editor/libeditor/DeleteNodeTxn.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 "DeleteNodeTxn.h"
   7 #include "nsDebug.h"
   8 #include "nsEditor.h"
   9 #include "nsError.h"
  10 #include "nsSelectionState.h" // nsRangeUpdater
  11 #include "nsAString.h"
  12
  13 using namespace mozilla;
  14
  15 DeleteNodeTxn::DeleteNodeTxn()
  16   : EditTxn(), mNode(), mParent(), mRefNode(), mRangeUpdater(nullptr)
  17 {
  18 }
  19
  20 DeleteNodeTxn::~DeleteNodeTxn()
  21 {
  22 }
  23
  24 NS_IMPL_CYCLE_COLLECTION_INHERITED(DeleteNodeTxn, EditTxn,
  25                                    mNode,
  26                                    mParent,
  27                                    mRefNode)
  28
  29 NS_IMPL_ADDREF_INHERITED(DeleteNodeTxn, EditTxn)
  30 NS_IMPL_RELEASE_INHERITED(DeleteNodeTxn, EditTxn)
  31 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DeleteNodeTxn)
  32 NS_INTERFACE_MAP_END_INHERITING(EditTxn)
  33
  34 nsresult
  35 DeleteNodeTxn::Init(nsEditor* aEditor, nsINode* aNode,
  36                     nsRangeUpdater* aRangeUpdater)
  37 {
  38   NS_ENSURE_TRUE(aEditor && aNode, NS_ERROR_NULL_POINTER);
  39   mEditor = aEditor;
  40   mNode = aNode;
  41   mParent = aNode->GetParentNode();
  42
  43   // do nothing if the node has a parent and it's read-only
  44   NS_ENSURE_TRUE(!mParent || mEditor->IsModifiableNode(mParent),
  45                  NS_ERROR_FAILURE);
  46
  47   mRangeUpdater = aRangeUpdater;
  48   return NS_OK;
  49 }
  50
  51
  52 NS_IMETHODIMP
  53 DeleteNodeTxn::DoTransaction()
  54 {
  55   NS_ENSURE_TRUE(mNode, NS_ERROR_NOT_INITIALIZED);
  56
  57   if (!mParent) {
  58     // this is a no-op, there's no parent to delete mNode from
  59     return NS_OK;
  60   }
  61
  62   // remember which child mNode was (by remembering which child was next);
  63   // mRefNode can be null
  64   mRefNode = mNode->GetNextSibling();
  65
  66   // give range updater a chance.  SelAdjDeleteNode() needs to be called
  67   // *before* we do the action, unlike some of the other nsRangeStore update
  68   // methods.
  69   if (mRangeUpdater) {
  70     mRangeUpdater->SelAdjDeleteNode(mNode->AsDOMNode());
  71   }
  72
  73   ErrorResult error;
  74   mParent->RemoveChild(*mNode, error);
  75   return error.ErrorCode();
  76 }
  77
  78 NS_IMETHODIMP
  79 DeleteNodeTxn::UndoTransaction()
  80 {
  81   if (!mParent) {
  82     // this is a legal state, the txn is a no-op
  83     return NS_OK;
  84   }
  85   if (!mNode) {
  86     return NS_ERROR_NULL_POINTER;
  87   }
  88
  89   ErrorResult error;
  90   mParent->InsertBefore(*mNode, mRefNode, error);
  91   return error.ErrorCode();
  92 }
  93
  94 NS_IMETHODIMP
  95 DeleteNodeTxn::RedoTransaction()
  96 {
  97   if (!mParent) {
  98     // this is a legal state, the txn is a no-op
  99     return NS_OK;
 100   }
 101   if (!mNode) {
 102     return NS_ERROR_NULL_POINTER;
 103   }
 104
 105   if (mRangeUpdater) {
 106     mRangeUpdater->SelAdjDeleteNode(mNode->AsDOMNode());
 107   }
 108
 109   ErrorResult error;
 110   mParent->RemoveChild(*mNode, error);
 111   return error.ErrorCode();
 112 }
 113
 114 NS_IMETHODIMP
 115 DeleteNodeTxn::GetTxnDescription(nsAString& aString)
 116 {
 117   aString.AssignLiteral("DeleteNodeTxn");
 118   return NS_OK;
 119 }