TCPDF - Is there a way to adjust single table row height?

Question

I am trying for two days now, with no result, to adjust a single rows min-height in a table, with no success.

I am using the following method to create my table:

<?php 
$html = <<<EOD
<table style="border:1px solid black;">
  <tr>
    <td>
      Text 1
    </td>
    <td>
      Text 2
    </td>
  </tr>
 </table>
EOD;

$this->writeHTMLCell($w=0, $h=0, $x='', $y='', $html, $border=0, $ln=1, $fill=0, $reseth=true, $align='', $autopadding=true);
?>

I already tried setting td padding, td margin, td height, tr height, with no success. I tried these from CSS and HTML too. The only thing I managed to achieve, is to see a row's height larger then the original value, but I want to make it shorter. I tried searching in the documentation of TCPDF, but the only thing I found is that TCPDF is not supporting padding and margin. Do any of you know some kind of "hack" to achieve my desired result?

Answer 1

What you're probably running into is the actual height of lines of text. Internally, TCPDF uses the cell height ratio to control the rendered line height. When you have a TD with a single line of text, the smallest you can make it is the line's total height. So the minimum size of a td cell is fontsize * cellheightratio + any cellpadding proscribed

cellpadding can come from the cellpadding attribute, so I set it to 0 for this example. I believe at least some of the padding dimensions can also be set with setCellPaddings before writing the HTML.

You can set the cell height ratio by using a line-height CSS declaration to make rows smaller. (You can also, of course, just reduce the font size as well.)

<?php

//For demonstration purposes, set line-height to be double the font size.
//You probably DON'T want to include this line unless you need really spaced
//out lines.
$this->setCellHeightRatio(2);

//Note that TCPDF will display whitespace from the beginning and ending
//of TD cells, at least as of version 5.9.206, so I removed it.
$html = <<<EOD
<table style="border:1px solid black;" border="1" cellpadding="0">
  <tr>
    <td>Row 1, Cell 1</td>
    <td>Row 1, Cell 2</td>
  </tr>
  <tr style="line-height: 100%;">
    <td>Row 2, Cell 1</td>
    <td>Row 2, Cell 2</td>
  </tr>
  <tr style="line-height: 80%;">
    <td>Row 3, Cell 1</td>
    <td>Row 3, Cell 2</td>
  </tr>
  <tr style="line-height: 50%;">
    <td>Row 4, Cell 1</td>
    <td>Row 4, Cell 2</td>
  </tr>
 </table>
EOD;

$this->writeHTMLCell($w=0, $h=0, $x='', $y='', $html, $border=0, $ln=1, $fill=0, $reseth=true, $align='', $autopadding=true);

The above code on my 5.9.206 installation produces this:

This works out to row 1 being big, twice the font size. Row 2 sets the line-height to be 100% of the font size. Row 3 is 80%. Row 4 there is 50%.

*Note that if your text wraps, it'll look terrible at very reduced line-heights.