Rebuild CFDE_TextEditEngine.

This CL rebuilds the text edit engine in a simpler fashion. Instead of
depending on multiple pages, paragraphs and buffer fields there is a
single text edit engine which contains a gap buffer.

This makes the code easier to understand and follow.

Change-Id: I10fe85603fa9ed15a647eaac2d931f113cd0c7b0
Reviewed-on: https://pdfium-review.googlesource.com/11990
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Reviewed-by: Ryan Harrison <rharrison@chromium.org>

1 files changed, 0 insertions, 316 deletions

diff --git a/xfa/fde/cfde_txtedtbuf.cpp b/xfa/fde/cfde_txtedtbuf.cpp
deleted file mode 100644
index caa223c697..0000000000
--- a/xfa/fde/cfde_txtedtbuf.cpp
+++ /dev/null
@@ -1,316 +0,0 @@
-// Copyright 2014 PDFium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
-
-#include "xfa/fde/cfde_txtedtbuf.h"
-
-#include <algorithm>
-#include <utility>
-
-#include "third_party/base/ptr_util.h"
-#include "third_party/base/stl_util.h"
-
-namespace {
-
-const int32_t kDefaultChunkSize = 1024;
-
-}  // namespace
-
-CFDE_TxtEdtBuf::CFDE_TxtEdtBuf() : m_chunkSize(kDefaultChunkSize), m_nTotal(0) {
-  m_chunks.push_back(pdfium::MakeUnique<ChunkHeader>(m_chunkSize));
-}
-
-CFDE_TxtEdtBuf::~CFDE_TxtEdtBuf() {}
-
-void CFDE_TxtEdtBuf::SetText(const CFX_WideString& wsText) {
-  ASSERT(!wsText.IsEmpty());
-
-  Clear();
-
-  int32_t nTextLength = wsText.GetLength();
-  int32_t nNeedCount = ((nTextLength - 1) / m_chunkSize + 1) -
-                       pdfium::CollectionSize<int32_t>(m_chunks);
-  for (int32_t i = 0; i < nNeedCount; ++i)
-    m_chunks.push_back(pdfium::MakeUnique<ChunkHeader>(m_chunkSize));
-
-  const wchar_t* lpSrcBuf = wsText.c_str();
-  int32_t nLeave = nTextLength;
-  int32_t nCopyedLength = m_chunkSize;
-  for (size_t i = 0; i < m_chunks.size() && nLeave > 0; ++i) {
-    if (nLeave < nCopyedLength)
-      nCopyedLength = nLeave;
-
-    ChunkHeader* chunk = m_chunks[i].get();
-    memcpy(chunk->wChars.data(), lpSrcBuf, nCopyedLength * sizeof(wchar_t));
-    nLeave -= nCopyedLength;
-    lpSrcBuf += nCopyedLength;
-    chunk->nUsed = nCopyedLength;
-  }
-  m_nTotal = nTextLength;
-}
-
-wchar_t CFDE_TxtEdtBuf::GetCharByIndex(int32_t nIndex) const {
-  ASSERT(nIndex >= 0 && nIndex < GetTextLength());
-
-  ChunkHeader* pChunkHeader = nullptr;
-  int32_t nTotal = 0;
-  for (const auto& chunk : m_chunks) {
-    pChunkHeader = chunk.get();
-    nTotal += pChunkHeader->nUsed;
-    if (nTotal > nIndex)
-      break;
-  }
-  ASSERT(pChunkHeader);
-
-  return pChunkHeader->wChars[pChunkHeader->nUsed - (nTotal - nIndex)];
-}
-
-CFX_WideString CFDE_TxtEdtBuf::GetRange(int32_t nBegin, int32_t nLength) const {
-  if (nLength == 0 || GetTextLength() == 0)
-    return CFX_WideString();
-
-  ASSERT(nBegin >= 0 && nLength > 0 && nBegin < GetTextLength() &&
-         nBegin + nLength <= GetTextLength());
-
-  int32_t chunkIndex = 0;
-  int32_t charIndex = 0;
-  std::tie(chunkIndex, charIndex) = Index2CP(nBegin);
-
-  int32_t nLeave = nLength;
-  CFX_WideString wsText;
-
-  int32_t nCopyLength = m_chunks[chunkIndex]->nUsed - charIndex;
-  wchar_t* lpSrcBuf = m_chunks[chunkIndex]->wChars.data() + charIndex;
-  while (nLeave > 0) {
