diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index ca12eef..cc43aa3 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -13,29 +13,7 @@
     <option name="TOOL_WINDOW_CONFIGURED_FILTER" value="Show only selected application" />
   </component>
   <component name="ChangeListManager">
-    <list default="true" id="01cec8ba-5f1d-44b7-b06a-c34760f7c254" name="Default Changelist" comment="">
-      <change beforePath="$PROJECT_DIR$/.gradle/5.1.1/executionHistory/executionHistory.bin" beforeDir="false" afterPath="$PROJECT_DIR$/.gradle/5.1.1/executionHistory/executionHistory.bin" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.gradle/5.1.1/executionHistory/executionHistory.lock" beforeDir="false" afterPath="$PROJECT_DIR$/.gradle/5.1.1/executionHistory/executionHistory.lock" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.gradle/5.1.1/fileHashes/fileHashes.bin" beforeDir="false" afterPath="$PROJECT_DIR$/.gradle/5.1.1/fileHashes/fileHashes.bin" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.gradle/5.1.1/fileHashes/fileHashes.lock" beforeDir="false" afterPath="$PROJECT_DIR$/.gradle/5.1.1/fileHashes/fileHashes.lock" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.gradle/5.1.1/fileHashes/resourceHashesCache.bin" beforeDir="false" afterPath="$PROJECT_DIR$/.gradle/5.1.1/fileHashes/resourceHashesCache.bin" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.gradle/5.1.1/javaCompile/classAnalysis.bin" beforeDir="false" afterPath="$PROJECT_DIR$/.gradle/5.1.1/javaCompile/classAnalysis.bin" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.gradle/5.1.1/javaCompile/jarAnalysis.bin" beforeDir="false" afterPath="$PROJECT_DIR$/.gradle/5.1.1/javaCompile/jarAnalysis.bin" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.gradle/5.1.1/javaCompile/javaCompile.lock" beforeDir="false" afterPath="$PROJECT_DIR$/.gradle/5.1.1/javaCompile/javaCompile.lock" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.gradle/5.1.1/javaCompile/taskHistory.bin" beforeDir="false" afterPath="$PROJECT_DIR$/.gradle/5.1.1/javaCompile/taskHistory.bin" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.gradle/buildOutputCleanup/buildOutputCleanup.lock" beforeDir="false" afterPath="$PROJECT_DIR$/.gradle/buildOutputCleanup/buildOutputCleanup.lock" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.gradle/buildOutputCleanup/outputFiles.bin" beforeDir="false" afterPath="$PROJECT_DIR$/.gradle/buildOutputCleanup/outputFiles.bin" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.idea/caches/build_file_checksums.ser" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/caches/build_file_checksums.ser" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.idea/misc.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/misc.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/README.md" beforeDir="false" afterPath="$PROJECT_DIR$/README.md" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/app/app.iml" beforeDir="false" afterPath="$PROJECT_DIR$/app/app.iml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/app/build.gradle" beforeDir="false" afterPath="$PROJECT_DIR$/app/build.gradle" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/app/src/main/AndroidManifest.xml" beforeDir="false" afterPath="$PROJECT_DIR$/app/src/main/AndroidManifest.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/app/src/main/java/com/moos/constraint/practice/MotionSampleActivity.kt" beforeDir="false" afterPath="$PROJECT_DIR$/app/src/main/java/com/moos/constraint/practice/MotionSampleActivity.kt" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/app/src/main/res/values/strings.xml" beforeDir="false" afterPath="$PROJECT_DIR$/app/src/main/res/values/strings.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/app/src/main/res/values/styles.xml" beforeDir="false" afterPath="$PROJECT_DIR$/app/src/main/res/values/styles.xml" afterDir="false" />
-    </list>
+    <list default="true" id="01cec8ba-5f1d-44b7-b06a-c34760f7c254" name="Default Changelist" comment="" />
     <option name="EXCLUDED_CONVERTED_TO_IGNORED" value="true" />
     <option name="SHOW_DIALOG" value="false" />
     <option name="HIGHLIGHT_CONFLICTS" value="true" />
@@ -91,8 +69,8 @@
         <entry file="file://$PROJECT_DIR$/app/src/main/res/layout/activity_motion_with_app_bar.xml">
           <provider editor-type-id="android-designer2" />
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="17">
-              <caret line="1" column="48" selection-start-line="1" selection-start-column="31" selection-end-line="1" selection-end-column="48" />
+            <state relative-caret-position="170">
+              <caret line="10" column="42" lean-forward="true" selection-start-line="10" selection-start-column="42" selection-end-line="10" selection-end-column="42" />
             </state>
           </provider>
         </entry>
@@ -805,8 +783,8 @@
     <entry file="file://$PROJECT_DIR$/app/src/main/res/layout/activity_motion_with_app_bar.xml">
       <provider editor-type-id="android-designer2" />
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="17">
-          <caret line="1" column="48" selection-start-line="1" selection-start-column="31" selection-end-line="1" selection-end-column="48" />
+        <state relative-caret-position="170">
+          <caret line="10" column="42" lean-forward="true" selection-start-line="10" selection-start-column="42" selection-end-line="10" selection-end-column="42" />
         </state>
       </provider>
     </entry>
diff --git a/README.md b/README.md
index a1da249..a95f3d2 100644
--- a/README.md
+++ b/README.md
@@ -6,11 +6,19 @@ This project contains android ConstraintLayout2.0 usages and MotionLayout usage,
 ## 最新进展
 
 - **ConstraintLayout 1.x** 功能大致实践完毕
+
 - **sample data** 用法应用完毕
+
 - **MotionLayout** 入门版实践完毕
+
 - 结合 MD 系列组件实现部分复杂交互效果
+
 - 发现一个问题：官方提供的demo在通过 DrawerMotion 与 CoordinatorLayout 中已有 Motion 交互时出现 NestedScrollView 滑动问题
 
+- Alpha version preview:
+
+  ![alpha-preview](https://github.com/Moosphan/ConstraintSample/blob/86e8ee00637364a1274ebf22db5ff92e9cfb4ce1/arts/motion_preview1.gif)
+
 ## 接下来
 
 - 解决上述问题