layout/mathml/nsMathMLSelectedFrame.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "nsMathMLSelectedFrame.h"
   8 #include "nsDisplayList.h"
   9
  10 using namespace mozilla;
  11
  12 nsMathMLSelectedFrame::~nsMathMLSelectedFrame() = default;
  13
  14 NS_IMETHODIMP
  15 nsMathMLSelectedFrame::TransmitAutomaticData() {
  16   // Note that to determine space-like and embellished op properties:
  17   //   - <semantics> behaves the same as <maction>
  18   //   - <annotation-xml> behaves the same as <mrow>
  19
  20   // The REC defines the following element to be space-like:
  21   // * an maction element whose selected sub-expression exists and is
  22   //   space-like;
  23   nsIMathMLFrame* mathMLFrame = do_QueryFrame(mSelectedFrame);
  24   if (mathMLFrame && mathMLFrame->IsSpaceLike()) {
  25     mPresentationData.flags |= NS_MATHML_SPACE_LIKE;
  26   } else {
  27     mPresentationData.flags &= ~NS_MATHML_SPACE_LIKE;
  28   }
  29
  30   // The REC defines the following element to be an embellished operator:
  31   // * an maction element whose selected sub-expression exists and is an
  32   //   embellished operator;
  33   mPresentationData.baseFrame = mSelectedFrame;
  34   GetEmbellishDataFrom(mSelectedFrame, mEmbellishData);
  35
  36   return NS_OK;
  37 }
  38
  39 nsresult nsMathMLSelectedFrame::ChildListChanged(int32_t aModType) {
  40   GetSelectedFrame();
  41   return nsMathMLContainerFrame::ChildListChanged(aModType);
  42 }
  43
  44 void nsMathMLSelectedFrame::SetInitialChildList(ChildListID aListID,
  45                                                 nsFrameList&& aChildList) {
  46   nsMathMLContainerFrame::SetInitialChildList(aListID, std::move(aChildList));
  47   // This very first call to GetSelectedFrame() will cause us to be marked as an
  48   // embellished operator if the selected child is an embellished operator
  49   GetSelectedFrame();
  50 }
  51
  52 //  Only paint the selected child...
  53 void nsMathMLSelectedFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
  54                                              const nsDisplayListSet& aLists) {
  55   // Report an error if something wrong was found in this frame.
  56   // We can't call nsDisplayMathMLError from here,
  57   // so ask nsMathMLContainerFrame to do the work for us.
  58   if (NS_MATHML_HAS_ERROR(mPresentationData.flags)) {
  59     nsMathMLContainerFrame::BuildDisplayList(aBuilder, aLists);
  60     return;
  61   }
  62
  63   DisplayBorderBackgroundOutline(aBuilder, aLists);
  64
  65   nsIFrame* childFrame = GetSelectedFrame();
  66   if (childFrame) {
  67     // Put the child's background directly onto the content list
  68     nsDisplayListSet set(aLists, aLists.Content());
  69     // The children should be in content order
  70     BuildDisplayListForChild(aBuilder, childFrame, set);
  71   }
  72
  73 #if defined(DEBUG) && defined(SHOW_BOUNDING_BOX)
  74   // visual debug
  75   DisplayBoundingMetrics(aBuilder, this, mReference, mBoundingMetrics, aLists);
  76 #endif
  77 }
  78
  79 /* virtual */
  80 nsIFrame::SizeComputationResult nsMathMLSelectedFrame::ComputeSize(
  81     gfxContext* aRenderingContext, WritingMode aWM, const LogicalSize& aCBSize,
  82     nscoord aAvailableISize, const LogicalSize& aMargin,
  83     const LogicalSize& aBorderPadding, const StyleSizeOverrides& aSizeOverrides,
  84     ComputeSizeFlags aFlags) {
  85   nsIFrame* childFrame = GetSelectedFrame();
  86   if (childFrame) {
  87     // Delegate size computation to the child frame.
  88     // Try to account for border/padding/margin on this frame and the child,
  89     // though we don't really support them during reflow anyway...
