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<?php
/**
* @package dompdf
* @link https://github.com/dompdf/dompdf
* @license http://www.gnu.org/copyleft/lesser.html GNU Lesser General Public License
*/
namespace Dompdf\FrameReflower;
use Dompdf\Dompdf;
use Dompdf\Helpers;
use Dompdf\Frame;
use Dompdf\Frame\Factory;
use Dompdf\FrameDecorator\AbstractFrameDecorator;
use Dompdf\FrameDecorator\Block;
/**
* Base reflower class
*
* Reflower objects are responsible for determining the width and height of
* individual frames. They also create line and page breaks as necessary.
*
* @package dompdf
*/
abstract class AbstractFrameReflower
{
/**
* Frame for this reflower
*
* @var AbstractFrameDecorator
*/
protected $_frame;
/**
* Cached min/max child size
*
* @var array
*/
protected $_min_max_child_cache;
/**
* Cached min/max size
*
* @var array
*/
protected $_min_max_cache;
/**
* AbstractFrameReflower constructor.
* @param AbstractFrameDecorator $frame
*/
function __construct(AbstractFrameDecorator $frame)
{
$this->_frame = $frame;
$this->_min_max_child_cache = null;
$this->_min_max_cache = null;
}
/**
* @return Dompdf
*/
function get_dompdf()
{
return $this->_frame->get_dompdf();
}
public function reset(): void
{
$this->_min_max_child_cache = null;
$this->_min_max_cache = null;
}
/**
* Determine the actual containing block for absolute and fixed position.
*
* https://www.w3.org/TR/CSS21/visudet.html#containing-block-details
*/
protected function determine_absolute_containing_block(): void
{
$frame = $this->_frame;
$style = $frame->get_style();
switch ($style->position) {
case "absolute":
$parent = $frame->find_positioned_parent();
if ($parent !== $frame->get_root()) {
$parent_style = $parent->get_style();
$parent_padding_box = $parent->get_padding_box();
//FIXME: an accurate measure of the positioned parent height
// is not possible until reflow has completed;
// we'll fall back to the parent's containing block,
// which is wrong for auto-height parents
if ($parent_style->height === "auto") {
$parent_containing_block = $parent->get_containing_block();
$containing_block_height = $parent_containing_block["h"] -
(float)$parent_style->length_in_pt([
$parent_style->margin_top,
$parent_style->margin_bottom,
$parent_style->border_top_width,
$parent_style->border_bottom_width
], $parent_containing_block["w"]);
} else {
$containing_block_height = $parent_padding_box["h"];
}
$frame->set_containing_block($parent_padding_box["x"], $parent_padding_box["y"], $parent_padding_box["w"], $containing_block_height);
break;
}
case "fixed":
$initial_cb = $frame->get_root()->get_first_child()->get_containing_block();
$frame->set_containing_block($initial_cb["x"], $initial_cb["y"], $initial_cb["w"], $initial_cb["h"]);
break;
default:
// Nothing to do, containing block already set via parent
break;
}
}
/**
* Collapse frames margins
* http://www.w3.org/TR/CSS21/box.html#collapsing-margins
*/
protected function _collapse_margins(): void
{
$frame = $this->_frame;
// Margins of float/absolutely positioned/inline-level elements do not collapse
if (!$frame->is_in_flow() || $frame->is_inline_level()
|| $frame->get_root() === $frame || $frame->get_parent() === $frame->get_root()
) {
return;
}
$cb = $frame->get_containing_block();
$style = $frame->get_style();
$t = $style->length_in_pt($style->margin_top, $cb["w"]);
$b = $style->length_in_pt($style->margin_bottom, $cb["w"]);
// Handle 'auto' values
if ($t === "auto") {
$style->set_used("margin_top", 0.0);
$t = 0.0;
}
if ($b === "auto") {
$style->set_used("margin_bottom", 0.0);
$b = 0.0;
}
// Collapse vertical margins:
$n = $frame->get_next_sibling();
if ( $n && !($n->is_block_level() && $n->is_in_flow()) ) {
while ($n = $n->get_next_sibling()) {
if ($n->is_block_level() && $n->is_in_flow()) {
break;
}
if (!$n->get_first_child()) {
$n = null;
break;
}
}
}
if ($n) {
$n_style = $n->get_style();
$n_t = (float)$n_style->length_in_pt($n_style->margin_top, $cb["w"]);
$b = $this->get_collapsed_margin_length($b, $n_t);
