Android - A View taking place but doesn't show up

Question

Here is the XML:

 <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/transparent" >

    <LinearLayout 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_toLeftOf="@+id/weightLossIndicator"
        android:paddingLeft="15dp"
        android:paddingRight="10dp"
        android:orientation="vertical">

        <TextView 
            android:id="@+id/weightValueTextView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:paddingTop="10dp"
            android:textColor="@android:color/black"
            android:textSize="30sp"
            android:textStyle="normal" />

        <TextView 
            android:id="@+id/weightDateTextView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="@android:color/black"
            android:textSize="20sp" />

        <TextView 
            android:id="@+id/weightDifferenceTextView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:paddingBottom="10dp"
            android:textColor="@android:color/black"
            android:textSize="20sp" />

    </LinearLayout>

    <ImageView 
        android:id="@+id/weightLossIndicator"
        android:layout_width="10dp"
        android:layout_height="match_parent"
        android:layout_alignParentRight="true"
        android:background="@color/change_green"/>

    <View 
        android:id="@+id/separator"
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:layout_alignParentBottom="true"
        android:layout_below="@+id/weightLossIndicator"
        android:layout_marginLeft="15dp"
        android:background="@color/dark_blue" />


</RelativeLayout>

The view weightLossIndicator doesn't appear on device and simulator although it affects the other elements on the layout (their position). The background color is opaque and does appear in the Graphical Layout.

Update: I tried to set a fixed height for the ImageView as 40 dp and guess what, it appears! Something wrong using match_parent but I don't know what. I also have to say, I am using this XML as ListView row layout.

Answer 1

<View
    android:id="@+id/separator"
    android:layout_width="match_parent"
    android:layout_height="1dp"
    android:layout_alignParentBottom="true"
    android:background="@color/dark_blue" />

<ImageView
    android:id="@+id/weightLossIndicator"
    android:layout_width="10dp"
    android:layout_height="match_parent"
    android:layout_above="@+id/separator"
    android:layout_alignParentRight="true"
    android:background="@color/change_green" />

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_above="@+id/separator"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:layout_toLeftOf="@+id/weightLossIndicator"
    android:orientation="vertical"
    android:paddingLeft="15dp"
    android:paddingRight="10dp" >

    <TextView
        android:id="@+id/weightValueTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:paddingTop="10dp"
        android:textColor="@android:color/black"
        android:textSize="30sp"
        android:textStyle="normal" />

    <TextView
        android:id="@+id/weightDateTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@android:color/black"
        android:textSize="20sp" />

    <TextView
        android:id="@+id/weightDifferenceTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:paddingBottom="10dp"
        android:textColor="@android:color/black"
        android:textSize="20sp" />
</LinearLayout>