Salih Erikci Salih Erikci - 5 months ago 36
Android Question

ScrollView auto scrolls to selectable TextView

I have a vertical

LinearLayout
inside a
ScrollView
. Everything was ok till setting the third
TextView
in
LinearLayout
selectable
.

After this change it auto scrolls to the third TextView.

What can cause the problem?

Before and after the change:

enter image description here enter image description here

the layout

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/roota_view"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_gravity="right"
android:orientation="vertical" >

<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.saliherikci.poemnotebook.ReadPoemActivity$PlaceholderFragment" >

<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:focusable="false"
android:focusableInTouchMode="false"
android:orientation="vertical" >

<TextView
android:id="@+id/poemTitleTextView"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Çanakkale Şehitlerine"
android:textColor="@color/poem_title"
android:textSize="24dp" />

<TextView
android:id="@+id/poemAuthorTextView"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="5dp"
android:text="Mehmet Akif ERSOY"
android:textAppearance="?android:attr/textAppearanceSmall"
android:textSize="11dp" />

<TextView
android:id="@+id/poemContentTextView"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Şu Boğaz harbi nedir? Var mı ki dünyâda eşi? "
android:textColor="@color/poem_content"
android:textIsSelectable="true"
android:textSize="10dp" />
</LinearLayout>
</ScrollView>

<LinearLayout
android:id="@+id/fontSizeView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="top|right"
android:background="@color/font_size_background"
android:orientation="vertical"
android:paddingBottom="5dp"
android:paddingLeft="15dp"
android:paddingRight="15dp"
android:paddingTop="5dp"
android:visibility="invisible" >

<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="top|right"
android:text="YAZI BOYUTU"
android:textAppearance="?android:attr/textAppearanceSmall"
android:textColor="#1a1a1a"
android:textSize="8dp" />

<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="top|right"
android:layout_marginTop="5dp"
android:dividerPadding="5dp"
android:orientation="horizontal"
android:showDividers="middle" >

<ImageButton
android:id="@+id/font_size_1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:background="@null"
android:src="@drawable/ic_font_size_black_1_active" />

<ImageButton
android:id="@+id/font_size_2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:layout_marginLeft="20dp"
android:background="@null"
android:src="@drawable/ic_font_size_black_2_inactive" />

<ImageButton
android:id="@+id/font_size_3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:layout_marginLeft="20dp"
android:background="@null"
android:src="@drawable/ic_font_size_black_3_inactive" />

<ImageButton
android:id="@+id/font_size_4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:layout_marginLeft="20dp"
android:background="@null"
android:src="@drawable/ic_font_size_black_4_inactive" />

<ImageButton
android:id="@+id/font_size_5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:background="@null"
android:src="@drawable/ic_font_size_black_5_inactive" />
</LinearLayout>
</LinearLayout>

</FrameLayout>

Answer

You're automatically scrolling to your third TextView because SrollView makes a call to ScrollView.scrollToChild upon ViewParent.requestChildFocus.

As per the docs is:

Called when a child of this parent wants focus

When you use android:textIsSelectable="true", you're essentially calling TextView.setTextIsSelectable(true), which makes calls to both View.setFocusable and View.setFocusableInTouchMode.

In short, to stop from automatically scrolling to your third TextView, give the first one some focus.

<TextView
    android:id="@+id/poemTitleTextView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:focusable="true"
    android:focusableInTouchMode="true"
    android:text="Çanakkale Şehitlerine"
    android:textColor="@color/poem_title"
    android:textSize="24dp"  />