.circleci/config.yml

@@ -0,0 +1,86 @@
+version: 2.1
+jobs:
+  build:
+    working_directory: ~/code
+    docker:
+      - image: circleci/android:api-29
+    environment:
+      JVM_OPTS: -Xmx3200m
+    steps:
+      - checkout
+      - restore_cache:
+          key: jars-{{ checksum "build.gradle" }}-{{ checksum  "app/build.gradle" }}
+      - run:
+          name: Download Dependencies
+          command: ./gradlew androidDependencies
+      - save_cache:
+          paths:
+            - ~/.gradle
+          key: jars-{{ checksum "build.gradle" }}-{{ checksum  "app/build.gradle" }}
+
+  tests:
+    working_directory: ~/code
+    docker:
+      - image: circleci/android:api-29
+    environment:
+      JVM_OPTS: -Xmx3200m
+    steps:
+      - checkout
+      - restore_cache:
+          key: jars-{{ checksum "build.gradle" }}-{{ checksum  "app/build.gradle" }}
+      - store_artifacts:
+          path: app/build/reports
+          destination: reports
+      - run:
+          name: Run Lint Test
+          command: ./gradlew lint
+      - run:
+          name: Run Tests
+          command: ./gradlew lint test
+      - store_artifacts:
+          path: app/build/reports
+          destination: reports
+      - store_test_results:
+          path: app/build/test-results
+
+  deploy:
+    working_directory: ~/code
+    docker:
+      - image: circleci/android:api-29
+    environment:
+      JVM_OPTS: -Xmx3200m
+    steps:
+      - checkout
+      - restore_cache:
+          key: jars-{{ checksum "build.gradle" }}-{{ checksum  "app/build.gradle" }}
+      - run:
+          name: Build Library
+          command: ./gradlew :expandable-recyclerview:assembleRelease
+      - run:
+          name: Export key
+          command: |
+            mkdir expandable-recyclerview/maven
+            echo ${GPG_KEY_CONTENTS} | base64 -d --ignore-garbage > expandable-recyclerview/maven/secret.gpg
+      - run:
+          name: Staging
+          command: ./gradlew :expandable-recyclerview:publishReleasePublicationToSonatypeRepository
+      - run:
+          name: Release Library
+          command: ./gradlew closeAndReleaseRepository
+
+workflows:
+  version: 2.1
+  build-and-deploy:
+    jobs:
+      - build:
+          filters:  # required since `deploy` has tag filters AND requires `build`
+            tags:
+              only: /.*/
+      - deploy:
+          requires:
+            - build
+          filters:
+            tags:
+              only: /v[0-9]{1,3}\.[0-9]{1,3}\.?[0-9]{0,3}.*/
+            branches:
+              ignore: /.*/

.idea/gradle.xml

@@ -15,6 +15,7 @@
             <option value="$PROJECT_DIR$/expandable-recyclerview" />
           </set>
         </option>
+        <option name="resolveModulePerSourceSet" value="false" />
       </GradleProjectSettings>
     </option>
   </component>

.idea/misc.xml

@@ -1,3 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="DesignSurface">
     <option name="filePathToZoomLevelMap">
@@ -9,7 +10,7 @@
       </map>
     </option>
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" default="true" project-jdk-name="11" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">

LICENSE

@@ -1,21 +1,201 @@
-MIT License
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
 
-Copyright (c) 2022 Adrian Kuta
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
 
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
+   1. Definitions.
 
