diff --git a/.gitignore b/.gitignore
index 09b993d..0bce669 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,8 +1,77 @@
+# Built application files
+*.apk
+*.ap_
+*.aab
+
+# Files for the ART/Dalvik VM
+*.dex
+
+# Java class files
+*.class
+app/.classpath
+
+# Generated files
+bin/
+gen/
+out/
+release/
+
+# Gradle files
+.gradle/
+build/
+
+# Local configuration file (sdk path, etc)
+local.properties
+
+# Proguard folder generated by Eclipse
+proguard/
+
+# Log Files
+*.log
+
+# Android Studio Navigation editor temp files
+.navigation/
+
+# Android Studio captures folder
+captures/
+
+# IntelliJ
 *.iml
-.gradle
-/local.properties
-/.idea
-.DS_Store
-/build
-/captures
+.idea/
+
+# Keystore files
+# Uncomment the following lines if you do not want to check your keystore files in.
+#*.jks
+#*.keystore
+
+# External native build folder generated in Android Studio 2.2 and later
 .externalNativeBuild
+
+# Google Services (e.g. APIs or Firebase)
+# google-services.json
+
+# Freeline
+freeline.py
+freeline/
+freeline_project_description.json
+
+# fastlane
+fastlane/report.xml
+fastlane/Preview.html
+fastlane/screenshots
+fastlane/test_output
+fastlane/readme.md
+
+# Version control
+vcs.xml
+
+# lint
+lint/intermediates/
+lint/generated/
+lint/outputs/
+lint/tmp/
+# lint/reports/
+
+.settings
+.env.*
+!.env.example
diff --git a/app/build.gradle b/app/build.gradle
index 2c29832..daa1880 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -1,13 +1,12 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 25
-    buildToolsVersion '26.0.2'
+    compileSdkVersion 29
 
     defaultConfig {
         applicationId "vn.luongvo.widget.iosswitchview.sample"
-        minSdkVersion 11
-        targetSdkVersion 25
+        minSdkVersion 25
+        targetSdkVersion 29
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
@@ -22,11 +21,11 @@ android {
 }
 
 dependencies {
-    compile 'com.android.support:appcompat-v7:25.2.0'
-    compile project(':library')
+    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation project(':library')
 
-    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
+    androidTestImplementation('com.android.support.test.espresso:espresso-core:2.2.2', {
         exclude group: 'com.android.support', module: 'support-annotations'
     })
-    testCompile 'junit:junit:4.12'
+    implementation 'junit:junit:4.12'
 }
diff --git a/app/src/main/java/vn/luongvo/widget/iosswitchview/sample/MainActivity.java b/app/src/main/java/vn/luongvo/widget/iosswitchview/sample/MainActivity.java
index 03b09ad..24d020a 100644
--- a/app/src/main/java/vn/luongvo/widget/iosswitchview/sample/MainActivity.java
+++ b/app/src/main/java/vn/luongvo/widget/iosswitchview/sample/MainActivity.java
@@ -1,10 +1,10 @@
 package vn.luongvo.widget.iosswitchview.sample;
 
 import android.os.Bundle;
-import android.support.v7.app.AppCompatActivity;
-import android.view.View;
 import android.widget.Toast;
 
+import androidx.appcompat.app.AppCompatActivity;
+
 import vn.luongvo.widget.iosswitchview.SwitchView;
 
 public class MainActivity extends AppCompatActivity {
@@ -14,7 +14,7 @@ protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
 
-        final SwitchView switchView = (SwitchView) findViewById(R.id.switchview);
+        final SwitchView switchView = findViewById(R.id.switchview);
         switchView.setOnCheckedChangeListener(new SwitchView.OnCheckedChangeListener() {
             @Override
             public void onCheckedChanged(SwitchView switchView, boolean isChecked) {
diff --git a/build.gradle b/build.gradle
index 7bdac0a..e00c062 100644
--- a/build.gradle
+++ b/build.gradle
@@ -6,7 +6,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.0.0'
+        classpath 'com.android.tools.build:gradle:3.5.3'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
@@ -16,6 +16,7 @@ buildscript {
 allprojects {
     repositories {
         jcenter()
+        google()
     }
 }
 
diff --git a/library/build.gradle b/library/build.gradle
index e55083d..7e5e19e 100644
--- a/library/build.gradle
+++ b/library/build.gradle
@@ -1,11 +1,11 @@
 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 25
-    buildToolsVersion '26.0.2'
+    compileSdkVersion 29
+    buildToolsVersion '28.0.3'
 
     defaultConfig {
-        minSdkVersion 11
+        minSdkVersion 14
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }
 
@@ -18,8 +18,8 @@ android {
 }
 
 dependencies {
-    testCompile 'junit:junit:4.12'
-    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
+    testImplementation 'junit:junit:4.12'
+    androidTestImplementation('com.android.support.test.espresso:espresso-core:2.2.2', {
         exclude group: 'com.android.support', module: 'support-annotations'
     })
 }
diff --git a/library/src/main/java/vn/luongvo/widget/iosswitchview/SwitchView.java b/library/src/main/java/vn/luongvo/widget/iosswitchview/SwitchView.java
index 882693e..80aff02 100644
--- a/library/src/main/java/vn/luongvo/widget/iosswitchview/SwitchView.java
+++ b/library/src/main/java/vn/luongvo/widget/iosswitchview/SwitchView.java
@@ -241,7 +241,7 @@ protected void onDraw(Canvas canvas) {
         final float scaleOffset = (bOnLeftX + bRadius - sCenterX) * (isChecked ? 1 - dsAnim : dsAnim);
         canvas.save();
         canvas.scale(scale, scale, sCenterX + scaleOffset, sCenterY);
-        paint.setColor(0xffffffff);
+        paint.setColor(colorOff);
         canvas.drawPath(sPath, paint);
         canvas.restore();
         // draw center bar