tor-browser

commit aa50a239e23842c526b42721560a33a1fd0b6c7f
parent 20427cb8aacdd00c41479e6ca91ae89acdf262a1
Author: Timothy Nikkel <tnikkel@gmail.com>
Date:   Sat, 22 Nov 2025 14:48:50 +0000

Bug 2001616. Create nsLayoutUtils::IsProperAncestorFrameConsideringContinuations function. r=layout-reviewers,emilio

Differential Revision: https://phabricator.services.mozilla.com/D273573

Diffstat:
M
layout/base/nsLayoutUtils.cpp
 | 
22
++++++++++++++++++++++
M
layout/base/nsLayoutUtils.h
 | 
11
+++++++++++

2 files changed, 33 insertions(+), 0 deletions(-)
diff --git a/layout/base/nsLayoutUtils.cpp b/layout/base/nsLayoutUtils.cpp
@@ -1103,6 +1103,28 @@ bool nsLayoutUtils::IsProperAncestorFrame(const nsIFrame* aAncestorFrame,
 }
 
 // static
+bool nsLayoutUtils::IsProperAncestorFrameConsideringContinuations(
+    const nsIFrame* aAncestorFrame, const nsIFrame* aFrame,
+    const nsIFrame* aCommonAncestor) {
+  MOZ_ASSERT(aAncestorFrame);
+  const nsIFrame* ancestorFirstContinuation =
+      aAncestorFrame->FirstContinuation();
+  if (!aFrame || aFrame->FirstContinuation() == ancestorFirstContinuation) {
+    return false;
+  }
+  const nsIFrame* commonFirstContinuation =
+      aCommonAncestor ? aCommonAncestor->FirstContinuation() : nullptr;
+  const nsIFrame* f = aFrame;
+  for (; f && f->FirstContinuation() != commonFirstContinuation;
+       f = f->GetParent()) {
+    if (f->FirstContinuation() == ancestorFirstContinuation) {
+      return true;
+    }
+  }
+  return f && commonFirstContinuation == ancestorFirstContinuation;
+}
+
+// static
 const nsIFrame* nsLayoutUtils::FillAncestors(
     const nsIFrame* aFrame, const nsIFrame* aStopAtAncestor,
     nsTArray<const nsIFrame*>* aAncestors) {
diff --git a/layout/base/nsLayoutUtils.h b/layout/base/nsLayoutUtils.h
@@ -474,6 +474,17 @@ class nsLayoutUtils {
                                     const nsIFrame* aCommonAncestor = nullptr);
 
   /**
+   * IsProperAncestorFrameConsideringContinuations checks whether aAncestorFrame
+   * or a continuation of it is an ancestor of aFrame and not equal to aFrame.
+   * @param aCommonAncestor nullptr, or a common ancestor of aFrame and
+   * aAncestorFrame. If non-null, this can bound the search and speed up
+   * the function
+   */
+  static bool IsProperAncestorFrameConsideringContinuations(
+      const nsIFrame* aAncestorFrame, const nsIFrame* aFrame,
+      const nsIFrame* aCommonAncestor = nullptr);
+
+  /**
    * Like IsProperAncestorFrame, but looks across document boundaries.
    *
    * Just like IsAncestorFrameCrossDoc, except that it returns false when