From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 02:47:55 +0200 Subject: Adding upstream version 124.0.1. Signed-off-by: Daniel Baumann --- layout/tables/SpanningCellSorter.h | 91 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100644 layout/tables/SpanningCellSorter.h (limited to 'layout/tables/SpanningCellSorter.h') diff --git a/layout/tables/SpanningCellSorter.h b/layout/tables/SpanningCellSorter.h new file mode 100644 index 0000000000..4de360497d --- /dev/null +++ b/layout/tables/SpanningCellSorter.h @@ -0,0 +1,91 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +// vim:cindent:ts=4:et:sw=4: +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef SpanningCellSorter_h +#define SpanningCellSorter_h + +/* + * Code to sort cells by their colspan, used by BasicTableLayoutStrategy. + */ + +#include "PLDHashTable.h" +#include "nsDebug.h" +#include "nsTArray.h" +#include "StackArena.h" + +/** + * The SpanningCellSorter is responsible for accumulating lists of cells + * with colspans so that those cells can later be enumerated, sorted + * from lowest number of columns spanned to highest. It does not use a + * stable sort (in fact, it currently reverses). + */ +class MOZ_STACK_CLASS SpanningCellSorter { + public: + SpanningCellSorter(); + ~SpanningCellSorter(); + + struct Item { + int32_t row, col; + Item* next; + }; + + /** + * Add a cell to the sorter. Returns false on out of memory. + * aColSpan is the number of columns spanned, and aRow/aCol are the + * position of the cell in the table (for GetCellInfoAt). + */ + bool AddCell(int32_t aColSpan, int32_t aRow, int32_t aCol); + + /** + * Get the next *list* of cells. Each list contains all the cells + * for a colspan value, and the lists are given in order from lowest + * to highest colspan. The colspan value is filled in to *aColSpan. + */ + Item* GetNext(int32_t* aColSpan); + + private: + enum State { ADDING, ENUMERATING_ARRAY, ENUMERATING_HASH, DONE }; + State mState; + + // store small colspans in an array for fast sorting and + // enumeration, and large colspans in a hash table + + enum { ARRAY_BASE = 2 }; + enum { ARRAY_SIZE = 8 }; + Item* mArray[ARRAY_SIZE]; + int32_t SpanToIndex(int32_t aSpan) { return aSpan - ARRAY_BASE; } + int32_t IndexToSpan(int32_t aIndex) { return aIndex + ARRAY_BASE; } + bool UseArrayForSpan(int32_t aSpan) { + NS_ASSERTION(SpanToIndex(aSpan) >= 0, "cell without colspan"); + return SpanToIndex(aSpan) < ARRAY_SIZE; + } + + PLDHashTable mHashTable; + struct HashTableEntry : public PLDHashEntryHdr { + int32_t mColSpan; + Item* mItems; + }; + + static const PLDHashTableOps HashTableOps; + + static PLDHashNumber HashTableHashKey(const void* key); + static bool HashTableMatchEntry(const PLDHashEntryHdr* hdr, const void* key); + + static int CompareHashTableEntry(HashTableEntry* a, HashTableEntry* b); + + /* state used only during enumeration */ + uint32_t mEnumerationIndex; // into mArray or mSortedHashTable + nsTArray mSortedHashTable; + + /* + * operator new is forbidden since we use the pres shell's stack + * memory, which much be pushed and popped at points matching a + * push/pop on the C++ stack. + */ + void* operator new(size_t sz) noexcept(true) { return nullptr; } +}; + +#endif -- cgit v1.2.3