editor/libeditor/PlaceholderTransaction.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "PlaceholderTransaction.h"
   7
   8 #include <utility>
   9
  10 #include "CompositionTransaction.h"
  11 #include "mozilla/EditorBase.h"
  12 #include "mozilla/Logging.h"
  13 #include "mozilla/ToString.h"
  14 #include "mozilla/dom/Selection.h"
  15 #include "nsGkAtoms.h"
  16 #include "nsQueryObject.h"
  17
  18 namespace mozilla {
  19
  20 using namespace dom;
  21
  22 PlaceholderTransaction::PlaceholderTransaction(
  23     EditorBase& aEditorBase, nsStaticAtom& aName,
  24     Maybe<SelectionState>&& aSelState)
  25     : mEditorBase(&aEditorBase),
  26       mCompositionTransaction(nullptr),
  27       mStartSel(*std::move(aSelState)),
  28       mAbsorb(true),
  29       mCommitted(false) {
  30   mName = &aName;
  31 }
  32
  33 NS_IMPL_CYCLE_COLLECTION_CLASS(PlaceholderTransaction)
  34
  35 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(PlaceholderTransaction,
  36                                                 EditAggregateTransaction)
  37   NS_IMPL_CYCLE_COLLECTION_UNLINK(mEditorBase);
  38   NS_IMPL_CYCLE_COLLECTION_UNLINK(mStartSel);
  39   NS_IMPL_CYCLE_COLLECTION_UNLINK(mEndSel);
  40 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
  41
  42 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(PlaceholderTransaction,
  43                                                   EditAggregateTransaction)
  44   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mEditorBase);
  45   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mStartSel);
  46   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mEndSel);
  47 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
  48
  49 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(PlaceholderTransaction)
  50 NS_INTERFACE_MAP_END_INHERITING(EditAggregateTransaction)
  51
  52 NS_IMPL_ADDREF_INHERITED(PlaceholderTransaction, EditAggregateTransaction)
  53 NS_IMPL_RELEASE_INHERITED(PlaceholderTransaction, EditAggregateTransaction)
  54
  55 void PlaceholderTransaction::AppendChild(EditTransactionBase& aTransaction) {
  56   mChildren.AppendElement(aTransaction);
  57 }
  58
  59 NS_IMETHODIMP PlaceholderTransaction::DoTransaction() {
  60   MOZ_LOG(
  61       GetLogModule(), LogLevel::Info,
  62       ("%p PlaceholderTransaction::%s this={ mName=%s }", this, __FUNCTION__,
  63        nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
  64   return NS_OK;
  65 }
  66
  67 NS_IMETHODIMP PlaceholderTransaction::UndoTransaction() {
  68   MOZ_LOG(GetLogModule(), LogLevel::Info,
  69           ("%p PlaceholderTransaction::%s this={ mName=%s } "
  70            "Start==============================",
  71            this, __FUNCTION__,
  72            nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
  73
  74   if (NS_WARN_IF(!mEditorBase)) {
  75     return NS_ERROR_NOT_INITIALIZED;
  76   }
  77
  78   // Undo transactions.
  79   nsresult rv = EditAggregateTransaction::UndoTransaction();
  80   if (NS_FAILED(rv)) {
  81     NS_WARNING("EditAggregateTransaction::UndoTransaction() failed");
  82     return rv;
  83   }
  84
  85   // now restore selection
  86   RefPtr<Selection> selection = mEditorBase->GetSelection();
  87   if (NS_WARN_IF(!selection)) {
  88     return NS_ERROR_FAILURE;
  89   }
  90   rv = mStartSel.RestoreSelection(*selection);
  91   NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
  92                        "SelectionState::RestoreSelection() failed");
  93
  94   MOZ_LOG(GetLogModule(), LogLevel::Info,
  95           ("%p PlaceholderTransaction::%s this={ mName=%s } "
  96            "End==============================",
  97            this, __FUNCTION__,
  98            nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
  99   return rv;
 100 }
 101
 102 NS_IMETHODIMP PlaceholderTransaction::RedoTransaction() {
 103   MOZ_LOG(GetLogModule(), LogLevel::Info,
 104           ("%p PlaceholderTransaction::%s this={ mName=%s } "
 105            "Start==============================",
 106            this, __FUNCTION__,
 107            nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 108
 109   if (NS_WARN_IF(!mEditorBase)) {
 110     return NS_ERROR_NOT_INITIALIZED;
 111   }
 112
 113   // Redo transactions.
