title: Android Login Screen Constraint Layout
body: <p>I am new to Android Studio and I am looking at a project an acquaintance did. See attached activity_login.xml shot.</p>
  <p><a href="https://i.stack.imgur.com/PtGfW.png" rel="nofollow noreferrer">Login Screen</a></p>
  <p>See also XML behind. Question is. What is this line(red arrow) and Why can't I add items to the bottom of the line and why can't I increase the Constraint Layout height any further? I'm new to this and this has me stumpt. Please help or show me where to look.</p>
  <pre><code>&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
  &lt;androidx.constraintlayout.widget.ConstraintLayout
  xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
  xmlns:app=&quot;http://schemas.android.com/apk/res-auto&quot;
  xmlns:tools=&quot;http://schemas.android.com/tools&quot;
  android:id=&quot;@+id/container&quot;
  android:layout_width=&quot;match_parent&quot;
  android:layout_height=&quot;match_parent&quot;
  tools:context=&quot;.views.activity.LoginActivity&quot;&gt;
  
  &lt;ScrollView
      android:layout_width=&quot;match_parent&quot;
      android:layout_height=&quot;match_parent&quot;
      android:scrollbars=&quot;vertical&quot;&gt;
  
      &lt;androidx.constraintlayout.widget.ConstraintLayout
          android:layout_width=&quot;match_parent&quot;
          android:layout_height=&quot;wrap_content&quot;&gt;
  
          &lt;!--  &lt;include layout=&quot;@layout/toolbar_layout&quot;/&gt;--&gt;
  
          &lt;ImageView
              android:id=&quot;@+id/logo&quot;
              android:layout_width=&quot;wrap_content&quot;
              android:layout_height=&quot;wrap_content&quot;
              android:layout_marginTop=&quot;@dimen/dimen_margin_90&quot;
              android:src=&quot;@drawable/logo_splash&quot;
              app:layout_constraintEnd_toEndOf=&quot;parent&quot;
              app:layout_constraintStart_toStartOf=&quot;parent&quot;
              app:layout_constraintTop_toTopOf=&quot;parent&quot; /&gt;
  
          &lt;EditText
              android:id=&quot;@+id/username&quot;
              android:layout_width=&quot;0dp&quot;
              android:layout_height=&quot;wrap_content&quot;
              android:layout_marginStart=&quot;@dimen/dimen_margin_20&quot;
              android:layout_marginTop=&quot;@dimen/dimen_margin_50&quot;
              android:layout_marginEnd=&quot;@dimen/dimen_margin_20&quot;
              android:background=&quot;@drawable/edt_custom_bg&quot;
              android:fontFamily=&quot;@font/roboto&quot;
              android:hint=&quot;@string/prompt_email&quot;
              android:inputType=&quot;text&quot;
              android:padding=&quot;@dimen/dimen_margin_10&quot;
              android:selectAllOnFocus=&quot;true&quot;
              android:textColor=&quot;@color/tertiary_text_color&quot;
              android:textColorHint=&quot;@color/primary_hint_text_color&quot;
              android:textSize=&quot;@dimen/size_18&quot;
              app:layout_constraintEnd_toEndOf=&quot;parent&quot;
              app:layout_constraintStart_toStartOf=&quot;parent&quot;
              app:layout_constraintTop_toBottomOf=&quot;@+id/logo&quot; /&gt;
  
