From 2bb3ab869935555915a913d97d4a7e8732fa29f3 Mon Sep 17 00:00:00 2001
From: wnhlee <2wheeh@gmail.com>
Date: Sun, 21 Apr 2024 12:54:37 +0900
Subject: [PATCH] feat: implement useBlockTypeActions

---
 ui/src/hooks/editor/use-block-type-actions.ts | 115 ++++++++++++++++++
 ui/src/lib/utils/editor/block-type-actions.ts |  45 +++++++
 2 files changed, 160 insertions(+)
 create mode 100644 ui/src/hooks/editor/use-block-type-actions.ts
 create mode 100644 ui/src/lib/utils/editor/block-type-actions.ts

diff --git a/ui/src/hooks/editor/use-block-type-actions.ts b/ui/src/hooks/editor/use-block-type-actions.ts
new file mode 100644
index 00000000..49825565
--- /dev/null
+++ b/ui/src/hooks/editor/use-block-type-actions.ts
@@ -0,0 +1,115 @@
+'use client';
+
+import { INSERT_ORDERED_LIST_COMMAND, INSERT_UNORDERED_LIST_COMMAND } from '@lexical/list';
+import type { HeadingTagType } from '@lexical/rich-text';
+import { $createHeadingNode, $createQuoteNode } from '@lexical/rich-text';
+import { $setBlocksType } from '@lexical/selection';
+import type { LexicalEditor } from 'lexical';
+import {
+  $createParagraphNode,
+  $getSelection,
+  $isRangeSelection,
+  COMMAND_PRIORITY_CRITICAL,
+  SELECTION_CHANGE_COMMAND,
+} from 'lexical';
+import { useCallback, useEffect, useState } from 'react';
+
+import {
+  $getBlockAndAnchorFromSelection,
+  $getBlockType,
+} from '@/lib/utils/editor/block-type-actions';
+
+const blockTypeToBlockName = {
+  paragraph: 'Normal',
+  quote: 'Quote',
+  h1: 'Heading 1',
+  h2: 'Heading 2',
+  h3: 'Heading 3',
+  bullet: 'Bulleted List',
+  number: 'Numbered List',
+};
+
+export function useBlockTypeActions({ editor }: { editor: LexicalEditor | undefined | null }) {
+  const [blockType, setBlockType] = useState<keyof typeof blockTypeToBlockName>('paragraph');
+
+  const $updateBlockType = useCallback(() => {
+    const selection = $getSelection();
+    const { blockNode, anchorNode } = $getBlockAndAnchorFromSelection(selection) ?? {};
+    const type = $getBlockType(blockNode, anchorNode);
+
+    if (type && type in blockTypeToBlockName) {
+      setBlockType(type as keyof typeof blockTypeToBlockName);
+    }
+  }, []);
+
+  useEffect(() => {
+    return editor?.registerCommand(
+      SELECTION_CHANGE_COMMAND,
+      () => {
+        $updateBlockType();
+        return false;
+      },
+      COMMAND_PRIORITY_CRITICAL
+    );
+  }, [editor, $updateBlockType]);
+
+  useEffect(() => {
+    return editor?.registerUpdateListener(({ editorState }) => {
+      editorState.read(() => {
+        $updateBlockType();
+      });
+    });
+  }, [editor, $updateBlockType]);
+
+  const formatParagraph = () => {
+    editor?.update(() => {
+      const selection = $getSelection();
+      if ($isRangeSelection(selection)) {
+        $setBlocksType(selection, () => $createParagraphNode());
+      }
+    });
+  };
+
+  const formatHeading = (headingType: HeadingTagType) => {
+    if (blockType !== headingType) {
+      editor?.update(() => {
+        const selection = $getSelection();
+        $setBlocksType(selection, () => $createHeadingNode(headingType));
+      });
+    }
+  };
+
+  const formatBulletList = () => {
+    if (blockType !== 'bullet') {
+      editor?.dispatchCommand(INSERT_UNORDERED_LIST_COMMAND, undefined);
+    } else {
+      formatParagraph();
+    }
+  };
+
+  const formatNumberedList = () => {
+    if (blockType !== 'number') {
+      editor?.dispatchCommand(INSERT_ORDERED_LIST_COMMAND, undefined);
+    } else {
+      formatParagraph();
+    }
+  };
+
+  const formatQuote = () => {
+    if (blockType !== 'quote') {
+      editor?.update(() => {
+        const selection = $getSelection();
+        $setBlocksType(selection, () => $createQuoteNode());
+      });
+    }
+  };
+
+  return {
+    blockType,
+    formatParagraph,
+    formatQuote,
+    formatHeading,
+    formatBulletList,
+    formatNumberedList,
+  };
+}
diff --git a/ui/src/lib/utils/editor/block-type-actions.ts b/ui/src/lib/utils/editor/block-type-actions.ts
new file mode 100644
index 00000000..cc6a5e91
--- /dev/null
+++ b/ui/src/lib/utils/editor/block-type-actions.ts
@@ -0,0 +1,45 @@
+import { $isListNode, ListNode } from '@lexical/list';
+import { $isHeadingNode } from '@lexical/rich-text';
+import { $findMatchingParent, $getNearestNodeOfType } from '@lexical/utils';
+import type { BaseSelection, LexicalNode } from 'lexical';
+import { $isRangeSelection, $isRootOrShadowRoot } from 'lexical';
+
+export function $getBlockAndAnchorFromSelection(selection: BaseSelection | null) {
+  if (!$isRangeSelection(selection)) {
+    return null;
+  }
+
+  const anchorNode = selection.anchor.getNode();
+  let blockNode =
+    anchorNode.getKey() === 'root'
+      ? anchorNode
+      : $findMatchingParent(anchorNode, (e) => {
+          const parent = e.getParent();
+          return parent !== null && $isRootOrShadowRoot(parent);
+        });
+
+  if (blockNode === null) {
+    blockNode = anchorNode.getTopLevelElementOrThrow();
+  }
+
+  return { blockNode, anchorNode };
+}
+
+export function $getBlockType(blockNode?: LexicalNode, anchorNode?: LexicalNode) {
+  if (!blockNode || !anchorNode) {
+    return null;
+  }
+
+  if ($isListNode(blockNode)) {
+    /*
+      list <- blockNode
+        listitem
+          list <- nestedListNode
+            listitem <- anchorNode
+    */
+    const nestedListNode = $getNearestNodeOfType(anchorNode, ListNode);
+    return nestedListNode ? nestedListNode.getListType() : blockNode.getListType();
+  } else {
+    return $isHeadingNode(blockNode) ? blockNode.getTag() : blockNode.getType();
+  }
+}