| // Copyright 2015 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 "third_party/blink/renderer/platform/fonts/orientation_iterator.h" |
| |
| #include <memory> |
| |
| namespace blink { |
| |
| OrientationIterator::OrientationIterator(const UChar* buffer, |
| unsigned buffer_size, |
| FontOrientation run_orientation) |
| : utf16_iterator_(std::make_unique<UTF16TextIterator>(buffer, buffer_size)), |
| buffer_size_(buffer_size), |
| at_end_(buffer_size == 0) { |
| // There's not much point in segmenting by isUprightInVertical if the text |
| // orientation is not "mixed". |
| DCHECK_EQ(run_orientation, FontOrientation::kVerticalMixed); |
| } |
| |
| bool OrientationIterator::Consume(unsigned* orientation_limit, |
| RenderOrientation* render_orientation) { |
| if (at_end_) |
| return false; |
| |
| RenderOrientation current_render_orientation = kOrientationInvalid; |
| UChar32 next_u_char32; |
| while (utf16_iterator_->Consume(next_u_char32)) { |
| if (current_render_orientation == kOrientationInvalid || |
| !Character::IsGraphemeExtended(next_u_char32)) { |
| RenderOrientation previous_render_orientation = |
| current_render_orientation; |
| current_render_orientation = |
| Character::IsUprightInMixedVertical(next_u_char32) |
| ? kOrientationKeep |
| : kOrientationRotateSideways; |
| if (previous_render_orientation != current_render_orientation && |
| previous_render_orientation != kOrientationInvalid) { |
| *orientation_limit = utf16_iterator_->Offset(); |
| *render_orientation = previous_render_orientation; |
| return true; |
| } |
| } |
| utf16_iterator_->Advance(); |
| } |
| *orientation_limit = buffer_size_; |
| *render_orientation = current_render_orientation; |
| at_end_ = true; |
| return true; |
| } |
| |
| } // namespace blink |