          &lt;!--&lt;EditText
              android:id=&quot;@+id/password&quot;
              android:layout_width=&quot;0dp&quot;
              android:layout_height=&quot;wrap_content&quot;
              android:layout_marginStart=&quot;@dimen/dimen_margin_20&quot;
              android:layout_marginEnd=&quot;@dimen/dimen_margin_20&quot;
              android:layout_marginTop=&quot;@dimen/dimen_margin_20&quot;
              android:hint=&quot;@string/prompt_password&quot;
              android:imeActionLabel=&quot;@string/action_sign_in_short&quot;
              android:imeOptions=&quot;actionDone&quot;
              android:inputType=&quot;textPassword&quot;
              android:selectAllOnFocus=&quot;true&quot;
              app:layout_constraintEnd_toEndOf=&quot;parent&quot;
              app:layout_constraintStart_toStartOf=&quot;parent&quot;
              app:layout_constraintTop_toBottomOf=&quot;@+id/username&quot;
              android:background=&quot;@drawable/edt_custom_bg&quot;
              android:fontFamily=&quot;@font/roboto&quot;
              android:textSize=&quot;@dimen/size_18&quot;
              android:autoLink=&quot;all&quot;
              app:passwordToggleEnabled=&quot;true&quot;
              android:padding=&quot;@dimen/dimen_margin_10&quot;
              android:textColor=&quot;@color/tertiary_text_color&quot;
              android:textColorHint=&quot;@color/primary_hint_text_color&quot;
              /&gt;
      --&gt;
  
  
          &lt;RelativeLayout
              android:id=&quot;@+id/rl_pass&quot;
              android:layout_width=&quot;match_parent&quot;
              android:layout_height=&quot;wrap_content&quot;
              android:layout_marginStart=&quot;@dimen/dimen_margin_20&quot;
              android:layout_marginTop=&quot;@dimen/dimen_margin_20&quot;
              android:layout_marginEnd=&quot;@dimen/dimen_margin_20&quot;
              android:background=&quot;@drawable/edt_custom_bg&quot;
              app:layout_constraintEnd_toEndOf=&quot;parent&quot;
              app:layout_constraintStart_toStartOf=&quot;parent&quot;
              app:layout_constraintTop_toBottomOf=&quot;@+id/username&quot;&gt;
  
              &lt;EditText
                  android:id=&quot;@+id/password&quot;
                  android:layout_width=&quot;match_parent&quot;
                  android:layout_height=&quot;wrap_content&quot;
                  android:layout_marginEnd=&quot;@dimen/dimen_margin_10&quot;
                  android:layout_toStartOf=&quot;@+id/show_pass_btn&quot;
                  android:autoLink=&quot;all&quot;
                  android:background=&quot;@null&quot;
                  android:fontFamily=&quot;@font/roboto&quot;
                  android:hint=&quot;@string/prompt_password&quot;
                  android:imeActionLabel=&quot;@string/action_sign_in_short&quot;
                  android:imeOptions=&quot;actionDone&quot;
                  android:inputType=&quot;textPassword&quot;
                  android:padding=&quot;@dimen/dimen_margin_10&quot;
                  android:selectAllOnFocus=&quot;true&quot;
                  android:textColor=&quot;@color/tertiary_text_color&quot;
                  android:textColorHint=&quot;@color/primary_hint_text_color&quot;
                  android:textSize=&quot;@dimen/size_18&quot;
                  app:passwordToggleEnabled=&quot;true&quot; /&gt;
  
              &lt;ImageView
                  android:id=&quot;@+id/show_pass_btn&quot;
                  android:layout_width=&quot;@dimen/dimen_margin_40&quot;
                  android:layout_height=&quot;@dimen/dimen_margin_40&quot;
                  android:layout_alignParentEnd=&quot;true&quot;
                  android:layout_centerVertical=&quot;true&quot;
                  android:layout_marginEnd=&quot;@dimen/dimen_margin_5&quot;
                  android:onClick=&quot;ShowHidePass&quot;
                  android:padding=&quot;@dimen/dimen_margin_5&quot;
                  android:src=&quot;@drawable/ic_eye_disable&quot; /&gt;
          &lt;/RelativeLayout&gt;
  
