Remove NGCaretNavigator

This is a follow-up of changing left/right caret movements from visual
to logical. As NGCaretNavigator is designed for visual caret movements,
it no longer serves any purpose here and hence is also removed.

Bug: 958831
Change-Id: I2b18cf81ca9a997851e05617927c608b4831abbe
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1602975Reviewed-by: Emil A Eklund <eae@chromium.org>
Commit-Queue: Xiaocheng Hu <xiaochengh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#658277}

third_party/blink/renderer/core/BUILD.gn

@@ -1982,7 +1982,6 @@ jumbo_source_set("unit_tests") {
     "layout/ng/exclusions/ng_exclusion_space_test.cc",
     "layout/ng/geometry/ng_box_strut_test.cc",
     "layout/ng/inline/ng_baseline_test.cc",
-    "layout/ng/inline/ng_caret_navigator_test.cc",
     "layout/ng/inline/ng_caret_position_test.cc",
     "layout/ng/inline/ng_inline_fragment_traversal_test.cc",
     "layout/ng/inline/ng_inline_items_builder_test.cc",

third_party/blink/renderer/core/editing/visible_position.cc

@@ -31,14 +31,13 @@
 #include "third_party/blink/renderer/core/dom/document.h"
 #include "third_party/blink/renderer/core/dom/text.h"
 #include "third_party/blink/renderer/core/editing/editing_utilities.h"
+#include "third_party/blink/renderer/core/editing/local_caret_rect.h"
 #include "third_party/blink/renderer/core/editing/ng_flat_tree_shorthands.h"
 #include "third_party/blink/renderer/core/editing/text_affinity.h"
 #include "third_party/blink/renderer/core/editing/visible_units.h"
 #include "third_party/blink/renderer/core/html/html_element.h"
 #include "third_party/blink/renderer/core/html_names.h"
 #include "third_party/blink/renderer/core/layout/layout_object.h"
-#include "third_party/blink/renderer/core/layout/ng/inline/ng_caret_navigator.h"
-#include "third_party/blink/renderer/core/layout/ng/inline/ng_inline_node.h"
 #include "third_party/blink/renderer/core/layout/ng/inline/ng_offset_mapping.h"
 #include "third_party/blink/renderer/platform/bindings/exception_state.h"
 #include "third_party/blink/renderer/platform/geometry/float_quad.h"
@@ -100,36 +99,10 @@ VisiblePositionTemplate<Strategy> VisiblePositionTemplate<Strategy>::Create(
     const PositionWithAffinityTemplate<Strategy> upstream_position(
         deep_position, TextAffinity::kUpstream);
 
-    if (!InSameLine(downstream_position, upstream_position))
+    if (AbsoluteCaretBoundsOf(downstream_position) !=
+        AbsoluteCaretBoundsOf(upstream_position)) {
       return VisiblePositionTemplate<Strategy>(upstream_position);
-
-    if (!NGOffsetMapping::AcceptsPosition(ToPositionInDOMTree(deep_position))) {
-      // editing/selection/mixed-editability-10.html reaches here.
-      // We can't check bidi in such case. Use downstream as the default.
-      // TODO(xiaochengh): Investigate why we reach here and how to work around.
-      return VisiblePositionTemplate<Strategy>(downstream_position);
     }
-
-    // Check if the position is at bidi boundary.
-    const LayoutObject* layout_object =
-        deep_position.AnchorNode()->GetLayoutObject();
-    DCHECK(layout_object) << position_with_affinity;
-    if (!layout_object->IsInline())
-      return VisiblePositionTemplate<Strategy>(downstream_position);
-    LayoutBlockFlow* const context =
-        NGOffsetMapping::GetInlineFormattingContextOf(*layout_object);
-    DCHECK(context);
-    DCHECK(context->IsLayoutNGMixin());
-
-    const NGOffsetMapping* mapping = NGInlineNode::GetOffsetMapping(context);
-    DCHECK(mapping);
-
-    const base::Optional<unsigned> offset =
-        mapping->GetTextContentOffset(ToPositionInDOMTree(deep_position));
-    DCHECK(offset.has_value());
-
-    if (NGCaretNavigator(*context).OffsetIsBidiBoundary(offset.value()))
-      return VisiblePositionTemplate<Strategy>(upstream_position);
     return VisiblePositionTemplate<Strategy>(downstream_position);
   }
 

third_party/blink/renderer/core/layout/BUILD.gn

@@ -329,8 +329,6 @@ blink_core_sources("layout") {
     "ng/inline/ng_baseline.h",
     "ng/inline/ng_bidi_paragraph.cc",
     "ng/inline/ng_bidi_paragraph.h",
-    "ng/inline/ng_caret_navigator.cc",
-    "ng/inline/ng_caret_navigator.h",
     "ng/inline/ng_caret_position.cc",
     "ng/inline/ng_caret_position.h",
     "ng/inline/ng_caret_rect.cc",

third_party/blink/renderer/core/layout/ng/inline/README.md

@@ -309,11 +309,6 @@ In a bird's‐eye view, it consists of two parts:
 content of an inline formatting context (computed in [pre-layout]) and DOM
 positions in the context. See [design doc](https://goo.gl/CJbxky) for details.
 