$style->set_used("margin_bottom", $b);
$n_style->set_used("margin_top", 0.0);
}
// Collapse our first child's margin, if there is no border or padding
if ($style->border_top_width == 0 && $style->length_in_pt($style->padding_top) == 0) {
$f = $this->_frame->get_first_child();
if ( $f && !($f->is_block_level() && $f->is_in_flow()) ) {
while ($f = $f->get_next_sibling()) {
if ($f->is_block_level() && $f->is_in_flow()) {
break;
}
if (!$f->get_first_child()) {
$f = null;
break;
}
}
}
// Margins are collapsed only between block-level boxes
if ($f) {
$f_style = $f->get_style();
$f_t = (float)$f_style->length_in_pt($f_style->margin_top, $cb["w"]);
$t = $this->get_collapsed_margin_length($t, $f_t);
$style->set_used("margin_top", $t);
$f_style->set_used("margin_top", 0.0);
}
}
// Collapse our last child's margin, if there is no border or padding
if ($style->border_bottom_width == 0 && $style->length_in_pt($style->padding_bottom) == 0) {
$l = $this->_frame->get_last_child();
if ( $l && !($l->is_block_level() && $l->is_in_flow()) ) {
while ($l = $l->get_prev_sibling()) {
if ($l->is_block_level() && $l->is_in_flow()) {
break;
}
if (!$l->get_last_child()) {
$l = null;
break;
}
}
}
// Margins are collapsed only between block-level boxes
if ($l) {
$l_style = $l->get_style();
$l_b = (float)$l_style->length_in_pt($l_style->margin_bottom, $cb["w"]);
$b = $this->get_collapsed_margin_length($b, $l_b);
$style->set_used("margin_bottom", $b);
$l_style->set_used("margin_bottom", 0.0);
}
}
}
/**
* Get the combined (collapsed) length of two adjoining margins.
*
* See http://www.w3.org/TR/CSS21/box.html#collapsing-margins.
*
* @param float $l1
* @param float $l2
*
* @return float
*/
private function get_collapsed_margin_length(float $l1, float $l2): float
{
if ($l1 < 0 && $l2 < 0) {
return min($l1, $l2); // min(x, y) = - max(abs(x), abs(y)), if x < 0 && y < 0
}
if ($l1 < 0 || $l2 < 0) {
return $l1 + $l2; // x + y = x - abs(y), if y < 0
}
return max($l1, $l2);
}
/**
* Handle relative positioning according to
* https://www.w3.org/TR/CSS21/visuren.html#relative-positioning.
*
* @param AbstractFrameDecorator $frame The frame to handle.
*/
protected function position_relative(AbstractFrameDecorator $frame): void
{
$style = $frame->get_style();
if ($style->position === "relative") {
$cb = $frame->get_containing_block();
$top = $style->length_in_pt($style->top, $cb["h"]);
$right = $style->length_in_pt($style->right, $cb["w"]);
$bottom = $style->length_in_pt($style->bottom, $cb["h"]);
$left = $style->length_in_pt($style->left, $cb["w"]);
// FIXME RTL case:
// if ($left !== "auto" && $right !== "auto") $left = -$right;
if ($left === "auto" && $right === "auto") {
$left = 0;
} elseif ($left === "auto") {
$left = -$right;
}
if ($top === "auto" && $bottom === "auto") {
$top = 0;
} elseif ($top === "auto") {
$top = -$bottom;
}
$frame->move($left, $top);
}
}
/**
* @param Block|null $block
*/
abstract function reflow(Block $block = null);
/**
* Resolve the `min-width` property.
*
* Resolves to 0 if not set or if a percentage and the containing-block
* width is not defined.
*
* @param float|null $cbw Width of the containing block.
*
* @return float
*/
protected function resolve_min_width(?float $cbw): float
{
$style = $this->_frame->get_style();
$min_width = $style->min_width;
return $min_width !== "auto"
? $style->length_in_pt($min_width, $cbw ?? 0)
: 0.0;
}
/**
* Resolve the `max-width` property.
*
* Resolves to `INF` if not set or if a percentage and the containing-block
* width is not defined.
*
* @param float|null $cbw Width of the containing block.
*
* @return float
*/
protected function resolve_max_width(?float $cbw): float
{
$style = $this->_frame->get_style();
$max_width = $style->max_width;
return $max_width !== "none"
? $style->length_in_pt($max_width, $cbw ?? INF)
: INF;
}
/**
* Resolve the `min-height` property.
*
* Resolves to 0 if not set or if a percentage and the containing-block
* height is not defined.
*
* @param float|null $cbh Height of the containing block.