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
 
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
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+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
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+
+      "Source" form shall mean the preferred form for making modifications,
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+
+      "Object" form shall mean any form resulting from mechanical
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+
+      "Work" shall mean the work of authorship, whether in Source or
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+      "Derivative Works" shall mean any work, whether in Source or Object
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+      editorial revisions, annotations, elaborations, or other modifications
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+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
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+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
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+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
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+      the terms of any separate license agreement you may have executed
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+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
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+
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+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
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+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
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+
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+
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+
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+
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+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

README.md

@@ -2,7 +2,7 @@
 
 [![maven](https://img.shields.io/maven-central/v/com.github.adriankuta/expandable-recyclerView?style=plastic)](https://mvnrepository.com/artifact/com.github.adriankuta/expandable-recyclerView)
 [![License](https://img.shields.io/github/license/AdrianKuta/Expandable-RecyclerView?style=plastic)](https://github.com/AdrianKuta/Expandable-RecyclerView/blob/master/LICENSE)
-[![Publish](https://github.com/AdrianKuta/Expandable-RecyclerView/actions/workflows/publish.yml/badge.svg)](https://github.com/AdrianKuta/Expandable-RecyclerView/actions/workflows/publish.yml)
+[![CircleCI](https://img.shields.io/circleci/build/github/AdrianKuta/Expandable-RecyclerView/master?label=CircleCI&style=plastic&logo=circleci)](https://circleci.com/gh/AdrianKuta/Expandable-RecyclerView)
 
 With this adapter you can add expand feature to regular RecyclerView.
 

app/build.gradle

@@ -3,13 +3,12 @@ apply plugin: 'kotlin-android'
 apply plugin: 'kotlin-kapt'
 
 android {
-    namespace 'com.github.adriankuta'
-    compileSdkVersion 33
-    buildToolsVersion "33.0.0"
+    compileSdkVersion 31
+    buildToolsVersion "31.0.0"
     defaultConfig {
         applicationId "com.github.adriankuta"
         minSdkVersion 23
-        targetSdkVersion 33
+        targetSdkVersion 31
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
@@ -23,17 +22,19 @@ android {
     buildFeatures {
         viewBinding true
     }
+    dataBinding {
+        enabled = true
+    }
 }
 
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation"org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
-    implementation 'androidx.appcompat:appcompat:1.6.1'
-    implementation 'androidx.core:core-ktx:1.10.1'
-    implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
-    implementation 'com.github.adriankuta:expandable-recyclerView:2.1.0'
-
+    implementation 'androidx.appcompat:appcompat:1.3.1'
+    implementation 'androidx.core:core-ktx:1.6.0'
+    implementation 'androidx.constraintlayout:constraintlayout:2.1.0'
+    implementation 'com.github.adriankuta:expandable-recyclerView:1.0.0'
     testImplementation 'junit:junit:4.13.2'
-    androidTestImplementation 'androidx.test.ext:junit:1.1.5'
-    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.3'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
 }

app/src/main/AndroidManifest.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.github.adriankuta">
 
     <application
         android:allowBackup="true"

app/src/main/java/com/github/adriankuta/ExpandableAdapter.kt

@@ -3,7 +3,6 @@ package com.github.adriankuta
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
-import androidx.core.view.isGone
 import androidx.recyclerview.widget.RecyclerView
 import com.github.adriankuta.databinding.ItemLevel1Binding
 import com.github.adriankuta.databinding.ItemLevel2Binding
@@ -13,16 +12,16 @@ import com.github.adriankuta.expandable_recyclerview.ExpandableTreeNode
 import com.github.adriankuta.expandable_recyclerview.expandableTree
 
 class ExpandableAdapter :
-    ExpandableRecyclerViewAdapter<Region, ExpandableAdapter.ExpandableViewHolder>() {
+    ExpandableRecyclerViewAdapter<String, ExpandableAdapter.ExpandableViewHolder>() {
 
-    private var tree: ExpandableTreeNode<Region>? = null
+    private var tree: ExpandableTreeNode<String>? = null
 
-    fun setTree(tree: ExpandableTreeNode<Region>) {
+    fun setTree(tree: ExpandableTreeNode<String>) {
         this.tree = tree
         notifyDataSetChanged()
     }
 
