| /* |
| * Copyright (C) 2011 Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "core/editing/markers/DocumentMarker.h" |
| |
| #include "core/editing/markers/TextMatchMarker.h" |
| #include "platform/wtf/StdLibExtras.h" |
| |
| namespace blink { |
| |
| DocumentMarker::~DocumentMarker() = default; |
| |
| DocumentMarker::DocumentMarker(unsigned start_offset, unsigned end_offset) |
| : start_offset_(start_offset), end_offset_(end_offset) { |
| DCHECK_LT(start_offset_, end_offset_); |
| } |
| |
| Optional<DocumentMarker::MarkerOffsets> |
| DocumentMarker::ComputeOffsetsAfterShift(unsigned offset, |
| unsigned old_length, |
| unsigned new_length) const { |
| MarkerOffsets result; |
| result.start_offset = StartOffset(); |
| result.end_offset = EndOffset(); |
| |
| // algorithm inspired by https://dom.spec.whatwg.org/#concept-cd-replace |
| // but with some changes |
| |
| // Deviation from the concept-cd-replace algorithm: second condition in the |
| // next line (don't include text inserted immediately before a marker in the |
| // marked range, but do include the new text if it's replacing text in the |
| // marked range) |
| if (StartOffset() > offset || (StartOffset() == offset && old_length == 0)) { |
| if (StartOffset() <= offset + old_length) { |
| // Marker start was in the replaced text. Move to end of new text |
| // (Deviation from the concept-cd-replace algorithm: that algorithm |
| // would move to the beginning of the new text here) |
| result.start_offset = offset + new_length; |
| } else { |
| // Marker start was after the replaced text. Shift by length |
| // difference |
| result.start_offset = StartOffset() + new_length - old_length; |
| } |
| } |
| |
| if (EndOffset() > offset) { |
| // Deviation from the concept-cd-replace algorithm: < instead of <= in |
| // the next line |
| if (EndOffset() < offset + old_length) { |
| // Marker end was in the replaced text. Move to beginning of new text |
| result.end_offset = offset; |
| } else { |
| // Marker end was after the replaced text. Shift by length difference |
| result.end_offset = EndOffset() + new_length - old_length; |
| } |
| } |
| |
| if (result.start_offset >= result.end_offset) |
| return WTF::nullopt; |
| |
| return result; |
| } |
| |
| void DocumentMarker::ShiftOffsets(int delta) { |
| start_offset_ += delta; |
| end_offset_ += delta; |
| } |
| |
| } // namespace blink |