diff --git a/.idea/compiler.xml b/.idea/compiler.xml
new file mode 100644
index 0000000..fb7f4a8
--- /dev/null
+++ b/.idea/compiler.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="CompilerConfiguration">
+    <bytecodeTargetLevel target="11" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/jarRepositories.xml b/.idea/jarRepositories.xml
new file mode 100644
index 0000000..eb2873e
--- /dev/null
+++ b/.idea/jarRepositories.xml
@@ -0,0 +1,30 @@
+<?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="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 703e5d4..7c7f635 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -5,7 +5,7 @@
       <configuration PROFILE_NAME="Debug" CONFIG_NAME="Debug" />
     </configurations>
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" project-jdk-name="1.8" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" default="false" 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 3f6fa34..8d3de0c 100644
--- a/.idea/modules.xml
+++ b/.idea/modules.xml
@@ -2,12 +2,9 @@
 <project version="4">
   <component name="ProjectModuleManager">
     <modules>
-      <module fileurl="file://$PROJECT_DIR$/.idea/Tri-State-Checkbox.iml" filepath="$PROJECT_DIR$/.idea/Tri-State-Checkbox.iml" />
-      <module fileurl="file://$PROJECT_DIR$/Tri-State-Checkbox.iml" filepath="$PROJECT_DIR$/Tri-State-Checkbox.iml" />
-      <module fileurl="file://$PROJECT_DIR$/app/app.iml" filepath="$PROJECT_DIR$/app/app.iml" />
-      <module fileurl="file://$PROJECT_DIR$/app/app.iml" filepath="$PROJECT_DIR$/app/app.iml" />
-      <module fileurl="file://$PROJECT_DIR$/library/library.iml" filepath="$PROJECT_DIR$/library/library.iml" />
-      <module fileurl="file://$PROJECT_DIR$/library/library.iml" filepath="$PROJECT_DIR$/library/library.iml" />
+      <module fileurl="file://$PROJECT_DIR$/.idea/modules/Tri-State-Checkbox.iml" filepath="$PROJECT_DIR$/.idea/modules/Tri-State-Checkbox.iml" />
+      <module fileurl="file://$PROJECT_DIR$/.idea/modules/app/Tri-State-Checkbox.app.iml" filepath="$PROJECT_DIR$/.idea/modules/app/Tri-State-Checkbox.app.iml" />
+      <module fileurl="file://$PROJECT_DIR$/.idea/modules/library/Tri-State-Checkbox.library.iml" filepath="$PROJECT_DIR$/.idea/modules/library/Tri-State-Checkbox.library.iml" />
     </modules>
   </component>
 </project>
\ No newline at end of file
diff --git a/.idea/runConfigurations.xml b/.idea/runConfigurations.xml
index 7f68460..e497da9 100644
--- a/.idea/runConfigurations.xml
+++ b/.idea/runConfigurations.xml
@@ -3,6 +3,7 @@
   <component name="RunConfigurationProducerService">
     <option name="ignoredProducers">
       <set>
+        <option value="com.android.tools.idea.compose.preview.runconfiguration.ComposePreviewRunConfigurationProducer" />
         <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" />
diff --git a/app/build.gradle b/app/build.gradle
index 645f66f..7443ad4 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -5,11 +5,11 @@ apply plugin: 'kotlin-android'
 apply plugin: 'kotlin-android-extensions'
 
 android {
-    compileSdkVersion 28
+    compileSdkVersion 30
     defaultConfig {
         applicationId "it.sephiroth.android.library.demo"
         minSdkVersion 23
-        targetSdkVersion 28
+        targetSdkVersion 30
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
@@ -20,17 +20,25 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
     }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_7
+        targetCompatibility JavaVersion.VERSION_1_7
+    }
+    kotlinOptions {
+        jvmTarget = '1.6' // Java 7 not supported by kotlinOptions jvmTarget
+    }
 }
 
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation project(':library')
 
