Sarson Sarson - 6 months ago 59
Android Question

Percentage width in a RelativeLayout

I am working on a form layout for a Login

Activity
in my Android App. The image below is how I want it to look like:

enter image description here

I was able to achieve this layout with the following XML. The problem is, it's a bit hackish. I had to hard-code a width for the host EditText. Specifically, I had to specify:

android:layout_width="172dp"


I'd really like to give a percentage width to the host and port EditText's . (Something like 80% for the host, 20% for the port.) Is this possible? The following XML works on my Droid, but it doesn't seem to work for all screens. I would really like a more robust solution.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/main"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >

<TextView
android:id="@+id/host_label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/home"
android:paddingLeft="15dp"
android:paddingTop="0dp"
android:text="host"
android:textColor="#a5d4e2"
android:textSize="25sp"
android:textStyle="normal" />

<TextView
android:id="@+id/port_label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/home"
android:layout_toRightOf="@+id/host_input"
android:paddingTop="0dp"
android:text="port"
android:textColor="#a5d4e2"
android:textSize="25sp"
android:textStyle="normal" />

<EditText
android:id="@+id/host_input"
android:layout_width="172dp"
android:layout_height="wrap_content"
android:layout_below="@id/host_label"
android:layout_marginLeft="15dp"
android:layout_marginRight="15dp"
android:layout_marginTop="4dp"
android:background="@android:drawable/editbox_background"
android:inputType="textEmailAddress" />

<EditText
android:id="@+id/port_input"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_below="@id/host_label"
android:layout_marginTop="4dp"
android:layout_toRightOf="@id/host_input"
android:background="@android:drawable/editbox_background"
android:inputType="number" />

<TextView
android:id="@+id/username_label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/host_input"
android:paddingLeft="15dp"
android:paddingTop="15dp"
android:text="username"
android:textColor="#a5d4e2"
android:textSize="25sp"
android:textStyle="normal" />

<EditText
android:id="@+id/username_input"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="@id/username_label"
android:layout_marginLeft="15dp"
android:layout_marginRight="15dp"
android:layout_marginTop="4dp"
android:background="@android:drawable/editbox_background"
android:inputType="textEmailAddress" />

<TextView
android:id="@+id/password_label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/username_input"
android:paddingLeft="15dp"
android:paddingTop="15dp"
android:text="password"
android:textColor="#a5d4e2"
android:textSize="25sp"
android:textStyle="normal" />

<EditText
android:id="@+id/password_input"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="@id/password_label"
android:layout_marginLeft="15dp"
android:layout_marginRight="15dp"
android:layout_marginTop="4dp"
android:background="@android:drawable/editbox_background"
android:inputType="textPassword" />

<ImageView
android:id="@+id/home"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_centerVertical="false"
android:paddingLeft="15dp"
android:paddingRight="15dp"
android:paddingTop="15dp"
android:scaleType="fitStart"
android:src="@drawable/home" />

<Button
android:id="@+id/login_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/password_input"
android:layout_marginLeft="15dp"
android:layout_marginTop="15dp"
android:text=" login "
android:textSize="18sp" >
</Button>

</RelativeLayout>

Answer

You are looking for the android:layout_weight attribute. It will allow you to use percentages to define your layout.

In the following example, the left button uses 70% of the space, and the right button 30%.

<LinearLayout
    android:layout_width="match_parent" 
    android:layout_height="wrap_content">

    <Button
        android:text="left" 
        android:layout_width="0dp" 
        android:layout_height="wrap_content" 
        android:layout_weight=".70" /> 

    <Button
        android:text="right" 
        android:layout_width="0dp" 
        android:layout_height="wrap_content" 
        android:layout_weight=".30" />

</LinearLayout>

It works the same with any kind of View, you can replace the buttons with some EditText to fit your needs.

Be sure to set the layout_width to 0dp or your views may not be scaled properly.

Note that the weight sum doesn't have to equal 1, I just find it easier to read like this. You can set the first weight to 7 and the second to 3 and it will give the same result.