Open Classmigueldeicaza.swiftgodot 0.45.0SwiftGodot

UndoRedo

Provides a high-level interface for implementing undo and redo operations.

class UndoRedo

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UndoRedo works by registering methods and property changes inside “actions”. You can create an action, then provide ways to do and undo this action using function calls and property changes, then commit the action.

When an action is committed, all of the do_* methods will run. If the undo method is used, the undo_* methods will run. If the redo method is used, once again, all of the do_* methods will run.

Here’s an example on how to add an action:

Before calling any of the add_(un)do_* methods, you need to first call createAction(name:mergeMode:backwardUndoOps:). Afterwards you need to call commitAction(execute:).

If you don’t need to register a method, you can leave addDoMethod(callable:) and addUndoMethod(callable:) out; the same goes for properties. You can also register more than one method/property.

If you are making an EditorPlugin and want to integrate into the editor’s undo history, use EditorUndoRedoManager instead.

If you are registering multiple properties/method which depend on one another, be aware that by default undo operation are called in the same order they have been added. Therefore instead of grouping do operation with their undo operations it is better to group do on one side and undo on the other as shown below.

This object emits the following signals:

versionChanged

Superclasses

class Object
Base class for all other classes in the engine.

Citizens in SwiftGodot

Conformances

protocol CustomStringConvertible
A type with a customized textual representation.
protocol Equatable
A type that can be compared for value equality.
protocol Hashable
A type that can be hashed into a Hasher to produce an integer hash value.
protocol Identifiable<ID>
A class of types whose instances hold the value of an entity with stable identity.
protocol VariantRepresentable
Types that conform to VariantRepresentable can be stored directly in Variant with no conversion. These include all of the Variant types from Godot (for example GString, Rect, Plane), Godot objects (those that subclass SwiftGodot.Object) as well as the built-in Swift types UInt8, Int64 and Double.
protocol VariantStorable
Types that conform to VariantStorable can be stored in a Variant and can be extracted back out of a Variant.

Types

enum MergeMode

Type members

class var godotClassName: StringName

Instance members

var versionChanged: SimpleSignal
Called when undo or redo was called.
func addDoMethod(callable: Callable)
Register a Callable that will be called when the action is committed.
func addDoProperty(object: Object?, property: StringName, value: Variant)
Register a property that would change its value to value when the action is committed.
func addDoReference(object: Object?)
Register a reference for “do” that will be erased if the “do” history is lost. This is useful mostly for new nodes created for the “do” call. Do not use for resources.
func addUndoMethod(callable: Callable)
Register a Callable that will be called when the action is undone.
func addUndoProperty(object: Object?, property: StringName, value: Variant)
Register a property that would change its value to value when the action is undone.
func addUndoReference(object: Object?)
Register a reference for “undo” that will be erased if the “undo” history is lost. This is useful mostly for nodes removed with the “do” call (not the “undo” call!).
func clearHistory(increaseVersion: Bool)
Clear the undo/redo history and associated references.
func commitAction(execute: Bool)
Commit the action. If execute is true (which it is by default), all “do” methods/properties are called/set when this function is called.
func createAction(name: String, mergeMode: UndoRedo.MergeMode, backwardUndoOps: Bool)
Create a new action. After this is called, do all your calls to addDoMethod(callable:), addUndoMethod(callable:), addDoProperty(object:property:value:), and addUndoProperty(object:property:value:), then commit the action with commitAction(execute:).
func endForceKeepInMergeEnds()
Stops marking operations as to be processed even if the action gets merged with another in the .mergeEnds mode. See startForceKeepInMergeEnds.
func getActionName(id: Int32) -> String
Gets the action name from its index.
func getCurrentAction() -> Int32
Gets the index of the current action.
func getCurrentActionName() -> String
Gets the name of the current action, equivalent to get_action_name(get_current_action()).
func getHistoryCount() -> Int32
Returns how many elements are in the history.
func getVersion() -> UInt
Gets the version. Every time a new action is committed, the UndoRedo’s version number is increased automatically.
func hasRedo() -> Bool
Returns true if a “redo” action is available.
func hasUndo() -> Bool
Returns true if an “undo” action is available.
func isCommittingAction() -> Bool
Returns true if the UndoRedo is currently committing the action, i.e. running its “do” method or property change (see commitAction(execute:)).
func redo() -> Bool
Redo the last action.
func startForceKeepInMergeEnds()
Marks the next “do” and “undo” operations to be processed even if the action gets merged with another in the .mergeEnds mode. Return to normal operation using endForceKeepInMergeEnds.
func undo() -> Bool
Undo the last action.