-    override fun getTreeNodes(): ExpandableTreeNode<Region> = tree ?: expandableTree(Region(""))
+    override fun getTreeNodes(): ExpandableTreeNode<String> = tree ?: expandableTree("")
 
     override fun onCreateViewHolder(parent: ViewGroup, nestLevel: Int): ExpandableViewHolder {
         return when (nestLevel) {
@@ -35,7 +34,7 @@ class ExpandableAdapter :
 
     override fun onBindViewHolder(
         holder: ExpandableViewHolder,
-        treeNode: ExpandableTreeNode<Region>,
+        treeNode: ExpandableTreeNode<String>,
         nestLevel: Int
     ) {
         holder.bind(treeNode) {
@@ -47,65 +46,41 @@ class ExpandableAdapter :
 
         class Level1(private val binding: ItemLevel1Binding) : ExpandableViewHolder(binding.root) {
             override fun bind(
-                node: ExpandableTreeNode<Region>,
-                onClickListener: ((ExpandableTreeNode<Region>) -> Unit)?
+                node: ExpandableTreeNode<String>,
+                onClickListener: ((ExpandableTreeNode<String>) -> Unit)?
             ) {
-                binding.apply {
-                    root.setOnClickListener { onClickListener?.invoke(node) }
-                    textView.text = node.value.name
-                    expandIcon.isGone = node.children.isEmpty()
-                    expandIcon.setImageResource(
-                        if (node.expanded)
-                            R.drawable.ic_expand_less_black_24dp
-                        else
-                            R.drawable.ic_expand_more_black_24dp
-                    )
-                }
+                binding.node = node
+                binding.root.setOnClickListener { onClickListener?.invoke(node) }
+                binding.executePendingBindings()
             }
         }
 
         class Level2(private val binding: ItemLevel2Binding) : ExpandableViewHolder(binding.root) {
             override fun bind(
-                node: ExpandableTreeNode<Region>,
-                onClickListener: ((ExpandableTreeNode<Region>) -> Unit)?
+                node: ExpandableTreeNode<String>,
+                onClickListener: ((ExpandableTreeNode<String>) -> Unit)?
             ) {
-                binding.apply {
-                    root.setOnClickListener { onClickListener?.invoke(node) }
-                    textView.text = node.value.name
-                    expandIcon.isGone = node.children.isEmpty()
-                    expandIcon.setImageResource(
-                        if (node.expanded)
-                            R.drawable.ic_expand_less_black_24dp
-                        else
-                            R.drawable.ic_expand_more_black_24dp
-                    )
-                }
+                binding.node = node
+                binding.root.setOnClickListener { onClickListener?.invoke(node) }
+                binding.executePendingBindings()
             }
         }
 
         class Level3(private val binding: ItemLevel3Binding) : ExpandableViewHolder(binding.root) {
             override fun bind(
-                node: ExpandableTreeNode<Region>,
-                onClickListener: ((ExpandableTreeNode<Region>) -> Unit)?
+                node: ExpandableTreeNode<String>,
+                onClickListener: ((ExpandableTreeNode<String>) -> Unit)?
             ) {
-                binding.apply {
-                    root.setOnClickListener { onClickListener?.invoke(node) }
-                    textView.text = node.value.name
-                    expandIcon.isGone = node.children.isEmpty()
-                    expandIcon.setImageResource(
-                        if (node.expanded)
-                            R.drawable.ic_expand_less_black_24dp
-                        else
-                            R.drawable.ic_expand_more_black_24dp
-                    )
-                }
+                binding.node = node
+                binding.root.setOnClickListener { onClickListener?.invoke(node) }
+                binding.executePendingBindings()
             }
         }
 
 
         abstract fun bind(
-            node: ExpandableTreeNode<Region>,
-            onClickListener: ((ExpandableTreeNode<Region>) -> Unit)? = null
+            node: ExpandableTreeNode<String>,
+            onClickListener: ((ExpandableTreeNode<String>) -> Unit)? = null
         )
 
     }

app/src/main/java/com/github/adriankuta/MainActivity.kt

@@ -2,6 +2,8 @@ package com.github.adriankuta
 
 import android.os.Bundle
 import androidx.appcompat.app.AppCompatActivity
+import androidx.recyclerview.widget.LinearLayoutManager
+import androidx.recyclerview.widget.RecyclerView
 import com.github.adriankuta.databinding.ActivityMainBinding
 import com.github.adriankuta.expandable_recyclerview.expandableTree
 
