openshot-audio
0.1.2
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#include <juce_UndoManager.h>
Classes | |
struct | ActionSet |
Friends | |
struct | ContainerDeletePolicy< ActionSet > |
Manages a list of undo/redo commands.
An UndoManager object keeps a list of past actions and can use these actions to move backwards and forwards through an undo history.
To use it, create subclasses of UndoableAction which perform all the actions you need, then when you need to actually perform an action, create one and pass it to the UndoManager's perform() method.
The manager also uses the concept of 'transactions' to group the actions together - all actions performed between calls to beginNewTransaction() are grouped together and are all undone/redone as a group.
The UndoManager is a ChangeBroadcaster, so listeners can register to be told when actions are performed or undone.
UndoManager::UndoManager | ( | int | maxNumberOfUnitsToKeep = 30000 , |
int | minimumTransactionsToKeep = 30 |
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Creates an UndoManager.
maxNumberOfUnitsToKeep | each UndoableAction object returns a value to indicate how much storage it takes up (UndoableAction::getSizeInUnits()), so this lets you specify the maximum total number of units that the undomanager is allowed to keep in memory before letting the older actions drop off the end of the list. |
minimumTransactionsToKeep | this specifies the minimum number of transactions that will be kept, even if this involves exceeding the amount of space specified in maxNumberOfUnitsToKeep |
UndoManager::~UndoManager | ( | ) |
Destructor.
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noexcept |
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noexcept |
Starts a new group of actions that together will be treated as a single transaction.
All actions that are passed to the perform() method between calls to this method are grouped together and undone/redone together by a single call to undo() or redo().
actionName | a description of the transaction that is about to be performed |
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noexcept |
Returns true if there's at least one action in the list to redo.
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noexcept |
Returns true if there's at least one action in the list to undo.
void UndoManager::clearUndoHistory | ( | ) |
Deletes all stored actions in the list.
void UndoManager::getActionsInCurrentTransaction | ( | Array< const UndoableAction *> & | actionsFound | ) | const |
Returns a list of the UndoableAction objects that have been performed during the transaction that is currently open.
Effectively, this is the list of actions that would be undone if undoCurrentTransactionOnly() were to be called now.
The first item in the list is the earliest action performed.
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noexcept |
Returns the name of the current transaction.
int UndoManager::getNumActionsInCurrentTransaction | ( | ) | const |
Returns the number of UndoableAction objects that have been performed during the transaction that is currently open.
int UndoManager::getNumberOfUnitsTakenUpByStoredCommands | ( | ) | const |
Returns the current amount of space to use for storing UndoableAction objects.
String UndoManager::getRedoDescription | ( | ) | const |
Time UndoManager::getTimeOfRedoTransaction | ( | ) | const |
Returns the time to which the state would be restored if redo() was to be called. If a redo isn't currently possible, it'll return Time::getCurrentTime().
Time UndoManager::getTimeOfUndoTransaction | ( | ) | const |
String UndoManager::getUndoDescription | ( | ) | const |
bool UndoManager::perform | ( | UndoableAction * | action | ) |
Performs an action and adds it to the undo history list.
action | the action to perform - this object will be deleted by the UndoManager when no longer needed |
bool UndoManager::perform | ( | UndoableAction * | action, |
const String & | actionName | ||
) |
Performs an action and also gives it a name.
action | the action to perform - this object will be deleted by the UndoManager when no longer needed |
actionName | if this string is non-empty, the current transaction will be given this name; if it's empty, the current transaction name will be left unchanged. See setCurrentTransactionName() |
bool UndoManager::redo | ( | ) |
Tries to redo the last transaction that was undone.
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noexcept |
Changes the name stored for the current transaction.
Each transaction is given a name when the beginNewTransaction() method is called, but this can be used to change that name without starting a new transaction.
void UndoManager::setMaxNumberOfStoredUnits | ( | int | maxNumberOfUnitsToKeep, |
int | minimumTransactionsToKeep | ||
) |
Sets the amount of space that can be used for storing UndoableAction objects.
maxNumberOfUnitsToKeep | each UndoableAction object returns a value to indicate how much storage it takes up (UndoableAction::getSizeInUnits()), so this lets you specify the maximum total number of units that the undomanager is allowed to keep in memory before letting the older actions drop off the end of the list. |
minimumTransactionsToKeep | this specifies the minimum number of transactions that will be kept, even if this involves exceeding the amount of space specified in maxNumberOfUnitsToKeep |
bool UndoManager::undo | ( | ) |
Tries to roll-back the last transaction.
bool UndoManager::undoCurrentTransactionOnly | ( | ) |
Tries to roll-back any actions that were added to the current transaction.
This will perform an undo() only if there are some actions in the undo list that were added after the last call to beginNewTransaction().
This is useful because it lets you call beginNewTransaction(), then perform an operation which may or may not actually perform some actions, and then call this method to get rid of any actions that might have been done without it rolling back the previous transaction if nothing was actually done.
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