The Tor Browser: layout/generic/nsHTMLReflowMetrics.h@b8a032363ba2 (annotated)

layout/generic/nsHTMLReflowMetrics.h@b8a032363ba2 (annotated)

layout/generic/nsHTMLReflowMetrics.h

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- 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/. */
 /* struct containing the output from nsIFrame::Reflow */
 #ifndef nsHTMLReflowMetrics_h___
 #define nsHTMLReflowMetrics_h___
 #include "nsRect.h"
 #include "nsBoundingMetrics.h"
 #include "WritingModes.h"
 //----------------------------------------------------------------------
 class nsHTMLReflowState;
 // Option flags
 #define NS_REFLOW_CALC_BOUNDING_METRICS  0x0001
 /**
  * When we store overflow areas as an array of scrollable and visual
  * overflow, we use these indices.
  *
  * eOverflowType_LENGTH is needed (for gcc 4.5.*, at least) to ensure
  * that 2 is a valid value of nsOverflowType for use in
  * NS_FOR_FRAME_OVERFLOW_TYPES.
  */
 enum nsOverflowType { eVisualOverflow, eScrollableOverflow,
                       eOverflowType_LENGTH };
 #define NS_FOR_FRAME_OVERFLOW_TYPES(var_)                                     \
   for (nsOverflowType var_ = nsOverflowType(0); var_ < 2;                     \
        var_ = nsOverflowType(var_ + 1))
 struct nsOverflowAreas {
 private:
   nsRect mRects[2];
 public:
   nsRect& Overflow(size_t aIndex) {
     NS_ASSERTION(aIndex < 2, "index out of range");
     return mRects[aIndex];
   }
   const nsRect& Overflow(size_t aIndex) const {
     NS_ASSERTION(aIndex < 2, "index out of range");
     return mRects[aIndex];
   }
   nsRect& VisualOverflow() { return mRects[eVisualOverflow]; }
   const nsRect& VisualOverflow() const { return mRects[eVisualOverflow]; }
   nsRect& ScrollableOverflow() { return mRects[eScrollableOverflow]; }
   const nsRect& ScrollableOverflow() const { return mRects[eScrollableOverflow]; }
   nsOverflowAreas() {
     // default-initializes to zero due to nsRect's default constructor
   }
   nsOverflowAreas(const nsRect& aVisualOverflow,
                   const nsRect& aScrollableOverflow)
   {
     mRects[eVisualOverflow] = aVisualOverflow;
     mRects[eScrollableOverflow] = aScrollableOverflow;
   }
   nsOverflowAreas(const nsOverflowAreas& aOther) {
     *this = aOther;
   }
   nsOverflowAreas& operator=(const nsOverflowAreas& aOther) {
     mRects[0] = aOther.mRects[0];
     mRects[1] = aOther.mRects[1];
     return *this;
   }
   bool operator==(const nsOverflowAreas& aOther) const {
     // Scrollable overflow is a point-set rectangle and visual overflow
     // is a pixel-set rectangle.
     return VisualOverflow().IsEqualInterior(aOther.VisualOverflow()) &&
            ScrollableOverflow().IsEqualEdges(aOther.ScrollableOverflow());
   }
   bool operator!=(const nsOverflowAreas& aOther) const {
     return !(*this == aOther);
   }
   nsOverflowAreas operator+(const nsPoint& aPoint) const {
     nsOverflowAreas result(*this);
     result += aPoint;
     return result;
   }
   nsOverflowAreas& operator+=(const nsPoint& aPoint) {
     mRects[0] += aPoint;
     mRects[1] += aPoint;
     return *this;
   }
   void Clear() {
     mRects[0].SetRect(0, 0, 0, 0);
     mRects[1].SetRect(0, 0, 0, 0);
   }
   // Mutates |this| by unioning both overflow areas with |aOther|.
   void UnionWith(const nsOverflowAreas& aOther);
   // Mutates |this| by unioning both overflow areas with |aRect|.
   void UnionAllWith(const nsRect& aRect);
   // Mutates |this| by setting both overflow areas to |aRect|.
   void SetAllTo(const nsRect& aRect);
 };
 /**
  * An nsCollapsingMargin represents a vertical collapsing margin between
  * blocks as described in section 8.3.1 of CSS2,
  * <URL: http://www.w3.org/TR/REC-CSS2/box.html#collapsing-margins >.