@@ -9,29 +11,32 @@ class MainActivity : AppCompatActivity() {
 
     private lateinit var binding: ActivityMainBinding
 
-
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_main)
         binding = ActivityMainBinding.inflate(layoutInflater)
-        setContentView(binding.root)
 
-        val tree = expandableTree(Region("World")) {
-            child(Region("North America")) {
-                child(Region("USA"))
+        val tree = expandableTree("World") {
+            child("North America") {
+                child("USA")
             }
-            child(Region("Europe")) {
-                child(Region("Poland")) {
-                    child(Region("Warsaw"))
+            child("Europe") {
+                child("Poland") {
+                    child("Warsaw")
                 }
-                child(Region("Germany"))
+                child("Germany")
             }
-            child(Region("Asia")) {
-                child(Region("China"))
+            child("Asia") {
+                child("China")
             }
         }
 
-        val adapter = ExpandableAdapter()
-        binding.recyclerView.adapter = adapter
-        adapter.setTree(tree)
+        with(binding) {
+            val adapter = ExpandableAdapter()
+            recyclerView.layoutManager = LinearLayoutManager(this@MainActivity, RecyclerView.VERTICAL, false)
+            recyclerView.adapter = adapter
+
+            adapter.setTree(tree)
+        }
     }
 }

app/src/main/java/com/github/adriankuta/Region.kt

@@ -1,3 +0,0 @@
-package com.github.adriankuta
-
-data class Region(val name: String)

app/src/main/res/layout/activity_main.xml

@@ -10,8 +10,6 @@
         android:id="@+id/recyclerView"
         android:layout_width="0dp"
         android:layout_height="0dp"
-        android:orientation="vertical"
-        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"

app/src/main/res/layout/item_level_1.xml

@@ -1,31 +1,44 @@
 <?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="wrap_content">
+<layout>
 
-    <ImageView
-        android:id="@+id/expand_icon"
-        android:layout_width="24dp"
-        android:layout_height="0dp"
-        android:scaleType="centerInside"
-        android:visibility="gone"
-        app:layout_constraintBottom_toBottomOf="@id/textView"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="@id/textView"
-        tools:src="@drawable/ic_expand_less_black_24dp"
-        tools:visibility="visible" />
+    <data>
 
-    <TextView
-        android:id="@+id/textView"
-        android:layout_width="0dp"
+        <variable
+            name="node"
+            type="com.github.adriankuta.expandable_recyclerview.ExpandableTreeNode&lt;String>" />
+
+        <import type="android.view.View" />
+    </data>
+
+    <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="wrap_content"
-        android:padding="8dp"
-        android:text="@{node.value}"
-        app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toEndOf="@id/expand_icon"
-        app:layout_constraintTop_toTopOf="parent"
-        tools:text="@tools:sample/full_names" />
-</androidx.constraintlayout.widget.ConstraintLayout>
+        tools:viewBindingIgnore="true">
+
+        <ImageView
+            android:id="@+id/expand_icon"
+            android:layout_width="24dp"
+            android:layout_height="0dp"
+            android:scaleType="centerInside"
+            android:src="@{node.expanded ? @drawable/ic_expand_more_black_24dp : @drawable/ic_expand_less_black_24dp}"
+            android:visibility="@{node.children.empty ? View.GONE : View.VISIBLE}"
+            app:layout_constraintBottom_toBottomOf="@id/textView"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toTopOf="@id/textView"
+            tools:src="@drawable/ic_expand_less_black_24dp" />
+
+        <TextView
+            android:id="@+id/textView"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:padding="8dp"
+            android:text="@{node.value}"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toEndOf="@id/expand_icon"
+            app:layout_constraintTop_toTopOf="parent"
+            tools:text="@tools:sample/full_names" />
+    </androidx.constraintlayout.widget.ConstraintLayout>
+</layout>

app/src/main/res/layout/item_level_2.xml

@@ -1,33 +1,46 @@
 <?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="wrap_content">
+<layout>
 
