diff --git a/.idea/compiler.xml b/.idea/compiler.xml
index 96cc43e..61a9130 100644
--- a/.idea/compiler.xml
+++ b/.idea/compiler.xml
@@ -1,22 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="CompilerConfiguration">
-    <resourceExtensions />
-    <wildcardResourcePatterns>
-      <entry name="!?*.java" />
-      <entry name="!?*.form" />
-      <entry name="!?*.class" />
-      <entry name="!?*.groovy" />
-      <entry name="!?*.scala" />
-      <entry name="!?*.flex" />
-      <entry name="!?*.kt" />
-      <entry name="!?*.clj" />
-      <entry name="!?*.aj" />
-    </wildcardResourcePatterns>
-    <annotationProcessing>
-      <profile default="true" name="Default" enabled="false">
-        <processorPath useClasspath="true" />
-      </profile>
-    </annotationProcessing>
+    <bytecodeTargetLevel target="1.8" />
   </component>
 </project>
\ No newline at end of file
diff --git a/.idea/gradle.xml b/.idea/gradle.xml
index 31a27b7..639d917 100644
--- a/.idea/gradle.xml
+++ b/.idea/gradle.xml
@@ -1,8 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="GradleMigrationSettings" migrationVersion="1" />
   <component name="GradleSettings">
     <option name="linkedExternalProjectsSettings">
       <GradleProjectSettings>
+        <option name="testRunner" value="GRADLE" />
         <option name="distributionType" value="DEFAULT_WRAPPED" />
         <option name="externalProjectPath" value="$PROJECT_DIR$" />
         <option name="modules">
diff --git a/.idea/jarRepositories.xml b/.idea/jarRepositories.xml
new file mode 100644
index 0000000..0f6eb2b
--- /dev/null
+++ b/.idea/jarRepositories.xml
@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="RemoteRepositoriesConfiguration">
+    <remote-repository>
+      <option name="id" value="central" />
+      <option name="name" value="Maven Central repository" />
+      <option name="url" value="https://repo1.maven.org/maven2" />
+    </remote-repository>
+    <remote-repository>
+      <option name="id" value="jboss.community" />
+      <option name="name" value="JBoss Community repository" />
+      <option name="url" value="https://repository.jboss.org/nexus/content/repositories/public/" />
+    </remote-repository>
+    <remote-repository>
+      <option name="id" value="maven2" />
+      <option name="name" value="maven2" />
+      <option name="url" value="https://maven.google.com" />
+    </remote-repository>
+    <remote-repository>
+      <option name="id" value="MavenRepo" />
+      <option name="name" value="MavenRepo" />
+      <option name="url" value="https://repo.maven.apache.org/maven2/" />
+    </remote-repository>
+    <remote-repository>
+      <option name="id" value="BintrayJCenter" />
+      <option name="name" value="BintrayJCenter" />
+      <option name="url" value="https://jcenter.bintray.com/" />
+    </remote-repository>
+    <remote-repository>
+      <option name="id" value="maven" />
+      <option name="name" value="maven" />
+      <option name="url" value="https://jitpack.io" />
+    </remote-repository>
+    <remote-repository>
+      <option name="id" value="Google" />
+      <option name="name" value="Google" />
+      <option name="url" value="https://dl.google.com/dl/android/maven2/" />
+    </remote-repository>
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
index 3be1ace..e5fc5dc 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,43 +1,57 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="EntryPointsManager">
-    <entry_points version="2.0" />
+  <component name="DesignSurface">
+    <option name="filePathToZoomLevelMap">
+      <map>
+        <entry key="..\:/Users/HP/AndroidStudioProjects/RecyclerTreeView/app/src/main/res/layout/item_dir.xml" value="0.2463768115942029" />
+      </map>
+    </option>
   </component>
   <component name="NullableNotNullManager">
     <option name="myDefaultNullable" value="android.support.annotation.Nullable" />
