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Diffstat (limited to 'editor/libeditor/PlaceholderTransaction.h')
-rw-r--r-- | editor/libeditor/PlaceholderTransaction.h | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/editor/libeditor/PlaceholderTransaction.h b/editor/libeditor/PlaceholderTransaction.h new file mode 100644 index 0000000000..35387d78be --- /dev/null +++ b/editor/libeditor/PlaceholderTransaction.h @@ -0,0 +1,99 @@ +/* -*- 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 PlaceholderTransaction_h +#define PlaceholderTransaction_h + +#include "EditAggregateTransaction.h" +#include "EditorForwards.h" +#include "SelectionState.h" + +#include "mozilla/Maybe.h" +#include "mozilla/WeakPtr.h" + +namespace mozilla { + +/** + * An aggregate transaction that knows how to absorb all subsequent + * transactions with the same name. This transaction does not "Do" anything. + * But it absorbs other transactions via merge, and can undo/redo the + * transactions it has absorbed. + */ + +class PlaceholderTransaction final : public EditAggregateTransaction, + public SupportsWeakPtr { + protected: + PlaceholderTransaction(EditorBase& aEditorBase, nsStaticAtom& aName, + Maybe<SelectionState>&& aSelState); + + public: + /** + * Creates a placeholder transaction. This never returns nullptr. + * + * @param aEditorBase The editor. + * @param aName The name of creating transaction. + * @param aSelState The selection state of aEditorBase. + */ + static already_AddRefed<PlaceholderTransaction> Create( + EditorBase& aEditorBase, nsStaticAtom& aName, + Maybe<SelectionState>&& aSelState) { + // Make sure to move aSelState into a local variable to null out the + // original Maybe<SelectionState> variable. + Maybe<SelectionState> selState(std::move(aSelState)); + RefPtr<PlaceholderTransaction> transaction = + new PlaceholderTransaction(aEditorBase, aName, std::move(selState)); + return transaction.forget(); + } + + NS_DECL_ISUPPORTS_INHERITED + + NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(PlaceholderTransaction, + EditAggregateTransaction) + // ------------ EditAggregateTransaction ----------------------- + + NS_DECL_EDITTRANSACTIONBASE + NS_DECL_EDITTRANSACTIONBASE_GETASMETHODS_OVERRIDE(PlaceholderTransaction) + + MOZ_CAN_RUN_SCRIPT NS_IMETHOD RedoTransaction() override; + NS_IMETHOD Merge(nsITransaction* aTransaction, bool* aDidMerge) override; + + nsresult EndPlaceHolderBatch(); + + void ForwardEndBatchTo(PlaceholderTransaction& aForwardingTransaction) { + mForwardingTransaction = &aForwardingTransaction; + } + + void Commit() { mCommitted = true; } + + nsresult RememberEndingSelection(); + + protected: + virtual ~PlaceholderTransaction() = default; + + // The editor for this transaction. + RefPtr<EditorBase> mEditorBase; + + WeakPtr<PlaceholderTransaction> mForwardingTransaction; + + // First IME txn in this placeholder - used for IME merging. + WeakPtr<CompositionTransaction> mCompositionTransaction; + + // These next two members store the state of the selection in a safe way. + // Selection at the start of the transaction is stored, as is the selection + // at the end. This is so that UndoTransaction() and RedoTransaction() can + // restore the selection properly. + + SelectionState mStartSel; + SelectionState mEndSel; + + // Do we auto absorb any and all transaction? + bool mAbsorb; + // Do we stop auto absorbing any matching placeholder transactions? + bool mCommitted; +}; + +} // namespace mozilla + +#endif // #ifndef PlaceholderTransaction_h |