| // Copyright 2017 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "core/layout/ng/ng_block_child_iterator.h" |
| |
| #include "core/layout/ng/ng_block_break_token.h" |
| #include "core/layout/ng/ng_layout_input_node.h" |
| |
| namespace blink { |
| |
| NGBlockChildIterator::NGBlockChildIterator(NGLayoutInputNode first_child, |
| NGBlockBreakToken* break_token) |
| : child_(first_child), break_token_(break_token), child_token_idx_(0) {} |
| |
| NGBlockChildIterator::Entry NGBlockChildIterator::NextChild() { |
| NGBreakToken* child_break_token = nullptr; |
| |
| if (break_token_) { |
| // If we're resuming layout after a fragmentainer break, we need to skip |
| // siblings that we're done with. We may have been able to fully lay out |
| // some node(s) preceding a node that we had to break inside (and therefore |
| // were not able to fully lay out). This happens when we have parallel |
| // flows [1], which are caused by floats, overflow, etc. |
| // |
| // [1] https://drafts.csswg.org/css-break/#parallel-flows |
| const auto& child_break_tokens = break_token_->ChildBreakTokens(); |
| |
| do { |
| // Early exit if we've exhausted our child break tokens. |
| if (child_token_idx_ >= child_break_tokens.size()) |
| break; |
| |
| // This child break token candidate doesn't match the current node, this |
| // node must be unfinished. |
| NGBreakToken* child_break_token_candidate = |
| child_break_tokens[child_token_idx_].Get(); |
| if (child_break_token_candidate->InputNode() != child_) |
| break; |
| |
| ++child_token_idx_; |
| |
| // We have only found a node if its break token is unfinished. |
| if (!child_break_token_candidate->IsFinished()) { |
| child_break_token = child_break_token_candidate; |
| break; |
| } |
| } while ((child_ = child_.NextSibling())); |
| } |
| |
| NGLayoutInputNode child = child_; |
| if (child_) |
| child_ = child_.NextSibling(); |
| |
| return Entry(child, child_break_token); |
| } |
| |
| } // namespace blink |