editor/libeditor/SplitElementTxn.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 <stdio.h>                      // for printf
   7
   8 #include "SplitElementTxn.h"
   9 #include "nsAString.h"
  10 #include "nsDebug.h"                    // for NS_ASSERTION, etc
  11 #include "nsEditor.h"                   // for nsEditor
  12 #include "nsError.h"                    // for NS_ERROR_NOT_INITIALIZED, etc
  13 #include "nsIContent.h"                 // for nsIContent
  14 #include "nsIDOMCharacterData.h"        // for nsIDOMCharacterData
  15 #include "nsIEditor.h"                  // for nsEditor::DebugDumpContent, etc
  16 #include "nsISelection.h"               // for nsISelection
  17 #include "nsISupportsUtils.h"           // for NS_ADDREF
  18
  19 using namespace mozilla;
  20
  21 // note that aEditor is not refcounted
  22 SplitElementTxn::SplitElementTxn()
  23   : EditTxn()
  24 {
  25 }
  26
  27 SplitElementTxn::~SplitElementTxn()
  28 {
  29 }
  30
  31 NS_IMPL_CYCLE_COLLECTION_INHERITED(SplitElementTxn, EditTxn,
  32                                    mParent,
  33                                    mNewLeftNode)
  34
  35 NS_IMPL_ADDREF_INHERITED(SplitElementTxn, EditTxn)
  36 NS_IMPL_RELEASE_INHERITED(SplitElementTxn, EditTxn)
  37 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(SplitElementTxn)
  38 NS_INTERFACE_MAP_END_INHERITING(EditTxn)
  39
  40 NS_IMETHODIMP SplitElementTxn::Init(nsEditor   *aEditor,
  41                                     nsIDOMNode *aNode,
  42                                     int32_t     aOffset)
  43 {
  44   NS_ASSERTION(aEditor && aNode, "bad args");
  45   if (!aEditor || !aNode) { return NS_ERROR_NOT_INITIALIZED; }
  46
  47   mEditor = aEditor;
  48   mExistingRightNode = do_QueryInterface(aNode);
  49   mOffset = aOffset;
  50   return NS_OK;
  51 }
  52
  53 NS_IMETHODIMP SplitElementTxn::DoTransaction(void)
  54 {
  55   NS_ASSERTION(mExistingRightNode && mEditor, "bad state");
  56   if (!mExistingRightNode || !mEditor) { return NS_ERROR_NOT_INITIALIZED; }
  57
  58   // create a new node
  59   nsresult result = mExistingRightNode->CloneNode(false, 1, getter_AddRefs(mNewLeftNode));
  60   NS_ASSERTION(((NS_SUCCEEDED(result)) && (mNewLeftNode)), "could not create element.");
  61   NS_ENSURE_SUCCESS(result, result);
  62   mEditor->MarkNodeDirty(mExistingRightNode);
  63
  64   // get the parent node
  65   result = mExistingRightNode->GetParentNode(getter_AddRefs(mParent));
  66   NS_ENSURE_SUCCESS(result, result);
  67   NS_ENSURE_TRUE(mParent, NS_ERROR_NULL_POINTER);
  68
  69   // insert the new node
  70   result = mEditor->SplitNodeImpl(mExistingRightNode, mOffset, mNewLeftNode, mParent);
  71   if (mNewLeftNode) {
  72     bool bAdjustSelection;
  73     mEditor->ShouldTxnSetSelection(&bAdjustSelection);
  74     if (bAdjustSelection)
  75     {
  76       nsCOMPtr<nsISelection> selection;
  77       result = mEditor->GetSelection(getter_AddRefs(selection));
  78       NS_ENSURE_SUCCESS(result, result);
  79       NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);
  80       result = selection->Collapse(mNewLeftNode, mOffset);
  81     }
  82     else
  83     {
  84       // do nothing - dom range gravity will adjust selection
  85     }
  86   }
  87   return result;
  88 }
  89
  90 NS_IMETHODIMP SplitElementTxn::UndoTransaction(void)
  91 {
  92   NS_ASSERTION(mEditor && mExistingRightNode && mNewLeftNode && mParent, "bad state");
  93   if (!mEditor || !mExistingRightNode || !mNewLeftNode || !mParent) {
  94     return NS_ERROR_NOT_INITIALIZED;
  95   }
  96
  97   // this assumes Do inserted the new node in front of the prior existing node
  98   nsCOMPtr<nsINode> right = do_QueryInterface(mExistingRightNode);
  99   nsCOMPtr<nsINode> left = do_QueryInterface(mNewLeftNode);
 100   nsCOMPtr<nsINode> parent = do_QueryInterface(mParent);
 101   return mEditor->JoinNodesImpl(right, left, parent);
 102 }
 103
 104 /* redo cannot simply resplit the right node, because subsequent transactions
 105  * on the redo stack may depend on the left node existing in its previous state.
 106  */
 107 NS_IMETHODIMP SplitElementTxn::RedoTransaction(void)
 108 {
 109   NS_ASSERTION(mEditor && mExistingRightNode && mNewLeftNode && mParent, "bad state");
 110   if (!mEditor || !mExistingRightNode || !mNewLeftNode || !mParent) {
 111     return NS_ERROR_NOT_INITIALIZED;
 112   }
 113
 114   nsresult result;
 115   nsCOMPtr<nsIDOMNode>resultNode;
 116   // first, massage the existing node so it is in its post-split state
 117   nsCOMPtr<nsIDOMCharacterData>rightNodeAsText = do_QueryInterface(mExistingRightNode);
 118   if (rightNodeAsText)
 119   {
 120     nsresult result = rightNodeAsText->DeleteData(0, mOffset);
 121     NS_ENSURE_SUCCESS(result, result);
 122   }
 123   else
 124   {
 125     nsCOMPtr<nsIDOMNode>child;
 126     nsCOMPtr<nsIDOMNode>nextSibling;
 127     result = mExistingRightNode->GetFirstChild(getter_AddRefs(child));
 128     int32_t i;
 129     for (i=0; i<mOffset; i++)
 130     {
 131       if (NS_FAILED(result)) {return result;}
 132       if (!child) {return NS_ERROR_NULL_POINTER;}
 133       child->GetNextSibling(getter_AddRefs(nextSibling));
 134       result = mExistingRightNode->RemoveChild(child, getter_AddRefs(resultNode));
 135       if (NS_SUCCEEDED(result))
 136       {
 137         result = mNewLeftNode->AppendChild(child, getter_AddRefs(resultNode));
 138       }
 139       child = do_QueryInterface(nextSibling);
 140     }
 141   }
 142   // second, re-insert the left node into the tree
 143   result = mParent->InsertBefore(mNewLeftNode, mExistingRightNode, getter_AddRefs(resultNode));
 144   return result;
 145 }
 146
 147
 148 NS_IMETHODIMP SplitElementTxn::GetTxnDescription(nsAString& aString)
 149 {
 150   aString.AssignLiteral("SplitElementTxn");
 151   return NS_OK;
 152 }
 153
 154 NS_IMETHODIMP SplitElementTxn::GetNewNode(nsIDOMNode **aNewNode)
 155 {
 156   NS_ENSURE_TRUE(aNewNode, NS_ERROR_NULL_POINTER);
 157   NS_ENSURE_TRUE(mNewLeftNode, NS_ERROR_NOT_INITIALIZED);
 158   *aNewNode = mNewLeftNode;
 159   NS_ADDREF(*aNewNode);
 160   return NS_OK;
 161 }