layout/xul/nsStackFrame.cpp
author Chris Manchester <cmanchester@mozilla.com>
Wed, 16 Jan 2019 22:46:38 +0000
changeset 514323 471d9fab61b34671f974dfa349e7972c200faa2b
parent 508163 6f3709b3878117466168c40affa7bca0b60cf75b
child 518473 525e804dc7e63855e026be9557af15340d71455a
permissions -rw-r--r--
Bug 1507631 - Remove mentions of MOZ_SIGN_CMD from the build system. r=nalexander Differential Revision: https://phabricator.services.mozilla.com/D16754

/* -*- 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/. */

//
// Eric Vaughan
// Netscape Communications
//
// See documentation in associated header file
//

#include "nsStackFrame.h"
#include "mozilla/ComputedStyle.h"
#include "nsIContent.h"
#include "nsCOMPtr.h"
#include "nsHTMLParts.h"
#include "nsIPresShell.h"
#include "nsCSSRendering.h"
#include "nsBoxLayoutState.h"
#include "nsStackLayout.h"
#include "nsDisplayList.h"

using namespace mozilla;

nsIFrame* NS_NewStackFrame(nsIPresShell* aPresShell, ComputedStyle* aStyle) {
  return new (aPresShell) nsStackFrame(aStyle);
}

NS_IMPL_FRAMEARENA_HELPERS(nsStackFrame)

nsStackFrame::nsStackFrame(ComputedStyle* aStyle)
    : nsBoxFrame(aStyle, kClassID) {
  nsCOMPtr<nsBoxLayout> layout;
  NS_NewStackLayout(layout);
  SetXULLayoutManager(layout);
}

// REVIEW: The old code put everything in the background layer. To be more
// consistent with the way other frames work, I'm putting everything in the
// Content() (i.e., foreground) layer (see nsFrame::BuildDisplayListForChild,
// the case for stacking context but non-positioned, non-floating frames).
// This could easily be changed back by hacking
// nsBoxFrame::BuildDisplayListInternal a bit more.
void nsStackFrame::BuildDisplayListForChildren(nsDisplayListBuilder* aBuilder,
                                               const nsDisplayListSet& aLists) {
  // BuildDisplayListForChild puts stacking contexts into the
  // PositionedDescendants list. So we need to map that list to
  // aLists.Content(). This is an easy way to do that.
  nsDisplayList* content = aLists.Content();
  nsDisplayListSet kidLists(content, content, content, content, content,
                            content);
  nsIFrame* kid = mFrames.FirstChild();
  while (kid) {
    // Force each child into its own true stacking context.
    BuildDisplayListForChild(aBuilder, kid, kidLists,
                             DISPLAY_CHILD_FORCE_STACKING_CONTEXT);
    kid = kid->GetNextSibling();
  }
}