     <option name="myDefaultNotNull" value="android.support.annotation.NonNull" />
     <option name="myNullables">
       <value>
-        <list size="4">
+        <list size="14">
           <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.Nullable" />
           <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nullable" />
           <item index="2" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.Nullable" />
           <item index="3" class="java.lang.String" itemvalue="android.support.annotation.Nullable" />
+          <item index="4" class="java.lang.String" itemvalue="androidx.annotation.Nullable" />
+          <item index="5" class="java.lang.String" itemvalue="androidx.annotation.RecentlyNullable" />
+          <item index="6" class="java.lang.String" itemvalue="com.android.annotations.Nullable" />
+          <item index="7" class="java.lang.String" itemvalue="javax.annotation.CheckForNull" />
+          <item index="8" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.qual.Nullable" />
+          <item index="9" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NullableDecl" />
+          <item index="10" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NullableType" />
+          <item index="11" class="java.lang.String" itemvalue="org.eclipse.jdt.annotation.Nullable" />
+          <item index="12" class="java.lang.String" itemvalue="io.reactivex.annotations.Nullable" />
+          <item index="13" class="java.lang.String" itemvalue="io.reactivex.rxjava3.annotations.Nullable" />
         </list>
       </value>
     </option>
     <option name="myNotNulls">
       <value>
-        <list size="4">
+        <list size="14">
           <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.NotNull" />
           <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nonnull" />
           <item index="2" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.NonNull" />
           <item index="3" class="java.lang.String" itemvalue="android.support.annotation.NonNull" />
+          <item index="4" class="java.lang.String" itemvalue="androidx.annotation.NonNull" />
+          <item index="5" class="java.lang.String" itemvalue="androidx.annotation.RecentlyNonNull" />
+          <item index="6" class="java.lang.String" itemvalue="com.android.annotations.NonNull" />
+          <item index="7" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.qual.NonNull" />
+          <item index="8" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NonNullDecl" />
+          <item index="9" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NonNullType" />
+          <item index="10" class="java.lang.String" itemvalue="org.eclipse.jdt.annotation.NonNull" />
+          <item index="11" class="java.lang.String" itemvalue="io.reactivex.annotations.NonNull" />
+          <item index="12" class="java.lang.String" itemvalue="io.reactivex.rxjava3.annotations.NonNull" />
+          <item index="13" class="java.lang.String" itemvalue="lombok.NonNull" />
         </list>
       </value>
     </option>
   </component>
-  <component name="ProjectLevelVcsManager" settingsEditedManually="false">
-    <OptionsSetting value="true" id="Add" />
-    <OptionsSetting value="true" id="Remove" />
-    <OptionsSetting value="true" id="Checkout" />
-    <OptionsSetting value="true" id="Update" />
-    <OptionsSetting value="true" id="Status" />
-    <OptionsSetting value="true" id="Edit" />
-    <ConfirmationsSetting value="0" id="Add" />
-    <ConfirmationsSetting value="0" id="Remove" />
-  </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_7" default="true" assert-keyword="true" jdk-15="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">
diff --git a/.idea/modules.xml b/.idea/modules.xml
index bb2e094..7ee6a0a 100644
--- a/.idea/modules.xml
+++ b/.idea/modules.xml
@@ -2,9 +2,9 @@
 <project version="4">
   <component name="ProjectModuleManager">
