UndoRedo Class |
Helper to manage undo/redo operations in the editor or custom tools. It works by registering methods and property changes inside "actions".
Common behavior is to create an action, then add do/undo calls to functions or property changes, then committing the action.
Here's an example on how to add an action to the Godot editor's own UndoRedo, from a plugin:
var undo_redo = get_undo_redo() # Method of EditorPlugin. func do_something(): pass # Put your code here. func undo_something(): pass # Put here the code that reverts what's done by "do_something()". func _on_MyButton_pressed(): var node = get_node("MyNode2D") undo_redo.create_action("Move the node") undo_redo.add_do_method(self, "do_something") undo_redo.add_undo_method(self, "undo_something") undo_redo.add_do_property(node, "position", Vector2(100,100)) undo_redo.add_undo_property(node, "position", node.position) undo_redo.commit_action()
CreateAction(String, UndoRedoMergeMode), AddDoMethod(Object, String, Object), AddUndoMethod(Object, String, Object), AddDoProperty(Object, String, Object), AddUndoProperty(Object, String, Object), and CommitAction should be called one after the other, like in the example. Not doing so could lead to crashes.
If you don't need to register a method, you can leave AddDoMethod(Object, String, Object) and AddUndoMethod(Object, String, Object) out; the same goes for properties. You can also register more than one method/property.
Namespace: Godot
public class UndoRedo : Object
The UndoRedo type exposes the following members.
Name | Description | |
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DynamicObject |
Gets a new DynamicGodotObject associated with this instance.
(Inherited from Object.) | |
NativeInstance | (Inherited from Object.) |
Name | Description | |
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_Get | Virtual method which can be overridden to customize the return value of Get(String). Returns the given property. Returns null if the property does not exist. | |
_GetPropertyList | Virtual method which can be overridden to customize the return value of GetPropertyList. Returns the object's property list as an Array of dictionaries. Each property's Dictionary must contain at least name: String and type: int (see VariantType) entries. Optionally, it can also include hint: int (see PropertyHint), hint_string: String, and usage: int (see PropertyUsageFlags). | |
_Notification | Called whenever the object receives a notification, which is identified in what by a constant. The base Object has two constants and , but subclasses such as Node define a lot more notifications which are also received by this method. | |
_Set | Virtual method which can be overridden to customize the return value of Set(String, Object). Sets a property. Returns true if the property exists. | |
AddDoMethod | Register a method that will be called when the action is committed. | |
AddDoProperty | Register a property value change for "do". | |
AddDoReference | 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. | |
AddUndoMethod | Register a method that will be called when the action is undone. | |
AddUndoProperty | Register a property value change for "undo". | |
AddUndoReference | 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!). | |
AddUserSignal | Adds a user-defined signal. Arguments are optional, but can be added as an Array of dictionaries, each containing name: String and type: int (see VariantType) entries. | |
Call | Calls the method on the object and returns the result. This method supports a variable number of arguments, so parameters are passed as a comma separated list. Example: call("set", "position", Vector2(42.0, 0.0)) Note: In C#, the method name must be specified as snake_case if it is defined by a built-in Godot node. This doesn't apply to user-defined methods where you should use the same convention as in the C# source (typically PascalCase). | |
CallDeferred | Calls the method on the object during idle time. This method supports a variable number of arguments, so parameters are passed as a comma separated list. Example: call_deferred("set", "position", Vector2(42.0, 0.0)) Note: In C#, the method name must be specified as snake_case if it is defined by a built-in Godot node. This doesn't apply to user-defined methods where you should use the same convention as in the C# source (typically PascalCase). | |
Callv | Calls the method on the object and returns the result. Contrarily to Call(String, Object), this method does not support a variable number of arguments but expects all parameters to be via a single Array. callv("set", [ "position", Vector2(42.0, 0.0) ]) | |
CanTranslateMessages | Returns true if the object can translate strings. See SetMessageTranslation(Boolean) and Tr(String). | |