-[NGCaretNavigator] provides functions for inspecting bidi levels and visual
-ordering of text content, and supports visual left/right caret movements in the
-text. See [design doc](http://bit.ly/2QVAwGq) for details.
-
-
 [ICU BiDi]: http://userguide.icu-project.org/transforms/bidi
 [UAX#9 Unicode Bidirectional Algorithm]: http://unicode.org/reports/tr9/
 [UAX#9 Resolving Embedding Levels]: http://www.unicode.org/reports/tr9/#Resolving_Embedding_Levels
@@ -322,7 +317,6 @@ text. See [design doc](http://bit.ly/2QVAwGq) for details.
 [FontBaseline]: ../../../platform/fonts/FontBaseline.h
 [NGBaselineAlgorithmType]: ng_baseline.h
 [NGBaselineRequest]: ng_baseline.h
-[NGCaretNavigator]: ng_caret_navigator.h
 [NGBidiParagraph]: ng_bidi_paragraph.h
 [NGBlockNode]: ../ng_block_node.h
 [NGBoxFragment]: ../ng_box_fragment.h

third_party/blink/renderer/core/layout/ng/inline/ng_caret_navigator.h

-// Copyright 2018 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.
-
-#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_NG_INLINE_NG_CARET_NAVIGATOR_H_
-#define THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_NG_INLINE_NG_CARET_NAVIGATOR_H_
-
-#include "base/optional.h"
-#include "third_party/blink/renderer/core/core_export.h"
-#include "third_party/blink/renderer/core/dom/document_lifecycle.h"
-#include "third_party/blink/renderer/core/editing/text_affinity.h"
-#include "third_party/blink/renderer/platform/text/text_direction.h"
-#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
-#include "third_party/blink/renderer/platform/wtf/vector.h"
-
-#include <unicode/ubidi.h>
-
-namespace blink {
-
-class LayoutBlockFlow;
-struct NGInlineNodeData;
-
-// Hosts the |text_content| of an inline formatting context and provides
-// bidi-related utilities, including checking bidi levels, computing visual
-// left/right characters and visual left/right caret movements.
-// Design doc: http://bit.ly/2QVAwGq
-class CORE_EXPORT NGCaretNavigator {
-  STACK_ALLOCATED();
-
- public:
-  explicit NGCaretNavigator(const LayoutBlockFlow&);
-  ~NGCaretNavigator();
-
-  const String& GetText() const;
-  bool IsBidiEnabled() const;
-
-  // Abstraction of a caret position in |text_|.
-  enum class PositionAnchorType { kBefore, kAfter };
-  struct Position {
-    // |index| is character index the |text_| string.
-    unsigned index;
-    PositionAnchorType type;
-
-    bool IsBeforeCharacter() const {
-      return type == PositionAnchorType::kBefore;
-    }
-
-    bool IsAfterCharacter() const { return type == PositionAnchorType::kAfter; }
-
-    bool operator==(const Position& other) const {
-      return index == other.index && type == other.type;
-    }
-  };
-
-  // Returns the bidi level or resolved direction of the character at the given
-  // logical |index|.
-  UBiDiLevel BidiLevelAt(unsigned index) const;
-  TextDirection TextDirectionAt(unsigned index) const;
-
-  // Returns true if the characters at indexes |offset - 1| and |offset| both
-  // exist and are at different bidi levels.
-  bool OffsetIsBidiBoundary(unsigned offset) const;
-
-  // Converts an (offset, affinity) pair into a |Position| type of this class.
-  // Intiontionally long name to indicate the hackiness for handling legacy
-  // callers.
-  Position CaretPositionFromTextContentOffsetAndAffinity(
-      unsigned offset,
-      TextAffinity affinity) const;
-
-  // Returns the visual left/right edge caret position of the character at the
-  // given logical |index|.
-  Position LeftEdgeOf(unsigned index) const;
-  Position RightEdgeOf(unsigned index) const;
-
-  // Left/right visual movements
-  // TODO(xiaochengh): Handle the following
-  // - Grapheme clusters
-
-  enum class VisualMovementResultType {
-    kWithinContext,
-    kBeforeContext,
-    kAfterContext,
-    kEnteredChildContext
-  };
-
-  // Given the character at the logical |index|, returns the logical index of
-  // the character at its left/right side.
-  struct VisualCharacterMovementResult {
-    bool IsWithinContext() const {
-      return type == VisualMovementResultType::kWithinContext;
-    }
-    bool IsBeforeContext() const {
-      return type == VisualMovementResultType::kBeforeContext;
-    }
-    bool IsAfterContext() const {
-      return type == VisualMovementResultType::kAfterContext;
-    }
-
-    VisualMovementResultType type;
-    base::Optional<unsigned> index;
-  };
-  VisualCharacterMovementResult LeftCharacterOf(unsigned index) const;
-  VisualCharacterMovementResult RightCharacterOf(unsigned index) const;
-
-  // Given a caret position, moves it left/right by one grapheme cluster and
-  // returns the result.
-  // Note: If we end up entering an inline block, the result |Position| is
