Issue #1233 - Part 1: Fix grid overflow and rendering issues by improving Layout CSS-Grid API

List of relevant patches applied:

1425599 part 1 - [css-grid] Change the track sizing algorithm for spanning items so that it accumulates individual item contributions to the plan by max() rather than incrementing the planned size directly.

Also, fix a bug when copying back the planned limits after updating it for the first span group. It should only copy back track sizes that were actaully spanned by those items, other content-sized tracks' limits should remain at "infinity".

1425599 part 2 - [css-grid] Factor out the min-sizing parts of the track sizing for spanned items to a templated method (idempotent change).

1425599 part 3 - [css-grid] Factor out most of the max-sizing parts of the track sizing for spanned items to a templated method (idempotent change).

1425599 part 4 - [css-grid] Factor out the starting base/limit size to a templated method (idempotent change).

1425599 part 5 - [css-grid] Make CollectGrowable a templated method so that it works with either base/limit sizes (idempotent change).

1425599 part 6 - [css-grid] Make the size distribution methods templated with the intent of merging them in a later patch (idempotent change).

This patch also introduces an eInfinitelyGrowable bit to help get rid of the 'limits' temporary track sizes in the next patch.

1425599 part 7 - [css-grid] Remove the 'limits' copy of track sizes since they are no longer needed (idempotent change).

1425599 part 8 - [css-grid] Factor out the fit-content clamping function from DistributeToTrackLimits and pass it as a param instead (idempotent change).

1425599 part 9 - [css-grid] Merge DistributeToTrackLimits/Bases (idempotent change).

1425599 part 10 - [css-grid] Make MarkExcludedTracks a static method since it doesn't use 'this' (idempotent change).

1425599 part 11 - [css-grid] Hoist the marking of excluded tracks out from GrowSelectedTracksUnlimited to a separate method (idempotent change).

1425599 part 12 - [css-grid] Merge CopyPlanToBase/Limits into a templated method instead (idempotent change).

1425599 part 13 - [css-grid] Merge Grow[Base|Limits]ForSpanningItems into a templated method instead (idempotent change).

1425599 part 14 - [css-grid] Use iterators instead of an array + start/end index for the item data (idempotent change).

1425599 part 16 - [css-grid] Make SizeContributionForPhase a template.

1425599 - [css-grid] Follow-up bustage fix for stupid compiler warnings.

1378481 - Assign 'roundingError' in the default branch too, to avoid a maybe-uninitialized compiler warning.

1423292 - [css-grid] Add a couple of ItemState bits to Dump(), and make an ItemState assertion stricter (DEBUG-only changes).

1373678 Part 1: Reduce grid line numbers by count of leading implicit lines, minimum 0.

1416350 - Part 1: Correctly account for removed 'auto-fit' tracks also when there are leading implicit tracks.

1416350 - Part 2: Correct logic for Grid API line numbering with leading implicit tracks.

1418727 part 1 - [css-grid] Introduce StateBitsForRange() that collects the union of the state bits for a range of tracks (idempotent change).

1418727 part 2 - [css-grid] Require that an item spans at least one track with an 'auto' min sizing function for Automatic Minimum Size to apply.

1 files changed, 27 insertions, 15 deletions

diff --git a/dom/grid/GridLines.cpp b/dom/grid/GridLines.cpp
index fac645c64..898885346 100644
--- a/dom/grid/GridLines.cpp
+++ b/dom/grid/GridLines.cpp
@@ -90,7 +90,9 @@ GridLines::SetLineInfo(const ComputedGridTrackInfo* aTrackInfo,
     for (uint32_t i = aTrackInfo->mStartFragmentTrack;
          i < aTrackInfo->mEndFragmentTrack + 1;
          i++) {
-      uint32_t line1Index = i + 1;
+      // Since line indexes are 1-based, calculate a 1-based value
+      // for this track to simplify some calculations.
+      const uint32_t line1Index = i + 1;
 
       startOfNextTrack = (i < aTrackInfo->mEndFragmentTrack) ?
                          aTrackInfo->mPositions[i] :
@@ -127,7 +129,8 @@ GridLines::SetLineInfo(const ComputedGridTrackInfo* aTrackInfo,
         }
       }
 
-      if (i >= aTrackInfo->mRepeatFirstTrack &&
+      if (i >= (aTrackInfo->mRepeatFirstTrack +
+                aTrackInfo->mNumLeadingImplicitTracks) &&
           repeatIndex < numRepeatTracks) {
         numAddedLines += AppendRemovedAutoFits(aTrackInfo,
                                                aLineInfo,
@@ -139,23 +142,30 @@ GridLines::SetLineInfo(const ComputedGridTrackInfo* aTrackInfo,
 
       RefPtr<GridLine> line = new GridLine(this);
       mLines.AppendElement(line);
+      MOZ_ASSERT(line1Index > 0, "line1Index must be positive.");
+      bool isBeforeFirstExplicit =
+        (line1Index <= aTrackInfo->mNumLeadingImplicitTracks);
+      // Calculate an actionable line number for this line, that could be used
+      // in a css grid property to align a grid item or area at that line.
+      // For implicit lines that appear before line 1, report a number of 0.
+      // We can't report negative indexes, because those have a different
+      // meaning in the css grid spec (negative indexes are negative-1-based
+      // from the end of the grid decreasing towards the front).
+      uint32_t lineNumber = isBeforeFirstExplicit ? 0 :
+        (line1Index - aTrackInfo->mNumLeadingImplicitTracks + numAddedLines);
+      GridDeclaration lineType =
+        (isBeforeFirstExplicit ||
+         line1Index > (aTrackInfo->mNumLeadingImplicitTracks +
+                       aTrackInfo->mNumExplicitTracks + 1))
+         ? GridDeclaration::Implicit
+         : GridDeclaration::Explicit;
       line->SetLineValues(
         lineNames,
         nsPresContext::AppUnitsToDoubleCSSPixels(lastTrackEdge),
         nsPresContext::AppUnitsToDoubleCSSPixels(startOfNextTrack -
                                                  lastTrackEdge),
-        line1Index + numAddedLines,
-        (
-          // Implicit if there are no explicit tracks, or if the index
-          // is before the first explicit track, or after
-          // a track beyond the last explicit track.
-          (aTrackInfo->mNumExplicitTracks == 0) ||
-          (i < aTrackInfo->mNumLeadingImplicitTracks) ||
-          (i > aTrackInfo->mNumLeadingImplicitTracks +
-               aTrackInfo->mNumExplicitTracks) ?
-            GridDeclaration::Implicit :
-            GridDeclaration::Explicit
-        )
+        lineNumber,
+        lineType
       );
 
       if (i < aTrackInfo->mEndFragmentTrack) {
@@ -215,11 +225,13 @@ GridLines::AppendRemovedAutoFits(const ComputedGridTrackInfo* aTrackInfo,
 
     RefPtr<GridLine> line = new GridLine(this);
     mLines.AppendElement(line);
+    uint32_t lineNumber = aTrackInfo->mRepeatFirstTrack +
+                          aRepeatIndex + 1;
     line->SetLineValues(
       aLineNames,
       nsPresContext::AppUnitsToDoubleCSSPixels(aLastTrackEdge),
       nsPresContext::AppUnitsToDoubleCSSPixels(0),
-      aTrackInfo->mRepeatFirstTrack + aRepeatIndex + 1,
+      lineNumber,
       GridDeclaration::Explicit
     );