 114   nsresult rv = EditAggregateTransaction::RedoTransaction();
 115   if (NS_FAILED(rv)) {
 116     NS_WARNING("EditAggregateTransaction::RedoTransaction() failed");
 117     return rv;
 118   }
 119
 120   // now restore selection
 121   RefPtr<Selection> selection = mEditorBase->GetSelection();
 122   if (NS_WARN_IF(!selection)) {
 123     return NS_ERROR_FAILURE;
 124   }
 125   rv = mEndSel.RestoreSelection(*selection);
 126   NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
 127                        "SelectionState::RestoreSelection() failed");
 128   MOZ_LOG(GetLogModule(), LogLevel::Info,
 129           ("%p PlaceholderTransaction::%s this={ mName=%s } "
 130            "End==============================",
 131            this, __FUNCTION__,
 132            nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 133   return rv;
 134 }
 135
 136 NS_IMETHODIMP PlaceholderTransaction::Merge(nsITransaction* aOtherTransaction,
 137                                             bool* aDidMerge) {
 138   if (NS_WARN_IF(!aDidMerge) || NS_WARN_IF(!aOtherTransaction)) {
 139     return NS_ERROR_INVALID_ARG;
 140   }
 141
 142   // set out param default value
 143   *aDidMerge = false;
 144
 145   if (mForwardingTransaction) {
 146     MOZ_ASSERT_UNREACHABLE(
 147         "tried to merge into a placeholder that was in "
 148         "forwarding mode!");
 149     return NS_ERROR_FAILURE;
 150   }
 151
 152   RefPtr<EditTransactionBase> otherTransactionBase =
 153       aOtherTransaction->GetAsEditTransactionBase();
 154   if (!otherTransactionBase) {
 155     MOZ_LOG(GetLogModule(), LogLevel::Debug,
 156             ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 157              "mName=%s } returned false due to non edit transaction",
 158              this, __FUNCTION__, aOtherTransaction,
 159              nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 160     return NS_OK;
 161   }
 162
 163   // We are absorbing all transactions if mAbsorb is lit.
 164   if (mAbsorb) {
 165     if (CompositionTransaction* otherCompositionTransaction =
 166             otherTransactionBase->GetAsCompositionTransaction()) {
 167       // special handling for CompositionTransaction's: they need to merge with
 168       // any previous CompositionTransaction in this placeholder, if possible.
 169       if (!mCompositionTransaction) {
 170         // this is the first IME txn in the placeholder
 171         mCompositionTransaction = otherCompositionTransaction;
 172         AppendChild(*otherCompositionTransaction);
 173       } else {
 174         bool didMerge;
 175         mCompositionTransaction->Merge(otherCompositionTransaction, &didMerge);
 176         if (!didMerge) {
 177           // it wouldn't merge.  Earlier IME txn is already committed and will
 178           // not absorb further IME txns.  So just stack this one after it
 179           // and remember it as a candidate for further merges.
 180           mCompositionTransaction = otherCompositionTransaction;
 181           AppendChild(*otherCompositionTransaction);
 182         }
 183       }
 184     } else {
 185       PlaceholderTransaction* otherPlaceholderTransaction =
 186           otherTransactionBase->GetAsPlaceholderTransaction();
 187       if (!otherPlaceholderTransaction) {
 188         // See bug 171243: just drop incoming placeholders on the floor.
 189         // Their children will be swallowed by this preexisting one.
 190         AppendChild(*otherTransactionBase);
 191       }
 192     }
 193     *aDidMerge = true;
 194     //  RememberEndingSelection();
 195     //  efficiency hack: no need to remember selection here, as we haven't yet
 196     //  finished the initial batch and we know we will be told when the batch
 197     //  ends. we can remeber the selection then.
 198     return NS_OK;
 199   }
 200
 201   // merge typing or IME or deletion transactions if the selection matches
 202   if (mCommitted ||
 203       (mName != nsGkAtoms::TypingTxnName && mName != nsGkAtoms::IMETxnName &&
 204        mName != nsGkAtoms::DeleteTxnName)) {
 205     MOZ_LOG(GetLogModule(), LogLevel::Debug,
 206             ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 207              "mName=%s } returned false due to non mergable transaction",
 208              this, __FUNCTION__, aOtherTransaction,
 209              nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 210     return NS_OK;
 211   }
 212
 213   PlaceholderTransaction* otherPlaceholderTransaction =
 214       otherTransactionBase->GetAsPlaceholderTransaction();
 215   if (!otherPlaceholderTransaction) {
 216     MOZ_LOG(GetLogModule(), LogLevel::Debug,
 217             ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 218              "mName=%s } returned false due to non placeholder transaction",
 219              this, __FUNCTION__, aOtherTransaction,
 220              nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 221     return NS_OK;
 222   }
 223
 224   RefPtr<nsAtom> otherTransactionName = otherPlaceholderTransaction->GetName();
 225   if (!otherTransactionName || otherTransactionName == nsGkAtoms::_empty ||
 226       otherTransactionName != mName) {
 227     MOZ_LOG(GetLogModule(), LogLevel::Debug,
 228             ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 229              "mName=%s } returned false due to non mergable placeholder "
 230              "transaction",
 231              this, __FUNCTION__, aOtherTransaction,
 232              nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 233     return NS_OK;
 234   }
 235
 236   // check if start selection of next placeholder matches
 237   // end selection of this placeholder
 238   // XXX Theese checks seem wrong.  The ending selection is initialized with
 239   //     actual Selection rather than expected Selection.  Therefore, even when
 240   //     web apps modifies Selection, we don't merge mergable transactions.
