C++ VisibleSelection::isNonOrphanedCaretOrRange方法代码示例

void InsertLineBreakCommand::doApply()
{
    deleteSelection();
    VisibleSelection selection = endingSelection();
    if (!selection.isNonOrphanedCaretOrRange())
        return;

    VisiblePosition caret(selection.visibleStart());
    // FIXME: If the node is hidden, we should still be able to insert text.
    // For now, we return to avoid a crash.  https://bugs.webkit.org/show_bug.cgi?id=40342
    if (caret.isNull())
        return;

    Position pos(caret.deepEquivalent());

    pos = positionAvoidingSpecialElementBoundary(pos);

    pos = positionOutsideTabSpan(pos);

    RefPtrWillBeRawPtr<Node> nodeToInsert = nullptr;
    if (shouldUseBreakElement(pos))
        nodeToInsert = HTMLBRElement::create(document());
    else
        nodeToInsert = document().createTextNode("\n");

    // FIXME: Need to merge text nodes when inserting just after or before text.

    if (isEndOfParagraph(caret) && !lineBreakExistsAtVisiblePosition(caret)) {
        bool needExtraLineBreak = !isHTMLHRElement(*pos.anchorNode()) && !isHTMLTableElement(*pos.anchorNode());

        insertNodeAt(nodeToInsert.get(), pos);

        if (needExtraLineBreak)
            insertNodeBefore(nodeToInsert->cloneNode(false), nodeToInsert);

        VisiblePosition endingPosition = createVisiblePosition(positionBeforeNode(nodeToInsert.get()));
        setEndingSelection(VisibleSelection(endingPosition, endingSelection().isDirectional()));
    } else if (pos.computeEditingOffset() <= caretMinOffset(pos.anchorNode())) {
        insertNodeAt(nodeToInsert.get(), pos);

        // Insert an extra br or '\n' if the just inserted one collapsed.
        if (!isStartOfParagraph(createVisiblePosition(positionBeforeNode(nodeToInsert.get()))))
            insertNodeBefore(nodeToInsert->cloneNode(false).get(), nodeToInsert.get());

        setEndingSelection(VisibleSelection(positionInParentAfterNode(*nodeToInsert), TextAffinity::Downstream, endingSelection().isDirectional()));
    // If we're inserting after all of the rendered text in a text node, or into a non-text node,
    // a simple insertion is sufficient.
    } else if (!pos.anchorNode()->isTextNode() || pos.computeOffsetInContainerNode() >= caretMaxOffset(pos.anchorNode())) {
        insertNodeAt(nodeToInsert.get(), pos);
        setEndingSelection(VisibleSelection(positionInParentAfterNode(*nodeToInsert), TextAffinity::Downstream, endingSelection().isDirectional()));
    } else if (pos.anchorNode()->isTextNode()) {
        // Split a text node
        Text* textNode = toText(pos.anchorNode());
        splitTextNode(textNode, pos.computeOffsetInContainerNode());
        insertNodeBefore(nodeToInsert, textNode);
        Position endingPosition = firstPositionInNode(textNode);

        // Handle whitespace that occurs after the split
        document().updateLayoutIgnorePendingStylesheets();
        // TODO(yosin) |isRenderedCharacter()| should be removed, and we should
        // use |VisiblePosition::characterAfter()|.
        if (!isRenderedCharacter(endingPosition)) {
            Position positionBeforeTextNode(positionInParentBeforeNode(*textNode));
            // Clear out all whitespace and insert one non-breaking space
            deleteInsignificantTextDownstream(endingPosition);
            ASSERT(!textNode->layoutObject() || textNode->layoutObject()->style()->collapseWhiteSpace());
            // Deleting insignificant whitespace will remove textNode if it contains nothing but insignificant whitespace.
            if (textNode->inDocument()) {
                insertTextIntoNode(textNode, 0, nonBreakingSpaceString());
            } else {
                RefPtrWillBeRawPtr<Text> nbspNode = document().createTextNode(nonBreakingSpaceString());
                insertNodeAt(nbspNode.get(), positionBeforeTextNode);
                endingPosition = firstPositionInNode(nbspNode.get());
            }
        }

        setEndingSelection(VisibleSelection(endingPosition, TextAffinity::Downstream, endingSelection().isDirectional()));
    }

    // Handle the case where there is a typing style.

