webview going under the toolbar

As the title implies the WebView is under th toolbar. When I started the project the toolbar appears in the app but is not coded. This toolbar behaves badly as when I access a full screen video and then I go back a white space apperas between the statusbar and the toolbar. Enter the coded toolbar.

Java code:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    WebView myWebView = (WebView) findViewById(R.id.webview);
    WebSettings webSettings = myWebView.getSettings();
    webSettings.setJavaScriptEnabled(true);
    webSettings.setAllowFileAccess(true);
    webSettings.setAppCacheEnabled(true);
    myWebView.loadUrl("https://www.tn.com.ar");
    myWebView.setWebViewClient(new WebViewClient() {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
            return false;
        }
    });
    myWebView.setWebChromeClient(new ChromeClient());

Layout

<?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=".MainActivity">

    <com.google.android.material.appbar.AppBarLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <androidx.appcompat.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="?attr/colorPrimary"
            android:minHeight="?attr/actionBarSize"
            android:theme="?attr/actionBarTheme"
            />

    </com.google.android.material.appbar.AppBarLayout>

    <WebView
        android:id="@+id/webview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        />

</androidx.constraintlayout.widget.ConstraintLayout>

>Solution :

You need to apply proper constraints to your WebView like this

Try this

<?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=".MainActivity">

  <com.google.android.material.appbar.AppBarLayout
      android:id="@+id/appbar"
      android:layout_width="0dp"
      android:layout_height="wrap_content"
      app:layout_constraintEnd_toEndOf="parent"
      app:layout_constraintStart_toStartOf="parent"
      app:layout_constraintTop_toTopOf="parent">

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/colorPrimary"
        android:minHeight="?attr/actionBarSize"
        android:theme="?attr/actionBarTheme"
        />

  </com.google.android.material.appbar.AppBarLayout>

  <WebView
      android:id="@+id/webview"
      android:layout_width="match_parent"
      android:layout_height="0dp"
      app:layout_constraintStart_toStartOf="parent"
      app:layout_constraintBottom_toBottomOf="parent"
      app:layout_constraintEnd_toEndOf="parent"
      app:layout_constraintTop_toBottomOf="@id/appbar"
      />

</androidx.constraintlayout.widget.ConstraintLayout>