C++ VisiblePosition::rootEditableElement方法代码示例

void InsertListCommand::doApply()
{
    if (!endingSelection().isNonOrphanedCaretOrRange())
        return;

    if (!endingSelection().rootEditableElement())
        return;

    VisiblePosition visibleEnd = endingSelection().visibleEnd();
    VisiblePosition visibleStart = endingSelection().visibleStart();
    // When a selection ends at the start of a paragraph, we rarely paint
    // the selection gap before that paragraph, because there often is no gap.
    // In a case like this, it's not obvious to the user that the selection
    // ends "inside" that paragraph, so it would be confusing if InsertUn{Ordered}List
    // operated on that paragraph.
    // FIXME: We paint the gap before some paragraphs that are indented with left
    // margin/padding, but not others.  We should make the gap painting more consistent and
    // then use a left margin/padding rule here.
    if (visibleEnd != visibleStart && isStartOfParagraph(visibleEnd, CanSkipOverEditingBoundary)) {
        setEndingSelection(VisibleSelection(visibleStart, visibleEnd.previous(CannotCrossEditingBoundary), endingSelection().isDirectional()));
        if (!endingSelection().rootEditableElement())
            return;
    }

    const HTMLQualifiedName& listTag = (m_type == OrderedList) ? olTag : ulTag;
    if (endingSelection().isRange()) {
        bool forceListCreation = false;
        VisibleSelection selection = selectionForParagraphIteration(endingSelection());
        ASSERT(selection.isRange());
        VisiblePosition startOfSelection = selection.visibleStart();
        VisiblePosition endOfSelection = selection.visibleEnd();
        VisiblePosition startOfLastParagraph = startOfParagraph(endOfSelection, CanSkipOverEditingBoundary);

        RefPtrWillBeRawPtr<Range> currentSelection = endingSelection().firstRange();
        RefPtrWillBeRawPtr<ContainerNode> scopeForStartOfSelection = nullptr;
        RefPtrWillBeRawPtr<ContainerNode> scopeForEndOfSelection = nullptr;
        // FIXME: This is an inefficient way to keep selection alive because
        // indexForVisiblePosition walks from the beginning of the document to the
        // endOfSelection everytime this code is executed. But not using index is hard
        // because there are so many ways we can los eselection inside doApplyForSingleParagraph.
        int indexForStartOfSelection = indexForVisiblePosition(startOfSelection, scopeForStartOfSelection);
        int indexForEndOfSelection = indexForVisiblePosition(endOfSelection, scopeForEndOfSelection);

        if (startOfParagraph(startOfSelection, CanSkipOverEditingBoundary) != startOfLastParagraph) {
            forceListCreation = !selectionHasListOfType(selection, listTag);

            VisiblePosition startOfCurrentParagraph = startOfSelection;
            while (startOfCurrentParagraph.isNotNull() && !inSameParagraph(startOfCurrentParagraph, startOfLastParagraph, CanCrossEditingBoundary)) {
                // doApply() may operate on and remove the last paragraph of the selection from the document
                // if it's in the same list item as startOfCurrentParagraph.  Return early to avoid an
                // infinite loop and because there is no more work to be done.
                // FIXME(<rdar://problem/5983974>): The endingSelection() may be incorrect here.  Compute
                // the new location of endOfSelection and use it as the end of the new selection.
                if (!startOfLastParagraph.deepEquivalent().inDocument())
                    return;
                setEndingSelection(startOfCurrentParagraph);

                // Save and restore endOfSelection and startOfLastParagraph when necessary
                // since moveParagraph and movePragraphWithClones can remove nodes.
                doApplyForSingleParagraph(forceListCreation, listTag, *currentSelection);
                if (endOfSelection.isNull() || endOfSelection.isOrphan() || startOfLastParagraph.isNull() || startOfLastParagraph.isOrphan()) {
                    endOfSelection = visiblePositionForIndex(indexForEndOfSelection, scopeForEndOfSelection.get());
                    // If endOfSelection is null, then some contents have been deleted from the document.
                    // This should never happen and if it did, exit early immediately because we've lost the loop invariant.
                    ASSERT(endOfSelection.isNotNull());
                    if (endOfSelection.isNull() || !endOfSelection.rootEditableElement())
                        return;
                    startOfLastParagraph = startOfParagraph(endOfSelection, CanSkipOverEditingBoundary);
                }

                startOfCurrentParagraph = startOfNextParagraph(endingSelection().visibleStart());
            }
            setEndingSelection(endOfSelection);
        }
        doApplyForSingleParagraph(forceListCreation, listTag, *currentSelection);
        // Fetch the end of the selection, for the reason mentioned above.
        if (endOfSelection.isNull() || endOfSelection.isOrphan()) {
            endOfSelection = visiblePositionForIndex(indexForEndOfSelection, scopeForEndOfSelection.get());
            if (endOfSelection.isNull())
                return;
        }
        if (startOfSelection.isNull() || startOfSelection.isOrphan()) {
            startOfSelection = visiblePositionForIndex(indexForStartOfSelection, scopeForStartOfSelection.get());
            if (startOfSelection.isNull())
                return;
        }
        setEndingSelection(VisibleSelection(startOfSelection, endOfSelection, endingSelection().isDirectional()));
        return;
    }

    ASSERT(endingSelection().firstRange());
    doApplyForSingleParagraph(false, listTag, *endingSelection().firstRange());
}