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 NS_IMETHODIMP PlaceholderTransaction::DoTransaction() {
  56   MOZ_LOG(
  57       GetLogModule(), LogLevel::Info,
  58       ("%p PlaceholderTransaction::%s this={ mName=%s }", this, __FUNCTION__,
  59        nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
  60   return NS_OK;
  61 }
  62
  63 NS_IMETHODIMP PlaceholderTransaction::UndoTransaction() {
  64   MOZ_LOG(GetLogModule(), LogLevel::Info,
  65           ("%p PlaceholderTransaction::%s this={ mName=%s } "
  66            "Start==============================",
  67            this, __FUNCTION__,
  68            nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
  69
  70   if (NS_WARN_IF(!mEditorBase)) {
  71     return NS_ERROR_NOT_INITIALIZED;
  72   }
  73
  74   // Undo transactions.
  75   nsresult rv = EditAggregateTransaction::UndoTransaction();
  76   if (NS_FAILED(rv)) {
  77     NS_WARNING("EditAggregateTransaction::UndoTransaction() failed");
  78     return rv;
  79   }
  80
  81   // now restore selection
  82   RefPtr<Selection> selection = mEditorBase->GetSelection();
  83   if (NS_WARN_IF(!selection)) {
  84     return NS_ERROR_FAILURE;
  85   }
  86   rv = mStartSel.RestoreSelection(*selection);
  87   NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
  88                        "SelectionState::RestoreSelection() failed");
  89
  90   MOZ_LOG(GetLogModule(), LogLevel::Info,
  91           ("%p PlaceholderTransaction::%s this={ mName=%s } "
  92            "End==============================",
  93            this, __FUNCTION__,
  94            nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
  95   return rv;
  96 }
  97
  98 NS_IMETHODIMP PlaceholderTransaction::RedoTransaction() {
  99   MOZ_LOG(GetLogModule(), LogLevel::Info,
 100           ("%p PlaceholderTransaction::%s this={ mName=%s } "
 101            "Start==============================",
 102            this, __FUNCTION__,
 103            nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 104
 105   if (NS_WARN_IF(!mEditorBase)) {
 106     return NS_ERROR_NOT_INITIALIZED;
 107   }
 108
 109   // Redo transactions.
 110   nsresult rv = EditAggregateTransaction::RedoTransaction();
 111   if (NS_FAILED(rv)) {
 112     NS_WARNING("EditAggregateTransaction::RedoTransaction() failed");
 113     return rv;
 114   }
 115
 116   // now restore selection
 117   RefPtr<Selection> selection = mEditorBase->GetSelection();
 118   if (NS_WARN_IF(!selection)) {
 119     return NS_ERROR_FAILURE;
 120   }
 121   rv = mEndSel.RestoreSelection(*selection);
 122   NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
 123                        "SelectionState::RestoreSelection() failed");
 124   MOZ_LOG(GetLogModule(), LogLevel::Info,
 125           ("%p PlaceholderTransaction::%s this={ mName=%s } "
 126            "End==============================",
 127            this, __FUNCTION__,
 128            nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 129   return rv;
 130 }
 131
 132 NS_IMETHODIMP PlaceholderTransaction::Merge(nsITransaction* aOtherTransaction,
 133                                             bool* aDidMerge) {
 134   if (NS_WARN_IF(!aDidMerge) || NS_WARN_IF(!aOtherTransaction)) {
 135     return NS_ERROR_INVALID_ARG;
 136   }
 137
 138   // set out param default value
 139   *aDidMerge = false;
 140
 141   if (mForwardingTransaction) {
 142     MOZ_ASSERT_UNREACHABLE(
 143         "tried to merge into a placeholder that was in "
 144         "forwarding mode!");
 145     return NS_ERROR_FAILURE;
 146   }
 147
 148   RefPtr<EditTransactionBase> otherTransactionBase =
 149       aOtherTransaction->GetAsEditTransactionBase();
 150   if (!otherTransactionBase) {
 151     MOZ_LOG(GetLogModule(), LogLevel::Debug,
 152             ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 153              "mName=%s } returned false due to non edit transaction",
 154              this, __FUNCTION__, aOtherTransaction,
 155              nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 156     return NS_OK;
 157   }
 158
 159   // We are absorbing all transactions if mAbsorb is lit.
 160   if (mAbsorb) {
 161     if (CompositionTransaction* otherCompositionTransaction =
 162             otherTransactionBase->GetAsCompositionTransaction()) {
 163       // special handling for CompositionTransaction's: they need to merge with
 164       // any previous CompositionTransaction in this placeholder, if possible.
