juce_UndoManager.h

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/*
  ==============================================================================
 
   This file is part of the JUCE library.
   Copyright (c) 2022 - Raw Material Software Limited
 
   JUCE is an open source library subject to commercial or open-source
   licensing.
 
   By using JUCE, you agree to the terms of both the JUCE 7 End-User License
   Agreement and JUCE Privacy Policy.
 
   End User License Agreement: www.juce.com/juce-7-licence
   Privacy Policy: www.juce.com/juce-privacy-policy
 
   Or: You may also use this code under the terms of the GPL v3 (see
   www.gnu.org/licenses).
 
   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.
 
  ==============================================================================
*/
 
namespace juce
{
 
//==============================================================================
class JUCE_API  UndoManager  : public ChangeBroadcaster
{
public:
    //==============================================================================
    UndoManager (int maxNumberOfUnitsToKeep = 30000,
                 int minimumTransactionsToKeep = 30);

    ~UndoManager() override;
 
    //==============================================================================
    void clearUndoHistory();

    int getNumberOfUnitsTakenUpByStoredCommands() const;

    void setMaxNumberOfStoredUnits (int maxNumberOfUnitsToKeep,
                                    int minimumTransactionsToKeep);
 
    //==============================================================================
    bool perform (UndoableAction* action);

    bool perform (UndoableAction* action, const String& actionName);

    void beginNewTransaction();

    void beginNewTransaction (const String& actionName);

    void setCurrentTransactionName (const String& newName);

    String getCurrentTransactionName() const;
 
    //==============================================================================
    bool canUndo() const;

    bool undo();

    bool undoCurrentTransactionOnly();

    String getUndoDescription() const;

    StringArray getUndoDescriptions() const;

    Time getTimeOfUndoTransaction() const;

    void getActionsInCurrentTransaction (Array<const UndoableAction*>& actionsFound) const;

    int getNumActionsInCurrentTransaction() const;
 
    //==============================================================================
    bool canRedo() const;

    bool redo();

    String getRedoDescription() const;

    StringArray getRedoDescriptions() const;

    Time getTimeOfRedoTransaction() const;

    bool isPerformingUndoRedo() const;
 
private:
    //==============================================================================
    struct ActionSet;
    OwnedArray<ActionSet> transactions, stashedFutureTransactions;
    String newTransactionName;
    int totalUnitsStored = 0, maxNumUnitsToKeep = 0, minimumTransactionsToKeep = 0, nextIndex = 0;
    bool newTransaction = true, isInsideUndoRedoCall = false;
    ActionSet* getCurrentSet() const;
    ActionSet* getNextSet() const;
    void moveFutureTransactionsToStash();
    void restoreStashedFutureTransactions();
    void dropOldTransactionsIfTooLarge();
 
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (UndoManager)
};
 
} // namespace juce