feat(with-history): improve redos logic to support withNewBatch handl…

…e(inspired by slate) (#996)

ref: ianstormtaylor/slate#5747

.changeset/chatty-kids-smile.md

@@ -0,0 +1,7 @@
+---
+'@plait/core': minor
+---
+
+improve redos logic to support withNewBatch handle(inspired by slate)
+
+ref: https://github.com/ianstormtaylor/slate/pull/5747

packages/core/src/interfaces/history.ts

@@ -8,3 +8,5 @@ export interface PlaitHistory {
 
 export const SAVING = new WeakMap<PlaitBoard, boolean | undefined>();
 export const MERGING = new WeakMap<PlaitBoard, boolean | undefined>();
+export const HISTORY = new WeakMap<PlaitBoard, History>();
+export const SPLITTING_ONCE = new WeakMap<PlaitBoard, boolean | undefined>();

packages/core/src/plugins/with-history.ts

@@ -66,6 +66,11 @@ export function withHistory<T extends PlaitBoard>(board: T) {
                 }
             }
 
+            if (PlaitHistoryBoard.isSplittingOnce(board)) {
+                merge = false;
+                PlaitHistoryBoard.setSplittingOnce(board, undefined);
+            }
+
             if (lastBatch && merge) {
                 lastBatch.push(op);
             } else {

packages/core/src/utils/history.ts

@@ -1,4 +1,6 @@
-import { MERGING, PlaitBoard, PlaitOperation, SAVING } from '../interfaces';
+// Credits to slate - https://github.com/ianstormtaylor/slate
+
+import { MERGING, PlaitBoard, PlaitOperation, SAVING, SPLITTING_ONCE } from '../interfaces';
 
 /**
  * Check whether to merge an operation into the previous operation.
@@ -51,6 +53,43 @@ export const PlaitHistoryBoard = {
         return MERGING.get(board);
     },
 
+    /**
+     * Get the splitting once flag's current value.
+     */
+
+    isSplittingOnce(board: PlaitBoard): boolean | undefined {
+        return SPLITTING_ONCE.get(board);
+    },
+
+    setSplittingOnce(board: PlaitBoard, value: boolean | undefined): void {
+        SPLITTING_ONCE.set(board, value);
+    },
+
+    /**
+     * Apply a series of changes inside a synchronous `fn`, These operations will
+     * be merged into the previous history.
+     */
+    withMerging(board: PlaitBoard, fn: () => void): void {
+        const prev = PlaitHistoryBoard.isMerging(board);
+        MERGING.set(board, true);
+        fn();
+        MERGING.set(board, prev);
+    },
+
+    /**
+     * Apply a series of changes inside a synchronous `fn`, ensuring that the first
+     * operation starts a new batch in the history. Subsequent operations will be
+     * merged as usual.
+     */
+    withNewBatch(board: PlaitBoard, fn: () => void): void {
+        const prev = PlaitHistoryBoard.isMerging(board);
+        MERGING.set(board, true);
+        SPLITTING_ONCE.set(board, true);
+        fn();
+        MERGING.set(board, prev);
+        SPLITTING_ONCE.delete(board);
+    },
+
     /**
      * Apply a series of changes inside a synchronous `fn`, without merging any of
      * the new operations into previous save point in the history.