Index: third_party/WebKit/Source/core/editing/state_machines/BackwardCodePointStateMachine.cpp |
diff --git a/third_party/WebKit/Source/core/editing/state_machines/BackwardCodePointStateMachine.cpp b/third_party/WebKit/Source/core/editing/state_machines/BackwardCodePointStateMachine.cpp |
new file mode 100644 |
index 0000000000000000000000000000000000000000..022aa03ad2643682269552429324f6bf01b60a17 |
--- /dev/null |
+++ b/third_party/WebKit/Source/core/editing/state_machines/BackwardCodePointStateMachine.cpp |
@@ -0,0 +1,69 @@ |
+// 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/editing/state_machines/BackwardCodePointStateMachine.h" |
+ |
+namespace blink { |
+ |
+enum class BackwardCodePointStateMachine::BackwardCodePointState { |
+ NotSurrogate, |
+ TrailSurrogate, |
+ Invalid, |
+}; |
+ |
+BackwardCodePointStateMachine::BackwardCodePointStateMachine() |
+ : m_state(BackwardCodePointState::NotSurrogate) {} |
+ |
+TextSegmentationMachineState |
+BackwardCodePointStateMachine::feedPrecedingCodeUnit(UChar codeUnit) { |
+ switch (m_state) { |
+ case BackwardCodePointState::NotSurrogate: |
+ if (U16_IS_LEAD(codeUnit)) { |
+ m_codeUnitsToBeDeleted = 0; |
+ m_state = BackwardCodePointState::Invalid; |
+ return TextSegmentationMachineState::Invalid; |
+ } |
+ ++m_codeUnitsToBeDeleted; |
+ if (U16_IS_TRAIL(codeUnit)) { |
+ m_state = BackwardCodePointState::TrailSurrogate; |
+ return TextSegmentationMachineState::NeedMoreCodeUnit; |
+ } |
+ return TextSegmentationMachineState::Finished; |
+ case BackwardCodePointState::TrailSurrogate: |
+ if (U16_IS_LEAD(codeUnit)) { |
+ ++m_codeUnitsToBeDeleted; |
+ m_state = BackwardCodePointState::NotSurrogate; |
+ return TextSegmentationMachineState::Finished; |
+ } |
+ m_codeUnitsToBeDeleted = 0; |
+ m_state = BackwardCodePointState::Invalid; |
+ return TextSegmentationMachineState::Invalid; |
+ case BackwardCodePointState::Invalid: |
+ m_codeUnitsToBeDeleted = 0; |
+ return TextSegmentationMachineState::Invalid; |
+ } |
+ NOTREACHED(); |
+ return TextSegmentationMachineState::Invalid; |
+} |
+ |
+TextSegmentationMachineState |
+BackwardCodePointStateMachine::feedFollowingCodeUnit(UChar codeUnit) { |
+ NOTREACHED(); |
+ return TextSegmentationMachineState::Invalid; |
+} |
+ |
+bool BackwardCodePointStateMachine::atCodePointBoundary() { |
+ return m_state == BackwardCodePointState::NotSurrogate; |
+} |
+ |
+int BackwardCodePointStateMachine::getBoundaryOffset() { |
+ return -m_codeUnitsToBeDeleted; |
+} |
+ |
+void BackwardCodePointStateMachine::reset() { |
+ m_codeUnitsToBeDeleted = 0; |
+ m_state = BackwardCodePointState::NotSurrogate; |
+} |
+ |
+} // namespace blink |