 165       if (!mCompositionTransaction) {
 166         // this is the first IME txn in the placeholder
 167         mCompositionTransaction = otherCompositionTransaction;
 168         DebugOnly<nsresult> rvIgnored =
 169             AppendChild(otherCompositionTransaction);
 170         NS_WARNING_ASSERTION(
 171             NS_SUCCEEDED(rvIgnored),
 172             "EditAggregateTransaction::AppendChild() failed, but ignored");
 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           DebugOnly<nsresult> rvIgnored =
 182               AppendChild(otherCompositionTransaction);
 183           NS_WARNING_ASSERTION(
 184               NS_SUCCEEDED(rvIgnored),
 185               "EditAggregateTransaction::AppendChild() failed, but ignored");
 186         }
 187       }
 188     } else {
 189       PlaceholderTransaction* otherPlaceholderTransaction =
 190           otherTransactionBase->GetAsPlaceholderTransaction();
 191       if (!otherPlaceholderTransaction) {
 192         // See bug 171243: just drop incoming placeholders on the floor.
 193         // Their children will be swallowed by this preexisting one.
 194         DebugOnly<nsresult> rvIgnored = AppendChild(otherTransactionBase);
 195         NS_WARNING_ASSERTION(
 196             NS_SUCCEEDED(rvIgnored),
 197             "EditAggregateTransaction::AppendChild() failed, but ignored");
 198       }
 199     }
 200     *aDidMerge = true;
 201     //  RememberEndingSelection();
 202     //  efficiency hack: no need to remember selection here, as we haven't yet
 203     //  finished the initial batch and we know we will be told when the batch
 204     //  ends. we can remeber the selection then.
 205     return NS_OK;
 206   }
 207
 208   // merge typing or IME or deletion transactions if the selection matches
 209   if (mCommitted ||
 210       (mName != nsGkAtoms::TypingTxnName && mName != nsGkAtoms::IMETxnName &&
 211        mName != nsGkAtoms::DeleteTxnName)) {
 212     MOZ_LOG(GetLogModule(), LogLevel::Debug,
 213             ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 214              "mName=%s } returned false due to non mergable transaction",
 215              this, __FUNCTION__, aOtherTransaction,
 216              nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 217     return NS_OK;
 218   }
 219
 220   PlaceholderTransaction* otherPlaceholderTransaction =
 221       otherTransactionBase->GetAsPlaceholderTransaction();
 222   if (!otherPlaceholderTransaction) {
 223     MOZ_LOG(GetLogModule(), LogLevel::Debug,
 224             ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 225              "mName=%s } returned false due to non placeholder transaction",
 226              this, __FUNCTION__, aOtherTransaction,
 227              nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 228     return NS_OK;
 229   }
 230
 231   RefPtr<nsAtom> otherTransactionName;
 232   DebugOnly<nsresult> rvIgnored = otherPlaceholderTransaction->GetName(
 233       getter_AddRefs(otherTransactionName));
 234   NS_WARNING_ASSERTION(NS_SUCCEEDED(rvIgnored),
 235                        "PlaceholderTransaction::GetName() failed, but ignored");
 236   if (!otherTransactionName || otherTransactionName == nsGkAtoms::_empty ||
 237       otherTransactionName != mName) {
 238     MOZ_LOG(GetLogModule(), LogLevel::Debug,
 239             ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 240              "mName=%s } returned false due to non mergable placeholder "
 241              "transaction",
 242              this, __FUNCTION__, aOtherTransaction,
 243              nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 244     return NS_OK;
 245   }
 246
 247   // check if start selection of next placeholder matches
 248   // end selection of this placeholder
 249   // XXX Theese checks seem wrong.  The ending selection is initialized with
 250   //     actual Selection rather than expected Selection.  Therefore, even when
 251   //     web apps modifies Selection, we don't merge mergable transactions.
 252
 253   // If the new transaction's starting Selection is not a caret, we shouldn't be
 254   // merged with it because it's probably caused deleting the selection.
 255   if (!otherPlaceholderTransaction->mStartSel.HasOnlyCollapsedRange()) {
 256     MOZ_LOG(GetLogModule(), LogLevel::Debug,
 257             ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 258              "mName=%s } returned false due to not collapsed selection at "
 259              "start of new transactions",
 260              this, __FUNCTION__, aOtherTransaction,
 261              nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 262     return NS_OK;
 263   }
 264
 265   // If our ending Selection is not a caret, we should not be merged with it
 266   // because we probably changed format of a block or style of text.
 267   if (!mEndSel.HasOnlyCollapsedRange()) {
 268     MOZ_LOG(GetLogModule(), LogLevel::Debug,
 269             ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 270              "mName=%s } returned false due to not collapsed selection at end "
 271              "of previous transactions",
 272              this, __FUNCTION__, aOtherTransaction,
 273              nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 274     return NS_OK;
 275   }
 276
 277   // If the caret positions are now in different root nodes, e.g., the previous
 278   // caret position was removed from the DOM tree, this merge should not be
 279   // done.
 280   const bool isPreviousCaretPointInSameRootOfNewCaretPoint = [&]() {
 281     nsINode* previousRootInCurrentDOMTree = mEndSel.GetCommonRootNode();
 282     return previousRootInCurrentDOMTree &&
 283            previousRootInCurrentDOMTree ==
 284                otherPlaceholderTransaction->mStartSel.GetCommonRootNode();
 285   }();
 286   if (!isPreviousCaretPointInSameRootOfNewCaretPoint) {
 287     MOZ_LOG(GetLogModule(), LogLevel::Debug,
 288             ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 289              "mName=%s } returned false due to the caret points are in "
 290              "different root nodes",
 291              this, __FUNCTION__, aOtherTransaction,
 292              nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 293     return NS_OK;
 294   }
 295
 296   // If the caret points of end of us and start of new transaction are not same,
 297   // we shouldn't merge them.
 298   if (!otherPlaceholderTransaction->mStartSel.Equals(mEndSel)) {
 299     MOZ_LOG(GetLogModule(), LogLevel::Debug,
 300             ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 301              "mName=%s } returned false due to caret positions were different",
 302              this, __FUNCTION__, aOtherTransaction,
 303              nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 304     return NS_OK;
 305   }
 306
 307   mAbsorb = true;  // we need to start absorbing again
 308   otherPlaceholderTransaction->ForwardEndBatchTo(*this);
 309   // AppendChild(editTransactionBase);
 310   // see bug 171243: we don't need to merge placeholders
 311   // into placeholders.  We just reactivate merging in the
 312   // pre-existing placeholder and drop the new one on the floor.  The
 313   // EndPlaceHolderBatch() call on the new placeholder will be
 314   // forwarded to this older one.
 315   rvIgnored = RememberEndingSelection();
 316   NS_WARNING_ASSERTION(
 317       NS_SUCCEEDED(rvIgnored),
 318       "PlaceholderTransaction::RememberEndingSelection() failed, but "
 319       "ignored");
 320   *aDidMerge = true;
 321   MOZ_LOG(GetLogModule(), LogLevel::Debug,
 322           ("%p PlaceholderTransaction::%s(aOtherTransaction=%p) this={ "
 323            "mName=%s } returned true",
 324            this, __FUNCTION__, aOtherTransaction,
 325            nsAtomCString(mName ? mName.get() : nsGkAtoms::_empty).get()));
 326   return NS_OK;
 327 }
 328
 329 nsresult PlaceholderTransaction::EndPlaceHolderBatch() {
 330   mAbsorb = false;
 331
 332   if (mForwardingTransaction) {
 333     if (mForwardingTransaction) {
 334       DebugOnly<nsresult> rvIgnored =
 335           mForwardingTransaction->EndPlaceHolderBatch();
 336       NS_WARNING_ASSERTION(
 337           NS_SUCCEEDED(rvIgnored),
 338           "PlaceholderTransaction::EndPlaceHolderBatch() failed, but ignored");
 339     }
 340   }
 341   // remember our selection state.
 342   nsresult rv = RememberEndingSelection();
 343   NS_WARNING_ASSERTION(
 344       NS_SUCCEEDED(rv),
 345       "PlaceholderTransaction::RememberEndingSelection() failed");
 346   return rv;
 347 }
 348
 349 nsresult PlaceholderTransaction::RememberEndingSelection() {
 350   if (NS_WARN_IF(!mEditorBase)) {
 351     return NS_ERROR_NOT_INITIALIZED;
 352   }
 353
 354   RefPtr<Selection> selection = mEditorBase->GetSelection();
 355   if (NS_WARN_IF(!selection)) {
 356     return NS_ERROR_FAILURE;
 357   }
 358   mEndSel.SaveSelection(*selection);
 359   return NS_OK;
 360 }
 361
 362 }  // namespace mozilla