relevant edges
foreach (TableLine textRow in lines)
{
int numRelevantEdges = 0;
if (firstTableRow != null && tableSpaceCount > 0)
{
// check to make sure this text row is within a line or so of the other lines already added
// if it's not, we should stop the table here
double tableLineThreshold = (totalRowSpacing / tableSpaceCount) * 2.5;
double lineDistance = prevRow.Bottom - textRow.Bottom; // bobld: textRow.Top - prevRow.Top
System.Diagnostics.Debug.Assert(lineDistance >= 0);
if (lineDistance > tableLineThreshold)
{
lastTableRow = prevRow;
break;
}
}
// for larger tables, be a little lenient on the number of relevant rows the text intersects
// for smaller tables, not so much - otherwise we'll end up treating paragraphs as tables too
int relativeEdgeDifferenceThreshold = 1;
if (relevantEdgeCount <= 3)
{
relativeEdgeDifferenceThreshold = 0;
}
foreach (TextEdge edge in relevantEdges)
{
if (textRow.IntersectsLine(edge.Line))
{
numRelevantEdges++;
}
}
// see if we have a candidate text row
if (numRelevantEdges >= (relevantEdgeCount - relativeEdgeDifferenceThreshold))
{
// keep track of table row spacing
if (prevRow != null && firstTableRow != null)
{
tableSpaceCount++;
totalRowSpacing += prevRow.Bottom - textRow.Bottom; // bobld: textRow.Top - prevRow.Top
}
// row is part of a table
if (table.Area == 0)
{
firstTableRow = textRow;
table.SetRect(textRow);
}
else
{
table.SetLeft(Math.Min(table.Left, textRow.Left));
table.SetBottom(Math.Min(table.Bottom, textRow.Bottom)); // bobld: Max
table.SetRight(Math.Max(table.Right, textRow.Right));
}
}
else
{
// no dice
// if we're at the end of the table, save the last row
if (firstTableRow != null && lastTableRow == null)
{
lastTableRow = prevRow;
}
}
prevRow = textRow;
}
// if we don't have a table now, we won't after the next step either
if (table.Area == 0)
{
return(null);
}
if (lastTableRow == null)
{
// takes care of one-row tables or tables that end at the bottom of a page
lastTableRow = prevRow;
}
// use the average row height and nearby horizontal lines to extend the table area
double avgRowHeight;
if (tableSpaceCount > 0)
{
System.Diagnostics.Debug.Assert(totalRowSpacing >= 0);
avgRowHeight = totalRowSpacing / tableSpaceCount;
}
else
{
avgRowHeight = lastTableRow.Height;
}
double rowHeightThreshold = avgRowHeight * 1.5;
// check lines after the bottom of the table
//foreach (Ruling ruling in sortedHorizontalRulings) //Line2D.Float
for (int i = horizontalRulings.Count - 1; i >= 0; i--) // reverse order
{
var ruling = horizontalRulings[i];
if (ruling.Y1 > table.Bottom) // bobld: <
{
continue;
}
double distanceFromTable = table.Bottom - ruling.Y2; // bobld: Y1
System.Diagnostics.Debug.Assert(distanceFromTable >= 0);
if (distanceFromTable <= rowHeightThreshold)
{
// use this ruling to help define the table
table.SetBottom(Math.Min(table.Bottom, ruling.Y2)); // bobld: Max Y1
table.SetLeft(Math.Min(table.Left, ruling.X1));
table.SetRight(Math.Max(table.Right, ruling.X2));
}
else
{
// no use checking any further
break;
}
}
// do the same for lines at the top, but make the threshold greater since table headings tend to be
// larger to fit up to three-ish rows of text (at least but we don't want to grab too much)
rowHeightThreshold = avgRowHeight * 3.8;
//for (int i = horizontalRulings.Count - 1; i >= 0; i--)
for (int i = 0; i < horizontalRulings.Count; i++)
{
Ruling ruling = horizontalRulings[i];
if (ruling.Y1 < table.Top) //bobld: >
{
continue;
}
double distanceFromTable = ruling.Y1 - table.Top; // bobld: table.Top - ruling.Y1
System.Diagnostics.Debug.Assert(distanceFromTable >= 0);
if (distanceFromTable <= rowHeightThreshold)
{
table.SetTop(Math.Max(table.Top, ruling.Y2)); // bobld: Min Y1
table.SetLeft(Math.Min(table.Left, ruling.X1));
table.SetRight(Math.Max(table.Right, ruling.X2));
}
else
{
break;
}
}
// add a bit of padding since the halved horizontal lines are a little fuzzy anyways
table.SetTop(Math.Ceiling(table.Top) + TABLE_PADDING_AMOUNT); // bobld: Floor -
table.SetBottom(Math.Floor(table.Bottom) - TABLE_PADDING_AMOUNT); // bobld: Ceiling +
table.SetLeft(Math.Floor(table.Left) - TABLE_PADDING_AMOUNT);
table.SetRight(Math.Ceiling(table.Right) + TABLE_PADDING_AMOUNT);
return(table);
}
