GridLayout grid layout

GridLayout grid layout

<?xml version="1.0" encoding="utf-8"?>
<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:rowCount="5"
    android:columnCount="4"
    >
    <!--
    Grid layout can also be used
        android:orientation="vertical"
        android:orientation="horizontal"
        Familiar with control placement
    -->
    <Button android:text="1"/>
    <Button android:text="2"/>
    <Button android:text="3"/>
    <Button android:text="/"/>
    <Button android:text="4"/>
    <Button android:text="5"/>
    <Button android:text="6"/>
    <Button android:text="*"/>
    <Button android:text="7"/>
    <Button android:text="8"/>
    <Button android:text="9"/>
    <Button android:text="-"/>

    <Button android:text="0"
        android:layout_columnSpan="2"
        android:layout_gravity="fill"/>
    <!--android:layout_columnSpan="2" occupies two grids horizontally,
    android:layout_gravity="fill" makes it visual
    android:layout_rowSpan="2" occupies two grids vertically -->
    <Button android:text="."/>
    <Button android:text="+"
        android:layout_rowSpan="2"
        android:layout_gravity="fill"/>
    <Button android:text="="
        android:layout_columnSpan="3"
        android:layout_gravity="fill"/>
</GridLayout>