layout/generic/nsRubyTextContainerFrame.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 /* rendering object for CSS "display: ruby-text-container" */
   8
   9 #include "nsRubyTextContainerFrame.h"
  10
  11 #include "mozilla/ComputedStyle.h"
  12 #include "mozilla/PresShell.h"
  13 #include "mozilla/UniquePtr.h"
  14 #include "mozilla/WritingModes.h"
  15 #include "nsLayoutUtils.h"
  16 #include "nsLineLayout.h"
  17 #include "nsPresContext.h"
  18
  19 using namespace mozilla;
  20
  21 //----------------------------------------------------------------------
  22
  23 // Frame class boilerplate
  24 // =======================
  25
  26 NS_QUERYFRAME_HEAD(nsRubyTextContainerFrame)
  27   NS_QUERYFRAME_ENTRY(nsRubyTextContainerFrame)
  28 NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
  29
  30 NS_IMPL_FRAMEARENA_HELPERS(nsRubyTextContainerFrame)
  31
  32 nsContainerFrame* NS_NewRubyTextContainerFrame(PresShell* aPresShell,
  33                                                ComputedStyle* aStyle) {
  34   return new (aPresShell)
  35       nsRubyTextContainerFrame(aStyle, aPresShell->GetPresContext());
  36 }
  37
  38 //----------------------------------------------------------------------
  39
  40 // nsRubyTextContainerFrame Method Implementations
  41 // ===============================================
  42
  43 #ifdef DEBUG_FRAME_DUMP
  44 nsresult nsRubyTextContainerFrame::GetFrameName(nsAString& aResult) const {
  45   return MakeFrameName(u"RubyTextContainer"_ns, aResult);
  46 }
  47 #endif
  48
  49 /* virtual */
  50 void nsRubyTextContainerFrame::SetInitialChildList(ChildListID aListID,
  51                                                    nsFrameList&& aChildList) {
  52   nsContainerFrame::SetInitialChildList(aListID, std::move(aChildList));
  53   if (aListID == FrameChildListID::Principal) {
  54     UpdateSpanFlag();
  55   }
  56 }
  57
  58 /* virtual */
  59 void nsRubyTextContainerFrame::AppendFrames(ChildListID aListID,
  60                                             nsFrameList&& aFrameList) {
  61   nsContainerFrame::AppendFrames(aListID, std::move(aFrameList));
  62   UpdateSpanFlag();
  63 }
  64
  65 /* virtual */
  66 void nsRubyTextContainerFrame::InsertFrames(
  67     ChildListID aListID, nsIFrame* aPrevFrame,
  68     const nsLineList::iterator* aPrevFrameLine, nsFrameList&& aFrameList) {
  69   nsContainerFrame::InsertFrames(aListID, aPrevFrame, aPrevFrameLine,
  70                                  std::move(aFrameList));
  71   UpdateSpanFlag();
  72 }
  73
  74 /* virtual */
  75 void nsRubyTextContainerFrame::RemoveFrame(DestroyContext& aContext,
  76                                            ChildListID aListID,
  77                                            nsIFrame* aOldFrame) {
  78   nsContainerFrame::RemoveFrame(aContext, aListID, aOldFrame);
  79   UpdateSpanFlag();
  80 }
  81
  82 void nsRubyTextContainerFrame::UpdateSpanFlag() {
  83   bool isSpan = false;
  84   // The continuation checks are safe here because spans never break.
  85   if (!GetPrevContinuation() && !GetNextContinuation()) {
  86     nsIFrame* onlyChild = mFrames.OnlyChild();
  87     if (onlyChild && onlyChild->IsPseudoFrame(GetContent())) {
  88       // Per CSS Ruby spec, if the only child of an rtc frame is
  89       // a pseudo rt frame, it spans all bases in the segment.
  90       isSpan = true;
  91     }
  92   }
  93
  94   if (isSpan) {
  95     AddStateBits(NS_RUBY_TEXT_CONTAINER_IS_SPAN);
  96   } else {
  97     RemoveStateBits(NS_RUBY_TEXT_CONTAINER_IS_SPAN);
  98   }
  99 }
 100
 101 /* virtual */
 102 void nsRubyTextContainerFrame::Reflow(nsPresContext* aPresContext,
 103                                       ReflowOutput& aDesiredSize,
 104                                       const ReflowInput& aReflowInput,
 105                                       nsReflowStatus& aStatus) {
 106   MarkInReflow();
 107   DO_GLOBAL_REFLOW_COUNT("nsRubyTextContainerFrame");
 108   MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!");
 109
 110   // Although a ruby text container may have continuations, returning
 111   // complete reflow status is still safe, since its parent, ruby frame,
 112   // ignores the status, and continuations of the ruby base container
 113   // will take care of our continuations.
 114   WritingMode rtcWM = GetWritingMode();
 115
 116   nscoord minBCoord = nscoord_MAX;
 117   nscoord maxBCoord = nscoord_MIN;
 118   // The container size is not yet known, so we use a dummy (0, 0) size.
 119   // The block-dir position will be corrected below after containerSize
 120   // is finalized.
 121   const nsSize dummyContainerSize;
 122   for (nsIFrame* child : mFrames) {
 123     MOZ_ASSERT(child->IsRubyTextFrame());
 124     LogicalRect rect = child->GetLogicalRect(rtcWM, dummyContainerSize);
 125     LogicalMargin margin = child->GetLogicalUsedMargin(rtcWM);
 126     nscoord blockStart = rect.BStart(rtcWM) - margin.BStart(rtcWM);
 127     minBCoord = std::min(minBCoord, blockStart);
 128     nscoord blockEnd = rect.BEnd(rtcWM) + margin.BEnd(rtcWM);
 129     maxBCoord = std::max(maxBCoord, blockEnd);
 130   }
 131
 132   if (!mFrames.IsEmpty()) {
 133     if (MOZ_UNLIKELY(minBCoord > maxBCoord)) {
 134       // XXX When bug 765861 gets fixed, this warning should be upgraded.
 135       NS_WARNING("bad block coord");
 136       minBCoord = maxBCoord = 0;
 137     }
 138     LogicalSize size(rtcWM, mISize, maxBCoord - minBCoord);
 139     nsSize containerSize = size.GetPhysicalSize(rtcWM);
 140     for (nsIFrame* child : mFrames) {
 141       // We reflowed the child with a dummy container size, as the true size
 142       // was not yet known at that time.
 143       LogicalPoint pos = child->GetLogicalPosition(rtcWM, dummyContainerSize);
 144       // Adjust block position to account for minBCoord,
 145       // then reposition child based on the true container width.
 146       pos.B(rtcWM) -= minBCoord;
 147       // Relative positioning hasn't happened yet.
 148       // So MovePositionBy should not be used here.
 149       child->SetPosition(rtcWM, pos, containerSize);
 150       nsContainerFrame::PlaceFrameView(child);
 151     }
 152     aDesiredSize.SetSize(rtcWM, size);
 153   } else {
 154     // If this ruby text container is empty, size it as if there were
 155     // an empty inline child inside.
 156     // Border and padding are suppressed on ruby text container, so we
 157     // create a dummy zero-sized borderPadding for setting BSize.
 158     aDesiredSize.ISize(rtcWM) = mISize;
 159     LogicalMargin borderPadding(rtcWM);
 160     nsLayoutUtils::SetBSizeFromFontMetrics(this, aDesiredSize, borderPadding,
 161                                            rtcWM, rtcWM);
 162   }
 163 }