How do I vertically align an item within a list using relative layout?

Question

I am using a list view in Android 1.5 to show a list of images and text next to the image. I am trying to vertically center the text but the text is at the top of the row instead of centered. Below is my layout:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/row"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:padding="10dip">

    <ImageView android:id="@+id/item_image" android:layout_width="wrap_content" 
        android:layout_height="wrap_content"  android:paddingRight="10dip" 
        android:src="@drawable/default_image" android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_alignParentBottom="true"
        android:layout_centerVertical="true"
        android:gravity="center_vertical"/>

    <TextView android:id="@+id/item_title" 
        android:layout_width="wrap_content" android:layout_height="wrap_content" 
        android:layout_toRightOf="@id/item_image" 
        android:layout_alignParentTop="true"
        android:layout_alignParentBottom="true"
        android:layout_centerVertical="true"
        android:gravity="center_vertical"
        />

</RelativeLayout>

It seems strange that I need to set alignParentTop="true" when I'm trying to vertically center the text, but if I don't the text does not even show up. What am I doing wrong?

Answer 1

Baseline directive would do it, but ImageView simply does not support baseline alignment as of today. You can work around this by creating a subclass of ImageView, override the getBaseline() method and return the height of the image.

Answer 2

EDIT following the comments:

It turns out making this work with RelativeLayout isn't easy. At the bottom of the answer I've included a RelativeLayout that gives the effect wanted, but only until it's included in a ListView. After that, the same problems as described in the question occurred. This was fixed by instead using LinearLayout(s).

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:paddingLeft="10dp"
    android:orientation="horizontal">

    <ImageView android:id="@+id/pickImageImage" 
        android:layout_width="100dp"
        android:layout_height="80dp"
        android:background="@drawable/icon"
        android:scaleType="fitXY"
        android:layout_marginRight="10dp"/>

    <TextView android:id="@+id/pickImageText" 
        android:layout_height="fill_parent"
        android:layout_width="fill_parent"
        android:gravity="left|center_vertical"
        android:text="I'm the text"/>

</LinearLayout>

If you want to have two text boxes, you can nest a second orientation="vertical" and LinearLayout after the ImageView and then put the text boxes in there.

This works, but I have to admit I don't know why the RelativeLayouts didn't. For example, this blog post by Romain Guy specifically says that the RelativeLayout should. When I tried it, I never got it to quite work; admittedly I didn't do it exactly as he did, but my only changes were with some attributes of the TextViews, which shouldn't have made that much of a difference.

---

Here's the original answer:

I think you're confusing Android with all those somewhat contradictory instructions in RelativeLayout. I reformatted your thing to this:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/row"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:padding="10dip">

    <ImageView android:id="@+id/item_image"
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content"
        android:paddingRight="10dip" 
        android:src="@drawable/icon"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"/>

    <TextView android:id="@+id/item_title" 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" 
        android:layout_toRightOf="@id/item_image" 
        android:layout_centerVertical="true"
        android:text="Blah!"/>

</RelativeLayout>

And that works fine. I removed many of your redundant android:layout_alignParentxxx because they weren't necessary. This view now comes up with the picture in the top left corner and the text vertically centered next to it. If you want the picture vertically centered as well, then you can't have the RelativeLayout be on android:layout_height="wrap_content" because it's trying to make itself no taller than the height of the picture. You'd have to specify a height, e.g. 80dp, and then set the ImageView to a fixed height like 60dp with android:scaleType="fitXY" to make it scale down to fit properly.

Answer 3

Was stuck on a similar issue for a while, but found this from CommonsWare:

"When you inflate the layout, use inflate(R.layout.whatever, parent, false), where parent is the ListView."

Works but only when you set the height of the row to a specific value (ie you can't use wrap_content).