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 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

 /* 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 "nsCOMPtr.h"

 #include "nsFrame.h"

 #include "nsPresContext.h"

 #include "nsLineLayout.h"

 #include "nsStyleConsts.h"

 #include "nsGkAtoms.h"

 #include "nsRenderingContext.h"

 #include "nsLayoutUtils.h"

 //FOR SELECTION

 #include "nsIContent.h"

 //END INCLUDES FOR SELECTION

 using namespace mozilla;

 class BRFrame : public nsFrame {

 public:

   NS_DECL_FRAMEARENA_HELPERS

   friend nsIFrame* NS_NewBRFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);

   virtual ContentOffsets CalcContentOffsetsFromFramePoint(nsPoint aPoint) MOZ_OVERRIDE;

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

   virtual FrameSearchResult PeekOffsetCharacter(bool aForward, int32_t* aOffset,

                                      bool aRespectClusters = true) MOZ_OVERRIDE;

   virtual FrameSearchResult PeekOffsetWord(bool aForward, bool aWordSelectEatSpace,

                               bool aIsKeyboardSelect, int32_t* aOffset,

                               PeekWordState* aState) MOZ_OVERRIDE;

   virtual nsresult Reflow(nsPresContext* aPresContext,

                           nsHTMLReflowMetrics& aDesiredSize,

                           const nsHTMLReflowState& aReflowState,

                           nsReflowStatus& aStatus) MOZ_OVERRIDE;

   virtual void AddInlineMinWidth(nsRenderingContext *aRenderingContext,

                                  InlineMinWidthData *aData) MOZ_OVERRIDE;

   virtual void AddInlinePrefWidth(nsRenderingContext *aRenderingContext,

                                   InlinePrefWidthData *aData) MOZ_OVERRIDE;

   virtual nscoord GetMinWidth(nsRenderingContext *aRenderingContext) MOZ_OVERRIDE;

   virtual nscoord GetPrefWidth(nsRenderingContext *aRenderingContext) MOZ_OVERRIDE;

   virtual nsIAtom* GetType() const MOZ_OVERRIDE;

   virtual nscoord GetBaseline() const MOZ_OVERRIDE;

   virtual bool IsFrameOfType(uint32_t aFlags) const MOZ_OVERRIDE

   {

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

                                              nsIFrame::eLineParticipant));

   }

 #ifdef ACCESSIBILITY

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

 #endif

 protected:

   BRFrame(nsStyleContext* aContext) : nsFrame(aContext) {}

   virtual ~BRFrame();

   nscoord mAscent;

 };

 nsIFrame*

 NS_NewBRFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)

 {

   return new (aPresShell) BRFrame(aContext);

 }

 NS_IMPL_FRAMEARENA_HELPERS(BRFrame)

 BRFrame::~BRFrame()

 {

 }

 nsresult

 BRFrame::Reflow(nsPresContext* aPresContext,

                 nsHTMLReflowMetrics& aMetrics,

                 const nsHTMLReflowState& aReflowState,

                 nsReflowStatus& aStatus)

 {

   DO_GLOBAL_REFLOW_COUNT("BRFrame");

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

   aMetrics.Height() = 0; // BR frames with height 0 are ignored in quirks

                        // mode by nsLineLayout::VerticalAlignFrames .

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

   aMetrics.Width() = 0;

   aMetrics.SetTopAscent(0);

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

   // behave like a BR.

   nsLineLayout* ll = aReflowState.mLineLayout;

   if (ll) {

     // 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.

       nsRefPtr<nsFontMetrics> fm;

       nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm),

         nsLayoutUtils::FontSizeInflationFor(this));

       aReflowState.rendContext->SetFont(fm); // FIXME: maybe not needed?

       if (fm) {

         nscoord logicalHeight = aReflowState.CalcLineHeight();

         aMetrics.Height() = logicalHeight;

         aMetrics.SetTopAscent(nsLayoutUtils::GetCenteredFontBaseline(fm, logicalHeight));

       }

       else {

         aMetrics.SetTopAscent(aMetrics.Height() = 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.

       aMetrics.Width() = 1;

     }

     // Return our reflow status

     uint32_t breakType = aReflowState.mStyleDisplay->mBreakType;

     if (NS_STYLE_CLEAR_NONE == breakType) {

       breakType = NS_STYLE_CLEAR_LINE;

     }

     aStatus = NS_INLINE_BREAK | NS_INLINE_BREAK_AFTER |

       NS_INLINE_MAKE_BREAK_TYPE(breakType);

     ll->SetLineEndsInBR(true);

   }

   else {

     aStatus = NS_FRAME_COMPLETE;

   }

   aMetrics.SetOverflowAreasToDesiredBounds();

   mAscent = aMetrics.TopAscent();

   NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aMetrics);

   return NS_OK;

 }

 /* virtual */ void

 BRFrame::AddInlineMinWidth(nsRenderingContext *aRenderingContext,

                            nsIFrame::InlineMinWidthData *aData)

 {

   aData->ForceBreak(aRenderingContext);

 }

 /* virtual */ void

 BRFrame::AddInlinePrefWidth(nsRenderingContext *aRenderingContext,

                             nsIFrame::InlinePrefWidthData *aData)

 {

   aData->ForceBreak(aRenderingContext);

 }

 /* virtual */ nscoord

 BRFrame::GetMinWidth(nsRenderingContext *aRenderingContext)

 {

   nscoord result = 0;

   DISPLAY_MIN_WIDTH(this, result);

   return result;

 }

 /* virtual */ nscoord

 BRFrame::GetPrefWidth(nsRenderingContext *aRenderingContext)

 {

   nscoord result = 0;

   DISPLAY_PREF_WIDTH(this, result);

   return result;

 }

 nsIAtom*

 BRFrame::GetType() const

 {

   return nsGkAtoms::brFrame;

 }

 nscoord

 BRFrame::GetBaseline() const

 {

   return mAscent;

 }

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

 {

   ContentOffsets offsets;

   offsets.content = mContent->GetParent();

   if (offsets.content) {

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

     offsets.secondaryOffset = offsets.offset;

     offsets.associateWithNext = true;

   }

   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,

                              bool aRespectClusters)

 {

   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;

   }

   return a11y::eHTMLBRType;

 }

 #endif