 241
 242   // If the new transaction's starting Selection is not a caret, we shouldn't be
 243   // merged with it because it's probably caused deleting the selection.
 244   if (!otherPlaceholderTransaction->mStartSel.HasOnlyCollapsedRange()) {
 245     MOZ_LOG(GetLogModule(), LogLevel::Debug,
 246             ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 247              "mName=%s } returned false due to not collapsed selection at "
 248              "start of new transactions",
 249              this, __FUNCTION__, aOtherTransaction,
 250              nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 251     return NS_OK;
 252   }
 253
 254   // If our ending Selection is not a caret, we should not be merged with it
 255   // because we probably changed format of a block or style of text.
 256   if (!mEndSel.HasOnlyCollapsedRange()) {
 257     MOZ_LOG(GetLogModule(), LogLevel::Debug,
 258             ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 259              "mName=%s } returned false due to not collapsed selection at end "
 260              "of previous transactions",
 261              this, __FUNCTION__, aOtherTransaction,
 262              nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 263     return NS_OK;
 264   }
 265
 266   // If the caret positions are now in different root nodes, e.g., the previous
 267   // caret position was removed from the DOM tree, this merge should not be
 268   // done.
 269   const bool isPreviousCaretPointInSameRootOfNewCaretPoint = [&]() {
 270     nsINode* previousRootInCurrentDOMTree = mEndSel.GetCommonRootNode();
 271     return previousRootInCurrentDOMTree &&
 272            previousRootInCurrentDOMTree ==
 273                otherPlaceholderTransaction->mStartSel.GetCommonRootNode();
 274   }();
 275   if (!isPreviousCaretPointInSameRootOfNewCaretPoint) {
 276     MOZ_LOG(GetLogModule(), LogLevel::Debug,
 277             ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 278              "mName=%s } returned false due to the caret points are in "
 279              "different root nodes",
 280              this, __FUNCTION__, aOtherTransaction,
 281              nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 282     return NS_OK;
 283   }
 284
 285   // If the caret points of end of us and start of new transaction are not same,
 286   // we shouldn't merge them.
 287   if (!otherPlaceholderTransaction->mStartSel.Equals(mEndSel)) {
 288     MOZ_LOG(GetLogModule(), LogLevel::Debug,
 289             ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 290              "mName=%s } returned false due to caret positions were different",
 291              this, __FUNCTION__, aOtherTransaction,
 292              nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 293     return NS_OK;
 294   }
 295
 296   mAbsorb = true;  // we need to start absorbing again
 297   otherPlaceholderTransaction->ForwardEndBatchTo(*this);
 298   // AppendChild(editTransactionBase);
 299   // see bug 171243: we don't need to merge placeholders
 300   // into placeholders.  We just reactivate merging in the
 301   // pre-existing placeholder and drop the new one on the floor.  The
 302   // EndPlaceHolderBatch() call on the new placeholder will be
 303   // forwarded to this older one.
 304   DebugOnly<nsresult> rvIgnored = RememberEndingSelection();
 305   NS_WARNING_ASSERTION(
 306       NS_SUCCEEDED(rvIgnored),
 307       "PlaceholderTransaction::RememberEndingSelection() failed, but "
 308       "ignored");
 309   *aDidMerge = true;
 310   MOZ_LOG(GetLogModule(), LogLevel::Debug,
 311           ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 312            "mName=%s } returned true",
 313            this, __FUNCTION__, aOtherTransaction,
 314            nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 315   return NS_OK;
 316 }
 317
 318 nsresult PlaceholderTransaction::EndPlaceHolderBatch() {
 319   mAbsorb = false;
 320
 321   if (mForwardingTransaction) {
 322     if (mForwardingTransaction) {
 323       DebugOnly<nsresult> rvIgnored =
 324           mForwardingTransaction->EndPlaceHolderBatch();
 325       NS_WARNING_ASSERTION(
 326           NS_SUCCEEDED(rvIgnored),
 327           "PlaceholderTransaction::EndPlaceHolderBatch() failed, but ignored");
 328     }
 329   }
 330   // remember our selection state.
 331   nsresult rv = RememberEndingSelection();
 332   NS_WARNING_ASSERTION(
 333       NS_SUCCEEDED(rv),
 334       "PlaceholderTransaction::RememberEndingSelection() failed");
 335   return rv;
 336 }
 337
 338 nsresult PlaceholderTransaction::RememberEndingSelection() {
 339   if (NS_WARN_IF(!mEditorBase)) {
 340     return NS_ERROR_NOT_INITIALIZED;
 341   }
 342
 343   RefPtr<Selection> selection = mEditorBase->GetSelection();
 344   if (NS_WARN_IF(!selection)) {
 345     return NS_ERROR_FAILURE;
 346   }
 347   mEndSel.SaveSelection(*selection);
 348   return NS_OK;
 349 }
 350
 351 }  // namespace mozilla