ConstraintLayout remains the recommended layout for achieving responsive design across various screen sizes.

To handle specific screen configurations, create alternative layout files in directories like res/layout-w600dp/. In Android Studio 3.0+, generate these by opening the default layout, clicking the Orientation for Preview icon, and selecting Create Other to add screen qualifiers such as minimum width.

Minimum width qualifiers define the smallest screen dimension in density-independant pixels (dp), independent of oreintation. Common breakpoints include:

• 320dp: typical phone screens
• 480dp: large phones around 5 inches
• 600dp: 7-inch tablets
• 720dp: 10-inch tablets

These values represent the window space available to the activity, accounting for system UI elements and multi-window mode.

For backward compatibility with versions before and after Android 3.2, use layout aliases to avoid duplicating files. Define a single-pane layout in res/layout/main.xml and a two-pane layout in res/layout/main_twopanes.xml. Then create alias files:

res/values-large/layout.xml:

<resources>
    <item name="main" type="layout">@layout/main_twopanes</item>
</resources>

res/values-sw600dp/layout.xml:

<resources>
    <item name="main" type="layout">@layout/main_twopanes</item>
</resources>

Convert dp units to pixels using the formula px = dp * (dpi / 160). In code, calculate pixel values based on display density:

private const val SCROLL_THRESHOLD_DP = 16.0f
private var scrollThresholdPx: Int = 0

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    val densityScale = resources.displayMetrics.density
    scrollThresholdPx = (SCROLL_THRESHOLD_DP * densityScale + 0.5f).toInt()
}

private static final float SCROLL_THRESHOLD_DP = 16.0f;
private int scrollThresholdPx;

scrollThresholdPx = (int) (SCROLL_THRESHOLD_DP * getResources().getDisplayMetrics().density + 0.5f);

Alternatively, use pre-scaled values from ViewConfiguration:

private val scrollThresholdPx = ViewConfiguration.get(context).scaledTouchSlop

private final int scrollThresholdPx = ViewConfiguration.get(context).getScaledTouchSlop();

For bitmap resources, provide alternatievs for different screen densities using the 3:4:6:8:12:16 scaling ratio. For a 48x48 pixel image at mdpi:

• 36x36 for ldpi
• 48x48 for mdpi
• 72x72 for hdpi
• 96x96 for xhdpi
• 144x144 for xxhdpi
• 192x192 for xxxhdpi

Density qualifiers include ldpi, mdpi, hdpi, xhdpi, xxhdpi, xxxhdpi, nodpi, and tvdpi for TV screens.

Use vector graphics for resolution-independent assets. Convert SVG files to Android vector drawables in Android Studio by right-clicking the res directory, selecting New > Vector Asset, choosing Local file (SVG, PSD), and following the import steps. The resulting XML file resides in res/drawable/ without density-specific directories.