Worked on the show tooltip in dialogfragment. Added example too.

app/build.gradle

@@ -1,4 +1,6 @@
 apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android-extensions'
+apply plugin: 'kotlin-android'
 
 android {
     compileSdkVersion project.COMPILE_SDK
@@ -15,6 +17,13 @@ android {
 
 dependencies {
     implementation 'androidx.appcompat:appcompat:1.0.2'
-    implementation 'com.github.florent37:viewtooltip:1.1.8'
-    //implementation project(path: ':viewtooltip')
+//    implementation 'com.github.florent37:viewtooltip:1.1.8'
+    implementation "androidx.core:core-ktx:+"
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
+    implementation project(path: ':viewtooltip')
+    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
+
+}
+repositories {
+    mavenCentral()
 }

app/src/main/java/florent37/github/com/viewtooltip/DialogFragmentInfo.kt

@@ -0,0 +1,41 @@
+package florent37.github.com.viewtooltip
+
+import android.app.Dialog
+import android.os.Bundle
+import android.util.Log
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.Button
+import androidx.fragment.app.DialogFragment
+import com.github.florent37.viewtooltip.ViewTooltip
+
+class DialogFragmentInfo : DialogFragment() {
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
+        val v = inflater.inflate(R.layout.dialog_fragment, container, false).also {
+
+
+            it.findViewById<Button>(R.id.top).setOnClickListener(View.OnClickListener {
+                ViewTooltip
+                        .on(this,  it.findViewById<Button>(R.id.top))
+                        // .customView(customView)
+                        .position(ViewTooltip.Position.TOP)
+                        .arrowSourceMargin(0)
+                        .arrowTargetMargin(0)
+                        .text(resources.getString(R.string.lorem))
+                        .clickToHide(true)
+                        .autoHide(false, 0)
+                        .animation(ViewTooltip.FadeTooltipAnimation(500))
+                        .onDisplay(ViewTooltip.ListenerDisplay { Log.d("ViewTooltip", "onDisplay") })
+                        .onHide({ Log.d("ViewTooltip", "onHide") })
+                        .show()
+            })
+        }
+        return v
+    }
+
+    override fun getDialog(): Dialog {
+        return super.getDialog()
+        dialog.getWindow().setLayout(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT)
+    }
+}

app/src/main/java/florent37/github/com/viewtooltip/MainActivity.java

@@ -124,6 +124,8 @@ public void onClick(View v) {
                         .position(ViewTooltip.Position.TOP)
                         .text("bottomLeft bottomLeft bottomLeft")
                         .show();
+                DialogFragmentInfo d = new DialogFragmentInfo();
+                d.show(MainActivity.this.getSupportFragmentManager(), "");
             }
         });
     }

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

@@ -0,0 +1,24 @@
+<?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"
+    android:gravity="center"
+    android:orientation="vertical"
+    >
+    <View
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"/>
+
+    <Button
+        android:id="@+id/top"
+        android:layout_width="100dp"
+        android:layout_height="50dp"
+        android:layout_marginEnd="8dp"
+        android:layout_marginBottom="8dp"
+        android:text="Button"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent" />
+</androidx.constraintlayout.widget.ConstraintLayout>

build.gradle

@@ -1,4 +1,5 @@
 buildscript {
+    ext.kotlin_version = '1.3.41'
     repositories {
         jcenter()
         google()
@@ -7,6 +8,7 @@ buildscript {
         classpath 'com.android.tools.build:gradle:3.2.1'
         classpath 'com.github.dcendents:android-maven-gradle-plugin:2.1'
         classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.8.0'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }
 
@@ -20,7 +22,7 @@ allprojects {
 ext{
     COMPILE_SDK=28
     TARGET_SDK=28
-    MIN_SDK = 14
+    MIN_SDK = 26
     sourceCompatibilityVersion = JavaVersion.VERSION_1_8
     targetCompatibilityVersion = JavaVersion.VERSION_1_8
 

viewtooltip/src/main/java/com/github/florent37/viewtooltip/ViewTooltip.java

@@ -21,6 +21,7 @@
 import androidx.fragment.app.Fragment;
 
 import android.text.Html;
+import android.util.Log;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewTreeObserver;
@@ -39,9 +40,10 @@ public class ViewTooltip {
     private View rootView;
     private final View view;
     private final TooltipView tooltip_view;
-
+    private MyContext myContext;
     private ViewTooltip(MyContext myContext, View view) {
         this.view = view;
+        this.myContext = myContext;
         this.tooltip_view = new TooltipView(myContext.getContext());
         final NestedScrollView scrollParent = findScrollParent(view);
         if (scrollParent != null) {
@@ -164,8 +166,8 @@ public TooltipView show() {
         if (activityContext != null && activityContext instanceof Activity) {
             final ViewGroup decorView = rootView != null ?
                     (ViewGroup) rootView :
-                    (ViewGroup) ((Activity) activityContext).getWindow().getDecorView();
-
+//                    (ViewGroup) ((Activity) activityContext).getWindow().getDecorView();
+                    (ViewGroup) myContext.getWindow().getDecorView();
             view.postDelayed(new Runnable() {
                 @Override
                 public void run() {