  *
  * All adjacent vertical margins collapse, and the resulting margin is
  * the sum of the largest positive margin included and the smallest (most
  * negative) negative margin included.
  */
 struct nsCollapsingMargin {
   private:
     nscoord mMostPos;  // the largest positive margin included
     nscoord mMostNeg;  // the smallest negative margin included
   public:
     nsCollapsingMargin()
         : mMostPos(0),
           mMostNeg(0)
       {
       }
     nsCollapsingMargin(const nsCollapsingMargin& aOther)
         : mMostPos(aOther.mMostPos),
           mMostNeg(aOther.mMostNeg)
       {
       }
     bool operator==(const nsCollapsingMargin& aOther)
       {
         return mMostPos == aOther.mMostPos &&
           mMostNeg == aOther.mMostNeg;
       }
     bool operator!=(const nsCollapsingMargin& aOther)
       {
         return !(*this == aOther);
       }
     nsCollapsingMargin& operator=(const nsCollapsingMargin& aOther)
       {
         mMostPos = aOther.mMostPos;
         mMostNeg = aOther.mMostNeg;
         return *this;
       }
     void Include(nscoord aCoord)
       {
         if (aCoord > mMostPos)
           mMostPos = aCoord;
         else if (aCoord < mMostNeg)
           mMostNeg = aCoord;
       }
     void Include(const nsCollapsingMargin& aOther)
       {
         if (aOther.mMostPos > mMostPos)
           mMostPos = aOther.mMostPos;
         if (aOther.mMostNeg < mMostNeg)
           mMostNeg = aOther.mMostNeg;
       }
     void Zero()
       {
         mMostPos = 0;
         mMostNeg = 0;
       }
     bool IsZero() const
       {
         return (mMostPos == 0) && (mMostNeg == 0);
       }
     nscoord get() const
       {
         return mMostPos + mMostNeg;
       }
 };
 /**
  * Reflow metrics used to return the frame's desired size and alignment
  * information.
  *
  * @see #Reflow()
  */
 class nsHTMLReflowMetrics {
 public:
   // XXXldb Should |aFlags| generally be passed from parent to child?
   // Some places do it, and some don't.  |aFlags| should perhaps go away
   // entirely.
   // XXX width/height/ascent are OUT parameters and so they shouldn't
   // have to be initialized, but there are some bad frame classes that
   // aren't properly setting them when returning from Reflow()...
   nsHTMLReflowMetrics(mozilla::WritingMode aWritingMode, uint32_t aFlags = 0)
     : mISize(0)
     , mBSize(0)
     , mBlockStartAscent(ASK_FOR_BASELINE)
     , mFlags(aFlags)
     , mWritingMode(aWritingMode)
   {}
   nsHTMLReflowMetrics(const nsHTMLReflowState& aState, uint32_t aFlags = 0);
   // ISize and BSize are logical-coordinate dimensions:
   // ISize is the size in the writing mode's inline direction (which equates to
   // width in horizontal writing modes, height in vertical ones), and BSize is
   // the size in the block-progression direction.
   nscoord ISize() const { return mISize; }
   nscoord BSize() const { return mBSize; }
   nscoord& ISize() { return mISize; }
   nscoord& BSize() { return mBSize; }
   // Width and Height are physical dimensions, independent of writing mode.
   // Accessing these is slightly more expensive than accessing the logical
   // dimensions (once vertical writing mode support is enabled); as far as
   // possible, client code should work purely with logical dimensions.
   nscoord Width() const { return mWritingMode.IsVertical() ? mBSize : mISize; }
   nscoord Height() const { return mWritingMode.IsVertical() ? mISize : mBSize; }
   // It's only meaningful to consider "ascent" on the block-start side of the
   // frame; asking for the "ascent" on any other side will just return zero.
   nscoord TopAscent() const
   {
     return mWritingMode.IsVertical() ? 0 : mBlockStartAscent;
   }
   nscoord LeftAscent() const
   {
     return mWritingMode.IsVertical() && mWritingMode.IsVerticalLR() ?
            mBlockStartAscent : 0;
   }
   nscoord RightAscent() const
   {
     return mWritingMode.IsVertical() && !mWritingMode.IsVerticalLR() ?
            mBlockStartAscent : 0;
   }
   nscoord& Width() { return mWritingMode.IsVertical() ? mBSize : mISize; }
   nscoord& Height() { return mWritingMode.IsVertical() ? mISize : mBSize; }
   // To set the ascent value, we must be sure we're working with the correct
   // writing mode, so either pass it to the logical setter...
   void SetBlockStartAscent(mozilla::WritingMode aWritingMode, nscoord aAscent)
   {
     NS_ASSERTION(aWritingMode == mWritingMode, "writing mode mismatch");
     mBlockStartAscent = aAscent;
   }
   // ...or call the appropriate physical setter (these will probably be removed
   // eventually).
   void SetTopAscent(nscoord aAscent)
   {
     NS_ASSERTION(!mWritingMode.IsVertical(), "writing mode mismatch");
     mBlockStartAscent = aAscent;
   }
   void SetLeftAscent(nscoord aAscent)
   {
     NS_ASSERTION(mWritingMode.IsVertical() && mWritingMode.IsVerticalLR(),
                  "writing mode mismatch");
     mBlockStartAscent = aAscent;
   }
   void SetRightAscent(nscoord aAscent)
   {
     NS_ASSERTION(mWritingMode.IsVertical() && !mWritingMode.IsVerticalLR(),
                  "writing mode mismatch");
     mBlockStartAscent = aAscent;
   }
   enum { ASK_FOR_BASELINE = nscoord_MAX };
   // Metrics that _exactly_ enclose the text to allow precise MathML placements.
   // If the NS_REFLOW_CALC_BOUNDING_METRICS flag is set, then the caller is
   // requesting that you also compute additional details about your inner
   // bounding box and italic correction. For example, the bounding box of
   // msup is the smallest rectangle that _exactly_ encloses both the text
   // of the base and the text of the superscript.
   nsBoundingMetrics mBoundingMetrics;  // [OUT]
   // Carried out bottom margin values. This is the collapsed
   // (generational) bottom margin value.
   nsCollapsingMargin mCarriedOutBottomMargin;
   // For frames that have content that overflow their content area
   // (HasOverflowAreas() is true) these rectangles represent the total
   // area of the frame including visible overflow, i.e., don't include
   // overflowing content that is hidden.  The rects are in the local
   // coordinate space of the frame, and should be at least as big as the
   // desired size. If there is no content that overflows, then the
   // overflow area is identical to the desired size and should be {0, 0,
   // width, height}.
   nsOverflowAreas mOverflowAreas;
   nsRect& VisualOverflow()
     { return mOverflowAreas.VisualOverflow(); }
   const nsRect& VisualOverflow() const
     { return mOverflowAreas.VisualOverflow(); }
   nsRect& ScrollableOverflow()
     { return mOverflowAreas.ScrollableOverflow(); }
   const nsRect& ScrollableOverflow() const
     { return mOverflowAreas.ScrollableOverflow(); }
   // Set all of mOverflowAreas to (0, 0, width, height).
   void SetOverflowAreasToDesiredBounds();
   // Union all of mOverflowAreas with (0, 0, width, height).
   void UnionOverflowAreasWithDesiredBounds();
   mozilla::WritingMode GetWritingMode() const { return mWritingMode; }
 private:
   nscoord mISize, mBSize; // [OUT] desired width and height (border-box)
   nscoord mBlockStartAscent; // [OUT] baseline (in Block direction), or ASK_FOR_BASELINE
 public:
   uint32_t mFlags;
 private:
   mozilla::WritingMode mWritingMode;
 };
 #endif /* nsHTMLReflowMetrics_h___ */

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layout/generic/nsHTMLReflowMetrics.h@b8a032363ba2 (annotated)

layout/generic/nsHTMLReflowMetrics.h