-    implementation"org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
-    implementation 'androidx.appcompat:appcompat:1.0.2'
-    implementation 'androidx.core:core-ktx:1.1.0-alpha03'
-    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
-    testImplementation 'junit:junit:4.12'
-    androidTestImplementation 'androidx.test:runner:1.1.1'
-    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
+    implementation"org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
+    implementation 'androidx.appcompat:appcompat:1.3.0'
+    implementation 'androidx.core:core-ktx:1.6.0-beta02'
+    implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
+    implementation 'com.google.android.material:material:1.3.0'
+    testImplementation 'junit:junit:4.13.2'
+    androidTestImplementation 'androidx.test:runner:1.3.0'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
 }
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index cc46f00..955bf02 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest package="it.sephiroth.android.library.demo"
-    xmlns:android="http://schemas.android.com/apk/res/android">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="it.sephiroth.android.library.demo">
 
     <application
         android:allowBackup="true"
@@ -9,6 +9,7 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
+        <activity android:name=".MainActivity2"></activity>
         <activity android:name=".MainActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
diff --git a/app/src/main/java/it/sephiroth/android/library/demo/MainActivity.kt b/app/src/main/java/it/sephiroth/android/library/demo/MainActivity.kt
index 77657c2..c723079 100644
--- a/app/src/main/java/it/sephiroth/android/library/demo/MainActivity.kt
+++ b/app/src/main/java/it/sephiroth/android/library/demo/MainActivity.kt
@@ -1,5 +1,6 @@
 package it.sephiroth.android.library.demo
 
+import android.content.Intent
 import android.os.Bundle
 import android.widget.CheckBox
 import androidx.appcompat.app.AppCompatActivity
@@ -27,6 +28,10 @@ class MainActivity : AppCompatActivity() {
                 listenToUpdates = true
             }
         }
+        buttonToJava.setOnClickListener{
+            val intent = Intent (this, MainActivity2::class.java)
+            startActivity(intent)
+        }
 
     }
 
diff --git a/app/src/main/java/it/sephiroth/android/library/demo/MainActivity2.java b/app/src/main/java/it/sephiroth/android/library/demo/MainActivity2.java
new file mode 100644
index 0000000..ffc484a
--- /dev/null
+++ b/app/src/main/java/it/sephiroth/android/library/demo/MainActivity2.java
@@ -0,0 +1,89 @@
+package it.sephiroth.android.library.demo;
+
+
+/**
+ * Thanks so much to om Yohanes
+ * for helped me to use this library
+ */
+
+import android.os.Bundle;
+import android.widget.CheckBox;
+import android.widget.CompoundButton;
+
+import androidx.appcompat.app.AppCompatActivity;
+
+import it.sephiroth.android.library.checkbox3state.CheckBox3;
+
+public class MainActivity2 extends AppCompatActivity {
+
+    private CheckBox3 checkBox1;
+    private boolean listenToUpdates = true;
+    private CheckBox[] checkBoxesArray;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_main2);
+        checkBox1 = findViewById(R.id.checkBox1);
+        checkBox1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
+                if (listenToUpdates) {
+                    listenToUpdates = false;
+                    if (!isChecked) {
+                        for (CheckBox it : checkBoxesArray) {
+                            it.setChecked(false);
+                        }
+                    } else if (isChecked) {
+                        for (CheckBox it : checkBoxesArray) {
+                            it.setChecked(true);
+                        }
+                    }
+                    checkBox1.setText(isChecked ? "Select None": "Select All");
+                    checkBox1.setCycle(R.array.sephiroth_checkbox3_cycleCheckedUncheckedOnly);
+                    listenToUpdates = true;
+                }
+            }
+        });
+    }
+
+    @Override
+    public void onContentChanged() {
+        super.onContentChanged();
+        checkBoxesArray = new CheckBox[] {findViewById(R.id.checkBox2), findViewById(R.id.checkBox3), findViewById(R.id.checkBox4)};
+
+        for (CheckBox it : checkBoxesArray) {
+            it.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+                @Override
+                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
+
+                    if (listenToUpdates) {
+                        listenToUpdates = false;
+                        int checkSize = 0;
+                        for (CheckBox checkBox : checkBoxesArray) {
+                            if (checkBox.isChecked()) {
+                                checkSize++;
+                            }
+                        }
+
+                        if (checkSize == checkBoxesArray.length) {
+                            checkBox1.setCycle(R.array.sephiroth_checkbox3_cycleCheckedUncheckedOnly);
+                            checkBox1.setChecked(true, false);
+                            checkBox1.setText("Select None");
+                        } else if (checkSize == 0) {
+                            checkBox1.setCycle(R.array.sephiroth_checkbox3_cycleCheckedUncheckedOnly);
+                            checkBox1.setChecked(false, false);
+                            checkBox1.setText("Select All");
+                        } else {
+                            checkBox1.setCycle(R.array.sephiroth_checkbox3_cycleAll);
+                            checkBox1.setChecked(false,true);
+                            checkBox1.setText("Select All");
+                        }
+                        listenToUpdates = true;
+                    }
+                }
+            });
+        }
+
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index eb0c471..7366cb0 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -62,4 +62,13 @@
         app:layout_constraintStart_toStartOf="@+id/checkBox3"
         app:layout_constraintTop_toBottomOf="@+id/checkBox3" />
 
