1 files changed, 94 insertions, 0 deletions
diff --git a/editor/libeditor/DeleteTextTransaction.h b/editor/libeditor/DeleteTextTransaction.h
new file mode 100644
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+++ b/editor/libeditor/DeleteTextTransaction.h
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef DeleteTextTransaction_h
+#define DeleteTextTransaction_h
+
+#include "mozilla/EditTransactionBase.h"
+#include "mozilla/dom/Text.h"
+#include "nsCOMPtr.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsID.h"
+#include "nsString.h"
+#include "nscore.h"
+
+namespace mozilla {
+
+class EditorBase;
+class RangeUpdater;
+
+/**
+ * A transaction that removes text from a content node.
+ */
+class DeleteTextTransaction final : public EditTransactionBase {
+ protected:
+  DeleteTextTransaction(EditorBase& aEditorBase, dom::Text& aTextNode,
+                        uint32_t aOffset, uint32_t aLengthToDelete);
+
+ public:
+  /**
+   * Creates a delete text transaction to remove given range.  This returns
+   * nullptr if it cannot modify the text node.
+   *
+   * @param aEditorBase         The provider of basic editing operations.
+   * @param aTextNode           The content node to remove text from.
+   * @param aOffset             The location in aElement to begin the deletion.
+   * @param aLenthToDelete      The length to delete.
+   */
+  static already_AddRefed<DeleteTextTransaction> MaybeCreate(
+      EditorBase& aEditorBase, dom::Text& aTextNode, uint32_t aOffset,
+      uint32_t aLengthToDelete);
+
+  /**
+   * Creates a delete text transaction to remove a previous or next character.
+   * Those methods MAY return nullptr.
+   *
+   * @param aEditorBase         The provider of basic editing operations.
+   * @param aTextNode           The content node to remove text from.
+   * @param aOffset             The location in aElement to begin the deletion.
+   */
+  static already_AddRefed<DeleteTextTransaction>
+  MaybeCreateForPreviousCharacter(EditorBase& aEditorBase, dom::Text& aTextNode,
+                                  uint32_t aOffset);
+  static already_AddRefed<DeleteTextTransaction> MaybeCreateForNextCharacter(
+      EditorBase& aEditorBase, dom::Text& aTextNode, uint32_t aOffset);
+
+  /**
+   * CanDoIt() returns true if there are enough members and can modify the
+   * text.  Otherwise, false.
+   */
+  bool CanDoIt() const;
+
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(DeleteTextTransaction,
+                                           EditTransactionBase)
+  NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
+
+  NS_DECL_EDITTRANSACTIONBASE
+  NS_DECL_EDITTRANSACTIONBASE_GETASMETHODS_OVERRIDE(DeleteTextTransaction)
+
+  dom::Text* GetText() const { return mTextNode; }
+  uint32_t Offset() const { return mOffset; }
+  uint32_t LengthToDelete() const { return mLengthToDelete; }
+
+ protected:
+  // The provider of basic editing operations.
+  RefPtr<EditorBase> mEditorBase;
+
+  // The CharacterData node to operate upon.
+  RefPtr<dom::Text> mTextNode;
+
+  // The offset into mTextNode where the deletion is to take place.
+  uint32_t mOffset;
+
+  // The length to delete.
+  uint32_t mLengthToDelete;
+
+  // The text that was deleted.
+  nsString mDeletedText;
+};
+
+}  // namespace mozilla
+
+#endif  // #ifndef DeleteTextTransaction_h