     <modules>
-      <module fileurl="file://$PROJECT_DIR$/RecyclerTreeView.iml" filepath="$PROJECT_DIR$/RecyclerTreeView.iml" />
-      <module fileurl="file://$PROJECT_DIR$/app/app.iml" filepath="$PROJECT_DIR$/app/app.iml" />
-      <module fileurl="file://$PROJECT_DIR$/recyclertreeview-lib/recyclertreeview-lib.iml" filepath="$PROJECT_DIR$/recyclertreeview-lib/recyclertreeview-lib.iml" />
+      <module fileurl="file://$PROJECT_DIR$/.idea/modules/RecyclerTreeView.iml" filepath="$PROJECT_DIR$/.idea/modules/RecyclerTreeView.iml" />
+      <module fileurl="file://$PROJECT_DIR$/.idea/modules/app/RecyclerTreeView.app.iml" filepath="$PROJECT_DIR$/.idea/modules/app/RecyclerTreeView.app.iml" />
+      <module fileurl="file://$PROJECT_DIR$/.idea/modules/recyclertreeview-lib/RecyclerTreeView.recyclertreeview-lib.iml" filepath="$PROJECT_DIR$/.idea/modules/recyclertreeview-lib/RecyclerTreeView.recyclertreeview-lib.iml" />
     </modules>
   </component>
 </project>
\ No newline at end of file
diff --git a/.idea/runConfigurations.xml b/.idea/runConfigurations.xml
deleted file mode 100644
index 7f68460..0000000
--- a/.idea/runConfigurations.xml
+++ /dev/null
@@ -1,12 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="RunConfigurationProducerService">
-    <option name="ignoredProducers">
-      <set>
-        <option value="org.jetbrains.plugins.gradle.execution.test.runner.AllInPackageGradleConfigurationProducer" />
-        <option value="org.jetbrains.plugins.gradle.execution.test.runner.TestClassGradleConfigurationProducer" />
-        <option value="org.jetbrains.plugins.gradle.execution.test.runner.TestMethodGradleConfigurationProducer" />
-      </set>
-    </option>
-  </component>
-</project>
\ No newline at end of file
diff --git a/.idea/vcs.xml b/.idea/vcs.xml
new file mode 100644
index 0000000..35eb1dd
--- /dev/null
+++ b/.idea/vcs.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="" vcs="Git" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/README.md b/README.md
index 703ac25..60254c5 100644
--- a/README.md
+++ b/README.md
@@ -19,7 +19,7 @@ allprojects {
 app build.gradle
 ```groovy
 dependencies {
-    compile 'com.github.TellH:RecyclerTreeView:1.2.0'
+    implementation 'com.github.AZKZero:RecyclerTreeView:1.3.0'
 }
 ```
 
@@ -27,7 +27,9 @@ dependencies {
 
 ### Quick Start
 
-- Create a Java bean class and  implement the LayoutItemType, to attach item layout id to it.
+- Create a Java bean class and  implement the LayoutItemType 
+- Attach item layout id to it.
+- Attach toggle view id to it. (also you can stop toggle entirely or use the full view as toggle)
 
 ```java
 public class Dir implements LayoutItemType {
@@ -41,12 +43,18 @@ public class Dir implements LayoutItemType {
     public int getLayoutId() {
         return R.layout.item_dir;
     }
+
+    @Override
+    public int getToggleViewId() {
+        return R.id.iv_arrow;
+    }
 }
 ```
 
 
 
 - Create a ViewBinder to bind view with the data bean. As you see, `provideViewHolder(View itemView)` corresponds for `onCreateViewHolder` in RecyclerView, and `bindView` corresponds for `onBindViewHolder` in RecyclerView. 
+- For safety, follow the same ids provided the bean files.
 
 ```java
 public class FileNodeBinder extends TreeViewBinder<FileNodeBinder.ViewHolder> {
@@ -66,6 +74,11 @@ public class FileNodeBinder extends TreeViewBinder<FileNodeBinder.ViewHolder> {
         return R.layout.item_file;
     }
 
+    @Override
+    public int getToggleViewId() {
+        return NO_TOGGLE_ATTACHED;
+    }
+
     public class ViewHolder extends TreeViewBinder.ViewHolder {
         public TextView tvName;
 
@@ -128,7 +141,7 @@ public class FileNodeBinder extends TreeViewBinder<FileNodeBinder.ViewHolder> {
             public boolean onClick(TreeNode node, RecyclerView.ViewHolder holder) {
                 if (!node.isLeaf()) {
                     //Update and toggle the node.
