When an app has layout content that might be longer than the height of the device and that content should be vertically scrollable, then we need to use a ScrollView.
To make any content vertically scrollable, simply wrap that content in a ScrollView:
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TextView
android:id="@+id/tv_long"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="@string/really_long_string" >
</TextView>
<Button
android:id="@+id/btn_act"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="View" >
</Button>
</LinearLayout>
</ScrollView>Note that a ScrollView can only contain a single child element so if you need multiple things to be scrollable, you need to wrap that content into a layout as shown above.
In certain situations, you want to position content beneath the end of the scrollable content area. For example for a "terms of service" where you can only accept once you've scrolled through all the content. In this case, you might need to apply the android:fillViewport property to "true". Read this post by Romain Guy for a detailed look at this use case.
Note that a TextView doesn't require a ScrollView and if you just need a scrolling TextView simply set the scrollbars property and apply the correct MovementMethod:
<TextView
android:id="@+id/tv_long"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:scrollbars = "vertical"
android:text="@string/really_long_string" >
</TextView>and then in the activity:
TextView tv = (TextView) findViewById(R.id.tv_long);
tv.setMovementMethod(new ScrollingMovementMethod());Now the TextView will automatically scroll vertically.
In other cases, we want content to horizontally scroll in which case we need to use the HorizontalScrollView instead like this:
<HorizontalScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<!-- child views in here -->
</LinearLayout>
</HorizontalScrollView>and now you have a horizontally scrolling view.
Adding a ScrollView within another ScrollView can be difficult. Most of the times it won’t end well. You will end up adding few workarounds. Instead, use the NestedScrollView as outlined here. A working sample can be found here as this is very useful when working with CoordinatorLayout
