function get_pages_traverse_block(&$box, &$next, &$previous, $penalty)
{
$locations = array();
// Absolute/fixed positioned blocks do not cause page breaks
// (CSS 2.1. 13.2.3 Content outside the page box)
$position = $box->get_css_property(CSS_POSITION);
if ($position == POSITION_FIXED || $position == POSITION_ABSOLUTE) {
return $locations;
}
// Fake cell boxes do not generate page break locations
if (is_a($box, 'FakeTableCellBox')) {
return $locations;
}
/**
* Check for breaks in block box vertical margin
*/
/**
* Check for pre-breaks
*/
if (PageBreakLocator::has_forced_page_break_before($box)) {
$location = new PageBreakLocation($box->get_top_margin(), FORCED_PAGE_BREAK_BONUS);
} elseif (!is_null($previous) && $previous->get_css_property(CSS_PAGE_BREAK_AFTER) == PAGE_BREAK_AVOID) {
$location = new PageBreakLocation($box->get_top_margin(), $penalty + PAGE_BREAK_AFTER_AVOID_PENALTY);
} elseif ($box->get_css_property(CSS_PAGE_BREAK_BEFORE) == PAGE_BREAK_AVOID) {
$location = new PageBreakLocation($box->get_top_margin(), $penalty + PAGE_BREAK_BEFORE_AVOID_PENALTY);
} else {
$location = new PageBreakLocation($box->get_top_margin(), $penalty);
}
$locations[] = $location;
/**
* Check for post-breaks
*/
if (PageBreakLocator::has_forced_page_break_after($box)) {
$location = new PageBreakLocation($box->get_bottom_margin(), FORCED_PAGE_BREAK_BONUS);
} elseif (!is_null($next) && $next->get_css_property(CSS_PAGE_BREAK_BEFORE) == PAGE_BREAK_AVOID) {
$location = new PageBreakLocation($box->get_bottom_margin(), $penalty + PAGE_BREAK_AFTER_AVOID_PENALTY);
} elseif ($box->get_css_property(CSS_PAGE_BREAK_AFTER) == PAGE_BREAK_AVOID) {
$location = new PageBreakLocation($box->get_bottom_margin(), $penalty + PAGE_BREAK_AFTER_AVOID_PENALTY);
} else {
$location = new PageBreakLocation($box->get_bottom_margin(), $penalty);
}
$locations[] = $location;
/**
* Check for breaks inside this box
* Note that this check should be done after page-break-before/after checks,
* as 'penalty' value may be modified here
*/
if ($box->get_css_property(CSS_PAGE_BREAK_INSIDE) == PAGE_BREAK_AVOID) {
$penalty += PAGE_BREAK_INSIDE_AVOID_PENALTY;
}
/**
* According to CSS 2.1, 13.3.5 'Best' page breaks,
* User agent shoud /Avoid breaking inside a block that has a border/
*
* From my point of view, top and bottom borders should not affect page
* breaks (as they're not broken by page break), while left and right ones - should.
*/
$border_left =& $box->get_css_property(CSS_BORDER_LEFT);
$border_right =& $box->get_css_property(CSS_BORDER_RIGHT);
$has_left_border = $border_left->style != BS_NONE && $border_left->width->getPoints() > 0;
$has_right_border = $border_left->style != BS_NONE && $border_left->width->getPoints() > 0;
if ($has_left_border || $has_right_border) {
$penalty += PAGE_BREAK_BORDER_PENALTY;
}
/**
* Process box content
*/
$locations = array_merge($locations, PageBreakLocator::get_pages_traverse($box, $penalty));
return $locations;
}