-                    onToggle(!node.isExpand(), holder);
+                    //onToggle(!node.isExpand(), holder); onToggle is now called automatically
                 }
                 return false;
             }
diff --git a/app/build.gradle b/app/build.gradle
index 17a0186..f68bc33 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -1,15 +1,15 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 26
-    buildToolsVersion "26.0.2"
+    compileSdkVersion 31
+    buildToolsVersion '30.0.3'
     defaultConfig {
         applicationId "tellh.com.recyclertreeview"
         minSdkVersion 14
-        targetSdkVersion 26
+        targetSdkVersion 31
         versionCode 1
         versionName "1.0"
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        testInstrumentationRunner 'androidx.test.runner.AndroidJUnitRunner'
     }
     buildTypes {
         release {
@@ -17,16 +17,20 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
 }
 
 dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
-    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+    androidTestCompile('androidx.test.espresso:espresso-core:3.1.0', {
         exclude group: 'com.android.support', module: 'support-annotations'
     })
-    compile 'com.android.support:appcompat-v7:26.1.0'
-    compile 'com.android.support:recyclerview-v7:26.1.0'
+    implementation 'androidx.appcompat:appcompat:1.4.0'
+    implementation 'androidx.recyclerview:recyclerview:1.2.1'
     testCompile 'junit:junit:4.12'
-    compile project(path: ':recyclertreeview-lib')
-//    compile 'com.github.TellH:RecyclerTreeView:1.2.0'
+    implementation project(path: ':recyclertreeview-lib')
+//    implementation 'com.github.TellH:RecyclerTreeView:1.2.0'
 }
diff --git a/app/src/androidTest/java/tellh/com/recyclertreeview/ExampleInstrumentedTest.java b/app/src/androidTest/java/tellh/com/recyclertreeview/ExampleInstrumentedTest.java
index 765282b..98d56ce 100644
--- a/app/src/androidTest/java/tellh/com/recyclertreeview/ExampleInstrumentedTest.java
+++ b/app/src/androidTest/java/tellh/com/recyclertreeview/ExampleInstrumentedTest.java
@@ -1,8 +1,8 @@
 package tellh.com.recyclertreeview;
 
 import android.content.Context;
-import android.support.test.InstrumentationRegistry;
-import android.support.test.runner.AndroidJUnit4;
+import androidx.test.platform.app.InstrumentationRegistry;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
diff --git a/app/src/main/java/tellh/com/recyclertreeview/MainActivity.java b/app/src/main/java/tellh/com/recyclertreeview/MainActivity.java
index 5fc3861..c81d23c 100644
--- a/app/src/main/java/tellh/com/recyclertreeview/MainActivity.java
+++ b/app/src/main/java/tellh/com/recyclertreeview/MainActivity.java
@@ -1,12 +1,13 @@
 package tellh.com.recyclertreeview;
 
 import android.os.Bundle;
-import android.support.v7.app.AppCompatActivity;
-import android.support.v7.widget.LinearLayoutManager;
-import android.support.v7.widget.RecyclerView;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.widget.ImageView;
+import android.widget.Toast;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -74,9 +75,10 @@ private void initData() {
         adapter.setOnTreeNodeListener(new TreeViewAdapter.OnTreeNodeListener() {
             @Override
             public boolean onClick(TreeNode node, RecyclerView.ViewHolder holder) {
+                Toast.makeText(MainActivity.this, "Item Clicked!", Toast.LENGTH_SHORT).show();
                 if (!node.isLeaf()) {
                     //Update and toggle the node.