          &lt;Button
              android:id=&quot;@+id/login&quot;
              android:layout_width=&quot;wrap_content&quot;
              android:layout_height=&quot;wrap_content&quot;
              android:layout_gravity=&quot;start&quot;
              android:layout_marginStart=&quot;@dimen/dimen_margin_50&quot;
              android:layout_marginTop=&quot;@dimen/dimen_margin_40&quot;
              android:layout_marginEnd=&quot;@dimen/dimen_margin_50&quot;
              android:background=&quot;@drawable/btn_bg&quot;
              android:fontFamily=&quot;@font/roboto_bold&quot;
              android:paddingStart=&quot;@dimen/dimen_margin_20&quot;
              android:paddingEnd=&quot;@dimen/dimen_margin_20&quot;
              android:text=&quot;@string/action_sign_in&quot;
              android:textColor=&quot;@color/button_text_color&quot;
              android:textSize=&quot;@dimen/size_16&quot;
              app:layout_constraintBottom_toBottomOf=&quot;parent&quot;
              app:layout_constraintEnd_toEndOf=&quot;parent&quot;
              app:layout_constraintStart_toStartOf=&quot;parent&quot;
              app:layout_constraintTop_toBottomOf=&quot;@+id/rl_pass&quot;
              app:layout_constraintVertical_bias=&quot;0.2&quot; /&gt;
  
  
          &lt;TextView
              android:id=&quot;@+id/forgot_pass&quot;
              style=&quot;@style/Widget.AppCompat.Button.Borderless.Colored&quot;
              android:layout_width=&quot;wrap_content&quot;
              android:layout_height=&quot;wrap_content&quot;
              android:layout_gravity=&quot;start&quot;
              android:layout_marginStart=&quot;@dimen/dimen_margin_50&quot;
              android:layout_marginTop=&quot;@dimen/dimen_margin_20&quot;
              android:layout_marginEnd=&quot;@dimen/dimen_margin_50&quot;
              android:fontFamily=&quot;@font/roboto_bold&quot;
              android:paddingStart=&quot;@dimen/dimen_margin_20&quot;
              android:paddingEnd=&quot;@dimen/dimen_margin_20&quot;
              android:text=&quot;@string/action_forgot_pass&quot;
              android:textAllCaps=&quot;false&quot;
              android:textColor=&quot;@color/tertiary_text_color&quot;
              android:textSize=&quot;@dimen/size_16&quot;
              app:layout_constraintBottom_toBottomOf=&quot;parent&quot;
              app:layout_constraintEnd_toEndOf=&quot;parent&quot;
              app:layout_constraintStart_toStartOf=&quot;parent&quot;
              app:layout_constraintTop_toBottomOf=&quot;@+id/login&quot;
              app:layout_constraintVertical_bias=&quot;0.2&quot; /&gt;
  
          &lt;ProgressBar
              android:id=&quot;@+id/loading&quot;
              android:layout_width=&quot;wrap_content&quot;
              android:layout_height=&quot;wrap_content&quot;
              android:layout_gravity=&quot;center&quot;
              android:layout_marginStart=&quot;32dp&quot;
              android:layout_marginTop=&quot;64dp&quot;
              android:layout_marginEnd=&quot;32dp&quot;
              android:layout_marginBottom=&quot;64dp&quot;
              android:visibility=&quot;gone&quot;
              app:layout_constraintBottom_toBottomOf=&quot;parent&quot;
              app:layout_constraintEnd_toEndOf=&quot;@+id/rl_pass&quot;
              app:layout_constraintStart_toStartOf=&quot;@+id/rl_pass&quot;
              app:layout_constraintTop_toTopOf=&quot;parent&quot;
              app:layout_constraintVertical_bias=&quot;0.3&quot; /&gt;
  
          &lt;TextView
              android:id=&quot;@+id/textView&quot;
              android:layout_width=&quot;0dp&quot;
              android:layout_height=&quot;0dp&quot;
              android:text=&quot;TextView&quot;
              app:layout_constraintBottom_toBottomOf=&quot;parent&quot;
              tools:layout_editor_absoluteX=&quot;0dp&quot; /&gt;
  
      &lt;/androidx.constraintlayout.widget.ConstraintLayout&gt;
  
  &lt;/ScrollView&gt;
  </code></pre>
  <p>&lt;/androidx.constraintlayout.widget.ConstraintLayout&gt;</p>