Android ScrollView set height for displayed content

Question

I'm having a lot of trouble trying solve the issue of having a static height scrollable area within a layout. I have three long lists that need to be displayed on the same screen and it would be entirely impractical to display all of the entries sequentially because then if you want to skip a category you need to scroll past possibly hundreds of entries.

Assume I have a scroll view with a Linear Layout inside of it, I want this to take up say, 250dp height on the screen at max and be independently scrollable once populated with more entries than can fit in 250dp's space.

What I have now is:

<ScrollView
    android:minWidth="25px"
    android:minHeight="150px"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:id="@+id/XXXXXXX"
    android:scrollbars="vertical">

    <LinearLayout
        android:orientation="vertical"
        android:minWidth="25px"
        android:minHeight="25px"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/XXXXXX" />
</ScrollView>

When populated, the scrollview and linearlayout just stretch as long as they needs to to fit the content and displays all of it instead of having a "window" of 250dp/px (any measurment would be nice) with the content scrollable within it.

I'm new to the android platform, so perhaps the answer is obvious and I just didn't understand the language, but any help would be greatly appreciated! Thank you

--- SOLVED: Put a linearLayout outside of the ScrollView with the height.

Answer 1

With some help from this answer I managed to wrap up a very basic ScrollView component you can use for this case:

Create a custom class extending a ScrollView and do the following modifications:

public class MaxHeightScrollView extends ScrollView {

    private int maxHeight;

    public MaxHeightScrollView(Context context) {
        super(context);
    }

    public MaxHeightScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs);
    }

    public MaxHeightScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs);
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public MaxHeightScrollView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        init(context, attrs);
    }

    private void init(Context context, AttributeSet attrs) {
        if (attrs != null) {
            TypedArray styledAttrs = context.obtainStyledAttributes(attrs, R.styleable.MaxHeightScrollView);
            maxHeight = styledAttrs.getDimensionPixelSize(R.styleable.MaxHeightScrollView_maxHeight, 200); //200 is a default value
            styledAttrs.recycle();
        }
    }

   @Override
   protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
       heightMeasureSpec = MeasureSpec.makeMeasureSpec(maxHeight, MeasureSpec.AT_MOST);
       super.onMeasure(widthMeasureSpec, heightMeasureSpec);
   }
}

And then one minor thing left is to declare your styleable in the attrs.xml file of your values folder(If you don't have one, just create an xml file with this name in the values folder of your project's res folder). Add the following lines there:

<declare-styleable name="MaxHeightScrollView">
    <attr name="maxHeight" format="dimension" />
</declare-styleable>

And use your new ScrollView as follows:

<com.yourpackage.MaxHeightScrollView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:maxHeight="300dp">
</com.yourpackage.MaxHeightScrollView>

Credits go to whizzle for quickly wrapping this up!