-  // either before or after the inline block, depending on from which side the
-  // inline block is entered. For example:
-  // RightPositionOf(abc|<inline-block>def</inline-block>ghi)
-  // -> {inline-block, PositionAnchorType::kBefore}
-  // LeftPositionOf(abc<inline-block>def</inline-block>|ghi)
-  // -> {inline-block, PositionAnchorType::kAfter}
-  struct VisualCaretMovementResult {
-    bool IsWithinContext() const {
-      return type == VisualMovementResultType::kWithinContext;
-    }
-    bool IsBeforeContext() const {
-      return type == VisualMovementResultType::kBeforeContext;
-    }
-    bool IsAfterContext() const {
-      return type == VisualMovementResultType::kAfterContext;
-    }
-    bool HasEnteredChildContext() const {
-      return type == VisualMovementResultType::kEnteredChildContext;
-    }
-
-    VisualMovementResultType type;
-    base::Optional<Position> position;
-  };
-  VisualCaretMovementResult LeftPositionOf(const Position&) const;
-  VisualCaretMovementResult RightPositionOf(const Position&) const;
-
-  // TODO(xiaochengh): Specify and implement the behavior in edge cases, e.g.,
-  // when the leftmost character of the first line is CSS-generated.
-  Position LeftmostPositionInFirstLine() const;
-  Position RightmostPositionInFirstLine() const;
-  Position LeftmostPositionInLastLine() const;
-  Position RightmostPositionInLastLine() const;
-
- private:
-  // A caret position is invalid if it is:
-  // - kAfter to a line break character.
-  // - Anchored to a collapsible space that's removed by line wrap.
-  // - Anchored to a character that's ignored in caret movement.
-  bool IsValidCaretPosition(const Position&) const;
-  bool IsLineBreak(unsigned index) const;
-  bool IsCollapsibleWhitespace(unsigned index) const;
-  bool IsCollapsedSpaceByLineWrap(unsigned index) const;
-  bool IsIgnoredInCaretMovement(unsigned index) const;
-
-  // Returns true if the character at |index| represents a child block
-  // formatting context that can be entered by caret navigation. Such contexts
-  // must be atomic inlines (inline block, inline table, ...) and must not host
-  // user agent shadow tree (which excludes, e.g., <input> and image alt text).
-  bool IsEnterableChildContext(unsigned index) const;
-
-  enum class MoveDirection { kTowardsLeft, kTowardsRight };
-  static MoveDirection OppositeDirectionOf(MoveDirection);
-  static bool TowardsSameDirection(MoveDirection, TextDirection);
-
-  // ------ Line-related functions ------
-
-  // A line contains a consecutive substring of |GetText()|. The lines should
-  // not overlap, and should together cover the entire |GetText()|.
-  struct Line {
-    unsigned start_offset;
-    unsigned end_offset;
-    TextDirection base_direction;
-  };
-  Line ContainingLineOf(unsigned index) const;
-  Vector<int32_t, 32> CharacterIndicesInVisualOrder(const Line&) const;
-  unsigned VisualMostForwardCharacterOf(const Line&,
-                                        MoveDirection direction) const;
-  unsigned VisualLastCharacterOf(const Line&) const;
-  unsigned VisualFirstCharacterOf(const Line&) const;
-
-  // ------ Implementation of public visual movement functions ------
-
-  Position EdgeOfInternal(unsigned index, MoveDirection) const;
-  VisualCharacterMovementResult MoveCharacterInternal(unsigned index,
-                                                      MoveDirection) const;
-  VisualCaretMovementResult MoveCaretInternal(const Position&,
-                                              MoveDirection) const;
-
-  // Performs a "minimal" caret movement to the left/right without validating
-  // the result. The result might be invalid due to, e.g., anchored to an
-  // unallowed character, being visually the same as the input, etc. It's a
-  // subroutine of |MoveCaretInternal|, who keeps calling it until both of the
-  // folliwng are satisfied:
-  // - We've reached a valid caret position.
-  // - During the process, the caret has moved passing a character on which
-  // |IsIgnoredInCaretMovement| is false (indicated by |has_passed_character|).
-  struct UnvalidatedVisualCaretMovementResult {
-    VisualMovementResultType type;
-    base::Optional<Position> position;
-    bool has_passed_character = false;
-  };
-  UnvalidatedVisualCaretMovementResult MoveCaretWithoutValidation(
-      const Position&,
-      MoveDirection) const;
-
-  const NGInlineNodeData& GetData() const;
-
-  const LayoutBlockFlow& context_;
-  DocumentLifecycle::DisallowTransitionScope disallow_transition_;
-};
-
-CORE_EXPORT std::ostream& operator<<(std::ostream&,
-                                     const NGCaretNavigator::Position&);
-
-}  // namespace blink
-
-#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_NG_INLINE_NG_CARET_NAVIGATOR_H_