-    <ImageView
-        android:id="@+id/expand_icon"
-        android:layout_width="24dp"
-        android:layout_height="0dp"
-        android:layout_marginStart="24dp"
-        android:scaleType="centerInside"
-        android:visibility="gone"
-        app:layout_constraintBottom_toBottomOf="@id/textView"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="@id/textView"
-        tools:src="@drawable/ic_expand_less_black_24dp"
-        tools:visibility="visible" />
+    <data>
 
-    <TextView
-        android:id="@+id/textView"
-        android:layout_width="0dp"
+        <variable
+            name="node"
+            type="com.github.adriankuta.expandable_recyclerview.ExpandableTreeNode&lt;String>" />
+
+        <import type="android.view.View" />
+    </data>
+
+    <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="wrap_content"
-        android:padding="8dp"
-        android:text="@{node.value}"
-        app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toEndOf="@id/expand_icon"
-        app:layout_constraintTop_toTopOf="parent"
-        app:layout_goneMarginStart="48dp"
-        tools:text="@tools:sample/full_names" />
-</androidx.constraintlayout.widget.ConstraintLayout>
+        tools:viewBindingIgnore="true">
+
+        <ImageView
+            android:id="@+id/expand_icon"
+            android:layout_width="24dp"
+            android:layout_height="0dp"
+            android:layout_marginStart="24dp"
+            android:scaleType="centerInside"
+            android:src="@{node.expanded ? @drawable/ic_expand_more_black_24dp : @drawable/ic_expand_less_black_24dp}"
+            android:visibility="@{node.children.empty ? View.GONE : View.VISIBLE}"
+            app:layout_constraintBottom_toBottomOf="@id/textView"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toTopOf="@id/textView"
+            tools:src="@drawable/ic_expand_less_black_24dp" />
+
+        <TextView
+            android:id="@+id/textView"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:padding="8dp"
+            android:text="@{node.value}"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toEndOf="@id/expand_icon"
+            app:layout_constraintTop_toTopOf="parent"
+            app:layout_goneMarginStart="48dp"
+            tools:text="@tools:sample/full_names" />
+    </androidx.constraintlayout.widget.ConstraintLayout>
+</layout>

app/src/main/res/layout/item_level_3.xml

@@ -1,33 +1,46 @@
 <?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="wrap_content">
+<layout>
 
-    <ImageView
-        android:id="@+id/expand_icon"
-        android:layout_width="24dp"
-        android:layout_height="0dp"
-        android:layout_marginStart="48dp"
-        android:scaleType="centerInside"
-        android:visibility="gone"
-        app:layout_constraintBottom_toBottomOf="@id/textView"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="@id/textView"
-        tools:src="@drawable/ic_expand_less_black_24dp"
-        tools:visibility="visible"/>
+    <data>
 
-    <TextView
-        android:id="@+id/textView"
-        android:layout_width="0dp"
+        <variable
+            name="node"
+            type="com.github.adriankuta.expandable_recyclerview.ExpandableTreeNode&lt;String>" />
+
+        <import type="android.view.View" />
+    </data>
+
+    <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="wrap_content"
-        android:padding="8dp"
-        android:text="@{node.value}"
-        app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toEndOf="@id/expand_icon"
-        app:layout_constraintTop_toTopOf="parent"
-        app:layout_goneMarginStart="96dp"
-        tools:text="@tools:sample/full_names" />
-</androidx.constraintlayout.widget.ConstraintLayout>
+        tools:viewBindingIgnore="true">
+
+        <ImageView
+            android:id="@+id/expand_icon"
+            android:layout_width="24dp"
+            android:layout_height="0dp"
+            android:layout_marginStart="48dp"
+            android:scaleType="centerInside"
+            android:src="@{node.expanded ? @drawable/ic_expand_more_black_24dp : @drawable/ic_expand_less_black_24dp}"
+            android:visibility="@{node.children.empty ? View.GONE : View.VISIBLE}"
+            app:layout_constraintBottom_toBottomOf="@id/textView"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toTopOf="@id/textView"
+            tools:src="@drawable/ic_expand_less_black_24dp" />
+
+        <TextView
+            android:id="@+id/textView"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:padding="8dp"
+            android:text="@{node.value}"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toEndOf="@id/expand_icon"
+            app:layout_constraintTop_toTopOf="parent"
+            app:layout_goneMarginStart="96dp"
+            tools:text="@tools:sample/full_names" />
+    </androidx.constraintlayout.widget.ConstraintLayout>
+</layout>

