Question

I have a xml layout to enter a pincode:

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#FF000000"
    android:orientation="vertical"
    android:weightSum="1" >

<LinearLayout
    android:layout_width="fill_parent"
    android:layout_height="0dp"
    android:layout_margin="5dp"
    android:layout_weight="0.2"
    android:background="@android:drawable/edit_text"
    android:gravity="center_vertical"
    android:orientation="horizontal" >

    <EditText
        android:id="@+id/pinDisplay"
        android:layout_width="0dip"
        android:layout_height="fill_parent"
        android:layout_weight="0.85"
        android:background="@null" />

    <ImageButton
        android:id="@+id/backspace"
        style="@android:style/Widget.Button"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:layout_gravity="center_vertical"
        android:layout_margin="3dp"
        android:layout_weight="0.15"
        android:gravity="center"
        android:src="@android:drawable/ic_input_delete" />
</LinearLayout>

<!-- Keypad section -->

<LinearLayout
    android:layout_width="fill_parent"
    android:layout_height="0dp"
    android:layout_weight="0.8"
    android:baselineAligned="false"
    android:orientation="vertical" >

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="0dp"
        android:layout_marginLeft="5dip"
        android:layout_marginRight="4dip"
        android:layout_weight="1"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/one"
            android:layout_width="0sp"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:text="1"
            android:textAppearance="@android:attr/text" />

        <Button
            android:id="@+id/two"
            android:layout_width="0sp"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:text="2" />

        <Button
            android:id="@+id/three"
            android:layout_width="0sp"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:text="3" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="0sp"
        android:layout_marginLeft="5dip"
        android:layout_marginRight="4dip"
        android:layout_weight="1"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/four"
            android:layout_width="0sp"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:text="4" />

        <Button
            android:id="@+id/five"
            android:layout_width="0sp"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:text="5" />

        <Button
            android:id="@+id/six"
            android:layout_width="0sp"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:text="6" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="0sp"
        android:layout_marginLeft="5dip"
        android:layout_marginRight="4dip"
        android:layout_weight="1"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/seven"
            android:layout_width="0sp"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:text="7" />

        <Button
            android:id="@+id/eight"
            android:layout_width="0sp"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:text="8" />

        <Button
            android:id="@+id/nine"
            android:layout_width="0sp"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:text="9" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="0sp"
        android:layout_marginBottom="10dip"
        android:layout_marginLeft="5dip"
        android:layout_marginRight="4dip"
        android:layout_weight="1"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/ok"
            android:layout_width="0sp"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:enabled="false"
            android:text="OK"
            android:textColor="#B8B8B8" />

        <Button
            android:id="@+id/zero"
            android:layout_width="0sp"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:text="0" />

        <Button
            android:id="@+id/clear"
            android:layout_width="0sp"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:text="Clear" />
    </LinearLayout>
  </LinearLayout>
</LinearLayout>

The layout is fine, but I get a lot of Lint warnings about nested weights.

Nested weights are bad for performance

I don’t really notice the layout loading slow or anything. What can I do to avoid nested weights? Or should I just leave it like it is?

Answer 1

You could use RelativeLayout to avoid the nested weights.

Nested weights are bad for performance because the number of measurements increase exponentially with each one nested.