layout/base/DepthOrderedFrameList.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "DepthOrderedFrameList.h"
   8 #include "nsIFrame.h"
   9 #include "nsContainerFrame.h"
  10
  11 namespace mozilla {
  12
  13 void DepthOrderedFrameList::Add(nsIFrame* aFrame) {
  14   // Is this root already scheduled for reflow?
  15   // FIXME: This could possibly be changed to a uniqueness assertion, with some
  16   // work in ResizeReflowIgnoreOverride (and maybe others?)
  17   // FIXME(emilio): Should probably reuse the traversal for insertion.
  18   if (Contains(aFrame)) {
  19     // We don't expect frame to change depths.
  20     MOZ_ASSERT(aFrame->GetDepthInFrameTree() ==
  21                mList[mList.IndexOf(aFrame)].mDepth);
  22     return;
  23   }
  24
  25   mList.InsertElementSorted(
  26       FrameAndDepth{aFrame, aFrame->GetDepthInFrameTree()},
  27       FrameAndDepth::CompareByReverseDepth{});
  28 }
  29
  30 void DepthOrderedFrameList::Remove(nsIFrame* aFrame) {
  31   mList.RemoveElement(aFrame);
  32 }
  33
  34 nsIFrame* DepthOrderedFrameList::PopShallowestRoot() {
  35   // List is sorted in order of decreasing depth, so there are no shallower
  36   // frames than the last one.
  37   const FrameAndDepth& lastFAD = mList.PopLastElement();
  38   nsIFrame* frame = lastFAD.mFrame;
  39   // We don't expect frame to change depths.
  40   MOZ_ASSERT(frame->GetDepthInFrameTree() == lastFAD.mDepth);
  41   return frame;
  42 }
  43
  44 bool DepthOrderedFrameList::FrameIsAncestorOfAnyElement(
  45     nsIFrame* aFrame) const {
  46   MOZ_ASSERT(aFrame);
  47
  48   // Look for a path from any element to aFrame, following GetParent(). This
  49   // check mirrors what FrameNeedsReflow() would have done if the reflow root
  50   // didn't get in the way.
  51   for (nsIFrame* f : mList) {
  52     do {
  53       if (f == aFrame) {
  54         return true;
  55       }
  56       f = f->GetParent();
  57     } while (f);
  58   }
  59
  60   return false;
  61 }
  62
  63 }  // namespace mozilla