-                    onToggle(!node.isExpand(), holder);
+//                    onToggle(!node.isExpand(), holder);
 //                    if (!node.isExpand())
 //                        adapter.collapseBrotherNode(node);
                 }
@@ -85,6 +87,8 @@ public boolean onClick(TreeNode node, RecyclerView.ViewHolder holder) {
 
             @Override
             public void onToggle(boolean isExpand, RecyclerView.ViewHolder holder) {
+                Toast.makeText(MainActivity.this, "Item Toggled!", Toast.LENGTH_SHORT).show();
+
                 DirectoryNodeBinder.ViewHolder dirViewHolder = (DirectoryNodeBinder.ViewHolder) holder;
                 final ImageView ivArrow = dirViewHolder.getIvArrow();
                 int rotateDegree = isExpand ? 90 : -90;
diff --git a/app/src/main/java/tellh/com/recyclertreeview/bean/Dir.java b/app/src/main/java/tellh/com/recyclertreeview/bean/Dir.java
index 035bbd9..3c27598 100644
--- a/app/src/main/java/tellh/com/recyclertreeview/bean/Dir.java
+++ b/app/src/main/java/tellh/com/recyclertreeview/bean/Dir.java
@@ -18,4 +18,9 @@ public Dir(String dirName) {
     public int getLayoutId() {
         return R.layout.item_dir;
     }
+
+    @Override
+    public int getToggleViewId() {
+        return R.id.iv_arrow;
+    }
 }
diff --git a/app/src/main/java/tellh/com/recyclertreeview/bean/File.java b/app/src/main/java/tellh/com/recyclertreeview/bean/File.java
index 03b5a89..bbf8115 100644
--- a/app/src/main/java/tellh/com/recyclertreeview/bean/File.java
+++ b/app/src/main/java/tellh/com/recyclertreeview/bean/File.java
@@ -18,4 +18,9 @@ public File(String fileName) {
     public int getLayoutId() {
         return R.layout.item_file;
     }
+
+    @Override
+    public int getToggleViewId() {
+        return NO_TOGGLE_ATTACHED;
+    }
 }
diff --git a/app/src/main/java/tellh/com/recyclertreeview/viewbinder/DirectoryNodeBinder.java b/app/src/main/java/tellh/com/recyclertreeview/viewbinder/DirectoryNodeBinder.java
index 4708b31..0b9294f 100644
--- a/app/src/main/java/tellh/com/recyclertreeview/viewbinder/DirectoryNodeBinder.java
+++ b/app/src/main/java/tellh/com/recyclertreeview/viewbinder/DirectoryNodeBinder.java
@@ -37,6 +37,11 @@ public int getLayoutId() {
         return R.layout.item_dir;
     }
 
+    @Override
+    public int getToggleViewId() {
+        return R.id.iv_arrow;
+    }
+
     public static class ViewHolder extends TreeViewBinder.ViewHolder {
         private ImageView ivArrow;
         private TextView tvName;
diff --git a/app/src/main/java/tellh/com/recyclertreeview/viewbinder/FileNodeBinder.java b/app/src/main/java/tellh/com/recyclertreeview/viewbinder/FileNodeBinder.java
index ebb2dd6..1970f01 100644
--- a/app/src/main/java/tellh/com/recyclertreeview/viewbinder/FileNodeBinder.java
+++ b/app/src/main/java/tellh/com/recyclertreeview/viewbinder/FileNodeBinder.java
@@ -29,6 +29,11 @@ public int getLayoutId() {
         return R.layout.item_file;
     }
 
+    @Override
+    public int getToggleViewId() {
+        return NO_TOGGLE_ATTACHED;
+    }
+
     public class ViewHolder extends TreeViewBinder.ViewHolder {
         public TextView tvName;
 
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index 869486d..a2bcdee 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<android.support.v7.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.recyclerview.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/rv"
diff --git a/build.gradle b/build.gradle
index 987db10..019c287 100644
--- a/build.gradle
+++ b/build.gradle
@@ -2,23 +2,26 @@
 
 buildscript {
     repositories {
+        google()
         jcenter()
+        mavenCentral()
+        maven { url "https://jitpack.io" }
+        maven { url 'https://maven.google.com' }
     }
     dependencies {
         //JitPack
-        classpath 'com.github.dcendents:android-maven-gradle-plugin:1.4.1'
-        classpath 'com.android.tools.build:gradle:3.0.1'
+        classpath 'com.android.tools.build:gradle:4.1.3'
+        classpath 'com.github.dcendents:android-maven-gradle-plugin:2.0'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
+        mavenCentral()
         maven { url "https://jitpack.io" }
-        maven {
-            url 'https://maven.google.com'
-        }
-        google()
+        maven { url 'https://maven.google.com' }
     }
 }
 
diff --git a/gradle.properties b/gradle.properties
index aac7c9b..9e6fce1 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -9,6 +9,8 @@
 
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
+android.enableJetifier=true
+android.useAndroidX=true
 org.gradle.jvmargs=-Xmx1536m
 
