editor/libeditor/DeleteTextTransaction.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 "DeleteTextTransaction.h"
   7
   8 #include "HTMLEditUtils.h"
   9 #include "mozilla/Assertions.h"
  10 #include "mozilla/EditorBase.h"
  11 #include "mozilla/EditorDOMPoint.h"
  12 #include "mozilla/SelectionState.h"
  13 #include "mozilla/dom/Selection.h"
  14 #include "nsDebug.h"
  15 #include "nsError.h"
  16 #include "nsISupportsImpl.h"
  17 #include "nsAString.h"
  18
  19 namespace mozilla {
  20
  21 using namespace dom;
  22
  23 // static
  24 already_AddRefed<DeleteTextTransaction> DeleteTextTransaction::MaybeCreate(
  25     EditorBase& aEditorBase, Text& aTextNode, uint32_t aOffset,
  26     uint32_t aLengthToDelete) {
  27   RefPtr<DeleteTextTransaction> transaction = new DeleteTextTransaction(
  28       aEditorBase, aTextNode, aOffset, aLengthToDelete);
  29   return transaction.forget();
  30 }
  31
  32 // static
  33 already_AddRefed<DeleteTextTransaction>
  34 DeleteTextTransaction::MaybeCreateForPreviousCharacter(EditorBase& aEditorBase,
  35                                                        Text& aTextNode,
  36                                                        uint32_t aOffset) {
  37   if (NS_WARN_IF(!aOffset)) {
  38     return nullptr;
  39   }
  40
  41   nsAutoString data;
  42   aTextNode.GetData(data);
  43   if (NS_WARN_IF(data.IsEmpty())) {
  44     return nullptr;
  45   }
  46
  47   uint32_t length = 1;
  48   uint32_t offset = aOffset - 1;
  49   if (offset && NS_IS_SURROGATE_PAIR(data[offset - 1], data[offset])) {
  50     ++length;
  51     --offset;
  52   }
  53   return DeleteTextTransaction::MaybeCreate(aEditorBase, aTextNode, offset,
  54                                             length);
  55 }
  56
  57 // static
  58 already_AddRefed<DeleteTextTransaction>
  59 DeleteTextTransaction::MaybeCreateForNextCharacter(EditorBase& aEditorBase,
  60                                                    Text& aTextNode,
  61                                                    uint32_t aOffset) {
  62   nsAutoString data;
  63   aTextNode.GetData(data);
  64   if (NS_WARN_IF(aOffset >= data.Length()) || NS_WARN_IF(data.IsEmpty())) {
  65     return nullptr;
  66   }
  67
  68   uint32_t length = 1;
  69   if (aOffset + 1 < data.Length() &&
  70       NS_IS_SURROGATE_PAIR(data[aOffset], data[aOffset + 1])) {
  71     ++length;
  72   }
  73   return DeleteTextTransaction::MaybeCreate(aEditorBase, aTextNode, aOffset,
  74                                             length);
  75 }
  76
  77 DeleteTextTransaction::DeleteTextTransaction(EditorBase& aEditorBase,
  78                                              Text& aTextNode, uint32_t aOffset,
  79                                              uint32_t aLengthToDelete)
  80     : mEditorBase(&aEditorBase),
  81       mTextNode(&aTextNode),
  82       mOffset(aOffset),
  83       mLengthToDelete(aLengthToDelete) {
  84   NS_ASSERTION(mTextNode->Length() >= aOffset + aLengthToDelete,
  85                "Trying to delete more characters than in node");
  86 }
  87
  88 NS_IMPL_CYCLE_COLLECTION_INHERITED(DeleteTextTransaction, EditTransactionBase,
  89                                    mEditorBase, mTextNode)
  90
  91 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DeleteTextTransaction)
  92 NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
  93
  94 bool DeleteTextTransaction::CanDoIt() const {
  95   if (NS_WARN_IF(!mTextNode) || NS_WARN_IF(!mEditorBase)) {
  96     return false;
  97   }
  98   return mEditorBase->IsTextEditor() ||
  99          HTMLEditUtils::IsSimplyEditableNode(*mTextNode);
 100 }
 101
 102 NS_IMETHODIMP DeleteTextTransaction::DoTransaction() {
 103   if (NS_WARN_IF(!CanDoIt())) {
 104     return NS_ERROR_NOT_AVAILABLE;
 105   }
 106
 107   // Get the text that we're about to delete
 108   ErrorResult error;
 109   mTextNode->SubstringData(mOffset, mLengthToDelete, mDeletedText, error);
 110   if (error.Failed()) {
 111     NS_WARNING("Text::SubstringData() failed");
 112     return error.StealNSResult();
 113   }
 114
 115   OwningNonNull<EditorBase> editorBase = *mEditorBase;
 116   OwningNonNull<Text> textNode = *mTextNode;
 117   editorBase->DoDeleteText(textNode, mOffset, mLengthToDelete, error);
 118   if (error.Failed()) {
 119     NS_WARNING("EditorBase::DoDeleteText() failed");
 120     return error.StealNSResult();
 121   }
 122
 123   editorBase->RangeUpdaterRef().SelAdjDeleteText(textNode, mOffset,
 124                                                  mLengthToDelete);
 125
 126   if (!editorBase->AllowsTransactionsToChangeSelection()) {
 127     return NS_OK;
 128   }
 129
 130   RefPtr<Selection> selection = editorBase->GetSelection();
 131   if (NS_WARN_IF(!selection)) {
 132     return NS_ERROR_FAILURE;
 133   }
 134   selection->CollapseInLimiter(EditorRawDOMPoint(textNode, mOffset), error);
 135   NS_WARNING_ASSERTION(!error.Failed(),
 136                        "Selection::CollapseInLimiter() failed");
 137   return error.StealNSResult();
 138 }
 139
 140 // XXX: We may want to store the selection state and restore it properly.  Was
 141 //     it an insertion point or an extended selection?
 142 NS_IMETHODIMP DeleteTextTransaction::UndoTransaction() {
 143   if (NS_WARN_IF(!CanDoIt())) {
 144     return NS_ERROR_NOT_AVAILABLE;
 145   }
 146   RefPtr<EditorBase> editorBase = mEditorBase;
 147   RefPtr<Text> textNode = mTextNode;
 148   ErrorResult error;
 149   editorBase->DoInsertText(*textNode, mOffset, mDeletedText, error);
 150   NS_WARNING_ASSERTION(!error.Failed(), "EditorBase::DoInsertText() failed");
 151   return error.StealNSResult();
 152 }
 153
 154 }  // namespace mozilla