1 files changed, 121 insertions, 0 deletions
diff --git a/dom/base/RangeUtils.h b/dom/base/RangeUtils.h
new file mode 100644
index 0000000000..219c99ce34
--- /dev/null
+++ b/dom/base/RangeUtils.h
@@ -0,0 +1,121 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_RangeUtils_h
+#define mozilla_RangeUtils_h
+
+#include "mozilla/Maybe.h"
+#include "mozilla/RangeBoundary.h"
+#include "nsIContent.h"
+#include "nsINode.h"
+
+namespace mozilla {
+
+namespace dom {
+class AbstractRange;
+}  // namespace dom
+
+class RangeUtils final {
+  typedef dom::AbstractRange AbstractRange;
+
+ public:
+  /**
+   * GetRawRangeBoundaryBefore() and GetRawRangeBoundaryAfter() retrieve
+   * RawRangeBoundary which points before or after aNode.
+   */
+  static const RawRangeBoundary GetRawRangeBoundaryAfter(nsINode* aNode) {
+    MOZ_ASSERT(aNode);
+
+    if (NS_WARN_IF(!aNode->IsContent())) {
+      return RawRangeBoundary();
+    }
+
+    nsINode* parentNode = aNode->GetParentNode();
+    if (!parentNode) {
+      return RawRangeBoundary();
+    }
+    RawRangeBoundary afterNode(parentNode, aNode->AsContent());
+    // If aNode isn't in the child nodes of its parent node, we hit this case.
+    // This may occur when we're called by a mutation observer while aNode is
+    // removed from the parent node.
+    if (NS_WARN_IF(
+            !afterNode.Offset(RawRangeBoundary::OffsetFilter::kValidOffsets))) {
+      return RawRangeBoundary();
+    }
+    return afterNode;
+  }
+
+  static const RawRangeBoundary GetRawRangeBoundaryBefore(nsINode* aNode) {
+    MOZ_ASSERT(aNode);
+
+    if (NS_WARN_IF(!aNode->IsContent())) {
+      return RawRangeBoundary();
+    }
+
+    nsINode* parentNode = aNode->GetParentNode();
+    if (!parentNode) {
+      return RawRangeBoundary();
+    }
+    // If aNode isn't in the child nodes of its parent node, we hit this case.
+    // This may occur when we're called by a mutation observer while aNode is
+    // removed from the parent node.
+    const Maybe<uint32_t> indexInParent = parentNode->ComputeIndexOf(aNode);
+    if (MOZ_UNLIKELY(NS_WARN_IF(indexInParent.isNothing()))) {
+      return RawRangeBoundary();
+    }
+    return RawRangeBoundary(parentNode, *indexInParent);
+  }
+
+  /**
+   * Compute the root node of aNode for initializing range classes.
+   * When aNode is in an anonymous subtree, this returns the shadow root or
+   * binding parent.  Otherwise, the root node of the document or document
+   * fragment.  If this returns nullptr, that means aNode can be neither the
+   * start container nor end container of any range.
+   */
+  static nsINode* ComputeRootNode(nsINode* aNode);
+
+  /**
+   * XXX nsRange should accept 0 - UINT32_MAX as offset.  However, users of
+   *     nsRange treat offset as int32_t.  Additionally, some other internal
+   *     APIs like nsINode::ComputeIndexOf_Deprecated() use int32_t.  Therefore,
+   *     nsRange should accept only 0 - INT32_MAX as valid offset for now.
+   */
+  static bool IsValidOffset(uint32_t aOffset) { return aOffset <= INT32_MAX; }
+
+  /**
+   * Return true if aStartContainer/aStartOffset and aEndContainer/aEndOffset
+   * are valid start and end points for a range.  Otherwise, return false.
+   */
+  static bool IsValidPoints(nsINode* aStartContainer, uint32_t aStartOffset,
+                            nsINode* aEndContainer, uint32_t aEndOffset) {
+    return IsValidPoints(RawRangeBoundary(aStartContainer, aStartOffset),
+                         RawRangeBoundary(aEndContainer, aEndOffset));
+  }
+  template <typename SPT, typename SRT, typename EPT, typename ERT>
+  static bool IsValidPoints(const RangeBoundaryBase<SPT, SRT>& aStartBoundary,
+                            const RangeBoundaryBase<EPT, ERT>& aEndBoundary);
+
+  /**
+   * The caller needs to ensure aNode is in the same doc like aAbstractRange.
+   */
+  static Maybe<bool> IsNodeContainedInRange(nsINode& aNode,
+                                            AbstractRange* aAbstractRange);
+
+  /**
+   * Utility routine to detect if a content node starts before a range and/or
+   * ends after a range.  If neither it is contained inside the range.
+   * Note that callers responsibility to ensure node in same doc as range.
+   */
+  static nsresult CompareNodeToRange(nsINode* aNode,
+                                     AbstractRange* aAbstractRange,
+                                     bool* aNodeIsBeforeRange,
+                                     bool* aNodeIsAfterRange);
+};
+
+}  // namespace mozilla
+
+#endif  // #ifndef mozilla_RangeUtils_h