layout/xul/nsStackFrame.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 //
   8 // Eric Vaughan
   9 // Netscape Communications
  10 //
  11 // See documentation in associated header file
  12 //
  13
  14 #include "nsStackFrame.h"
  15 #include "mozilla/ComputedStyle.h"
  16 #include "nsIContent.h"
  17 #include "nsCOMPtr.h"
  18 #include "nsHTMLParts.h"
  19 #include "nsIPresShell.h"
  20 #include "nsCSSRendering.h"
  21 #include "nsBoxLayoutState.h"
  22 #include "nsStackLayout.h"
  23 #include "nsDisplayList.h"
  24
  25 using namespace mozilla;
  26
  27 nsIFrame* NS_NewStackFrame(nsIPresShell* aPresShell, ComputedStyle* aStyle) {
  28   return new (aPresShell) nsStackFrame(aStyle);
  29 }
  30
  31 NS_IMPL_FRAMEARENA_HELPERS(nsStackFrame)
  32
  33 nsStackFrame::nsStackFrame(ComputedStyle* aStyle)
  34     : nsBoxFrame(aStyle, kClassID) {
  35   nsCOMPtr<nsBoxLayout> layout;
  36   NS_NewStackLayout(layout);
  37   SetXULLayoutManager(layout);
  38 }
  39
  40 // REVIEW: The old code put everything in the background layer. To be more
  41 // consistent with the way other frames work, I'm putting everything in the
  42 // Content() (i.e., foreground) layer (see nsFrame::BuildDisplayListForChild,
  43 // the case for stacking context but non-positioned, non-floating frames).
  44 // This could easily be changed back by hacking
  45 // nsBoxFrame::BuildDisplayListInternal a bit more.
  46 void nsStackFrame::BuildDisplayListForChildren(nsDisplayListBuilder* aBuilder,
  47                                                const nsDisplayListSet& aLists) {
  48   // BuildDisplayListForChild puts stacking contexts into the
  49   // PositionedDescendants list. So we need to map that list to
  50   // aLists.Content(). This is an easy way to do that.
  51   nsDisplayList* content = aLists.Content();
  52   nsDisplayListSet kidLists(content, content, content, content, content,
  53                             content);
  54   nsIFrame* kid = mFrames.FirstChild();
  55   while (kid) {
  56     // Force each child into its own true stacking context.
  57     BuildDisplayListForChild(aBuilder, kid, kidLists,
  58                              DISPLAY_CHILD_FORCE_STACKING_CONTEXT);
  59     kid = kid->GetNextSibling();
  60   }
  61 }