AdapterView Must Not Declare Inline Children

ID

kotlin.android_adapter_children

Severity

low

Remediation Complexity

trivial

Remediation Risk

low

Remediation Effort

low

Resource

Reliability

Language

Kotlin

Tags

android, reliability

Description

Reports AdapterView subclasses (ListView, GridView, Spinner, Gallery, ExpandableListView) that declare inline child elements in Android layout XML files. The Android framework silently ignores any children declared in XML for these views because their content is populated programmatically via an Adapter.

Rationale

AdapterView is designed to be populated at runtime by an Adapter that maps data to child views on demand. When developers add child elements directly inside a ListView or GridView in XML, those children are silently discarded. The UI appears empty, leading to confusion.

<!-- Bad: ListView with inline children (silently ignored) -->
<ListView
    android:id="@+id/list"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="This text is never displayed" />
</ListView>

Remediation

Remove all inline children from the AdapterView element. Instead, define the item layout in a separate XML file and supply it through an Adapter in your Activity or Fragment code.

<!-- Good: empty AdapterView, populated by adapter -->
<ListView
    android:id="@+id/list"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" />
// Populate the ListView programmatically
val list = findViewById<ListView>(R.id.list)
val adapter = ArrayAdapter(this, android.R.layout.simple_list_item_1, items)
list.adapter = adapter

References