-    if (nLeave <= nCopyLength)
-      nCopyLength = nLeave;
-
-    wsText += CFX_WideStringC(lpSrcBuf, nCopyLength);
-
-    ++chunkIndex;
-    if (chunkIndex >= pdfium::CollectionSize<int32_t>(m_chunks))
-      break;
-
-    lpSrcBuf = m_chunks[chunkIndex]->wChars.data();
-    nLeave -= nCopyLength;
-    nCopyLength = m_chunks[chunkIndex]->nUsed;
-  }
-  return wsText;
-}
-
-void CFDE_TxtEdtBuf::Insert(int32_t nPos, const CFX_WideString& wsText) {
-  ASSERT(nPos >= 0 && nPos <= m_nTotal);
-
-  int32_t nLength = wsText.GetLength();
-  ASSERT(nLength > 0);
-
-  int32_t chunkIndex = 0;
-  int32_t charIndex = 0;
-  std::tie(chunkIndex, charIndex) = Index2CP(nPos);
-
-  if (charIndex != 0) {
-    auto newChunk = pdfium::MakeUnique<ChunkHeader>(m_chunkSize);
-
-    ChunkHeader* chunk = m_chunks[chunkIndex].get();
-    int32_t nCopy = chunk->nUsed - charIndex;
-
-    memcpy(newChunk->wChars.data(), chunk->wChars.data() + charIndex,
-           nCopy * sizeof(wchar_t));
-    chunk->nUsed -= nCopy;
-    ++chunkIndex;
-
-    newChunk->nUsed = nCopy;
-    m_chunks.insert(m_chunks.begin() + chunkIndex, std::move(newChunk));
-    charIndex = 0;
-  }
-
-  const wchar_t* lpText = wsText.c_str();
-  if (chunkIndex != 0) {
-    ChunkHeader* chunk = m_chunks[chunkIndex - 1].get();
-    if (chunk->nUsed != m_chunkSize) {
-      chunkIndex--;
-      int32_t nCopy = std::min(nLength, m_chunkSize - chunk->nUsed);
-      memcpy(chunk->wChars.data() + chunk->nUsed, lpText,
-             nCopy * sizeof(wchar_t));
-      lpText += nCopy;
-      nLength -= nCopy;
-      chunk->nUsed += nCopy;
-      ++chunkIndex;
-    }
-  }
-
-  while (nLength > 0) {
-    auto chunk = pdfium::MakeUnique<ChunkHeader>(m_chunkSize);
-
-    int32_t nCopy = std::min(nLength, m_chunkSize);
-    memcpy(chunk->wChars.data(), lpText, nCopy * sizeof(wchar_t));
-    lpText += nCopy;
-    nLength -= nCopy;
-    chunk->nUsed = nCopy;
-    m_chunks.insert(m_chunks.begin() + chunkIndex, std::move(chunk));
-    ++chunkIndex;
-  }
-
-  m_nTotal += wsText.GetLength();
-}
-
-void CFDE_TxtEdtBuf::Delete(int32_t nIndex, int32_t nLength) {
-  ASSERT(nLength > 0 && nIndex >= 0 && nIndex + nLength <= m_nTotal);
-
-  int32_t endChunkIndex = 0;
-  int32_t endCharIndex = 0;
-  std::tie(endChunkIndex, endCharIndex) = Index2CP(nIndex + nLength - 1);
-  m_nTotal -= nLength;
-
-  int32_t nFirstPart = endCharIndex + 1;
-  int32_t nMovePart = m_chunks[endChunkIndex]->nUsed - nFirstPart;
-  if (nMovePart != 0) {
-    int32_t nDelete = std::min(nFirstPart, nLength);
-    memmove(m_chunks[endChunkIndex]->wChars.data() + nFirstPart - nDelete,
-            m_chunks[endChunkIndex]->wChars.data() + nFirstPart,
-            nMovePart * sizeof(wchar_t));
-    m_chunks[endChunkIndex]->nUsed -= nDelete;
-    nLength -= nDelete;
-    --endChunkIndex;
-  }
-
-  while (nLength > 0) {
-    int32_t nDeleted = std::min(m_chunks[endChunkIndex]->nUsed, nLength);
-    m_chunks[endChunkIndex]->nUsed -= nDeleted;
-    if (m_chunks[endChunkIndex]->nUsed == 0)
-      m_chunks.erase(m_chunks.begin() + endChunkIndex);
-
-    nLength -= nDeleted;
-    --endChunkIndex;
-  }
-}
-
-void CFDE_TxtEdtBuf::Clear() {
-  for (auto& chunk : m_chunks)
