layout/generic/nsBackdropFrame.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 /* rendering object for CSS "::backdrop" */
   8
   9 #include "nsBackdropFrame.h"
  10
  11 #include "mozilla/PresShell.h"
  12 #include "nsDisplayList.h"
  13
  14 using namespace mozilla;
  15
  16 NS_IMPL_FRAMEARENA_HELPERS(nsBackdropFrame)
  17
  18 #ifdef DEBUG_FRAME_DUMP
  19 nsresult nsBackdropFrame::GetFrameName(nsAString& aResult) const {
  20   return MakeFrameName(u"Backdrop"_ns, aResult);
  21 }
  22 #endif
  23
  24 /* virtual */
  25 ComputedStyle* nsBackdropFrame::GetParentComputedStyle(
  26     nsIFrame** aProviderFrame) const {
  27   // Style context of backdrop pseudo-element does not inherit from
  28   // any element, per the Fullscreen API spec.
  29   *aProviderFrame = nullptr;
  30   return nullptr;
  31 }
  32
  33 /* virtual */
  34 void nsBackdropFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
  35                                        const nsDisplayListSet& aLists) {
  36   DO_GLOBAL_REFLOW_COUNT_DSP("nsBackdropFrame");
  37   // We want this frame to always be there even if its display value is
  38   // none or contents so that we can respond to style change on it. To
  39   // support those values, we skip painting ourselves in those cases.
  40   auto display = StyleDisplay()->mDisplay;
  41   if (display == mozilla::StyleDisplay::None ||
  42       display == mozilla::StyleDisplay::Contents) {
  43     return;
  44   }
  45
  46   DisplayBorderBackgroundOutline(aBuilder, aLists);
  47 }
  48
  49 /* virtual */
  50 LogicalSize nsBackdropFrame::ComputeAutoSize(
  51     gfxContext* aRenderingContext, WritingMode aWM, const LogicalSize& aCBSize,
  52     nscoord aAvailableISize, const LogicalSize& aMargin,
  53     const LogicalSize& aBorderPadding, const StyleSizeOverrides& aSizeOverrides,
  54     ComputeSizeFlags aFlags) {
  55   // Note that this frame is a child of the viewport frame.
  56   LogicalSize result(aWM, 0xdeadbeef, NS_UNCONSTRAINEDSIZE);
  57   if (aFlags.contains(ComputeSizeFlag::ShrinkWrap)) {
  58     result.ISize(aWM) = 0;
  59   } else {
  60     result.ISize(aWM) =
  61         aAvailableISize - aMargin.ISize(aWM) - aBorderPadding.ISize(aWM);
  62   }
  63   return result;
  64 }
  65
  66 /* virtual */
  67 void nsBackdropFrame::Reflow(nsPresContext* aPresContext,
  68                              ReflowOutput& aDesiredSize,
  69                              const ReflowInput& aReflowInput,
  70                              nsReflowStatus& aStatus) {
  71   MarkInReflow();
  72   DO_GLOBAL_REFLOW_COUNT("nsBackdropFrame");
  73   DISPLAY_REFLOW(aPresContext, this, aReflowInput, aDesiredSize, aStatus);
  74   MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!");
  75
  76   // Note that this frame is a child of the viewport frame.
  77   WritingMode wm = aReflowInput.GetWritingMode();
  78   aDesiredSize.SetSize(wm, aReflowInput.ComputedSizeWithBorderPadding(wm));
  79 }