 # When configured, Gradle will run in incubating parallel mode.
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index fc9b829..4537766 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Mon Dec 28 10:00:20 PST 2015
+#Sat Nov 20 11:26:04 BDT 2021
 distributionBase=GRADLE_USER_HOME
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.6.1-bin.zip
 distributionPath=wrapper/dists
-zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-all.zip
+zipStoreBase=GRADLE_USER_HOME
diff --git a/recyclertreeview-lib/build.gradle b/recyclertreeview-lib/build.gradle
index ac459f5..f033c37 100644
--- a/recyclertreeview-lib/build.gradle
+++ b/recyclertreeview-lib/build.gradle
@@ -2,16 +2,16 @@ apply plugin: 'com.android.library'
 apply plugin: 'com.github.dcendents.android-maven'
 group='com.github.tellh'
 android {
-    compileSdkVersion 26
-    buildToolsVersion "26.0.2"
+    compileSdkVersion 31
+    buildToolsVersion '30.0.3'
 
     defaultConfig {
         minSdkVersion 14
-        targetSdkVersion 26
+        targetSdkVersion 31
         versionCode 1
         versionName "1.0"
 
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        testInstrumentationRunner 'androidx.test.runner.AndroidJUnitRunner'
 
     }
     buildTypes {
@@ -20,12 +20,16 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
 }
 
 dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
-    compile 'com.android.support:appcompat-v7:26.1.0'
-    compile 'com.android.support:recyclerview-v7:26.1.0'
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+    implementation 'androidx.appcompat:appcompat:1.4.0'
+    implementation 'androidx.recyclerview:recyclerview:1.2.1'
 }
 
 tasks.withType(JavaCompile) {
diff --git a/recyclertreeview-lib/src/main/java/tellh/com/recyclertreeview_lib/LayoutItemType.java b/recyclertreeview-lib/src/main/java/tellh/com/recyclertreeview_lib/LayoutItemType.java
index 8f7dc25..4d03d60 100644
--- a/recyclertreeview-lib/src/main/java/tellh/com/recyclertreeview_lib/LayoutItemType.java
+++ b/recyclertreeview-lib/src/main/java/tellh/com/recyclertreeview_lib/LayoutItemType.java
@@ -5,5 +5,10 @@
  */
 
 public interface LayoutItemType {
+    int NO_TOGGLE_ATTACHED = -99;
+    int ATTACH_FULL_VIEW_AS_TOGGLE=-88;
+
     int getLayoutId();
+
+    int getToggleViewId();
 }
diff --git a/recyclertreeview-lib/src/main/java/tellh/com/recyclertreeview_lib/TreeNode.java b/recyclertreeview-lib/src/main/java/tellh/com/recyclertreeview_lib/TreeNode.java
index 02f6741..a05387f 100644
--- a/recyclertreeview-lib/src/main/java/tellh/com/recyclertreeview_lib/TreeNode.java
+++ b/recyclertreeview-lib/src/main/java/tellh/com/recyclertreeview_lib/TreeNode.java
@@ -1,6 +1,6 @@
 package tellh.com.recyclertreeview_lib;
 
-import android.support.annotation.NonNull;
+import androidx.annotation.NonNull;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/recyclertreeview-lib/src/main/java/tellh/com/recyclertreeview_lib/TreeViewAdapter.java b/recyclertreeview-lib/src/main/java/tellh/com/recyclertreeview_lib/TreeViewAdapter.java
index eb973bf..439a587 100644
--- a/recyclertreeview-lib/src/main/java/tellh/com/recyclertreeview_lib/TreeViewAdapter.java
+++ b/recyclertreeview-lib/src/main/java/tellh/com/recyclertreeview_lib/TreeViewAdapter.java
@@ -2,14 +2,15 @@
 
 import android.os.Build;
 import android.os.Bundle;
-import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
-import android.support.v7.util.DiffUtil;
-import android.support.v7.widget.RecyclerView;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.recyclerview.widget.DiffUtil;
+import androidx.recyclerview.widget.RecyclerView;
+
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
@@ -87,12 +88,21 @@ public void onBindViewHolder(RecyclerView.ViewHolder holder, int position, List<