third_party/blink/renderer/core/layout/ng/inline/ng_offset_mapping.cc

@@ -12,7 +12,6 @@
 #include "third_party/blink/renderer/core/editing/ephemeral_range.h"
 #include "third_party/blink/renderer/core/editing/position.h"
 #include "third_party/blink/renderer/core/layout/layout_text_fragment.h"
-#include "third_party/blink/renderer/core/layout/ng/inline/ng_caret_navigator.h"
 #include "third_party/blink/renderer/core/layout/ng/inline/ng_inline_node.h"
 #include "third_party/blink/renderer/core/layout/ng/ng_block_node.h"
 #include "third_party/blink/renderer/platform/text/character.h"
@@ -509,16 +508,6 @@ Position NGOffsetMapping::GetLastPosition(unsigned offset) const {
   return CreatePositionForOffsetMapping(node, dom_offset);
 }
 
-PositionWithAffinity NGOffsetMapping::GetPositionWithAffinity(
-    const NGCaretNavigator::Position& position) const {
-  if (position.IsBeforeCharacter()) {
-    return PositionWithAffinity(GetLastPosition(position.index),
-                                TextAffinity::kDownstream);
-  }
-  return PositionWithAffinity(GetFirstPosition(position.index + 1),
-                              TextAffinity::kUpstream);
-}
-
 bool NGOffsetMapping::HasBidiControlCharactersOnly(unsigned start,
                                                    unsigned end) const {
   DCHECK_LE(start, end);

third_party/blink/renderer/core/layout/ng/inline/ng_offset_mapping.h

@@ -9,7 +9,6 @@
 #include "third_party/blink/renderer/core/core_export.h"
 #include "third_party/blink/renderer/core/dom/node.h"
 #include "third_party/blink/renderer/core/editing/forward.h"
-#include "third_party/blink/renderer/core/layout/ng/inline/ng_caret_navigator.h"
 #include "third_party/blink/renderer/platform/heap/handle.h"
 #include "third_party/blink/renderer/platform/heap/persistent.h"
 #include "third_party/blink/renderer/platform/wtf/allocator.h"
@@ -219,13 +218,6 @@ class CORE_EXPORT NGOffsetMapping {
   Position GetFirstPosition(unsigned) const;
   Position GetLastPosition(unsigned) const;
 
-  // Converts the given caret position on text content to a PositionWithAffinity
-  // in DOM. If |position| is before a character, the function creates a
-  // downstream position before |GetLastPosition()| of the character; otherwise,
-  // it returns an upstream position after |GetFirstPosition()| of the character
-  PositionWithAffinity GetPositionWithAffinity(
-      const NGCaretNavigator::Position& position) const;
-
   // Returns all NGOffsetMappingUnits whose text content ranges has non-empty
   // (but possibly collapsed) intersection with (start, end). Note that units
   // that only "touch" |start| or |end| are excluded.

third_party/blink/renderer/core/layout/ng/inline/ng_offset_mapping_builder.cc

@@ -7,7 +7,6 @@
 #include <utility>
 #include "third_party/blink/renderer/core/layout/layout_text.h"
 #include "third_party/blink/renderer/core/layout/layout_text_fragment.h"
-#include "third_party/blink/renderer/core/layout/ng/inline/ng_caret_navigator.h"
 #include "third_party/blink/renderer/core/layout/ng/inline/ng_offset_mapping.h"
 
 namespace blink {