+    <androidx.appcompat.widget.AppCompatButton
+        android:id="@+id/buttonToJava"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        app:layout_constraintStart_toStartOf="@id/checkBox1"
+        android:text="Sample in Java Code"
+        app:layout_constraintTop_toBottomOf="@id/checkBox4"
+        android:textColor="@android:color/black"/>
+
 </androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/app/src/main/res/layout/activity_main2.xml b/app/src/main/res/layout/activity_main2.xml
new file mode 100644
index 0000000..3511236
--- /dev/null
+++ b/app/src/main/res/layout/activity_main2.xml
@@ -0,0 +1,66 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context=".MainActivity2">
+
+    <androidx.appcompat.widget.AppCompatTextView
+        android:id="@+id/textView1"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginEnd="16dp"
+        android:layout_marginStart="16dp"
+        android:layout_marginTop="16dp"
+        android:text="Let's pretend this is a multi-selection option. Just select any of the checkbox preferences to see the behavior of the tri state checkbox below."
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <it.sephiroth.android.library.checkbox3state.CheckBox3
+        android:id="@+id/checkBox1"
+        style="@style/Sephiroth.Widget.Checkbox3"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="16dp"
+        android:layout_marginTop="24dp"
+        android:checked="false"
+        android:enabled="true"
+        android:text="Select All"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/textView1"
+        app:sephiroth_checkbox3_checkableCycle="@array/sephiroth_checkbox3_cycleCheckedUncheckedOnly"
+        app:sephiroth_checkbox3_indeterminate="false" />
+
+    <CheckBox
+        android:id="@+id/checkBox2"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="8dp"
+        android:layout_marginTop="8dp"
+        android:checked="false"
+        android:enabled="true"
+        android:text="Single Option 1"
+        app:layout_constraintStart_toStartOf="@+id/checkBox1"
+        app:layout_constraintTop_toBottomOf="@+id/checkBox1" />
+
+    <CheckBox
+        android:id="@+id/checkBox3"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="8dp"
+        android:text="Option 2"
+        app:layout_constraintStart_toStartOf="@+id/checkBox2"
+        app:layout_constraintTop_toBottomOf="@+id/checkBox2" />
+
+    <CheckBox
+        android:id="@+id/checkBox4"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="8dp"
+        android:text="Another Option"
+        app:layout_constraintStart_toStartOf="@+id/checkBox3"
+        app:layout_constraintTop_toBottomOf="@+id/checkBox3" />
+
+
+</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/build.gradle b/build.gradle
index d7835ba..3c7fcc4 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,14 +1,14 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
-    ext.kotlin_version = '1.3.11'
+    ext.kotlin_version = '1.5.0'
     repositories {
         google()
         jcenter()
 
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.4.0-alpha10'
+        classpath 'com.android.tools.build:gradle:4.2.1'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 2caec75..0547045 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.1-milestone-1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.7.1-all.zip
diff --git a/library/build.gradle b/library/build.gradle
index f55e25e..d736682 100644
--- a/library/build.gradle
+++ b/library/build.gradle
@@ -41,6 +41,9 @@ android {
             includeAndroidResources = true
         }
     }
+    kotlinOptions {
+        jvmTarget = '1.6' // Java 7 not supported by kotlinOptions jvmTarget
+    }
 
 }