Sticky headers in Android Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set a sticky header in a RecyclerView using a LayoutManager.

Android Kotlin

recyclerView.layoutManager = [1]

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AStaggeredGridLayoutManager(2, LinearLayoutManager.VERTICAL)

BLinearLayoutManager(this)

CGridLayoutManager(this, 2)

DFlexboxLayoutManager(this)

Attempts:

3 left

💡 Hint

Common Mistakes

Using GridLayoutManager when a simple vertical list is needed.

Forgetting to assign a LayoutManager to the RecyclerView.

LinearLayoutManager arranges items vertically or horizontally and is commonly used with sticky headers.

2fill in blank

medium

Complete the code to create a sticky header by attaching an ItemDecoration to the RecyclerView.

Android Kotlin

val stickyHeaderDecoration = [1](adapter)
recyclerView.addItemDecoration(stickyHeaderDecoration)

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ASnapHelper

BDividerItemDecoration

CItemTouchHelper

DStickyHeaderItemDecoration

Attempts:

3 left

💡 Hint

Common Mistakes

Using DividerItemDecoration which only draws dividers, not sticky headers.

Confusing ItemTouchHelper with decorations.

StickyHeaderItemDecoration is a custom or library class used to create sticky headers in RecyclerView.

3fill in blank

hard

Fix the error in the adapter method to provide header IDs for sticky headers.

Android Kotlin

override fun getHeaderId(position: Int): Long {
    return [1]
}

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A-1L

B0L

Citems[position].headerId

Dposition.toLong()

Attempts:

3 left

💡 Hint

Common Mistakes

Returning position.toLong() which treats each item as a separate header.

Returning 0L which groups all items under one header.

Returning the headerId from the item at the given position groups items under the same header.

4fill in blank

hard

Fill both blanks to implement the onDrawOver method for drawing sticky headers.

Android Kotlin

override fun onDrawOver(c: Canvas, parent: RecyclerView, state: RecyclerView.State) {
    val topChild = parent.getChildAt(0) ?: return
    val topChildPosition = parent.getChildAdapterPosition(topChild)
    val header = [1](parent, topChildPosition)
    val contactPoint = header.bottom
    val childInContact = parent.[2](parent.width / 2f, contactPoint)
    // Draw header logic here
}

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AgetHeaderView

BfindChildViewUnder

CgetChildAt

DgetChildAdapterPosition

Attempts:

3 left

💡 Hint

Common Mistakes

Using getChildAt instead of findChildViewUnder for contact point detection.

Confusing getChildAdapterPosition with getHeaderView.

getHeaderView gets the header view for the position, and findChildViewUnder finds the child view at a specific y coordinate.

5fill in blank

hard

Fill all three blanks to complete the sticky header touch event handling.

Android Kotlin

override fun onInterceptTouchEvent(rv: RecyclerView, e: MotionEvent): Boolean {
    val headerView = rv.[1](e.x, e.y)
    if (headerView != null) {
        val position = rv.getChildAdapterPosition(headerView)
        [2](position)
        return true
    }
    return false
}

fun [3](position: Int) {
    // Handle header click
}

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AfindChildViewUnder

BonHeaderClick

CnotifyHeaderClick

DhandleHeaderClick

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong method names for click handling.

Not checking if headerView is null before proceeding.

findChildViewUnder locates the header view under touch, onHeaderClick is called on click, and handleHeaderClick defines the click behavior.