/**
* Check if $frame will fit on the page. If the frame does not fit,
* the frame tree is modified so that a page break occurs in the
* correct location.
*
* @param Frame $frame the frame to check
*
* @return Frame the frame following the page break
*/
function check_page_break(Frame $frame)
{
// Do not split if we have already or if the frame was already
// pushed to the next page (prevents infinite loops)
if ($this->_page_full || $frame->_already_pushed) {
return false;
}
// If the frame is absolute of fixed it shouldn't break
$p = $frame;
do {
if ($p->is_absolute()) {
return false;
}
} while ($p = $p->get_parent());
$margin_height = $frame->get_margin_height();
// FIXME If the row is taller than the page and
// if it the first of the page, we don't break
if ($frame->get_style()->display === "table-row" && !$frame->get_prev_sibling() && $margin_height > $this->get_margin_height()) {
return false;
}
// Determine the frame's maximum y value
$max_y = $frame->get_position("y") + $margin_height;
// If a split is to occur here, then the bottom margins & paddings of all
// parents of $frame must fit on the page as well:
$p = $frame->get_parent();
while ($p) {
$max_y += $p->get_style()->computed_bottom_spacing();
$p = $p->get_parent();
}
// Check if $frame flows off the page
if ($max_y <= $this->_bottom_page_margin) {
// no: do nothing
return false;
}
Helpers::dompdf_debug("page-break", "check_page_break");
Helpers::dompdf_debug("page-break", "in_table: " . $this->_in_table);
// yes: determine page break location
$iter = $frame;
$flg = false;
$in_table = $this->_in_table;
Helpers::dompdf_debug("page-break", "Starting search");
while ($iter) {
// echo "\nbacktrack: " .$iter->get_node()->nodeName ." ".spl_object_hash($iter->get_node()). "";
if ($iter === $this) {
Helpers::dompdf_debug("page-break", "reached root.");
// We've reached the root in our search. Just split at $frame.
break;
}
if ($this->_page_break_allowed($iter)) {
Helpers::dompdf_debug("page-break", "break allowed, splitting.");
$iter->split(null, true);
$this->_page_full = true;
$this->_in_table = $in_table;
$frame->_already_pushed = true;
return true;
}
if (!$flg && ($next = $iter->get_last_child())) {
Helpers::dompdf_debug("page-break", "following last child.");
if ($next->is_table()) {
$this->_in_table++;
}
$iter = $next;
continue;
}
if ($next = $iter->get_prev_sibling()) {
Helpers::dompdf_debug("page-break", "following prev sibling.");
if ($next->is_table() && !$iter->is_table()) {
$this->_in_table++;
} else {
if (!$next->is_table() && $iter->is_table()) {
$this->_in_table--;
}
}
$iter = $next;
$flg = false;
continue;
}
if ($next = $iter->get_parent()) {
Helpers::dompdf_debug("page-break", "following parent.");
if ($iter->is_table()) {
$this->_in_table--;
}
$iter = $next;
$flg = true;
continue;
}
break;
}
$this->_in_table = $in_table;
// No valid page break found. Just break at $frame.
Helpers::dompdf_debug("page-break", "no valid break found, just splitting.");
// If we are in a table, backtrack to the nearest top-level table row
if ($this->_in_table) {
$iter = $frame;
while ($iter && $iter->get_style()->display !== "table-row" && $iter->get_style()->display !== 'table-row-group') {
$iter = $iter->get_parent();
}
$iter->split(null, true);
} else {
$frame->split(null, true);
}
$this->_page_full = true;
$frame->_already_pushed = true;
return true;
}
