Why doesn't this HorizontalScrollView fills the parent?

Question

I've made a layout that worked fine with a vertical scroll view, but I need to make another one with a horizontal scroll view. I just changed ScrollView to HorizontalScrollView:

        <?xml version="1.0" encoding="utf-8"?>
        <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical" >

            <HorizontalScrollView
                android:layout_weight="1"
                android:scrollbars="none"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content" >

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:orientation="vertical" >
               <RelativeLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content" >

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_centerVertical="true"
                    android:layout_marginLeft="10dp"
                    android:text="@string/activity_visibilidade_cronologia_aula_subtitulo"
                    android:textSize="16dp" />

                <ImageButton
                    android:id="@+id/activity_visibilidade_cronologia_aula_btn_info"
                    android:layout_width="32dp"
                    android:layout_height="32dp"
                    android:layout_alignParentRight="true"
                    android:layout_marginRight="10dp"
                    android:background="@null"
                    android:scaleType="fitXY"
                    android:src="@drawable/btn_info" />
            </RelativeLayout>

            <LinearLayout
                android:id="@+id/activity_visibilidade_cronologia_aula_linear_conteudo"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical" >
            </LinearLayout>

            <Button
                android:id="@+id/activity_visibilidade_cronologia_aula_btn_confimar"
                android:layout_width="165dp"
                android:layout_height="35dp"
                android:layout_centerVertical="true"
                android:layout_gravity="right"
                android:layout_marginBottom="10dp"
                android:layout_marginRight="10dp"
                android:layout_marginTop="10dp"
                android:background="@drawable/botao_add_confirmar"
                android:text="@string/dialogo_alterar_classe_confirmar"
                android:textColor="@color/branco" />
        </LinearLayout>
    </HorizontalScrollView>

</LinearLayout>

And its result is:

Why doesn't HorizontalScrollView fills the parent, is there something wrong?

Answer 1

I solved merging all your advices and also using android:fillViewport="true" my final code is:

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <include layout="@layout/layout_titulo_views" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical" >

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content" >

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:layout_marginLeft="10dp"
                android:text="@string/activity_visibilidade_cronologia_aula_subtitulo"
                android:textSize="16dp" />

            <ImageButton
                android:id="@+id/activity_visibilidade_cronologia_aula_btn_info"
                android:layout_width="32dp"
                android:layout_height="32dp"
                android:layout_alignParentRight="true"
                android:layout_marginRight="10dp"
                android:background="@null"
                android:scaleType="fitXY"
                android:src="@drawable/btn_info" />
        </RelativeLayout>

        <HorizontalScrollView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:fillViewport="true"
            android:scrollbars="horizontal" >

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal" >

                <LinearLayout
                    android:id="@+id/activity_visibilidade_cronologia_aula_linear_conteudo"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:orientation="vertical" >
                </LinearLayout>
            </LinearLayout>
        </HorizontalScrollView>

        <Button
            android:id="@+id/activity_visibilidade_cronologia_aula_btn_confimar"
            android:layout_width="165dp"
            android:layout_height="35dp"
            android:layout_centerVertical="true"
            android:layout_gravity="right"
            android:layout_marginBottom="10dp"
            android:layout_marginRight="10dp"
            android:layout_marginTop="10dp"
            android:background="@drawable/botao_add_confirmar"
            android:text="@string/dialogo_alterar_classe_confirmar"
            android:textColor="@color/branco" />
    </LinearLayout>

</LinearLayout>

Thank you all

Answer 2

I found teh problem. In addition to removing the weight sum, you need to change the linear layout orientation to horizontal.

<LinearLayout
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="horizontal" >