-    chunk->nUsed = 0;
-  m_nTotal = 0;
-}
-
-void CFDE_TxtEdtBuf::SetChunkSizeForTesting(size_t size) {
-  ASSERT(size > 0);
-
-  m_chunkSize = size;
-  m_chunks.clear();
-  m_chunks.push_back(pdfium::MakeUnique<ChunkHeader>(m_chunkSize));
-}
-
-std::pair<int32_t, int32_t> CFDE_TxtEdtBuf::Index2CP(int32_t nIndex) const {
-  ASSERT(nIndex <= GetTextLength());
-
-  if (nIndex == m_nTotal)
-    return {m_chunks.size() - 1, m_chunks.back()->nUsed};
-
-  int32_t chunkIndex = 0;
-  int32_t nTotal = 0;
-  for (auto& chunk : m_chunks) {
-    nTotal += chunk->nUsed;
-    if (nTotal > nIndex)
-      break;
-
-    ++chunkIndex;
-  }
-
-  return {chunkIndex, m_chunks[chunkIndex]->nUsed - (nTotal - nIndex)};
-}
-
-CFDE_TxtEdtBuf::ChunkHeader::ChunkHeader(int32_t chunkSize) : nUsed(0) {
-  wChars.resize(chunkSize);
-}
-
-CFDE_TxtEdtBuf::ChunkHeader::~ChunkHeader() {}
-
-CFDE_TxtEdtBuf::Iterator::Iterator(CFDE_TxtEdtBuf* pBuf, wchar_t wcAlias)
-    : m_pBuf(pBuf),
-      m_nCurChunk(0),
-      m_nCurIndex(0),
-      m_nIndex(0),
-      m_Alias(wcAlias) {
-  ASSERT(m_pBuf);
-}
-
-CFDE_TxtEdtBuf::Iterator::~Iterator() {}
-
-bool CFDE_TxtEdtBuf::Iterator::Next(bool bPrev) {
-  if (bPrev) {
-    if (m_nIndex == 0)
-      return false;
-
-    ASSERT(m_nCurChunk < pdfium::CollectionSize<int32_t>(m_pBuf->m_chunks));
-
-    if (m_nCurIndex > 0) {
-      --m_nCurIndex;
-    } else {
-      while (m_nCurChunk > 0) {
-        --m_nCurChunk;
-        ChunkHeader* chunk = m_pBuf->m_chunks[m_nCurChunk].get();
-        if (chunk->nUsed > 0) {
-          m_nCurIndex = chunk->nUsed - 1;
-          break;
-        }
-      }
-    }
-    ASSERT(m_nCurChunk >= 0);
-
-    --m_nIndex;
-    return true;
-  }
-
-  if (m_nIndex >= (m_pBuf->m_nTotal - 1))
-    return false;
-
-  ASSERT(m_nCurChunk < pdfium::CollectionSize<int32_t>(m_pBuf->m_chunks));
-
-  if (m_pBuf->m_chunks[m_nCurChunk]->nUsed != (m_nCurIndex + 1)) {
-    ++m_nCurIndex;
-  } else {
-    while (m_nCurChunk <
-           pdfium::CollectionSize<int32_t>(m_pBuf->m_chunks) - 1) {
-      ++m_nCurChunk;
-      if (m_pBuf->m_chunks[m_nCurChunk]->nUsed > 0) {
-        m_nCurIndex = 0;
-        break;
-      }
-    }
-  }
-  ++m_nIndex;
-  return true;
-}
-
-void CFDE_TxtEdtBuf::Iterator::SetAt(int32_t nIndex) {
-  ASSERT(nIndex >= 0 && nIndex < m_pBuf->m_nTotal);
-
-  std::tie(m_nCurChunk, m_nCurIndex) = m_pBuf->Index2CP(nIndex);
-  m_nIndex = nIndex;
-}
-
-int32_t CFDE_TxtEdtBuf::Iterator::GetAt() const {
-  return m_nIndex;
-}
-
-wchar_t CFDE_TxtEdtBuf::Iterator::GetChar() const {
-  ASSERT(m_nIndex >= 0 && m_nIndex < m_pBuf->m_nTotal);
-
-  if (m_Alias != 0 && m_nIndex != (m_pBuf->m_nTotal - 1))
-    return m_Alias;
-  return m_pBuf->m_chunks[m_nCurChunk]->wChars[m_nCurIndex];
-}
-
-bool CFDE_TxtEdtBuf::Iterator::IsEOF(bool bTail) const {
-  return bTail ? m_nIndex == (m_pBuf->GetTextLength() - 2) : m_nIndex == 0;
-}
-
-std::unique_ptr<IFX_CharIter> CFDE_TxtEdtBuf::Iterator::Clone() const {
-  auto pIter = pdfium::MakeUnique<CFDE_TxtEdtBuf::Iterator>(m_pBuf, 0);
-  pIter->m_nCurChunk = m_nCurChunk;
-  pIter->m_nCurIndex = m_nCurIndex;
-  pIter->m_nIndex = m_nIndex;
-  pIter->m_Alias = m_Alias;
-  return pIter;
-}