如何在iText7中填充行的剩余空间

Question

I'm trying to fill the remaining space of the last line of a paragraph using iText7 with C#:

var par = new Paragraph(text);
par.Add(c);
document.Add(par);

How can i add - char to fill the space left by the line? Something like LineSeparator(new DashedLine() but from the beginning on the last character of my paragraph instead of new line.

Answer 1

You can use the concept of tabs and tab stops for it. This concept is not iText-specific. Roughly speaking you can define points (tab stops) and adding a tab would "jump" to the next point. In your case the tab stop is the end of the line and you only need one tab.

Here is a complete example that uses small dashes on the baseline as the filling. You can implement ILineDrawer yourself to customize the behavior or subclass/configure an existing implementation. The code is in Java, but to convert it to C# you basically need to do some capitalization and that's it.

Document doc = ....;
Paragraph p = new Paragraph("Hello world").add(new Tab());
ILineDrawer filling = new DashedLine();
PageSize pageSize = doc.getPdfDocument().getDefaultPageSize();
Rectangle effectivePageSize = doc.getPageEffectiveArea(pageSize);
float rightTabStopPoint = effectivePageSize.getWidth();
TabStop tabStop = new TabStop(rightTabStopPoint, TabAlignment.LEFT, filling);
p.addTabStops(tabStop);
doc.add(p); 

Result looks as follows: