Commit 4b20ea11 authored by Ting-Yu Lin's avatar Ting-Yu Lin
Browse files

Bug 1790312 Part 2 - Remove flex item's normal position snapshot in ReflowChildren(). r=dholbert 

ReflowChildren() only cares about the flex item's normal position, so we don't
need to output the relative position from `MoveFlexItemToFinalPosition()`.

By making `aFramePos` const for `MoveFlexItemToFinalPosition`, we can delete
`itemNormalBPos` because `framePos` cannot be changed after calling
`MoveFlexItemToFinalPosition`.

This patch shouldn't change the behavior.

Differential Revision: https://phabricator.services.mozilla.com/D157079
parent 19e8ae9b

layout/generic/nsFlexContainerFrame.cpp

+8 −11
Original line number Diff line number Diff line
@@ -5321,10 +5321,6 @@ std::tuple<nscoord, bool> nsFlexContainerFrame::ReflowChildren( 
      // (i.e. its frame rect), instead of the container's content-box:

      framePos += containerContentBoxOrigin;



      // (Intentionally snapshotting this before ApplyRelativePositioning, to

      // maybe use for setting the flex container's baseline.)

      const nscoord itemNormalBPos = framePos.B(flexWM);



      // Check if we actually need to reflow the item -- if the item's position

      // is below the available space's block-end, push it to our next-in-flow;

      // if it does need a reflow, and we already reflowed it with the right
@@ -5372,7 +5368,7 @@ std::tuple<nscoord, bool> nsFlexContainerFrame::ReflowChildren( 
        // edge.

        maxBlockEndEdgeOfChildren =

            std::max(maxBlockEndEdgeOfChildren,

                     itemNormalBPos + item.Frame()->BSize(flexWM));

                     framePos.B(flexWM) + item.Frame()->BSize(flexWM));

      }



      // If the item has auto margins, and we were tracking the UsedMargin
@@ -5390,7 +5386,7 @@ std::tuple<nscoord, bool> nsFlexContainerFrame::ReflowChildren( 
      // children), then use this child's first baseline as the container's

      // baseline.

      if (&item == firstItem && aFlr.mAscent == nscoord_MIN) {

        aFlr.mAscent = itemNormalBPos + item.ResolvedAscent(true);

        aFlr.mAscent = framePos.B(flexWM) + item.ResolvedAscent(true);

      }

    }

  }
@@ -5561,10 +5557,11 @@ void nsFlexContainerFrame::PopulateReflowOutput( 
}



void nsFlexContainerFrame::MoveFlexItemToFinalPosition(

    const FlexItem& aItem, LogicalPoint& aFramePos,

    const FlexItem& aItem, const LogicalPoint& aFramePos,

    const nsSize& aContainerSize) {

  const WritingMode outerWM = aItem.ContainingBlockWM();

  const nsStyleDisplay* display = aItem.Frame()->StyleDisplay();

  LogicalPoint pos(aFramePos);

  if (display->IsRelativelyOrStickyPositionedStyle()) {

    // If the item is relatively positioned, look up its offsets (cached from

    // previous reflow). A sticky positioned item can pass a dummy
@@ -5578,13 +5575,13 @@ void nsFlexContainerFrame::MoveFlexItemToFinalPosition( 
          "relpos previously-reflowed frame should've cached its offsets");

      logicalOffsets = LogicalMargin(outerWM, *cachedOffsets);

    }

    ReflowInput::ApplyRelativePositioning(

        aItem.Frame(), outerWM, logicalOffsets, &aFramePos, aContainerSize);

    ReflowInput::ApplyRelativePositioning(aItem.Frame(), outerWM,

                                          logicalOffsets, &pos, aContainerSize);

  }



  FLEX_LOG("Moving flex item %p to its desired position %s", aItem.Frame(),

           ToString(aFramePos).c_str());

  aItem.Frame()->SetPosition(outerWM, aFramePos, aContainerSize);

           ToString(pos).c_str());

  aItem.Frame()->SetPosition(outerWM, pos, aContainerSize);

  PositionFrameView(aItem.Frame());

  PositionChildViews(aItem.Frame());

}

layout/generic/nsFlexContainerFrame.h

+1 −1
Original line number Diff line number Diff line
@@ -585,7 +585,7 @@ class nsFlexContainerFrame final : public nsContainerFrame { 
   *                        that we call, to interpret aFramePos correctly).

   */

  void MoveFlexItemToFinalPosition(const FlexItem& aItem,

                                   mozilla::LogicalPoint& aFramePos,

                                   const mozilla::LogicalPoint& aFramePos,

                                   const nsSize& aContainerSize);

  /**

   * Helper-function to reflow a child frame, at its final position determined