状HTML方式(基于单元格的内容)是一个计算列宽
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27-09-2019 - |
题
我有数据的一个网格,我想出口到RTF,PDF等使用各种(而不是完美的)PHP转换器/发生器。
我所缺少的是大多数基于字符串的在细胞中的长度列宽的HTML表自动调整(字符串包含换行符,其复杂的事情一点,因为它们应该被保留)。
我需要一种算法,考虑到细胞(纯文本),表中的总宽度和字符的平均宽度的内容,将返回一个宽度为每个列。我不想重新发明轮子,如果事情已经可用。
当然,如果字体是可变的宽度,但是近似会做就好它不能是完美的。或者它可以具有与宽度为每个字符可配置的表。
任何暗示,将不胜感激。
解决方案
这是不容易的。
在PHPExcel,当小区被设置为autowidth,我们使用GD库imagettfbbox()函数
// font size should really be supplied in pixels in GD2,
// but since GD2 seems to assume 72dpi, pixels and points are the same
$fontFile = self::getTrueTypeFontFileFromFont($font);
$textBox = imagettfbbox($font->getSize(), $rotation, $fontFile, $text);
// Get corners positions
$lowerLeftCornerX = $textBox[0];
$lowerLeftCornerY = $textBox[1];
$lowerRightCornerX = $textBox[2];
$lowerRightCornerY = $textBox[3];
$upperRightCornerX = $textBox[4];
$upperRightCornerY = $textBox[5];
$upperLeftCornerX = $textBox[6];
$upperLeftCornerY = $textBox[7];
// Consider the rotation when calculating the width
$textWidth = max($lowerRightCornerX - $upperLeftCornerX, $upperRightCornerX - $lowerLeftCornerX);
return $textWidth;
这是非常密集的,虽然,特别是大型工作表中工作时,因此我们还具有替代的(近似)方法
// Calculate column width in pixels. We assume fixed glyph width. Result varies with font name and size.
switch ($fontName) {
case 'Calibri':
// value 8.26 was found via interpolation by inspecting real Excel files with Calibri 11 font.
$columnWidth = (int) (8.26 * PHPExcel_Shared_String::CountCharacters($columnText));
$columnWidth = $columnWidth * $fontSize / 11; // extrapolate from font size
break;
case 'Arial':
// value 7 was found via interpolation by inspecting real Excel files with Arial 10 font.
$columnWidth = (int) (7 * PHPExcel_Shared_String::CountCharacters($columnText));
$columnWidth = $columnWidth * $fontSize / 10; // extrapolate from font size
break;
case 'Verdana':
// value 8 was found via interpolation by inspecting real Excel files with Verdana 10 font.
$columnWidth = (int) (8 * PHPExcel_Shared_String::CountCharacters($columnText));
$columnWidth = $columnWidth * $fontSize / 10; // extrapolate from font size
break;
default:
// just assume Calibri
$columnWidth = (int) (8.26 * PHPExcel_Shared_String::CountCharacters($columnText));
$columnWidth = $columnWidth * $fontSize / 11; // extrapolate from font size
break;
}
// Calculate approximate rotated column width
if ($rotation !== 0) {
if ($rotation == -165) {
// stacked text
$columnWidth = 4; // approximation
} else {
// rotated text
$columnWidth = $columnWidth * cos(deg2rad($rotation))
+ $fontSize * abs(sin(deg2rad($rotation))) / 5; // approximation
}
}
// pixel width is an integer
$columnWidth = (int) $columnWidth;
return $columnWidth;
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