*
* @return float
*/
protected function resolve_min_height(?float $cbh): float
{
$style = $this->_frame->get_style();
$min_height = $style->min_height;
return $min_height !== "auto"
? $style->length_in_pt($min_height, $cbh ?? 0)
: 0.0;
}
/**
* Resolve the `max-height` property.
*
* Resolves to `INF` if not set or if a percentage and the containing-block
* height is not defined.
*
* @param float|null $cbh Height of the containing block.
*
* @return float
*/
protected function resolve_max_height(?float $cbh): float
{
$style = $this->_frame->get_style();
$max_height = $style->max_height;
return $max_height !== "none"
? $style->length_in_pt($style->max_height, $cbh ?? INF)
: INF;
}
/**
* Get the minimum and maximum preferred width of the contents of the frame,
* as requested by its children.
*
* @return array A two-element array of min and max width.
*/
public function get_min_max_child_width(): array
{
if (!is_null($this->_min_max_child_cache)) {
return $this->_min_max_child_cache;
}
$low = [];
$high = [];
for ($iter = $this->_frame->get_children(); $iter->valid(); $iter->next()) {
$inline_min = 0;
$inline_max = 0;
// Add all adjacent inline widths together to calculate max width
while ($iter->valid() && ($iter->current()->is_inline_level() || $iter->current()->get_style()->display === "-dompdf-image")) {
/** @var AbstractFrameDecorator */
$child = $iter->current();
$child->get_reflower()->_set_content();
$minmax = $child->get_min_max_width();
if (in_array($child->get_style()->white_space, ["pre", "nowrap"], true)) {
$inline_min += $minmax["min"];
} else {
$low[] = $minmax["min"];
}
$inline_max += $minmax["max"];
$iter->next();
}
if ($inline_min > 0) {
$low[] = $inline_min;
}
if ($inline_max > 0) {
$high[] = $inline_max;
}
// Skip children with absolute position
if ($iter->valid() && !$iter->current()->is_absolute()) {
/** @var AbstractFrameDecorator */
$child = $iter->current();
$child->get_reflower()->_set_content();
list($low[], $high[]) = $child->get_min_max_width();
}
}
$min = count($low) ? max($low) : 0;
$max = count($high) ? max($high) : 0;
return $this->_min_max_child_cache = [$min, $max];
}
/**
* Get the minimum and maximum preferred content-box width of the frame.
*
* @return array A two-element array of min and max width.
*/
public function get_min_max_content_width(): array
{
return $this->get_min_max_child_width();
}
/**
* Get the minimum and maximum preferred border-box width of the frame.
*
* Required for shrink-to-fit width calculation, as used in automatic table
* layout, absolute positioning, float and inline-block. This provides a
* basic implementation. Child classes should override this or
* `get_min_max_content_width` as necessary.
*
* @return array An array `[0 => min, 1 => max, "min" => min, "max" => max]`
* of min and max width.
*/
public function get_min_max_width(): array
{
if (!is_null($this->_min_max_cache)) {
return $this->_min_max_cache;
}
$style = $this->_frame->get_style();
[$min, $max] = $this->get_min_max_content_width();
// Account for margins, borders, and padding
$dims = [
$style->padding_left,
$style->padding_right,
$style->border_left_width,
$style->border_right_width,
$style->margin_left,
$style->margin_right
];
// The containing block is not defined yet, treat percentages as 0
$delta = (float) $style->length_in_pt($dims, 0);
$min += $delta;
$max += $delta;
return $this->_min_max_cache = [$min, $max, "min" => $min, "max" => $max];
}
/**
* Parses a CSS string containing quotes and escaped hex characters
*
* @param $string string The CSS string to parse
* @param $single_trim
* @return string
*/
protected function _parse_string($string, $single_trim = false)
{
if ($single_trim) {
$string = preg_replace('/^[\"\']/', "", $string);
$string = preg_replace('/[\"\']$/', "", $string);
} else {
$string = trim($string, "'\"");
}
$string = str_replace(["\\\n", '\\"', "\\'"],
["", '"', "'"], $string);
// Convert escaped hex characters into ascii characters (e.g. \A => newline)
$string = preg_replace_callback("/\\\\([0-9a-fA-F]{0,6})/",
function ($matches) { return \Dompdf\Helpers::unichr(hexdec($matches[1])); },
$string);
return $string;
}
/**
* Parses a CSS "quotes" property
*
