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UndoRedo

繼承： Object

為實作撤銷和重做操作提供高階介面。

說明

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:

var undo_redo = UndoRedo.new()

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_my_button_pressed():
    var node = get_node("MyNode2D")
    undo_redo.create_action("Move the node")
    undo_redo.add_do_method(do_something)
    undo_redo.add_undo_method(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()

private UndoRedo _undoRedo;

public override void _Ready()
{
    _undoRedo = new UndoRedo();
}

public void DoSomething()
{
    // Put your code here.
}

public void UndoSomething()
{
    // Put here the code that reverts what's done by "DoSomething()".
}

private void OnMyButtonPressed()
{
    var node = GetNode<Node2D>("MyNode2D");
    _undoRedo.CreateAction("Move the node");
    _undoRedo.AddDoMethod(new Callable(this, MethodName.DoSomething));
    _undoRedo.AddUndoMethod(new Callable(this, MethodName.UndoSomething));
    _undoRedo.AddDoProperty(node, "position", new Vector2(100, 100));
    _undoRedo.AddUndoProperty(node, "position", node.Position);
    _undoRedo.CommitAction();
}

Before calling any of the add_(un)do_* methods, you need to first call create_action(). Afterwards you need to call commit_action().

If you don't need to register a method, you can leave add_do_method() and add_undo_method() 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.

undo_redo.create_action("Add object")

# DO
undo_redo.add_do_method(_create_object)
undo_redo.add_do_method(_add_object_to_singleton)

# UNDO
undo_redo.add_undo_method(_remove_object_from_singleton)
undo_redo.add_undo_method(_destroy_that_object)

undo_redo.commit_action()

_undo_redo.CreateAction("Add object");

// DO
_undo_redo.AddDoMethod(new Callable(this, MethodName.CreateObject));
_undo_redo.AddDoMethod(new Callable(this, MethodName.AddObjectToSingleton));

// UNDO
_undo_redo.AddUndoMethod(new Callable(this, MethodName.RemoveObjectFromSingleton));
_undo_redo.AddUndoMethod(new Callable(this, MethodName.DestroyThatObject));

_undo_redo.CommitAction();

屬性

int

max_steps

0

方法

void	add_do_method(callable: Callable)
void	add_do_property(object: Object, property: StringName, value: Variant)
void	add_do_reference(object: Object)
void	add_undo_method(callable: Callable)
void	add_undo_property(object: Object, property: StringName, value: Variant)
void	add_undo_reference(object: Object)
void	clear_history(increase_version: bool = true)
void	commit_action(execute: bool = true)
void	create_action(name: String, merge_mode: MergeMode = 0, backward_undo_ops: bool = false)
void	end_force_keep_in_merge_ends()
String	get_action_name(id: int)
int	get_current_action()
String	get_current_action_name() const
int	get_history_count()
int	get_version() const
bool	has_redo() const
bool	has_undo() const
bool	is_committing_action() const
bool	redo()
void	start_force_keep_in_merge_ends()
bool	undo()

訊號

version_changed() 🔗

當 undo() 或 redo() 被呼叫時呼叫。

列舉

enum MergeMode: 🔗

MergeMode MERGE_DISABLE = 0

使“do”/“undo”操作保持在單獨的動作中。

MergeMode MERGE_ENDS = 1

Merges this action with the previous one if they have the same name. Keeps only the first action's "undo" operations and the last action's "do" operations. Useful for sequential changes to a single value.

MergeMode MERGE_ALL = 2

Merges this action with the previous one if they have the same name.

屬性說明

int max_steps = 0 🔗

void set_max_steps(value: int)
int get_max_steps()

The maximum number of steps that can be stored in the undo/redo history. If the number of stored steps exceeds this limit, older steps are removed from history and can no longer be reached by calling undo(). A value of 0 or lower means no limit.

方法說明

void add_do_method(callable: Callable) 🔗

註冊 Callable，會在提交動作時呼叫。

void add_do_property(object: Object, property: StringName, value: Variant) 🔗

註冊 property，會在提交動作時將其值更改為 value。

void add_do_reference(object: Object) 🔗

Register a reference to an object that will be erased if the "do" history is deleted. This is useful for objects added by the "do" action and removed by the "undo" action.

When the "do" history is deleted, if the object is a RefCounted, it will be unreferenced. Otherwise, it will be freed. Do not use for resources.

var node = Node2D.new()
undo_redo.create_action("Add node")
undo_redo.add_do_method(add_child.bind(node))
undo_redo.add_do_reference(node)
undo_redo.add_undo_method(remove_child.bind(node))
undo_redo.commit_action()

void add_undo_method(callable: Callable) 🔗

註冊 Callable，會在撤銷動作時呼叫。

void add_undo_property(object: Object, property: StringName, value: Variant) 🔗

註冊 property，會在撤銷動作時將其值更改為 value。

void add_undo_reference(object: Object) 🔗

Register a reference to an object that will be erased if the "undo" history is deleted. This is useful for objects added by the "undo" action and removed by the "do" action.

When the "undo" history is deleted, if the object is a RefCounted, it will be unreferenced. Otherwise, it will be freed. Do not use for resources.

var node = $Node2D
undo_redo.create_action("Remove node")
undo_redo.add_do_method(remove_child.bind(node))
undo_redo.add_undo_method(add_child.bind(node))
undo_redo.add_undo_reference(node)
undo_redo.commit_action()

void clear_history(increase_version: bool = true) 🔗

清除撤銷/重做歷史和相關的引用。

將 false 傳遞給 increase_version 將防止在清除歷史記錄時增加版本號。

void commit_action(execute: bool = true) 🔗

提交動作。如果 execute 為 true（預設情況），則會在呼叫此函式時呼叫/設定所有“執行（do）”方法/屬性。

void create_action(name: String, merge_mode: MergeMode = 0, backward_undo_ops: bool = false) 🔗

Create a new action. After this is called, do all your calls to add_do_method(), add_undo_method(), add_do_property(), and add_undo_property(), then commit the action with commit_action().

The way actions are merged is dictated by merge_mode.

The way undo operation are ordered in actions is dictated by backward_undo_ops. When backward_undo_ops is false undo option are ordered in the same order they were added. Which means the first operation to be added will be the first to be undone.

void end_force_keep_in_merge_ends() 🔗

停止將操作標記為要處理，即使該動作在 MERGE_ENDS 模式下與另一個動作合併。請參閱 start_force_keep_in_merge_ends()。

String get_action_name(id: int) 🔗

根據索引獲取動作名稱。

int get_current_action() 🔗

獲取目前動作的索引。

String get_current_action_name() const 🔗

獲取目前動作的名稱，等價於 get_action_name(get_current_action())。

int get_history_count() 🔗

返回歷史中有多少元素。

int get_version() const 🔗

獲取版本。每次提交一個新的操作，UndoRedo 的版本號都會自動增加。

這主要用於檢查保存的版本是否發生了更改。

bool has_redo() const 🔗

有“重做”動作可用時返回 true。

bool has_undo() const 🔗

有“撤銷”動作可用時返回 true。

bool is_committing_action() const 🔗

如果 UndoRedo 目前正在提交動作，即運作其“do”的方法或屬性變化，則返回 true（請參閱 commit_action()）。

bool redo() 🔗

Redo the last action. Returns false if there was no action to redo.

void start_force_keep_in_merge_ends() 🔗

標記要處理的下一個“執行”和“撤銷”操作，即使該動作在 MERGE_ENDS 模式下與另一個動作合併。使用 end_force_keep_in_merge_ends() 返回到正常操作。

bool undo() 🔗

Undo the last action. Returns false if there was no action to undo.