ClearHistory | Clear the undo/redo history and associated references. Passing false to increase_version will prevent the version number to be increased from this. | |
CommitAction | Commit the action. All "do" methods/properties are called/set when this function is called. | |
Connect | Connects a signal to a method on a target object. Pass optional binds to the call as an Array of parameters. These parameters will be passed to the method after any parameter used in the call to EmitSignal(String, Object). Use flags to set deferred or one-shot connections. See ObjectConnectFlags constants. A signal can only be connected once to a method. It will throw an error if already connected, unless the signal was connected with . To avoid this, first, use IsConnected(String, Object, String) to check for existing connections. If the target is destroyed in the game's lifecycle, the connection will be lost. Examples: connect("pressed", self, "_on_Button_pressed") # BaseButton signal connect("text_entered", self, "_on_LineEdit_text_entered") # LineEdit signal connect("hit", self, "_on_Player_hit", [ weapon_type, damage ]) # User-defined signal An example of the relationship between binds passed to Connect(String, Object, String, Array, UInt32) and parameters used when calling EmitSignal(String, Object): connect("hit", self, "_on_Player_hit", [ weapon_type, damage ]) # weapon_type and damage are passed last emit_signal("hit", "Dark lord", 5) # "Dark lord" and 5 are passed first func _on_Player_hit(hit_by, level, weapon_type, damage): print("Hit by %s (lvl %d) with weapon %s for %d damage" % [hit_by, level, weapon_type, damage]) | |
CreateAction | Create a new action. After this is called, do all your calls to AddDoMethod(Object, String, Object), AddUndoMethod(Object, String, Object), AddDoProperty(Object, String, Object), and AddUndoProperty(Object, String, Object), then commit the action with CommitAction. The way actions are merged is dictated by the merge_mode argument. See UndoRedoMergeMode for details. | |
Disconnect | Disconnects a signal from a method on the given target. If you try to disconnect a connection that does not exist, the method will throw an error. Use IsConnected(String, Object, String) to ensure that the connection exists. | |
Dispose | (Inherited from Object.) | |
Dispose(Boolean) | (Inherited from Object.) | |
EmitSignal | Emits the given signal. The signal must exist, so it should be a built-in signal of this class or one of its parent classes, or a user-defined signal. This method supports a variable number of arguments, so parameters are passed as a comma separated list. Example: emit_signal("hit", weapon_type, damage) emit_signal("game_over") | |
Equals | (Inherited from Object.) | |
Finalize | (Inherited from Object.) | |
Free | Deletes the object from memory immediately. For Nodes, you may want to use QueueFree to queue the node for safe deletion at the end of the current frame. Important: If you have a variable pointing to an object, it will not be assigned to null once the object is freed. Instead, it will point to a previously freed instance and you should validate it with @GDScript.is_instance_valid before attempting to call its methods or access its properties. | |
Get | Returns the Variant value of the given property. If the property doesn't exist, this will return null. Note: In C#, the property name must be specified as snake_case if it is defined by a built-in Godot node. This doesn't apply to user-defined properties where you should use the same convention as in the C# source (typically PascalCase). | |
GetClass | Returns the object's class as a String. | |
GetCurrentActionName | Gets the name of the current action. | |
GetHashCode | (Inherited from Object.) | |
GetIncomingConnections | Returns an Array of dictionaries with information about signals that are connected to the object. Each Dictionary contains three String entries: - source is a reference to the signal emitter. - signal_name is the name of the connected signal. - method_name is the name of the method to which the signal is connected. | |
GetIndexed | Gets the object's property indexed by the given NodePath. The node path should be relative to the current object and can use the colon character (:) to access nested properties. Examples: "position:x" or "material:next_pass:blend_mode". | |
GetInstanceId | Returns the object's unique instance ID. This ID can be saved in EncodedObjectAsID, and can be used to retrieve the object instance with @GDScript.instance_from_id. | |
GetMeta | Returns the object's metadata entry for the given name. | |
GetMetaList | Returns the object's metadata as a String. | |
GetMethodList | Returns the object's methods and their signatures as an Array. | |
GetPropertyList | Returns the object's property list as an Array of dictionaries. Each property's Dictionary contain at least name: String and type: int (see VariantType) entries. Optionally, it can also include hint: int (see PropertyHint), hint_string: String, and usage: int (see PropertyUsageFlags). | |
