third_party/WebKit/Source/core/editing/EditingStrategy.cpp

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "config.h"
   6 #include "core/editing/EditingStrategy.h"
   7
   8 #include "core/editing/EditingUtilities.h"
   9 #include "core/layout/LayoutObject.h"
  10
  11 namespace blink {
  12
  13 // If a node can contain candidates for VisiblePositions, return the offset of
  14 // the last candidate, otherwise return the number of children for container
  15 // nodes and the length for unrendered text nodes.
  16 template <typename Traversal>
  17 int EditingAlgorithm<Traversal>::caretMaxOffset(const Node& node)
  18 {
  19     // For rendered text nodes, return the last position that a caret could
  20     // occupy.
  21     if (node.isTextNode() && node.layoutObject())
  22         return node.layoutObject()->caretMaxOffset();
  23     // For containers return the number of children. For others do the same as
  24     // above.
  25     return lastOffsetForEditing(&node);
  26 }
  27
  28 template <typename Traversal>
  29 bool EditingAlgorithm<Traversal>::isEmptyNonEditableNodeInEditable(const Node* node)
  30 {
  31     // Editability is defined the DOM tree rather than the composed tree. For example:
  32     // DOM:
  33     //   <host><span>unedittable</span><shadowroot><div ce><content /></div></shadowroot></host>
  34     // Composed Tree:
  35     //   <host><div ce><span1>unedittable</span></div></host>
  36     // e.g. editing/shadow/breaking-editing-boundaries.html
  37     return !Traversal::hasChildren(*node) && !node->hasEditableStyle() && node->parentNode() && node->parentNode()->hasEditableStyle();
  38 }
  39
  40 template <typename Traversal>
  41 bool EditingAlgorithm<Traversal>::editingIgnoresContent(const Node* node)
  42 {
  43     return !node->canContainRangeEndPoint() || isEmptyNonEditableNodeInEditable(node);
  44 }
  45
  46 template <typename Traversal>
  47 int EditingAlgorithm<Traversal>::lastOffsetForEditing(const Node* node)
  48 {
  49     ASSERT(node);
  50     if (!node)
  51         return 0;
  52     if (node->offsetInCharacters())
  53         return node->maxCharacterOffset();
  54
  55     if (Traversal::hasChildren(*node))
  56         return Traversal::countChildren(*node);
  57
  58     // FIXME: Try return 0 here.
  59
  60     if (!editingIgnoresContent(node))
  61         return 0;
  62
  63     // editingIgnoresContent uses the same logic in
  64     // isEmptyNonEditableNodeInEditable (EditingUtilities.cpp). We don't
  65     // understand why this function returns 1 even when the node doesn't have
  66     // children.
  67     return 1;
  68 }
  69
  70 template <typename Strategy>
  71 Node* EditingAlgorithm<Strategy>::rootUserSelectAllForNode(Node* node)
  72 {
  73     if (!node || !nodeIsUserSelectAll(node))
  74         return nullptr;
  75     Node* parent = Strategy::parent(*node);
  76     if (!parent)
  77         return node;
  78
  79     Node* candidateRoot = node;
  80     while (parent) {
  81         if (!parent->layoutObject()) {
  82             parent = Strategy::parent(*parent);
  83             continue;
  84         }
  85         if (!nodeIsUserSelectAll(parent))
  86             break;
  87         candidateRoot = parent;
  88         parent = Strategy::parent(*candidateRoot);
  89     }
  90     return candidateRoot;
  91 }
  92
  93 template class CORE_TEMPLATE_EXPORT EditingAlgorithm<NodeTraversal>;
  94 template class CORE_TEMPLATE_EXPORT EditingAlgorithm<ComposedTreeTraversal>;
  95
  96 } // namespace blink