static bool isDeletableElement(const Node* node)
{
if (!node || !node->isHTMLElement() || !node->inDocument() || !node->rendererIsEditable())
return false;
// In general we want to only draw the UI around object of a certain area, but we still keep the min width/height to
// make sure we don't end up with very thin or very short elements getting the UI.
const int minimumArea = 2500;
const int minimumWidth = 48;
const int minimumHeight = 16;
const unsigned minimumVisibleBorders = 1;
RenderObject* renderer = node->renderer();
if (!renderer || !renderer->isBox())
return false;
// Disallow the body element since it isn't practical to delete, and the deletion UI would be clipped.
if (node->hasTagName(bodyTag))
return false;
// Disallow elements with any overflow clip, since the deletion UI would be clipped as well. <rdar://problem/6840161>
if (renderer->hasOverflowClip())
return false;
// Disallow Mail blockquotes since the deletion UI would get in the way of editing for these.
if (isMailBlockquote(node))
return false;
RenderBox* box = toRenderBox(renderer);
IntRect borderBoundingBox = box->borderBoundingBox();
if (borderBoundingBox.width() < minimumWidth || borderBoundingBox.height() < minimumHeight)
return false;
if ((borderBoundingBox.width() * borderBoundingBox.height()) < minimumArea)
return false;
if (box->isTable())
return true;
if (node->hasTagName(ulTag) || node->hasTagName(olTag) || node->hasTagName(iframeTag))
return true;
if (box->isOutOfFlowPositioned())
return true;
if (box->isRenderBlock() && !box->isTableCell()) {
const RenderStyle& style = box->style();
// Allow blocks that have background images
if (style.hasBackgroundImage()) {
for (const FillLayer* background = style.backgroundLayers(); background; background = background->next()) {
if (background->image() && background->image()->canRender(box, 1))
return true;
}
}
// Allow blocks with a minimum number of non-transparent borders
unsigned visibleBorders = style.borderTop().isVisible() + style.borderBottom().isVisible() + style.borderLeft().isVisible() + style.borderRight().isVisible();
if (visibleBorders >= minimumVisibleBorders)
return true;
// Allow blocks that have a different background from it's parent
ContainerNode* parentNode = node->parentNode();
if (!parentNode)
return false;
RenderObject* parentRenderer = parentNode->renderer();
if (!parentRenderer)
return false;
const RenderStyle& parentStyle = parentRenderer->style();
if (box->hasBackground() && (!parentRenderer->hasBackground() || style.visitedDependentColor(CSSPropertyBackgroundColor) != parentStyle.visitedDependentColor(CSSPropertyBackgroundColor)))
return true;
}
return false;
}
