/* -*- 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/. */

/* rendering object for CSS "::backdrop" */

#include "nsBackdropFrame.h"

#include "nsDisplayList.h"

using namespace mozilla;

NS_IMPL_FRAMEARENA_HELPERS(nsBackdropFrame)

#ifdef DEBUG_FRAME_DUMP

nsresult

nsBackdropFrame::GetFrameName(nsAString& aResult) const

{

  return MakeFrameName(NS_LITERAL_STRING("Backdrop"), aResult);

}

#endif

/* virtual */ ComputedStyle*

nsBackdropFrame::GetParentComputedStyle(nsIFrame** aProviderFrame) const

{

  // Style context of backdrop pseudo-element does not inherit from

  // any element, per the Fullscreen API spec.

  *aProviderFrame = nullptr;

  return nullptr;

}

/* virtual */ void

nsBackdropFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,

                                  const nsDisplayListSet& aLists)

{

  DO_GLOBAL_REFLOW_COUNT_DSP("nsBackdropFrame");

  // We want this frame to always be there even if its display value is

  // none or contents so that we can respond to style change on it. To

  // support those values, we skip painting ourselves in those cases.

  auto display = StyleDisplay()->mDisplay;

  if (display == mozilla::StyleDisplay::None ||

      display == mozilla::StyleDisplay::Contents) {

    return;

  }

  DisplayBorderBackgroundOutline(aBuilder, aLists);

}

/* virtual */ LogicalSize

nsBackdropFrame::ComputeAutoSize(gfxContext*         aRenderingContext,

                                 WritingMode         aWM,

                                 const LogicalSize&  aCBSize,

                                 nscoord             aAvailableISize,

                                 const LogicalSize&  aMargin,

                                 const LogicalSize&  aBorder,

                                 const LogicalSize&  aPadding,

                                 ComputeSizeFlags    aFlags)

{

  // Note that this frame is a child of the viewport frame.

  LogicalSize result(aWM, 0xdeadbeef, NS_UNCONSTRAINEDSIZE);

  if (aFlags & ComputeSizeFlags::eShrinkWrap) {

    result.ISize(aWM) = 0;

  } else {

    result.ISize(aWM) = aAvailableISize - aMargin.ISize(aWM) -

                        aBorder.ISize(aWM) - aPadding.ISize(aWM);

  }

  return result;

}

/* virtual */ void

nsBackdropFrame::Reflow(nsPresContext* aPresContext,

                        ReflowOutput& aDesiredSize,

                        const ReflowInput& aReflowInput,

                        nsReflowStatus& aStatus)

{

  MarkInReflow();

  DO_GLOBAL_REFLOW_COUNT("nsBackdropFrame");

  DISPLAY_REFLOW(aPresContext, this, aReflowInput, aDesiredSize, aStatus);

  MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!");

  // Note that this frame is a child of the viewport frame.

  WritingMode wm = aReflowInput.GetWritingMode();

  LogicalMargin borderPadding = aReflowInput.ComputedLogicalBorderPadding();

  nscoord isize = aReflowInput.ComputedISize() + borderPadding.IStartEnd(wm);

  nscoord bsize = aReflowInput.ComputedBSize() + borderPadding.BStartEnd(wm);

  aDesiredSize.SetSize(wm, LogicalSize(wm, isize, bsize));

}