layout/generic/nsGridContainerFrame.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=2 et sw=2 tw=80: */
   3 /* This Source Code is subject to the terms of the Mozilla Public License
   4  * version 2.0 (the "License"). You can obtain a copy of the License at
   5  * http://mozilla.org/MPL/2.0/. */
   6
   7 /* rendering object for CSS "display: grid | inline-grid" */
   8
   9 #include "nsGridContainerFrame.h"
  10
  11 #include "nsCSSAnonBoxes.h"
  12 #include "nsPresContext.h"
  13 #include "nsStyleContext.h"
  14
  15 using namespace mozilla;
  16
  17 //----------------------------------------------------------------------
  18
  19 // Frame class boilerplate
  20 // =======================
  21
  22 NS_QUERYFRAME_HEAD(nsGridContainerFrame)
  23   NS_QUERYFRAME_ENTRY(nsGridContainerFrame)
  24 NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
  25
  26 NS_IMPL_FRAMEARENA_HELPERS(nsGridContainerFrame)
  27
  28 nsContainerFrame*
  29 NS_NewGridContainerFrame(nsIPresShell* aPresShell,
  30                          nsStyleContext* aContext)
  31 {
  32   return new (aPresShell) nsGridContainerFrame(aContext);
  33 }
  34
  35
  36 //----------------------------------------------------------------------
  37
  38 // nsGridContainerFrame Method Implementations
  39 // ===========================================
  40
  41 void
  42 nsGridContainerFrame::Reflow(nsPresContext*           aPresContext,
  43                              nsHTMLReflowMetrics&     aDesiredSize,
  44                              const nsHTMLReflowState& aReflowState,
  45                              nsReflowStatus&          aStatus)
  46 {
  47   DO_GLOBAL_REFLOW_COUNT("nsGridContainerFrame");
  48   DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
  49
  50   if (IsFrameTreeTooDeep(aReflowState, aDesiredSize, aStatus)) {
  51     return;
  52   }
  53
  54 #ifdef DEBUG
  55   SanityCheckAnonymousGridItems();
  56 #endif // DEBUG
  57
  58   LogicalMargin bp = aReflowState.ComputedLogicalBorderPadding();
  59   bp.ApplySkipSides(GetLogicalSkipSides());
  60   nscoord contentBSize = GetEffectiveComputedBSize(aReflowState);
  61   if (contentBSize == NS_AUTOHEIGHT) {
  62     contentBSize = 0;
  63   }
  64   WritingMode wm = aReflowState.GetWritingMode();
  65   LogicalSize finalSize(wm,
  66                         aReflowState.ComputedISize() + bp.IStartEnd(wm),
  67                         contentBSize + bp.BStartEnd(wm));
  68   aDesiredSize.SetSize(wm, finalSize);
  69   aDesiredSize.SetOverflowAreasToDesiredBounds();
  70   aStatus = NS_FRAME_COMPLETE;
  71   NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
  72 }
  73
  74 nsIAtom*
  75 nsGridContainerFrame::GetType() const
  76 {
  77   return nsGkAtoms::gridContainerFrame;
  78 }
  79
  80 #ifdef DEBUG_FRAME_DUMP
  81 nsresult
  82 nsGridContainerFrame::GetFrameName(nsAString& aResult) const
  83 {
  84   return MakeFrameName(NS_LITERAL_STRING("GridContainer"), aResult);
  85 }
  86 #endif
  87
  88 #ifdef DEBUG
  89 static bool
  90 FrameWantsToBeInAnonymousGridItem(nsIFrame* aFrame)
  91 {
  92   // Note: This needs to match the logic in
  93   // nsCSSFrameConstructor::FrameConstructionItem::NeedsAnonFlexOrGridItem()
  94   return (aFrame->IsFrameOfType(nsIFrame::eLineParticipant) ||
  95           nsGkAtoms::placeholderFrame == aFrame->GetType());
  96 }
  97
  98 // Debugging method, to let us assert that our anonymous grid items are
  99 // set up correctly -- in particular, we assert:
 100 //  (1) we don't have any inline non-replaced children
 101 //  (2) we don't have any consecutive anonymous grid items
 102 //  (3) we don't have any empty anonymous grid items
 103 //  (4) all children are on the expected child lists
 104 void
 105 nsGridContainerFrame::SanityCheckAnonymousGridItems() const
 106 {
 107   // XXX handle kOverflowContainersList / kExcessOverflowContainersList
 108   // when we implement fragmentation?
 109   ChildListIDs noCheckLists = kAbsoluteList | kFixedList;
 110   ChildListIDs checkLists = kPrincipalList | kOverflowList;
 111   for (nsIFrame::ChildListIterator childLists(this);
 112        !childLists.IsDone(); childLists.Next()) {
 113     if (!checkLists.Contains(childLists.CurrentID())) {
 114       MOZ_ASSERT(noCheckLists.Contains(childLists.CurrentID()),
 115                  "unexpected non-empty child list");
 116       continue;
 117     }
 118
 119     bool prevChildWasAnonGridItem = false;
 120     nsFrameList children = childLists.CurrentList();
 121     for (nsFrameList::Enumerator e(children); !e.AtEnd(); e.Next()) {
 122       nsIFrame* child = e.get();
 123       MOZ_ASSERT(!FrameWantsToBeInAnonymousGridItem(child),
 124                  "frame wants to be inside an anonymous grid item, "
 125                  "but it isn't");
 126       if (child->StyleContext()->GetPseudo() ==
 127             nsCSSAnonBoxes::anonymousGridItem) {
 128 /*
 129   XXX haven't decided yet whether to reorder children or not.
 130   XXX If we do, we want this assertion instead of the one below.
 131         MOZ_ASSERT(!prevChildWasAnonGridItem ||
 132                    HasAnyStateBits(NS_STATE_GRID_CHILDREN_REORDERED),
 133                    "two anon grid items in a row (shouldn't happen, unless our "
 134                    "children have been reordered with the 'order' property)");
 135 */
 136         MOZ_ASSERT(!prevChildWasAnonGridItem, "two anon grid items in a row");
 137         nsIFrame* firstWrappedChild = child->GetFirstPrincipalChild();
 138         MOZ_ASSERT(firstWrappedChild,
 139                    "anonymous grid item is empty (shouldn't happen)");
 140         prevChildWasAnonGridItem = true;
 141       } else {
 142         prevChildWasAnonGridItem = false;
 143       }
 144     }
 145   }
 146 }
 147 #endif // DEBUG