    RefPtrWillBeRawPtr<EditingStyle> typingStyle = document().frame()->selection().typingStyle();

    if (typingStyle && !typingStyle->isEmpty()) {
        // Apply the typing style to the inserted line break, so that if the selection
        // leaves and then comes back, new input will have the right style.
        // FIXME: We shouldn't always apply the typing style to the line break here,
        // see <rdar://problem/5794462>.
        applyStyle(typingStyle.get(), firstPositionInOrBeforeNode(nodeToInsert.get()), lastPositionInOrAfterNode(nodeToInsert.get()));
        // Even though this applyStyle operates on a Range, it still sets an endingSelection().
        // It tries to set a VisibleSelection around the content it operated on. So, that VisibleSelection
        // will either (a) select the line break we inserted, or it will (b) be a caret just
        // before the line break (if the line break is at the end of a block it isn't selectable).
        // So, this next call sets the endingSelection() to a caret just after the line break
        // that we inserted, or just before it if it's at the end of a block.
        setEndingSelection(endingSelection().visibleEnd());
    }

    rebalanceWhitespace();
}

void InsertLineBreakCommand::doApply(EditingState* editingState) {
  deleteSelection(editingState);
  if (editingState->isAborted())
    return;

  document().updateStyleAndLayoutIgnorePendingStylesheets();

  VisibleSelection selection = endingSelection();
  if (!selection.isNonOrphanedCaretOrRange())
    return;

  // TODO(xiaochengh): Stop storing VisiblePositions through mutations.
  VisiblePosition caret(selection.visibleStart());
  // FIXME: If the node is hidden, we should still be able to insert text. For
  // now, we return to avoid a crash.
  // https://bugs.webkit.org/show_bug.cgi?id=40342
  if (caret.isNull())
    return;

  Position pos(caret.deepEquivalent());

  pos = positionAvoidingSpecialElementBoundary(pos, editingState);
  if (editingState->isAborted())
    return;

  pos = positionOutsideTabSpan(pos);

  Node* nodeToInsert = nullptr;
  if (shouldUseBreakElement(pos))
    nodeToInsert = HTMLBRElement::create(document());
  else
    nodeToInsert = document().createTextNode("\n");

  document().updateStyleAndLayoutIgnorePendingStylesheets();

  // FIXME: Need to merge text nodes when inserting just after or before text.

  if (isEndOfParagraph(createVisiblePosition(caret.toPositionWithAffinity())) &&
      !lineBreakExistsAtVisiblePosition(caret)) {
    bool needExtraLineBreak = !isHTMLHRElement(*pos.anchorNode()) &&
                              !isHTMLTableElement(*pos.anchorNode());

    insertNodeAt(nodeToInsert, pos, editingState);
    if (editingState->isAborted())
      return;

    if (needExtraLineBreak) {
      Node* extraNode;
      // TODO(tkent): Can we remove HTMLTextFormControlElement dependency?
      if (HTMLTextFormControlElement* textControl =
              enclosingTextFormControl(nodeToInsert)) {
        extraNode = textControl->createPlaceholderBreakElement();
        // The placeholder BR should be the last child.  There might be
        // empty Text nodes at |pos|.
        appendNode(extraNode, nodeToInsert->parentNode(), editingState);
      } else {
        extraNode = nodeToInsert->cloneNode(false);
        insertNodeAfter(extraNode, nodeToInsert, editingState);
      }
      if (editingState->isAborted())
        return;
      nodeToInsert = extraNode;
    }

    setEndingSelection(SelectionInDOMTree::Builder()
                           .collapse(Position::beforeNode(nodeToInsert))
                           .setIsDirectional(endingSelection().isDirectional())
                           .build());
  } else if (pos.computeEditingOffset() <= caretMinOffset(pos.anchorNode())) {
    insertNodeAt(nodeToInsert, pos, editingState);
    if (editingState->isAborted())
      return;
    document().updateStyleAndLayoutIgnorePendingStylesheets();

    // Insert an extra br or '\n' if the just inserted one collapsed.
    if (!isStartOfParagraph(VisiblePosition::beforeNode(nodeToInsert))) {
      insertNodeBefore(nodeToInsert->cloneNode(false), nodeToInsert,
                       editingState);
      if (editingState->isAborted())
        return;
    }

    setEndingSelection(SelectionInDOMTree::Builder()
                           .collapse(Position::inParentAfterNode(*nodeToInsert))
                           .setIsDirectional(endingSelection().isDirectional())
                           .build());
    // If we're inserting after all of the rendered text in a text node, or into
    // a non-text node, a simple insertion is sufficient.
  } else if (!pos.anchorNode()->isTextNode() ||
             pos.computeOffsetInContainerNode() >=
                 caretMaxOffset(pos.anchorNode())) {
    insertNodeAt(nodeToInsert, pos, editingState);
    if (editingState->isAborted())
      return;
    setEndingSelection(SelectionInDOMTree::Builder()
                           .collapse(Position::inParentAfterNode(*nodeToInsert))
                           .setIsDirectional(endingSelection().isDirectional())
                           .build());
  } else if (pos.anchorNode()->isTextNode()) {
    // Split a text node
//.........这里部分代码省略.........