/system/helpers/dompdf/include/page_frame_decorator.cls.php
PHP | 603 lines | 293 code | 102 blank | 208 comment | 79 complexity | 8260a5fc97deacb517b483d482c84241 MD5 | raw file
Possible License(s): LGPL-2.1
- <?php
- /**
- * @package dompdf
- * @link http://www.dompdf.com/
- * @author Benj Carson <benjcarson@digitaljunkies.ca>
- * @license http://www.gnu.org/copyleft/lesser.html GNU Lesser General Public License
- */
- /**
- * Decorates frames for page layout
- *
- * @access private
- * @package dompdf
- */
- class Page_Frame_Decorator extends Frame_Decorator {
- /**
- * y value of bottom page margin
- *
- * @var float
- */
- protected $_bottom_page_margin;
- /**
- * Flag indicating page is full.
- *
- * @var bool
- */
- protected $_page_full;
- /**
- * Number of tables currently being reflowed
- *
- * @var int
- */
- protected $_in_table;
- /**
- * The pdf renderer
- *
- * @var Renderer
- */
- protected $_renderer;
-
- /**
- * This page's floating frames
- *
- * @var array
- */
- protected $_floating_frames = array();
- //........................................................................
- /**
- * Class constructor
- *
- * @param Frame $frame the frame to decorate
- * @param DOMPDF $dompdf
- */
- function __construct(Frame $frame, DOMPDF $dompdf) {
- parent::__construct($frame, $dompdf);
- $this->_page_full = false;
- $this->_in_table = 0;
- $this->_bottom_page_margin = null;
- }
- /**
- * Set the renderer used for this pdf
- *
- * @param Renderer $renderer the renderer to use
- */
- function set_renderer($renderer) {
- $this->_renderer = $renderer;
- }
- /**
- * Return the renderer used for this pdf
- *
- * @return Renderer
- */
- function get_renderer() {
- return $this->_renderer;
- }
- /**
- * Set the frame's containing block. Overridden to set $this->_bottom_page_margin.
- *
- * @param float $x
- * @param float $y
- * @param float $w
- * @param float $h
- */
- function set_containing_block($x = null, $y = null, $w = null, $h = null) {
- parent::set_containing_block($x,$y,$w,$h);
- //$w = $this->get_containing_block("w");
- if ( isset($h) )
- $this->_bottom_page_margin = $h; // - $this->_frame->get_style()->length_in_pt($this->_frame->get_style()->margin_bottom, $w);
- }
- /**
- * Returns true if the page is full and is no longer accepting frames.
- *
- * @return bool
- */
- function is_full() {
- return $this->_page_full;
- }
- /**
- * Start a new page by resetting the full flag.
- */
- function next_page() {
- $this->_floating_frames = array();
- $this->_renderer->new_page();
- $this->_page_full = false;
- }
- /**
- * Indicate to the page that a table is currently being reflowed.
- */
- function table_reflow_start() {
- $this->_in_table++;
- }
- /**
- * Indicate to the page that table reflow is finished.
- */
- function table_reflow_end() {
- $this->_in_table--;
- }
- /**
- * Return whether we are currently in a nested table or not
- *
- * @return bool
- */
- function in_nested_table() {
- return $this->_in_table > 1;
- }
-
- /**
- * Check if a forced page break is required before $frame. This uses the
- * frame's page_break_before property as well as the preceeding frame's
- * page_break_after property.
- *
- * @link http://www.w3.org/TR/CSS21/page.html#forced
- *
- * @param Frame $frame the frame to check
- * @return bool true if a page break occured
- */
- function check_forced_page_break(Frame $frame) {
-
- // Skip check if page is already split
- if ( $this->_page_full )
- return null;
- $block_types = array("block", "list-item", "table", "inline");
- $page_breaks = array("always", "left", "right");
- $style = $frame->get_style();
- if ( !in_array($style->display, $block_types) )
- return false;
- // Find the previous block-level sibling
- $prev = $frame->get_prev_sibling();
- while ( $prev && !in_array($prev->get_style()->display, $block_types) )
- $prev = $prev->get_prev_sibling();
- if ( in_array($style->page_break_before, $page_breaks) ) {
- // Prevent cascading splits
- $frame->split(null, true);
- // We have to grab the style again here because split() resets
- // $frame->style to the frame's orignal style.
