paulxstretch/deps/juce/modules/juce_data_structures/undomanager/juce_UndoableAction.h
essej 25bd5d8adb git subrepo clone --branch=sono6good https://github.com/essej/JUCE.git deps/juce
subrepo:
  subdir:   "deps/juce"
  merged:   "b13f9084e"
upstream:
  origin:   "https://github.com/essej/JUCE.git"
  branch:   "sono6good"
  commit:   "b13f9084e"
git-subrepo:
  version:  "0.4.3"
  origin:   "https://github.com/ingydotnet/git-subrepo.git"
  commit:   "2f68596"
2022-04-18 17:51:22 -04:00

101 lines
3.5 KiB
C++

/*
==============================================================================
This file is part of the JUCE library.
Copyright (c) 2020 - 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 6 End-User License
Agreement and JUCE Privacy Policy (both effective as of the 16th June 2020).
End User License Agreement: www.juce.com/juce-6-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
{
//==============================================================================
/**
Used by the UndoManager class to store an action which can be done
and undone.
@see UndoManager
@tags{DataStructures}
*/
class JUCE_API UndoableAction
{
protected:
/** Creates an action. */
UndoableAction() = default;
public:
/** Destructor. */
virtual ~UndoableAction() = default;
//==============================================================================
/** Overridden by a subclass to perform the action.
This method is called by the UndoManager, and shouldn't be used directly by
applications.
Be careful not to make any calls in a perform() method that could call
recursively back into the UndoManager::perform() method
@returns true if the action could be performed.
@see UndoManager::perform
*/
virtual bool perform() = 0;
/** Overridden by a subclass to undo the action.
This method is called by the UndoManager, and shouldn't be used directly by
applications.
Be careful not to make any calls in an undo() method that could call
recursively back into the UndoManager::perform() method
@returns true if the action could be undone without any errors.
@see UndoManager::perform
*/
virtual bool undo() = 0;
//==============================================================================
/** Returns a value to indicate how much memory this object takes up.
Because the UndoManager keeps a list of UndoableActions, this is used
to work out how much space each one will take up, so that the UndoManager
can work out how many to keep.
The default value returned here is 10 - units are arbitrary and
don't have to be accurate.
@see UndoManager::getNumberOfUnitsTakenUpByStoredCommands,
UndoManager::setMaxNumberOfStoredUnits
*/
virtual int getSizeInUnits() { return 10; }
/** Allows multiple actions to be coalesced into a single action object, to reduce storage space.
If possible, this method should create and return a single action that does the same job as
this one followed by the supplied action.
If it's not possible to merge the two actions, the method should return a nullptr.
*/
virtual UndoableAction* createCoalescedAction (UndoableAction* nextAction) { ignoreUnused (nextAction); return nullptr; }
};
} // namespace juce