Improve layouts

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

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
-<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<FrameLayout
+		xmlns:android="http://schemas.android.com/apk/res/android"
 		android:id="@+id/container"
 		android:layout_width="match_parent"
 		android:layout_height="match_parent">

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

@@ -2,24 +2,34 @@
 <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">
 
-    <TextView
+	<androidx.appcompat.widget.Toolbar
+			android:id="@+id/toolbar"
+			android:layout_width="match_parent"
+			android:layout_height="?attr/actionBarSize"
+			app:layout_constraintEnd_toEndOf="parent"
+			app:layout_constraintStart_toStartOf="parent"
+			app:layout_constraintTop_toTopOf="parent"
+			app:title="@string/app_name"/>
+
+	<androidx.appcompat.widget.AppCompatTextView
 			android:id="@+id/text"
 			android:textColor="@color/white"
 			android:layout_width="wrap_content"
 			android:layout_height="wrap_content"
 			app:layout_constraintEnd_toEndOf="parent"
-            app:layout_constraintStart_toStartOf="parent"
 			android:layout_marginStart="8dp"
-            app:layout_constraintTop_toTopOf="@+id/chart"
-            android:layout_marginTop="8dp"/>
+			android:layout_marginTop="8dp"
+			app:layout_constraintStart_toStartOf="parent"
+			app:layout_constraintTop_toBottomOf="@+id/toolbar"/>
 
 	<com.github.mikephil.charting.charts.LineChart
 			android:id="@+id/chart"
-            android:layout_width="match_parent"
-            android:layout_height="match_parent"/>
+			android:layout_width="50dp"
+			android:layout_height="50dp" app:layout_constraintTop_toBottomOf="@+id/toolbar" android:layout_marginBottom="8dp"
+			app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" android:layout_marginEnd="8dp"
+			app:layout_constraintStart_toStartOf="parent" android:layout_marginStart="8dp"/>
 
 </androidx.constraintlayout.widget.ConstraintLayout>