     public void onBindViewHolder(final RecyclerView.ViewHolder holder, int position) {
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
             holder.itemView.setPaddingRelative(displayNodes.get(position).getHeight() * padding, 3, 3, 3);
-        }else {
+        } else {
             holder.itemView.setPadding(displayNodes.get(position).getHeight() * padding, 3, 3, 3);
         }
-        holder.itemView.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View v) {
+        int toggleViewId = LayoutItemType.NO_TOGGLE_ATTACHED;
+        try {
+            toggleViewId = displayNodes.get(position).getContent().getToggleViewId();
+        } catch (Exception ignored) {
+        }
+        holder.itemView.setOnClickListener(v -> {
+            TreeNode selectedNode = displayNodes.get(holder.getLayoutPosition());
+            if (onTreeNodeListener != null && onTreeNodeListener.onClick(selectedNode, holder))
+                return;
+        });
+        if (toggleViewId != LayoutItemType.NO_TOGGLE_ATTACHED)
+            (toggleViewId == LayoutItemType.ATTACH_FULL_VIEW_AS_TOGGLE ? holder.itemView : holder.itemView.findViewById(toggleViewId)).setOnClickListener(v -> {
                 TreeNode selectedNode = displayNodes.get(holder.getLayoutPosition());
                 // Prevent multi-click during the short interval.
                 try {
@@ -104,8 +114,8 @@ public void onClick(View v) {
                 }
                 holder.itemView.setTag(System.currentTimeMillis());
 
-                if (onTreeNodeListener != null && onTreeNodeListener.onClick(selectedNode, holder))
-                    return;
+                /*if (onTreeNodeListener != null && onTreeNodeListener.onClick(selectedNode, holder))
+                    return;*/
                 if (selectedNode.isLeaf())
                     return;
                 // This TreeNode was locked to click.
@@ -117,8 +127,9 @@ public void onClick(View v) {
                 } else {
                     notifyItemRangeRemoved(positionStart, removeChildNodes(selectedNode, true));
                 }
-            }
-        });
+                if (onTreeNodeListener != null)
+                    onTreeNodeListener.onToggle(!selectedNode.isExpand(), holder);
+            });
         for (TreeViewBinder viewBinder : viewBinders) {
             if (viewBinder.getLayoutId() == displayNodes.get(position).getContent().getLayoutId())
                 viewBinder.bindView(holder, position, displayNodes.get(position));
@@ -181,12 +192,14 @@ public void setOnTreeNodeListener(OnTreeNodeListener onTreeNodeListener) {
     public interface OnTreeNodeListener {
         /**
          * called when TreeNodes were clicked.
+         *
          * @return weather consume the click event.
          */
         boolean onClick(TreeNode node, RecyclerView.ViewHolder holder);
 
         /**
          * called when TreeNodes were toggle.
+         *
          * @param isExpand the status of TreeNodes after being toggled.
          */
         void onToggle(boolean isExpand, RecyclerView.ViewHolder holder);
diff --git a/recyclertreeview-lib/src/main/java/tellh/com/recyclertreeview_lib/TreeViewBinder.java b/recyclertreeview-lib/src/main/java/tellh/com/recyclertreeview_lib/TreeViewBinder.java
index aa55e3b..76cc461 100644
--- a/recyclertreeview-lib/src/main/java/tellh/com/recyclertreeview_lib/TreeViewBinder.java
+++ b/recyclertreeview-lib/src/main/java/tellh/com/recyclertreeview_lib/TreeViewBinder.java
@@ -1,7 +1,7 @@
 package tellh.com.recyclertreeview_lib;
 
-import android.support.annotation.IdRes;
-import android.support.v7.widget.RecyclerView;
+import androidx.annotation.IdRes;
+import androidx.recyclerview.widget.RecyclerView;
 import android.view.View;