/**
* Takes the element's page-relative position and returns the left and top CSS offsets
* These CSS offsets are relative to the closest positioned ancestor, which must be found by crawling the hierarchy
* @param IdmlElement $element
* @return array
*/
protected function adjustOffsetsToRefPoint(IdmlElement $element)
{
// Get the element's page-relative position and first ancestor
$xOffset = $element->getPosition('left');
$yOffset = $element->getPosition('top');
// If this element has no ancestors, return its page-relative offsets
if (!isset($element->parentElement)) {
return array($xOffset, $yOffset);
}
$ancestor = $element->parentElement;
while (!is_null($ancestor)) {
// SVG elements are produced as siblings, so they are never an ancestor in produced html
// Stories aren't IdmlElements, and so have no position. But they may have ancestors that do.
if (is_a($ancestor, 'IdmlSvgShape') || is_a($ancestor, 'IdmlStory')) {
$ancestor = $ancestor->parentElement;
continue;
}
// If the ancestor has no position, continue to the next ancestor
if (!$ancestor->hasPosition('left') || !$ancestor->hasPosition('top')) {
$ancestor = $ancestor->parentElement;
continue;
}
// If we encountered an IdmlStory, use its text frame
if (is_a($ancestor, 'IdmlStory')) {
$ancestor = $ancestor->idmlTextFrame;
continue;
}
// If the ancestor's positions are not set, get the next ancestor
if (!$ancestor->hasPositions()) {
$ancestor = $ancestor->parentElement;
continue;
}
$ancestorLeft = $ancestor->getPosition('left');
$ancestorTop = $ancestor->getPosition('top');
// If the ancestor is positioned, return offsets calculated relative to the ancestor
if (isset($ancestorLeft) && !is_null($ancestorLeft)) {
return array($xOffset - $ancestorLeft, $yOffset - $ancestorTop);
}
// Step up the chain and reiterate
$ancestor = $ancestor->parentElement;
}
// No positioned ancestor was found: return page-relative position
return array($xOffset, $yOffset);
}