GetScript | Returns the object's Script instance, or null if none is assigned. | |
GetSignalConnectionList | Returns an Array of connections for the given signal. | |
GetSignalList | Returns the list of signals as an Array of dictionaries. | |
GetType | (Inherited from Object.) | |
GetVersion | Gets the version. Every time a new action is committed, the UndoRedo's version number is increased automatically. This is useful mostly to check if something changed from a saved version. | |
HasMeta | Returns true if a metadata entry is found with the given name. | |
HasMethod | Returns true if the object contains the given method. | |
HasRedo | Returns true if a "redo" action is available. | |
HasSignal | Returns true if the given signal exists. | |
HasUndo | Returns true if an "undo" action is available. | |
HasUserSignal | Returns true if the given user-defined signal exists. Only signals added using AddUserSignal(String, Array) are taken into account. | |
IsBlockingSignals | Returns true if signal emission blocking is enabled. | |
IsClass | Returns true if the object inherits from the given class. | |
IsCommitingAction | Returns true if the UndoRedo is currently committing the action, i.e. running its "do" method or property change (see CommitAction). | |
IsConnected | Returns true if a connection exists for a given signal, target, and method. | |
IsQueuedForDeletion | Returns true if the QueueFree method was called for the object. | |
MemberwiseClone | (Inherited from Object.) | |
Notification | Send a given notification to the object, which will also trigger a call to the _Notification(Int32) method of all classes that the object inherits from. If reversed is true, _Notification(Int32) is called first on the object's own class, and then up to its successive parent classes. If reversed is false, _Notification(Int32) is called first on the highest ancestor (Object itself), and then down to its successive inheriting classes. | |
PropertyListChangedNotify | Notify the editor that the property list has changed, so that editor plugins can take the new values into account. Does nothing on export builds. | |
Redo | Redo the last action. | |
RemoveMeta | Removes a given entry from the object's metadata. See also SetMeta(String, Object). | |
Set | Assigns a new value to the given property. If the property does not exist, nothing will happen. Note: In C#, the property name must be specified as snake_case if it is defined by a built-in Godot node. This doesn't apply to user-defined properties where you should use the same convention as in the C# source (typically PascalCase). | |
SetBlockSignals | If set to true, signal emission is blocked. | |
SetDeferred | Assigns a new value to the given property, after the current frame's physics step. This is equivalent to calling Set(String, Object) via CallDeferred(String, Object), i.e. call_deferred("set", property, value). Note: In C#, the property name must be specified as snake_case if it is defined by a built-in Godot node. This doesn't apply to user-defined properties where you should use the same convention as in the C# source (typically PascalCase). | |
SetIndexed | Assigns a new value to the property identified by the NodePath. The node path should be relative to the current object and can use the colon character (:) to access nested properties. Example: set_indexed("position", Vector2(42, 0)) set_indexed("position:y", -10) print(position) # (42, -10) | |
SetMessageTranslation | Defines whether the object can translate strings (with calls to Tr(String)). Enabled by default. | |
SetMeta | Adds, changes or removes a given entry in the object's metadata. Metadata are serialized and can take any Variant value. To remove a given entry from the object's metadata, use RemoveMeta(String). Metadata is also removed if its value is set to null. This means you can also use set_meta("name", null) to remove metadata for "name". | |
SetScript | Assigns a script to the object. Each object can have a single script assigned to it, which are used to extend its functionality. If the object already had a script, the previous script instance will be freed and its variables and state will be lost. The new script's method will be called. | |
ToSignal |
Returns a new SignalAwaiter awaiter configured to complete when the instance
source emits the signal specified by the signal parameter.
(Inherited from Object.) | |
ToString | (Inherited from Object.) | |
Tr | Translates a message using translation catalogs configured in the Project Settings. Only works if message translation is enabled (which it is by default), otherwise it returns the message unchanged. See SetMessageTranslation(Boolean). | |
Undo | Undo the last action. |