android:windowSoftInputMode="adjustResize" doesn't make any difference?

I have a faux dialog which uses this layout:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout    xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_height="match_parent"
                android:layout_width="match_parent"
                android:id="@+id/containerPageConatiner">

    <FrameLayout    android:id="@+id/dialogHolder"
                    android:layout_height="wrap_content"
                    android:layout_width="wrap_content"
                    android:padding="15dp"
                    android:layout_gravity="center"
                    android:background="@drawable/panel_picture_frame_bg_focus_blue"/>    
</FrameLayout> 

I place a fragment inside the <FrameLayout> depending on the dialog which is opening - The activity controlling the Dialog looks like this:

<activity
    android:label="@string/app_name"
    android:name=".activity.DialogActivity"
    android:theme="@style/CustomTheme.Screen.Transparent" 
    android:windowSoftInputMode="adjustResize">

Unfortunately when you click on an edit text inside of the dialog, no resizing takes place. The windowSoftInputMode literally makes no difference as the functionality is the same as pan mode.

Documentation says "This of course only works for applications that have a resizeable area that can be reduced to make enough space" but doesn't tell you what it means by "a resizeable area" and makes me think that in some way I don't have a resizeable area?

If anyone knows what's up can they help me out?

EDIT

Surrounding the dialog like so doesn't change anything:

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

    <View
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_weight="1" />

    <FrameLayout    
        android:id="@+id/dialogHolder"
        android:layout_height="wrap_content"
    android:layout_width="wrap_content"
        android:padding="15dp"
        android:layout_gravity="center"
        android:background="@drawable/panel_picture_frame_bg_focus_blue"/>

    <View
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_weight="1" />
</LinearLayout>

EDIT2

Scrollview as parent doesn't help either:

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/containerPageConatiner"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <FrameLayout
            android:id="@+id/dialogHolder"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:padding="15dp" />

</ScrollView>

I created a new project in order to try and get the basic features working for window resizing and the slowly moved it towards the target peice of my project. Doing this I tracked the problem down to this:

In my theme hierarchy I had this property:

<item name="android:windowFullscreen">true</item> 

which was burried at the level of Theme.Black.NoTitleBar.FullScreen - An ancestor of my custom theme.

The documentation suggests that this is a "Flag indicating whether this window should fill the entire screen". That sounds like a good thing to have if you have an app which takes up the whole screen... Except it still takes up the whole screen without the flag.

In fact, once you've taken this out, there is absolutely no change in the app at all... apart from adjustResize now works perfectly.