iText 7 prevent cell to split on page break

Question

I'm trying to generate a PDF with table that contains cells with shapes.
I override CellRenderer class and inside the new class I draw shapes in DrawableCellRenderer#draw.
Sometimes when the table needs to split and the cell has row span I want to prevent it from splitting and to begin in the next page.

I tried to setKeepTogether(true) but it didn't worked. Nested tables didn't work as well.

Here is the code I use:

public void test2() {
        try {
            pdfDocument = new PdfDocument(new PdfWriter(filePath));
            document = new Document(pdfDocument);
            Table masterTable = new Table(2).setExtendBottomRowOnSplit(true);
            masterTable.addHeaderCell(new Cell().add(new Paragraph("icon")))
            .addHeaderCell(new Cell().add(new Paragraph("i")));
            int rowSpan = 15;
            for(int i = 0; i < 50; i++) {

                Cell cell = new Cell(rowSpan, 1);
                cell.setNextRenderer(new DrawableCellRenderer(cell, SOME_SHAPE));
                cell.setKeepTogether(true);
                masterTable.addCell(cell);

                for(int j = 0; j < rowSpan; j++) {
                    cell = new Cell();
                    cell.add(new Paragraph(i + ", " + j));
                    masterTable.addCell(cell);
                }
            }
            document.add(masterTable);
        } catch (FileNotFoundException e) {
            ErrorMessage.outPrintln(ErrorMessage.DEBUG,
                    e.getMessage());
        } finally {
            pdfDocument.close();
        }
    }

I want to prevent this and achieve that.
Thanks in advance.

Answer 1

This code should achieve what you want more or less. It requires for your to set the fixed column width though

Document document = new Document(pdfDocument);
Table masterTable = new Table(1).setExtendBottomRowOnSplit(true);
UnitValue[] columnWidths = UnitValue.createPointArray(new float[] {50, 100});
float borderThickness = 0.5f;
Border solidBorder = new SolidBorder(borderThickness);
Table innerHeader = new Table(columnWidths)
        .addCell(new Cell().setBorder(Border.NO_BORDER).setBorderRight(solidBorder).add(new Paragraph("icon")))
        .addCell(new Cell().setBorder(Border.NO_BORDER).setBorderLeft(solidBorder).add(new Paragraph("i")));
masterTable.addHeaderCell(new Cell().setBorder(Border.NO_BORDER)
        .setBorderTop(solidBorder).setBorderLeft(solidBorder).setBorderRight(solidBorder)
        .setPadding(0).add(innerHeader));
int rowSpan = 15;
for(int i = 0; i < 50; i++) {
    Table innerTable = new Table(columnWidths).setKeepTogether(true);
    Cell cell = new Cell(rowSpan, 1).setBorder(Border.NO_BORDER).setBorderRight(solidBorder)
            .setBorderBottom(solidBorder);
    innerTable.addCell(cell);

    for(int j = 0; j < rowSpan; j++) {
        cell = new Cell().setBorder(Border.NO_BORDER).setBorderLeft(solidBorder);
        cell.add(new Paragraph(i + ", " + j));
        if (j == rowSpan - 1) {
            cell.setBorderBottom(solidBorder);
        }
        innerTable.addCell(cell);
    }

    masterTable.addCell(new Cell().setPadding(0).add(innerTable));
}
document.add(masterTable);

Result looks like this:

There is an artifact of two sequential borders not being collapsed though: