editor/libeditor/DeleteNodeTransaction.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 "DeleteNodeTransaction.h"
   7
   8 #include "HTMLEditUtils.h"
   9 #include "mozilla/EditorBase.h"
  10 #include "mozilla/Logging.h"
  11 #include "mozilla/SelectionState.h"  // RangeUpdater
  12 #include "mozilla/TextEditor.h"
  13 #include "mozilla/ToString.h"
  14 #include "nsDebug.h"
  15 #include "nsError.h"
  16 #include "nsAString.h"
  17
  18 namespace mozilla {
  19
  20 // static
  21 already_AddRefed<DeleteNodeTransaction> DeleteNodeTransaction::MaybeCreate(
  22     EditorBase& aEditorBase, nsIContent& aContentToDelete) {
  23   RefPtr<DeleteNodeTransaction> transaction =
  24       new DeleteNodeTransaction(aEditorBase, aContentToDelete);
  25   if (NS_WARN_IF(!transaction->CanDoIt())) {
  26     return nullptr;
  27   }
  28   return transaction.forget();
  29 }
  30
  31 DeleteNodeTransaction::DeleteNodeTransaction(EditorBase& aEditorBase,
  32                                              nsIContent& aContentToDelete)
  33     : mEditorBase(&aEditorBase),
  34       mContentToDelete(&aContentToDelete),
  35       mParentNode(aContentToDelete.GetParentNode()) {
  36   MOZ_DIAGNOSTIC_ASSERT_IF(
  37       aEditorBase.IsHTMLEditor(),
  38       HTMLEditUtils::IsRemovableNode(aContentToDelete) ||
  39           // It's okay to delete text node if it's added by `HTMLEditor` since
  40           // remaining it may be noisy for the users.
  41           (aContentToDelete.IsText() &&
  42            aContentToDelete.HasFlag(NS_MAYBE_MODIFIED_FREQUENTLY)));
  43   NS_ASSERTION(
  44       !aEditorBase.IsHTMLEditor() ||
  45           HTMLEditUtils::IsRemovableNode(aContentToDelete),
  46       "Deleting non-editable text node, please write a test for this!!");
  47 }
  48
  49 std::ostream& operator<<(std::ostream& aStream,
  50                          const DeleteNodeTransaction& aTransaction) {
  51   aStream << "{ mContentToDelete=" << aTransaction.mContentToDelete.get();
  52   if (aTransaction.mContentToDelete) {
  53     aStream << " (" << *aTransaction.mContentToDelete << ")";
  54   }
  55   aStream << ", mParentNode=" << aTransaction.mParentNode.get();
  56   if (aTransaction.mParentNode) {
  57     aStream << " (" << *aTransaction.mParentNode << ")";
  58   }
  59   aStream << ", mRefContent=" << aTransaction.mRefContent.get();
  60   if (aTransaction.mRefContent) {
  61     aStream << " (" << *aTransaction.mRefContent << ")";
  62   }
  63   aStream << ", mEditorBase=" << aTransaction.mEditorBase.get() << " }";
  64   return aStream;
  65 }
  66
  67 NS_IMPL_CYCLE_COLLECTION_INHERITED(DeleteNodeTransaction, EditTransactionBase,
  68                                    mEditorBase, mContentToDelete, mParentNode,
  69                                    mRefContent)
  70
  71 NS_IMPL_ADDREF_INHERITED(DeleteNodeTransaction, EditTransactionBase)
  72 NS_IMPL_RELEASE_INHERITED(DeleteNodeTransaction, EditTransactionBase)
  73 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DeleteNodeTransaction)
  74 NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
  75
  76 bool DeleteNodeTransaction::CanDoIt() const {
  77   if (NS_WARN_IF(!mContentToDelete) || NS_WARN_IF(!mEditorBase) ||
  78       !mParentNode) {
  79     return false;
  80   }
  81   return mEditorBase->IsTextEditor() ||
  82          HTMLEditUtils::IsSimplyEditableNode(*mParentNode);
  83 }
  84
  85 NS_IMETHODIMP DeleteNodeTransaction::DoTransaction() {
  86   MOZ_LOG(GetLogModule(), LogLevel::Info,
  87           ("%p DeleteNodeTransaction::%s this=%s", this, __FUNCTION__,
  88            ToString(*this).c_str()));
  89
  90   if (NS_WARN_IF(!CanDoIt())) {
  91     return NS_OK;
  92   }
  93
  94   MOZ_ASSERT_IF(mEditorBase->IsTextEditor(), !mContentToDelete->IsText());
  95
  96   // Remember which child mContentToDelete was (by remembering which child was
  97   // next).  Note that mRefContent can be nullptr.
  98   mRefContent = mContentToDelete->GetNextSibling();
  99
 100   // give range updater a chance.  SelAdjDeleteNode() needs to be called
 101   // *before* we do the action, unlike some of the other RangeItem update
 102   // methods.
 103   mEditorBase->RangeUpdaterRef().SelAdjDeleteNode(*mContentToDelete);
 104
 105   OwningNonNull<nsINode> parentNode = *mParentNode;
 106   OwningNonNull<nsIContent> contentToDelete = *mContentToDelete;
 107   ErrorResult error;
 108   parentNode->RemoveChild(contentToDelete, error);
 109   NS_WARNING_ASSERTION(!error.Failed(), "nsINode::RemoveChild() failed");
 110   return error.StealNSResult();
 111 }
 112
 113 NS_IMETHODIMP DeleteNodeTransaction::UndoTransaction() {
 114   MOZ_LOG(GetLogModule(), LogLevel::Info,
 115           ("%p DeleteNodeTransaction::%s this=%s", this, __FUNCTION__,
 116            ToString(*this).c_str()));
 117
 118   if (NS_WARN_IF(!CanDoIt())) {
 119     // This is a legal state, the transaction is a no-op.
 120     return NS_OK;
 121   }
 122   ErrorResult error;
 123   OwningNonNull<EditorBase> editorBase = *mEditorBase;
 124   OwningNonNull<nsINode> parentNode = *mParentNode;
 125   OwningNonNull<nsIContent> contentToDelete = *mContentToDelete;
 126   nsCOMPtr<nsIContent> refContent = mRefContent;
 127   // XXX Perhaps, we should check `refContent` is a child of `parentNode`,
 128   //     and if it's not, we should stop undoing or something.
 129   parentNode->InsertBefore(contentToDelete, refContent, error);
 130   // InsertBefore() may call MightThrowJSException() even if there is no error.
 131   // We don't need the flag here.
 132   error.WouldReportJSException();
 133   if (error.Failed()) {
 134     NS_WARNING("nsINode::InsertBefore() failed");
 135     return error.StealNSResult();
 136   }
 137   return NS_OK;
 138 }
 139
 140 NS_IMETHODIMP DeleteNodeTransaction::RedoTransaction() {
 141   MOZ_LOG(GetLogModule(), LogLevel::Info,
 142           ("%p DeleteNodeTransaction::%s this=%s", this, __FUNCTION__,
 143            ToString(*this).c_str()));
 144
 145   if (NS_WARN_IF(!CanDoIt())) {
 146     // This is a legal state, the transaction is a no-op.
 147     return NS_OK;
 148   }
 149
 150   mEditorBase->RangeUpdaterRef().SelAdjDeleteNode(*mContentToDelete);
 151
 152   OwningNonNull<nsINode> parentNode = *mParentNode;
 153   OwningNonNull<nsIContent> contentToDelete = *mContentToDelete;
 154   ErrorResult error;
 155   parentNode->RemoveChild(contentToDelete, error);
 156   NS_WARNING_ASSERTION(!error.Failed(), "nsINode::RemoveChild() failed");
 157   return error.StealNSResult();
 158 }
 159
 160 }  // namespace mozilla