diff --git a/src/Kernel/Store/TextStore.ts b/src/Kernel/Store/TextStore.ts
index a7dc47b..0fd0bb8 100644
--- a/src/Kernel/Store/TextStore.ts
+++ b/src/Kernel/Store/TextStore.ts
@@ -169,6 +169,10 @@ export class TextStore {
     history.exec(command)
   }
 
+  getAtoms(index: number, length: number) {
+    return this._slice(index, length)
+  }
+
   toPlain(): string {
     return this._store.reduce((text, current) => text + current.text, '')
   }
diff --git a/src/Kernel/index.ts b/src/Kernel/index.ts
index 6d00366..9c121c5 100644
--- a/src/Kernel/index.ts
+++ b/src/Kernel/index.ts
@@ -3,11 +3,23 @@ import { HistoryManager } from './HistoryManager'
 import { Slide } from './Slide'
 import { TableBlock } from '@BlockHub/TableBlock/TableBlock'
 import { PictureBlock } from '@BlockHub/PictureBlock/PictureBlock'
+import { EventManager } from './EventManager'
+import { TextAtom } from './Store/TextStore'
+
+interface RichTextStateChange {
+  selection: {
+    index: number
+    length: number
+  }
+  atoms: Array<TextAtom>
+}
 
 export const kernel = {
   currentIndex: 0,
   slides: [new Slide([new TextBoxBlock(100, 50), new TableBlock(400, 300, 4, 3), new PictureBlock(100, 300)])],
 
+  richTextObserver: new EventManager<RichTextStateChange>(),
+
   get currentSlide() {
     return this.slides[this.currentIndex]
   },
diff --git a/src/RichText/RichText.ts b/src/RichText/RichText.ts
index 4b254c2..639670f 100644
--- a/src/RichText/RichText.ts
+++ b/src/RichText/RichText.ts
@@ -1,9 +1,12 @@
 import type { AttributeValue, TextStore } from '@Kernel/Store/TextStore'
-import { SelectionHandler } from './handler/SelectionHandler'
+import { Selection, SelectionHandler } from './handler/SelectionHandler'
 import { EventHandler } from './handler/EventHandler'
+import { EventManager } from '@Kernel/EventManager'
+import { kernel } from '@Kernel/index'
 
 export interface RichTextController {
   format(name: string, value: AttributeValue): void
+  formatAll(name: string, value: AttributeValue): void
 }
 
 export class RichText {
@@ -16,8 +19,19 @@ export class RichText {
   setSelectionByInput = this.selectionHandler.setSelectionByInput.bind(this.selectionHandler)
   setSelectionByNative = this.selectionHandler.setSelectionByNative.bind(this.selectionHandler)
 
+  events = {
+    selectChange: new EventManager<Selection>(),
+  }
+
   constructor(textStore: TextStore) {
     this.textStore = textStore
+    this.events.selectChange.on((selection) => {
+      const atoms = textStore.getAtoms(selection.index, selection.length)
+      kernel.richTextObserver.emit({
+        selection: selection,
+        atoms: atoms,
+      })
+    })
   }
 
   mount(element: HTMLElement) {
@@ -34,6 +48,14 @@ export class RichText {
         })
         this.setSelectionByInput({ index, length })
       },
+      formatAll: (name: string, value: AttributeValue) => {
+        const index = 0
+        const length = this.textStore.length
+        this.textStore.format(index, length, {
+          [name]: value,
+        })
+        this.setSelectionByInput({ index, length })
+      },
     }
   }
 }
diff --git a/src/RichText/handler/EventHandler.ts b/src/RichText/handler/EventHandler.ts
index e4362a3..31054fc 100644
--- a/src/RichText/handler/EventHandler.ts
+++ b/src/RichText/handler/EventHandler.ts
@@ -3,6 +3,7 @@ import { handleInput } from './utils/handleInput'
 
 export class EventHandler {
   richText: RichText
+  _isCurrentElement: boolean = false
   _isComposing: boolean
 
   constructor(richText: RichText) {
@@ -10,7 +11,23 @@ export class EventHandler {
     this._isComposing = false
   }
 
+  onSelectionChange() {
+    const range = document.getSelection()?.getRangeAt(0) as Range
+    this._isCurrentElement = range.intersectsNode(this.richText.element as HTMLElement)
+    if (!this._isCurrentElement) {
+      return
+    }
+    if (this._isComposing) {
+      // prevent modify inner selection by native selection change
+      return
+    }
+    this.richText.setSelectionByNative()
+  }
+
   onBeforeInput(event: InputEvent) {
+    if (!this._isCurrentElement) {
+      return
+    }
     event.preventDefault()
     if (this._isComposing) {
       return
@@ -23,10 +40,16 @@ export class EventHandler {
   }
 
   onCompositionStart() {
+    if (!this._isCurrentElement) {
+      return
+    }
     this._isComposing = true
   }
 
   onCompositionEnd(event: CompositionEvent) {
+    if (!this._isCurrentElement) {
+      return
+    }
     this._isComposing = false
     const data = event.data
     // https://github.com/w3c/input-events/issues/137
@@ -39,14 +62,6 @@ export class EventHandler {
     })
   }
 
-  onSelectionChange() {
-    if (this._isComposing) {
-      // prevent modify inner selection by native selection change
-      return
-    }
-    this.richText.setSelectionByNative()
-  }
-
   mount() {
     const element = this.richText.element as HTMLElement
     element.addEventListener('beforeinput', this.onBeforeInput.bind(this))
diff --git a/src/RichText/handler/SelectionHandler.ts b/src/RichText/handler/SelectionHandler.ts
index d5923c7..622ac2e 100644
--- a/src/RichText/handler/SelectionHandler.ts
+++ b/src/RichText/handler/SelectionHandler.ts
@@ -64,12 +64,17 @@ export class SelectionHandler {
     nativeSelection?.addRange(range)
   }
 
+  private _setSelection(selection: Selection) {
+    this._selection = selection
+    this.richText.events.selectChange.emit(selection)
+  }
+
   getSelection() {
     return { ...this._selection }
   }
 
   setSelectionByInput(selection: Selection) {
-    this._selection = selection
+    this._setSelection(selection)
     this._updateNativeSelection()
   }
 
@@ -103,9 +108,16 @@ export class SelectionHandler {
       }
       currentIndex += 1
     }
-    this._selection = {
+
+    // avoid _setSelection redundantly
+    const { index: oldIndex, length: oldLength } = this.getSelection()
+    if (oldIndex === selectionIndex && oldLength === selectionLength) {
+      return
+    }
+
+    this._setSelection({
       index: selectionIndex,
       length: selectionLength,
-    }
+    })
   }
 }
diff --git a/src/UserInterface/ToolBar/components/Home/FontStyle.vue b/src/UserInterface/ToolBar/components/Home/FontStyle.vue
index 53d84ab..f4bb9bd 100644
--- a/src/UserInterface/ToolBar/components/Home/FontStyle.vue
+++ b/src/UserInterface/ToolBar/components/Home/FontStyle.vue
@@ -1,6 +1,11 @@
 <script setup lang="ts">
 import { FontSizeTwo, AddText, ClearFormat, TextBold, TextItalic, TextUnderline, Strikethrough, BackgroundColor } from '@icon-park/vue-next'
 import MenuWrapper from '../MenuWrapper.vue'
+import { kernel } from '@Kernel/index'
+
+kernel.richTextObserver.on((newState) => {
+  console.log('newState', newState)
+})
 </script>
 
 <template>