- $frame->get_style()->page_break_before = "auto";
- $this->_page_full = true;
-
- return true;
- }
- if ( $prev && in_array($prev->get_style()->page_break_after, $page_breaks) ) {
- // Prevent cascading splits
- $frame->split(null, true);
- $prev->get_style()->page_break_after = "auto";
- $this->_page_full = true;
- return true;
- }
-
- if( $prev && $prev->get_last_child() && $frame->get_node()->nodeName != "body" ) {
- $prev_last_child = $prev->get_last_child();
- if ( in_array($prev_last_child->get_style()->page_break_after, $page_breaks) ) {
- $frame->split(null, true);
- $prev_last_child->get_style()->page_break_after = "auto";
- $this->_page_full = true;
- return true;
- }
- }
- return false;
- }
- /**
- * Determine if a page break is allowed before $frame
- * http://www.w3.org/TR/CSS21/page.html#allowed-page-breaks
- *
- * In the normal flow, page breaks can occur at the following places:
- *
- * 1. In the vertical margin between block boxes. When a page
- * break occurs here, the used values of the relevant
- * 'margin-top' and 'margin-bottom' properties are set to '0'.
- * 2. Between line boxes inside a block box.
- *
- * These breaks are subject to the following rules:
- *
- * * Rule A: Breaking at (1) is allowed only if the
- * 'page-break-after' and 'page-break-before' properties of
- * all the elements generating boxes that meet at this margin
- * allow it, which is when at least one of them has the value
- * 'always', 'left', or 'right', or when all of them are
- * 'auto'.
- *
- * * Rule B: However, if all of them are 'auto' and the
- * nearest common ancestor of all the elements has a
- * 'page-break-inside' value of 'avoid', then breaking here is
- * not allowed.
- *
- * * Rule C: Breaking at (2) is allowed only if the number of
- * line boxes between the break and the start of the enclosing
- * block box is the value of 'orphans' or more, and the number
- * of line boxes between the break and the end of the box is
- * the value of 'widows' or more.
- *
- * * Rule D: In addition, breaking at (2) is allowed only if
- * the 'page-break-inside' property is 'auto'.
- *
- * If the above doesn't provide enough break points to keep
- * content from overflowing the page boxes, then rules B and D are
- * dropped in order to find additional breakpoints.
- *
- * If that still does not lead to sufficient break points, rules A
- * and C are dropped as well, to find still more break points.
- *
- * We will also allow breaks between table rows. However, when
- * splitting a table, the table headers should carry over to the
- * next page (but they don't yet).
- *
- * @param Frame $frame the frame to check
- * @return bool true if a break is allowed, false otherwise
- */
- protected function _page_break_allowed(Frame $frame) {
- $block_types = array("block", "list-item", "table", "-dompdf-image");
- dompdf_debug("page-break", "_page_break_allowed(" . $frame->get_node()->nodeName. ")");
- $display = $frame->get_style()->display;
- // Block Frames (1):
- if ( in_array($display, $block_types) ) {
- // Avoid breaks within table-cells
- if ( $this->_in_table ) {
- dompdf_debug("page-break", "In table: " . $this->_in_table);
- return false;
- }
- // Rules A & B
- if ( $frame->get_style()->page_break_before === "avoid" ) {
- dompdf_debug("page-break", "before: avoid");
- return false;
- }
- // Find the preceeding block-level sibling
- $prev = $frame->get_prev_sibling();
- while ( $prev && !in_array($prev->get_style()->display, $block_types) )
- $prev = $prev->get_prev_sibling();
- // Does the previous element allow a page break after?
- if ( $prev && $prev->get_style()->page_break_after === "avoid" ) {
- dompdf_debug("page-break", "after: avoid");
- return false;
- }
- // If both $prev & $frame have the same parent, check the parent's
- // page_break_inside property.
- $parent = $frame->get_parent();
- if ( $prev && $parent && $parent->get_style()->page_break_inside === "avoid" ) {
- dompdf_debug("page-break", "parent inside: avoid");
- return false;
- }
- // To prevent cascading page breaks when a top-level element has
- // page-break-inside: avoid, ensure that at least one frame is
- // on the page before splitting.
- if ( $parent->get_node()->nodeName === "body" && !$prev ) {
- // We are the body's first child
- dompdf_debug("page-break", "Body's first child.");
- return false;
- }
- // If the frame is the first block-level frame, use the value from
- // $frame's parent instead.
- if ( !$prev && $parent )
- return $this->_page_break_allowed( $parent );
- dompdf_debug("page-break", "block: break allowed");
- return true;
- }
- // Inline frames (2):
- else if ( in_array($display, Style::$INLINE_TYPES) ) {
- // Avoid breaks within table-cells
- if ( $this->_in_table ) {
- dompdf_debug("page-break", "In table: " . $this->_in_table);
- return false;
- }
- // Rule C
- $block_parent = $frame->find_block_parent();
- if ( count($block_parent->get_line_boxes() ) < $frame->get_style()->orphans ) {
- dompdf_debug("page-break", "orphans");
- return false;
- }
- // FIXME: Checking widows is tricky without having laid out the
- // remaining line boxes. Just ignore it for now...
- // Rule D
- $p = $block_parent;
- while ($p) {
- if ( $p->get_style()->page_break_inside === "avoid" ) {
- dompdf_debug("page-break", "parent->inside: avoid");
- return false;
- }
- $p = $p->find_block_parent();
- }
- // To prevent cascading page breaks when a top-level element has
- // page-break-inside: avoid, ensure that at least one frame with
- // some content is on the page before splitting.