* https://www.w3.org/TR/css-content-3/#quotes
*
* @return array An array of pairs of quotes
*/
protected function _parse_quotes(): array
{
$quotes = $this->_frame->get_style()->quotes;
if ($quotes === "none") {
return [];
}
if ($quotes === "auto") {
// TODO: Use typographically appropriate quotes for the current
// language here
return [['"', '"'], ["'", "'"]];
}
// Matches quote types
$re = '/(\'[^\']*\')|(\"[^\"]*\")/';
// Split on spaces, except within quotes
if (!preg_match_all($re, $quotes, $matches, PREG_SET_ORDER)) {
return [];
}
$quotes_array = [];
foreach ($matches as $_quote) {
$quotes_array[] = $this->_parse_string($_quote[0], true);
}
return array_chunk($quotes_array, 2);
}
/**
* Parses the CSS "content" property
*
* https://www.w3.org/TR/CSS21/generate.html#content
*
* @return string The resulting string
*/
protected function _parse_content(): string
{
$style = $this->_frame->get_style();
$content = $style->content;
if ($content === "normal" || $content === "none") {
return "";
}
$quotes = $this->_parse_quotes();
$text = "";
foreach ($content as $val) {
// String
if (in_array(mb_substr($val, 0, 1), ['"', "'"], true)) {
$text .= $this->_parse_string($val);
continue;
}
$val = mb_strtolower($val);
// Keywords
if ($val === "open-quote") {
// FIXME: Take quotation depth into account
if (isset($quotes[0][0])) {
$text .= $quotes[0][0];
}
continue;
} elseif ($val === "close-quote") {
// FIXME: Take quotation depth into account
if (isset($quotes[0][1])) {
$text .= $quotes[0][1];
}
continue;
} elseif ($val === "no-open-quote") {
// FIXME: Increment quotation depth
continue;
} elseif ($val === "no-close-quote") {
// FIXME: Decrement quotation depth
continue;
}
// attr()
if (mb_substr($val, 0, 5) === "attr(") {
$i = mb_strpos($val, ")");
if ($i === false) {
continue;
}
$attr = trim(mb_substr($val, 5, $i - 5));
if ($attr === "") {
continue;
}
$text .= $this->_frame->get_parent()->get_node()->getAttribute($attr);
continue;
}
// counter()/counters()
if (mb_substr($val, 0, 7) === "counter") {
// Handle counter() references:
// http://www.w3.org/TR/CSS21/generate.html#content
$i = mb_strpos($val, ")");
if ($i === false) {
continue;
}
preg_match('/(counters?)(^\()*?\(\s*([^\s,]+)\s*(,\s*["\']?([^"\'\)]*)["\']?\s*(,\s*([^\s)]+)\s*)?)?\)/i', $val, $args);
$counter_id = $args[3];
if (strtolower($args[1]) === "counter") {
// counter(name [,style])
if (isset($args[5])) {
$type = trim($args[5]);
} else {
$type = "decimal";
}
$p = $this->_frame->lookup_counter_frame($counter_id);
$text .= $p->counter_value($counter_id, $type);
} elseif (strtolower($args[1]) === "counters") {
// counters(name, string [,style])
if (isset($args[5])) {
$string = $this->_parse_string($args[5]);
} else {
$string = "";
}
if (isset($args[7])) {
$type = trim($args[7]);
} else {
$type = "decimal";
}
$p = $this->_frame->lookup_counter_frame($counter_id);
$tmp = [];
while ($p) {
// We only want to use the counter values when they actually increment the counter
if (array_key_exists($counter_id, $p->_counters)) {
array_unshift($tmp, $p->counter_value($counter_id, $type));
}
$p = $p->lookup_counter_frame($counter_id);
}
$text .= implode($string, $tmp);
} else {
// countertops?
}
continue;
}
}
return $text;
}
/**
* Handle counters and set generated content if the frame is a
* generated-content frame.
*/
protected function _set_content(): void
{
$frame = $this->_frame;
if ($frame->content_set) {
return;
}
$style = $frame->get_style();
if (($reset = $style->counter_reset) !== "none") {
$frame->reset_counters($reset);
}
if (($increment = $style->counter_increment) !== "none") {
$frame->increment_counters($increment);
}
if ($frame->get_node()->nodeName === "dompdf_generated") {
$content = $this->_parse_content();
if ($content !== "") {
$node = $frame->get_node()->ownerDocument->createTextNode($content);
$new_style = $style->get_stylesheet()->create_style();
$new_style->inherit($style);
$new_frame = new Frame($node);
$new_frame->set_style($new_style);
Factory::decorate_frame($new_frame, $frame->get_dompdf(), $frame->get_root());
$frame->append_child($new_frame);
}
}
$frame->content_set = true;
}
}
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