/* -*- 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 HTML <br> elements */

#include "gfxContext.h"

#include "nsCOMPtr.h"

#include "nsContainerFrame.h"

#include "nsFontMetrics.h"

#include "nsFrame.h"

#include "nsPresContext.h"

#include "nsLineLayout.h"

#include "nsStyleConsts.h"

#include "nsGkAtoms.h"

#include "nsLayoutUtils.h"

//FOR SELECTION

#include "nsIContent.h"

//END INCLUDES FOR SELECTION

using namespace mozilla;

namespace mozilla {

class BRFrame final : public nsFrame

{

public:

  NS_DECL_FRAMEARENA_HELPERS(BRFrame)

  friend nsIFrame* ::NS_NewBRFrame(nsIPresShell* aPresShell, ComputedStyle* aStyle);

  ContentOffsets CalcContentOffsetsFromFramePoint(const nsPoint& aPoint) override;

  virtual FrameSearchResult PeekOffsetNoAmount(bool aForward, int32_t* aOffset) override;

  virtual FrameSearchResult

  PeekOffsetCharacter(bool aForward, int32_t* aOffset,

                      PeekOffsetCharacterOptions aOptions =

                        PeekOffsetCharacterOptions()) override;

  virtual FrameSearchResult PeekOffsetWord(bool aForward, bool aWordSelectEatSpace,

                              bool aIsKeyboardSelect, int32_t* aOffset,

                              PeekWordState* aState) override;

  virtual void Reflow(nsPresContext* aPresContext,

                          ReflowOutput& aDesiredSize,

                          const ReflowInput& aReflowInput,

                          nsReflowStatus& aStatus) override;

  virtual void AddInlineMinISize(gfxContext *aRenderingContext,

                                 InlineMinISizeData *aData) override;

  virtual void AddInlinePrefISize(gfxContext *aRenderingContext,

                                  InlinePrefISizeData *aData) override;

  virtual nscoord GetMinISize(gfxContext *aRenderingContext) override;

  virtual nscoord GetPrefISize(gfxContext *aRenderingContext) override;

  virtual nscoord GetLogicalBaseline(mozilla::WritingMode aWritingMode) const override;

  virtual bool IsFrameOfType(uint32_t aFlags) const override

  {

    return nsFrame::IsFrameOfType(aFlags & ~(nsIFrame::eReplaced |

                                             nsIFrame::eLineParticipant));

  }

#ifdef ACCESSIBILITY

  virtual mozilla::a11y::AccType AccessibleType() override;

#endif

protected:

  explicit BRFrame(ComputedStyle* aStyle)

    : nsFrame(aStyle, kClassID)

    , mAscent(NS_INTRINSIC_WIDTH_UNKNOWN)

  {}

  virtual ~BRFrame();

  nscoord mAscent;

};

} // namespace mozilla

nsIFrame*

NS_NewBRFrame(nsIPresShell* aPresShell, ComputedStyle* aStyle)

{

  return new (aPresShell) BRFrame(aStyle);

}

NS_IMPL_FRAMEARENA_HELPERS(BRFrame)

BRFrame::~BRFrame()

{

}

void

BRFrame::Reflow(nsPresContext* aPresContext,

                ReflowOutput& aMetrics,

                const ReflowInput& aReflowInput,

                nsReflowStatus& aStatus)

{

  MarkInReflow();

  DO_GLOBAL_REFLOW_COUNT("BRFrame");

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

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

  WritingMode wm = aReflowInput.GetWritingMode();

  LogicalSize finalSize(wm);

  finalSize.BSize(wm) = 0; // BR frames with block size 0 are ignored in quirks

                           // mode by nsLineLayout::VerticalAlignFrames .

                           // However, it's not always 0.  See below.

  finalSize.ISize(wm) = 0;

  aMetrics.SetBlockStartAscent(0);

  // Only when the BR is operating in a line-layout situation will it

  // behave like a BR. Additionally, we suppress breaks from BR inside

  // of ruby frames. To determine if we're inside ruby, we have to rely

  // on the *parent's* ShouldSuppressLineBreak() method, instead of our

  // own, because we may have custom "display" value that makes our

  // ShouldSuppressLineBreak() return false.

  nsLineLayout* ll = aReflowInput.mLineLayout;

  if (ll && !GetParent()->Style()->ShouldSuppressLineBreak()) {

    // Note that the compatibility mode check excludes AlmostStandards

    // mode, since this is the inline box model.  See bug 161691.

    if ( ll->LineIsEmpty() ||

         aPresContext->CompatibilityMode() == eCompatibility_FullStandards ) {

      // The line is logically empty; any whitespace is trimmed away.

      //

      // If this frame is going to terminate the line we know

      // that nothing else will go on the line. Therefore, in this

      // case, we provide some height for the BR frame so that it

      // creates some vertical whitespace.  It's necessary to use the

      // line-height rather than the font size because the

      // quirks-mode fix that doesn't apply the block's min

      // line-height makes this necessary to make BR cause a line

      // of the full line-height

      // We also do this in strict mode because BR should act like a

      // normal inline frame.  That line-height is used is important

      // here for cases where the line-height is less than 1.