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 = '1.8.22'
+    ext.kotlin_version = '1.5.30'
     repositories {
         google()
         mavenCentral()
 
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:7.3.1'
+        classpath 'com.android.tools.build:gradle:7.0.2'
         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

expandable-recyclerview/build.gradle

@@ -6,15 +6,14 @@ afterEvaluate {
 }
 
 android {
-    namespace 'com.github.adriankuta.expandable_recyclerview'
-    compileSdkVersion 33
-    buildToolsVersion "33.0.0"
+    compileSdkVersion 31
+    buildToolsVersion "31.0.0"
 
 
     defaultConfig {
         minSdkVersion 23
-        targetSdkVersion 33
-        versionName "2.1.2"
+        targetSdkVersion 31
+        versionName "2.0.0"
 
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         consumerProguardFiles 'consumer-rules.pro'
@@ -31,14 +30,14 @@ android {
 
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
-    implementation 'androidx.appcompat:appcompat:1.6.1'
-    implementation 'androidx.core:core-ktx:1.10.1'
-    api "androidx.recyclerview:recyclerview:1.3.0"
-    api "com.github.adriankuta:tree-structure:3.0.2"
+    implementation 'androidx.appcompat:appcompat:1.3.1'
+    implementation 'androidx.core:core-ktx:1.6.0'
+    implementation "androidx.recyclerview:recyclerview:1.2.1"
+    implementation "com.github.adriankuta:tree-structure:2.0.3"
 
     testImplementation 'junit:junit:4.13.2'
-    androidTestImplementation 'androidx.test.ext:junit:1.1.5'
-    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.3'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
 }
 
 ext {

expandable-recyclerview/src/androidTest/java/com/github/adriankuta/expandable_recyclerview/ExampleInstrumentedTest.kt

@@ -1,11 +1,13 @@
 package com.github.adriankuta.expandable_recyclerview
 
-import androidx.test.ext.junit.runners.AndroidJUnit4
 import androidx.test.platform.app.InstrumentationRegistry
-import org.junit.Assert.*
+import androidx.test.ext.junit.runners.AndroidJUnit4
+
 import org.junit.Test
 import org.junit.runner.RunWith
 
+import org.junit.Assert.*
+
 /**
  * Instrumented test, which will execute on an Android device.
  *

expandable-recyclerview/src/main/AndroidManifest.xml

@@ -1 +1,2 @@
-<manifest />
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.github.adriankuta.expandable_recyclerview" />

expandable-recyclerview/src/main/java/com/github/adriankuta/expandable_recyclerview/ExpandableTreeNode.kt

@@ -7,7 +7,7 @@ class ExpandableTreeNode<T>(value: T) : TreeNode<T>(value) {
 
     var expanded: Boolean = true
 
-    override fun child(value: T, childDeclaration: ChildDeclaration<T>?): ExpandableTreeNode<T> {
+    override fun child(value: T, childDeclaration: ChildDeclaration<T>?) : ExpandableTreeNode<T> {
         val newChild = ExpandableTreeNode(value)
         if (childDeclaration != null)
             newChild.childDeclaration()

expandable-recyclerview/src/test/java/com/github/adriankuta/expandable_recyclerview/ExampleUnitTest.kt

@@ -1,8 +1,9 @@
 package com.github.adriankuta.expandable_recyclerview
 
-import org.junit.Assert.assertEquals
 import org.junit.Test
 
+import org.junit.Assert.*
+
 /**
  * Example local unit test, which will execute on the development machine (host).
  *

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-7.4-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.0.2-all.zip