- $prev = $frame->get_prev_sibling();
- while ( $prev && ($prev->is_text_node() && trim($prev->get_node()->nodeValue) == "") )
- $prev = $prev->get_prev_sibling();
- if ( $block_parent->get_node()->nodeName === "body" && !$prev ) {
- // We are the body's first child
- dompdf_debug("page-break", "Body's first child.");
- return false;
- }
- // Skip breaks on empty text nodes
- if ( $frame->is_text_node() &&
- $frame->get_node()->nodeValue == "" )
- return false;
- dompdf_debug("page-break", "inline: break allowed");
- return true;
- // Table-rows
- } else if ( $display === "table-row" ) {
- // Simply check if the parent table's page_break_inside property is
- // not 'avoid'
- $p = Table_Frame_Decorator::find_parent_table($frame);
- while ($p) {
- if ( $p->get_style()->page_break_inside === "avoid" ) {
- dompdf_debug("page-break", "parent->inside: avoid");
- return false;
- }
- $p = $p->find_block_parent();
- }
- // Avoid breaking after the first row of a table
- if ( $p && $p->get_first_child() === $frame) {
- dompdf_debug("page-break", "table: first-row");
- return false;
- }
- // If this is a nested table, prevent the page from breaking
- if ( $this->_in_table > 1 ) {
- dompdf_debug("page-break", "table: nested table");
- return false;
- }
- dompdf_debug("page-break","table-row/row-groups: break allowed");
- return true;
- } else if ( in_array($display, Table_Frame_Decorator::$ROW_GROUPS) ) {
- // Disallow breaks at row-groups: only split at row boundaries
- return false;
- } else {
- dompdf_debug("page-break", "? " . $frame->get_style()->display . "");
- return false;
- }
- }
- /**
- * 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 ) {
- $style = $p->get_style();
- $max_y += $style->length_in_pt(array($style->margin_bottom,
- $style->padding_bottom,
- $style->border_bottom_width));
- $p = $p->get_parent();
- }
- // Check if $frame flows off the page
- if ( $max_y <= $this->_bottom_page_margin )
- // no: do nothing
- return false;
- dompdf_debug("page-break", "check_page_break");
- dompdf_debug("page-break", "in_table: " . $this->_in_table);
- // yes: determine page break location
- $iter = $frame;
- $flg = false;
- $in_table = $this->_in_table;
- dompdf_debug("page-break","Starting search");
- while ( $iter ) {
- // echo "\nbacktrack: " .$iter->get_node()->nodeName ." ".spl_object_hash($iter->get_node()). "";
- if ( $iter === $this ) {
- 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) ) {
- 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() ) {
- dompdf_debug("page-break", "following last child.");
- if ( $next->is_table() )
- $this->_in_table++;
- $iter = $next;
- continue;
- }
- if ( $next = $iter->get_prev_sibling() ) {
- 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--;
- // Avoid bug with whitespace after blocks
- while ( $next = $iter->get_last_child() ) {
- // Already selected last child, do nothing more
- }
- $iter = $next;
- $flg = false;
- continue;
- }
- if ( $next = $iter->get_parent() ) {
- 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.
- 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 ) {
- $num_tables = $this->_in_table - 1;
- $iter = $frame;
- while ( $iter && $num_tables && $iter->get_style()->display !== "table" ) {
- $iter = $iter->get_parent();
- $num_tables--;
- }
- $iter = $frame;
- while ($iter && $iter->get_style()->display !== "table-row" )
- $iter = $iter->get_parent();
- }
- $frame->split(null, true);
- $this->_page_full = true;
- $frame->_already_pushed = true;
- return true;
-
- }
- //........................................................................
- function split(Frame $frame = null, $force_pagebreak = false) {
- // Do nothing
- }
- /**
- * Add a floating frame
- *
- * @param Frame $frame
- *
- * @return void
- */
- function add_floating_frame(Frame $frame) {
- array_unshift($this->_floating_frames, $frame);
- }
-
- /**
- * @return Frame[]
- */
- function get_floating_frames() {
- return $this->_floating_frames;
- }
- public function remove_floating_frame($key) {
- unset($this->_floating_frames[$key]);
- }
- public function get_lowest_float_offset(Frame $child) {
- $style = $child->get_style();
- $side = $style->clear;
- $float = $style->float;
-
- $y = 0;
-
- foreach($this->_floating_frames as $key => $frame) {
- if ( $side === "both" || $frame->get_style()->float === $side ) {
- $y = max($y, $frame->get_position("y") + $frame->get_margin_height());
-
- if ( $float !== "none" ) {
- $this->remove_floating_frame($key);
- }
- }
- }
-
- return $y;
- }
- }