  90     const nscoord availableISize =
  91         aAvailableISize - aBorderPadding.ISize(aWM) - aMargin.ISize(aWM);
  92     const LogicalSize cbSize = aCBSize - aBorderPadding - aMargin;
  93     SizeComputationInput offsetState(childFrame, aRenderingContext, aWM,
  94                                      availableISize);
  95     const auto bpSize = offsetState.ComputedLogicalBorderPadding(aWM).Size(aWM);
  96     auto size = childFrame->ComputeSize(
  97         aRenderingContext, aWM, cbSize, availableISize,
  98         offsetState.ComputedLogicalMargin(aWM).Size(aWM), bpSize,
  99         aSizeOverrides, aFlags);
 100     return {size.mLogicalSize + bpSize, size.mAspectRatioUsage};
 101   }
 102   return {LogicalSize(aWM), AspectRatioUsage::None};
 103 }
 104
 105 // Only reflow the selected child ...
 106 void nsMathMLSelectedFrame::Reflow(nsPresContext* aPresContext,
 107                                    ReflowOutput& aDesiredSize,
 108                                    const ReflowInput& aReflowInput,
 109                                    nsReflowStatus& aStatus) {
 110   MarkInReflow();
 111   MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!");
 112
 113   mPresentationData.flags &= ~NS_MATHML_ERROR;
 114   aDesiredSize.ClearSize();
 115   aDesiredSize.SetBlockStartAscent(0);
 116   mBoundingMetrics = nsBoundingMetrics();
 117   nsIFrame* childFrame = GetSelectedFrame();
 118   if (childFrame) {
 119     WritingMode wm = childFrame->GetWritingMode();
 120     LogicalSize availSize = aReflowInput.ComputedSize(wm);
 121     availSize.BSize(wm) = NS_UNCONSTRAINEDSIZE;
 122     ReflowInput childReflowInput(aPresContext, aReflowInput, childFrame,
 123                                  availSize);
 124     ReflowChild(childFrame, aPresContext, aDesiredSize, childReflowInput,
 125                 aStatus);
 126     SaveReflowAndBoundingMetricsFor(childFrame, aDesiredSize,
 127                                     aDesiredSize.mBoundingMetrics);
 128     mBoundingMetrics = aDesiredSize.mBoundingMetrics;
 129   }
 130   FinalizeReflow(aReflowInput.mRenderingContext->GetDrawTarget(), aDesiredSize);
 131 }
 132
 133 // Only place the selected child ...
 134 /* virtual */
 135 nsresult nsMathMLSelectedFrame::Place(DrawTarget* aDrawTarget,
 136                                       bool aPlaceOrigin,
 137                                       ReflowOutput& aDesiredSize) {
 138   nsIFrame* childFrame = GetSelectedFrame();
 139
 140   if (mInvalidMarkup) {
 141     // Calling PlaceForError when mathml.error_message_layout_for_invalid_markup
 142     // is disabled causes assertion failures because nsMathMLSelectedFrame only
 143     // performs layout of the selected child. However, this code is only reached
 144     // when mathml.legacy_maction_and_semantics_implementations is enabled, so
 145     // it is out the scope of the mrow fallback described in MathML Core and
 146     // nsMathMLSelectedFrame will go away in the future. So for now let's
 147     // continue to always layout this case as an 'invalid-markup' message.
 148     return ReflowError(aDrawTarget, aDesiredSize);
 149   }
 150
 151   aDesiredSize.ClearSize();
 152   aDesiredSize.SetBlockStartAscent(0);
 153   mBoundingMetrics = nsBoundingMetrics();
 154   if (childFrame) {
 155     GetReflowAndBoundingMetricsFor(childFrame, aDesiredSize, mBoundingMetrics);
 156     if (aPlaceOrigin) {
 157       FinishReflowChild(childFrame, PresContext(), aDesiredSize, nullptr, 0, 0,
 158                         ReflowChildFlags::Default);
 159     }
 160     mReference.x = 0;
 161     mReference.y = aDesiredSize.BlockStartAscent();
 162   }
 163   aDesiredSize.mBoundingMetrics = mBoundingMetrics;
 164   return NS_OK;
 165 }