Question

I’m trying to make 4 buttons, evenly spaced in a portrait view on Android.

The space should scale up and down depending on the screen size, with an even amount of space between each button and the borders.

I tried using linear layout, weight and layout gravity but it seems that I cannot center the button vertically.

Is this a bug of Android layout? More probably is just me.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_weight="1"
android:layout_gravity="center"
>
<Button
android:id="@+id/btn_f"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="btn_f"
>
</Button>
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_weight="1"
android:layout_gravity="center"
>
<Button
android:id="@+id/btn_b"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="btn_b"
>
</Button>
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_weight="1"
android:layout_gravity="center"
>
<Button
android:id="@+id/btn_a"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="btn_a"
>
</Button>
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_weight="1"
android:layout_gravity="center"
>
<Button
android:id="@+id/settings"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Settings"
>
</Button>
</LinearLayout>
</LinearLayout>

Answer 1

Try something like this:

<?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:orientation="vertical"
    >
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        android:orientation="vertical"
        android:layout_weight="1"
        android:gravity="center"
        >
        <Button
            android:id="@+id/btn_f"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="btn_f"
            />
    </LinearLayout>
    <!-- etc -->
</LinearLayout>

The changes from your original layout are that each inner LinearLayout has a height of zero and a gravity (not layout_gravity) of center. This should cause all the inner linear layouts to have the same height, evenly splitting the parent height, without stretching the buttons themselves.