1	<?php
2
3	declare(strict_types=1);
4
5	namespace Drupal\display_builder;
6
7	use Drupal\Component\Render\FormattableMarkup;
8
9	/**
10	* History interface.
11	*
12	* When you implement Undo and Redo, you want to keep track of the history
13	* of this state at different points in time.
14	*
15	* Inspired from https://redux.js.org/usage/implementing-undo-history
16	*/
17	interface HistoryInterface {
18
19	/**
20	* Get current step.
21	*
22	* @return \Drupal\display_builder\HistoryStep|null
23	*   The current data.
24	*/
25	public function getCurrent(): ?HistoryStep;
26
27	/**
28	* Get the state of the current step.
29	*
30	* @return array
31	*   The current state.
32	*/
33	public function getCurrentState(): array;
34
35	/**
36	* Set a new present.
37	*
38	* @param array $state
39	*   The state to set.
40	* @param string|\Drupal\Component\Render\FormattableMarkup $log_message
41	*   (Optional) The log message.
42	* @param bool $check_hash
43	*   (Optional) Should check hash to avoid duplicates. Default to TRUE.
44	*/
45	public function setNewPresent(array $state, FormattableMarkup|string $log_message = '', bool $check_hash = TRUE): void;
46
47	/**
48	* Get number of past logs.
49	*
50	* @return int
51	*   The number of past logs.
52	*/
53	public function getCountPast(): int;
54
55	/**
56	* Get number of future logs.
57	*
58	* @return int
59	*   The number of future logs.
60	*/
61	public function getCountFuture(): int;
62
63	/**
64	* Move history to the last past state.
65	*/
66	public function undo(): void;
67
68	/**
69	* Move history to the first future state.
70	*/
71	public function redo(): void;
72
73	/**
74	* Reset history to the current state.
75	*/
76	public function clear(): void;
77
78	}

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