Layout Weight distribution wrongly interpreted

Question

I want to define a composite layout where the header and footer LinearLayout blocks take 10% of the view and body block the remaining 80%. Without setting weights, all 3 blocks have the same size, so I have set the weight of header and footer layout to 10 and body to 80 with weight sum 100 but this had an unwanted result that actually is opposite to the one expected, and body despite has the higher weight disappears due to the fact header and footer block take all the available space.

Layout code

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

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:weightSum="100">

    <LinearLayout
        android:id="@+id/header"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="10"
        android:baselineAligned="false"
        android:orientation="horizontal">

        <RelativeLayout
            android:id="@+id/head"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="5dp"
            android:background="@drawable/hf"
            android:padding="5dp">

            <TextView
                android:id="@+id/texthead"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:gravity="center"
                android:text="Sample head" />

            <ImageView
                android:id="@+id/imageh"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                app:srcCompat="@drawable/him" />

        </RelativeLayout>

    </LinearLayout>

    <LinearLayout
        android:id="@+id/body"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="80"
        android:baselineAligned="false"
        android:orientation="horizontal">

        <RelativeLayout
            android:id="@+id/bd0"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="5dp"
            android:background="@drawable/bdf"
            android:padding="10dp">

            <TextView
                android:id="@+id/textbd0"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="1dp"
                android:gravity="center"
                android:text="Lorem ipsum" />

            <ImageView
                android:id="@+id/imageView1"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                app:srcCompat="@drawable/bdim" />

        </RelativeLayout>

        <RelativeLayout
            android:id="@+id/bd1"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="5dp"
            android:background="@drawable/bdf"
            android:padding="10dp">

            <TextView
                android:id="@+id/textbd1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="1dp"
                android:gravity="center"
                android:text="Lorem ipsum" />

            <ImageView
                android:id="@+id/imageView2"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                app:srcCompat="@drawable/bdim" />

        </RelativeLayout>

    </LinearLayout>

    <LinearLayout
        android:id="@+id/footer"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="10"
        android:baselineAligned="false"
        android:orientation="horizontal">

        <RelativeLayout
            android:id="@+id/ft"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="5dp"
            android:background="@drawable/ftf"
            android:padding="5dp">

            <TextView
                android:id="@+id/textft"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:gravity="center"
                android:text="Sample footer" />

            <ImageView
                android:id="@+id/imageft"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                app:srcCompat="@drawable/ftim" />

        </RelativeLayout>

    </LinearLayout>

</LinearLayout>

wieght only applies if the elements are set to 0dp in the direction of the layout (so for a vetical layout, the height). Also, your layout is really inefficient, you have a lot of unneeded layers. The entire thing could be turned into a single contraint layout and perform what you want more easily. — Gabe Sechan, Jul 13 '22 at 00:56
@GabeSechan thanks, the layers are needed, this is a simplified version — AndreaF, Jul 13 '22 at 01:02

score 0 · Accepted Answer · answered Jul 13 '22 at 00:59

Try the following code:

(You can undo the background changes I did, it was just so I could visualize what was going on.)

According to the following post: Android layout weight not working as I thought -- you need to set your wanted attribute to 0dp for layout_weight to work properly.

In summary: by setting the height to match_parent, you are confusing the XML compiler and it doesn't know how to apply layout_weight properly.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:weightSum="100">

    <LinearLayout
        android:id="@+id/header"
        android:background="@color/material_dynamic_neutral30"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="10"
        android:baselineAligned="false"
        android:orientation="horizontal">

        <RelativeLayout
            android:id="@+id/head"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="5dp"
            android:background="@color/black"
            android:padding="5dp">

            <TextView
                android:id="@+id/texthead"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:gravity="center"
                android:text="Sample head" />

            <ImageView
                android:id="@+id/imageh"
                android:layout_width="match_parent"
                android:layout_height="match_parent"/>

        </RelativeLayout>

    </LinearLayout>

    <LinearLayout
        android:id="@+id/body"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="80"
        android:background="@color/teal_200"
        android:baselineAligned="false"
        android:orientation="horizontal">

        <RelativeLayout
            android:id="@+id/bd0"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="5dp"
            android:background="@color/cardview_light_background"
            android:padding="10dp">

            <TextView
                android:id="@+id/textbd0"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="1dp"
                android:gravity="center"
                android:text="Lorem ipsum" />
        </RelativeLayout>

        <RelativeLayout
            android:id="@+id/bd1"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="5dp"
            android:background="@color/teal_200"
            android:padding="10dp">

            <TextView
                android:id="@+id/textbd1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="1dp"
                android:gravity="center"
                android:text="Lorem ipsum" />

        </RelativeLayout>

    </LinearLayout>

    <LinearLayout
        android:id="@+id/footer"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="10"
        android:background="@color/teal_700"
        android:baselineAligned="false"
        android:orientation="horizontal">

        <RelativeLayout
            android:id="@+id/ft"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="5dp"
            android:background="@color/material_dynamic_neutral30"
            android:padding="5dp">

            <TextView
                android:id="@+id/textft"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:gravity="center"
                android:text="Sample footer" />
        </RelativeLayout>

    </LinearLayout>

</LinearLayout>

Layout Weight distribution wrongly interpreted

1 Answers1