refactor(editor): improve element adapters (#11473)

blocksuite/affine/gfx/brush/src/adapter/index.ts

@@ -0,0 +1,2 @@
+export * from './markdown';
+export * from './plain-text';

blocksuite/affine/gfx/brush/src/adapter/markdown/index.ts

@@ -0,0 +1,18 @@
+import { ElementToMarkdownAdapterExtension } from '@blocksuite/affine-block-surface';
+
+export const brushToMarkdownAdapterMatcher = ElementToMarkdownAdapterExtension({
+  name: 'brush',
+  match: elementModel => elementModel.type === 'brush',
+  toAST: () => {
+    const content = `Brush Stroke`;
+    return {
+      type: 'paragraph',
+      children: [
+        {
+          type: 'text',
+          value: content,
+        },
+      ],
+    };
+  },
+});

blocksuite/affine/gfx/brush/src/adapter/plain-text/index.ts

@@ -0,0 +1,11 @@
+import { ElementToPlainTextAdapterExtension } from '@blocksuite/affine-block-surface';
+
+export const brushToPlainTextAdapterMatcher =
+  ElementToPlainTextAdapterExtension({
+    name: 'brush',
+    match: elementModel => elementModel.type === 'brush',
+    toAST: () => {
+      const content = `Brush Stroke`;
+      return { content };
+    },
+  });

blocksuite/affine/gfx/brush/src/index.ts

@@ -1,3 +1,4 @@
+export * from './adapter';
 export * from './brush-tool';
 export * from './element-renderer';
 export * from './eraser-tool';