layout/tables/SpanningCellSorter.h@6474c204b198 (annotated)
layout/tables/SpanningCellSorter.h
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
| michael@0 | 1 | /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ |
| michael@0 | 2 | // vim:cindent:ts=4:et:sw=4: |
| michael@0 | 3 | /* This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 4 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 5 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 6 | |
| michael@0 | 7 | #ifndef SpanningCellSorter_h |
| michael@0 | 8 | #define SpanningCellSorter_h |
| michael@0 | 9 | |
| michael@0 | 10 | /* |
| michael@0 | 11 | * Code to sort cells by their colspan, used by BasicTableLayoutStrategy. |
| michael@0 | 12 | */ |
| michael@0 | 13 | |
| michael@0 | 14 | #include "pldhash.h" |
| michael@0 | 15 | #include "nsDebug.h" |
| michael@0 | 16 | #include "StackArena.h" |
| michael@0 | 17 | |
| michael@0 | 18 | class nsIPresShell; |
| michael@0 | 19 | |
| michael@0 | 20 | /** |
| michael@0 | 21 | * The SpanningCellSorter is responsible for accumulating lists of cells |
| michael@0 | 22 | * with colspans so that those cells can later be enumerated, sorted |
| michael@0 | 23 | * from lowest number of columns spanned to highest. It does not use a |
| michael@0 | 24 | * stable sort (in fact, it currently reverses). |
| michael@0 | 25 | */ |
| michael@0 | 26 | class MOZ_STACK_CLASS SpanningCellSorter { |
| michael@0 | 27 | public: |
| michael@0 | 28 | SpanningCellSorter(); |
| michael@0 | 29 | ~SpanningCellSorter(); |
| michael@0 | 30 | |
| michael@0 | 31 | struct Item { |
| michael@0 | 32 | int32_t row, col; |
| michael@0 | 33 | Item *next; |
| michael@0 | 34 | }; |
| michael@0 | 35 | |
| michael@0 | 36 | /** |
| michael@0 | 37 | * Add a cell to the sorter. Returns false on out of memory. |
| michael@0 | 38 | * aColSpan is the number of columns spanned, and aRow/aCol are the |
| michael@0 | 39 | * position of the cell in the table (for GetCellInfoAt). |
| michael@0 | 40 | */ |
| michael@0 | 41 | bool AddCell(int32_t aColSpan, int32_t aRow, int32_t aCol); |
| michael@0 | 42 | |
| michael@0 | 43 | /** |
| michael@0 | 44 | * Get the next *list* of cells. Each list contains all the cells |
| michael@0 | 45 | * for a colspan value, and the lists are given in order from lowest |
| michael@0 | 46 | * to highest colspan. The colspan value is filled in to *aColSpan. |
| michael@0 | 47 | */ |
| michael@0 | 48 | Item* GetNext(int32_t *aColSpan); |
| michael@0 | 49 | private: |
| michael@0 | 50 | |
| michael@0 | 51 | enum State { ADDING, ENUMERATING_ARRAY, ENUMERATING_HASH, DONE }; |
| michael@0 | 52 | State mState; |
| michael@0 | 53 | |
| michael@0 | 54 | // store small colspans in an array for fast sorting and |
| michael@0 | 55 | // enumeration, and large colspans in a hash table |
| michael@0 | 56 | |
| michael@0 | 57 | enum { ARRAY_BASE = 2 }; |
| michael@0 | 58 | enum { ARRAY_SIZE = 8 }; |
| michael@0 | 59 | Item *mArray[ARRAY_SIZE]; |
| michael@0 | 60 | int32_t SpanToIndex(int32_t aSpan) { return aSpan - ARRAY_BASE; } |
| michael@0 | 61 | int32_t IndexToSpan(int32_t aIndex) { return aIndex + ARRAY_BASE; } |
| michael@0 | 62 | bool UseArrayForSpan(int32_t aSpan) { |
| michael@0 | 63 | NS_ASSERTION(SpanToIndex(aSpan) >= 0, "cell without colspan"); |
| michael@0 | 64 | return SpanToIndex(aSpan) < ARRAY_SIZE; |
| michael@0 | 65 | } |
| michael@0 | 66 | |
| michael@0 | 67 | PLDHashTable mHashTable; |
| michael@0 | 68 | struct HashTableEntry : public PLDHashEntryHdr { |
| michael@0 | 69 | int32_t mColSpan; |
| michael@0 | 70 | Item *mItems; |
| michael@0 | 71 | }; |
| michael@0 | 72 | |
| michael@0 | 73 | static const PLDHashTableOps HashTableOps; |
| michael@0 | 74 | |
| michael@0 | 75 | static PLDHashNumber |
| michael@0 | 76 | HashTableHashKey(PLDHashTable *table, const void *key); |
| michael@0 | 77 | static bool |
| michael@0 | 78 | HashTableMatchEntry(PLDHashTable *table, const PLDHashEntryHdr *hdr, |
| michael@0 | 79 | const void *key); |
| michael@0 | 80 | |
| michael@0 | 81 | static PLDHashOperator |
| michael@0 | 82 | FillSortedArray(PLDHashTable *table, PLDHashEntryHdr *hdr, |
| michael@0 | 83 | uint32_t number, void *arg); |
| michael@0 | 84 | |
| michael@0 | 85 | static int SortArray(const void *a, const void *b, void *closure); |
| michael@0 | 86 | |
| michael@0 | 87 | /* state used only during enumeration */ |
| michael@0 | 88 | uint32_t mEnumerationIndex; // into mArray or mSortedHashTable |
| michael@0 | 89 | HashTableEntry **mSortedHashTable; |
| michael@0 | 90 | |
| michael@0 | 91 | /* |
| michael@0 | 92 | * operator new is forbidden since we use the pres shell's stack |
| michael@0 | 93 | * memory, which much be pushed and popped at points matching a |
| michael@0 | 94 | * push/pop on the C++ stack. |
| michael@0 | 95 | */ |
| michael@0 | 96 | void* operator new(size_t sz) CPP_THROW_NEW { return nullptr; } |
| michael@0 | 97 | }; |
| michael@0 | 98 | |
| michael@0 | 99 | #endif |