      RefPtr<nsFontMetrics> fm =

        nsLayoutUtils::GetInflatedFontMetricsForFrame(this);

      if (fm) {

        nscoord logicalHeight = aReflowInput.CalcLineHeight();

        finalSize.BSize(wm) = logicalHeight;

        aMetrics.SetBlockStartAscent(nsLayoutUtils::GetCenteredFontBaseline(

                                       fm, logicalHeight, wm.IsLineInverted()));

      }

      else {

        aMetrics.SetBlockStartAscent(aMetrics.BSize(wm) = 0);

      }

      // XXX temporary until I figure out a better solution; see the

      // code in nsLineLayout::VerticalAlignFrames that zaps minY/maxY

      // if the width is zero.

      // XXX This also fixes bug 10036!

      // Warning: nsTextControlFrame::CalculateSizeStandard depends on

      // the following line, see bug 228752.

      // The code below in AddInlinePrefISize also adds 1 appunit to width

      finalSize.ISize(wm) = 1;

    }

    // Return our reflow status

    StyleClear breakType = aReflowInput.mStyleDisplay->mBreakType;

    if (StyleClear::None == breakType) {

      breakType = StyleClear::Line;

    }

    aStatus.SetInlineLineBreakAfter(breakType);

    ll->SetLineEndsInBR(true);

  }

  aMetrics.SetSize(wm, finalSize);

  aMetrics.SetOverflowAreasToDesiredBounds();

  mAscent = aMetrics.BlockStartAscent();

  NS_FRAME_SET_TRUNCATION(aStatus, aReflowInput, aMetrics);

}

/* virtual */ void

BRFrame::AddInlineMinISize(gfxContext *aRenderingContext,

                           nsIFrame::InlineMinISizeData *aData)

{

  if (!GetParent()->Style()->ShouldSuppressLineBreak()) {

    aData->ForceBreak();

  }

}

/* virtual */ void

BRFrame::AddInlinePrefISize(gfxContext *aRenderingContext,

                            nsIFrame::InlinePrefISizeData *aData)

{

  if (!GetParent()->Style()->ShouldSuppressLineBreak()) {

    // Match the 1 appunit width assigned in the Reflow method above

    aData->mCurrentLine += 1;

    aData->ForceBreak();

  }

}

/* virtual */ nscoord

BRFrame::GetMinISize(gfxContext *aRenderingContext)

{

  nscoord result = 0;

  DISPLAY_MIN_INLINE_SIZE(this, result);

  return result;

}

/* virtual */ nscoord

BRFrame::GetPrefISize(gfxContext *aRenderingContext)

{

  nscoord result = 0;

  DISPLAY_PREF_INLINE_SIZE(this, result);

  return result;

}

nscoord

BRFrame::GetLogicalBaseline(mozilla::WritingMode aWritingMode) const

{

  return mAscent;

}

nsIFrame::ContentOffsets BRFrame::CalcContentOffsetsFromFramePoint(const nsPoint& aPoint)

{

  ContentOffsets offsets;

  offsets.content = mContent->GetParent();

  if (offsets.content) {

    offsets.offset = offsets.content->ComputeIndexOf(mContent);

    offsets.secondaryOffset = offsets.offset;

    offsets.associate = CARET_ASSOCIATE_AFTER;

  }

  return offsets;

}

nsIFrame::FrameSearchResult

BRFrame::PeekOffsetNoAmount(bool aForward, int32_t* aOffset)

{

  NS_ASSERTION (aOffset && *aOffset <= 1, "aOffset out of range");

  int32_t startOffset = *aOffset;

  // If we hit the end of a BR going backwards, go to its beginning and stay there.

  if (!aForward && startOffset != 0) {

    *aOffset = 0;

    return FOUND;

  }

  // Otherwise, stop if we hit the beginning, continue (forward) if we hit the end.

  return (startOffset == 0) ? FOUND : CONTINUE;

}

nsIFrame::FrameSearchResult

BRFrame::PeekOffsetCharacter(bool aForward, int32_t* aOffset,

                             PeekOffsetCharacterOptions aOptions)

{

  NS_ASSERTION (aOffset && *aOffset <= 1, "aOffset out of range");

  // Keep going. The actual line jumping will stop us.

  return CONTINUE;

}

nsIFrame::FrameSearchResult

BRFrame::PeekOffsetWord(bool aForward, bool aWordSelectEatSpace, bool aIsKeyboardSelect,

                        int32_t* aOffset, PeekWordState* aState)

{

  NS_ASSERTION (aOffset && *aOffset <= 1, "aOffset out of range");

  // Keep going. The actual line jumping will stop us.

  return CONTINUE;

}

#ifdef ACCESSIBILITY

a11y::AccType

BRFrame::AccessibleType()

{

  nsIContent *parent = mContent->GetParent();

  if (parent && parent->IsRootOfNativeAnonymousSubtree() &&

      parent->GetChildCount() == 1) {

    // This <br> is the only node in a text control, therefore it is the hacky

    // "bogus node" used when there is no text in the control

    return a11y::eNoType;

  }

  // Trailing HTML br element don't play any difference. We don't need to expose

  // it to AT (see bug https://bugzilla.mozilla.org/show_bug.cgi?id=899433#c16

  // for details).

  if (!mContent->GetNextSibling() && !GetNextSibling()) {

    return a11y::eNoType;

  }

  return a11y::eHTMLBRType;

}

#endif