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97 lines
3.5 KiB
C++
97 lines
3.5 KiB
C++
/*
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==============================================================================
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This file is part of the JUCE library - "Jules' Utility Class Extensions"
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Copyright 2004-7 by Raw Material Software ltd.
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------------------------------------------------------------------------------
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JUCE can be redistributed and/or modified under the terms of the
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GNU General Public License, as published by the Free Software Foundation;
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either version 2 of the License, or (at your option) any later version.
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JUCE is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with JUCE; if not, visit www.gnu.org/licenses or write to the
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Free Software Foundation, Inc., 59 Temple Place, Suite 330,
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Boston, MA 02111-1307 USA
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------------------------------------------------------------------------------
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If you'd like to release a closed-source product which uses JUCE, commercial
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licenses are also available: visit www.rawmaterialsoftware.com/juce for
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more information.
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==============================================================================
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*/
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#ifndef __JUCE_UNDOABLEACTION_JUCEHEADER__
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#define __JUCE_UNDOABLEACTION_JUCEHEADER__
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//==============================================================================
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/**
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Used by the UndoManager class to store an action which can be done
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and undone.
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@see UndoManager
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*/
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class JUCE_API UndoableAction
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{
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protected:
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/** Creates an action. */
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UndoableAction() throw() {}
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public:
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/** Destructor. */
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virtual ~UndoableAction() {}
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//==============================================================================
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/** Overridden by a subclass to perform the action.
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This method is called by the UndoManager, and shouldn't be used directly by
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applications.
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Be careful not to make any calls in a perform() method that could call
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recursively back into the UndoManager::perform() method
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@returns true if the action could be performed.
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@see UndoManager::perform
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*/
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virtual bool perform() = 0;
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/** Overridden by a subclass to undo the action.
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This method is called by the UndoManager, and shouldn't be used directly by
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applications.
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Be careful not to make any calls in an undo() method that could call
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recursively back into the UndoManager::perform() method
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@returns true if the action could be undone without any errors.
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@see UndoManager::perform
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*/
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virtual bool undo() = 0;
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//==============================================================================
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/** Returns a value to indicate how much memory this object takes up.
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Because the UndoManager keeps a list of UndoableActions, this is used
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to work out how much space each one will take up, so that the UndoManager
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can work out how many to keep.
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The default value returned here is 10 - units are arbitrary and
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don't have to be accurate.
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@see UndoManager::getNumberOfUnitsTakenUpByStoredCommands,
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UndoManager::setMaxNumberOfStoredUnits
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*/
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virtual int getSizeInUnits() { return 10; }
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};
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#endif // __JUCE_UNDOABLEACTION_JUCEHEADER__
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