Display new Activity on top of previous Activity but only partially cover the previous Activity

Question

I have an Activity A which has a "down" button (see image above). When I press this button, I want to launch an Activity B on top of Activity A such that some of Activity A at the bottom is still visible. Activity B can in turn launch a number of other Activities (C, D etc) such that they only display within the same screen area as B. Does anybody know whether this is possible and, if so, how I can go about it?

Edit

I am aware that I can add android:theme="@android:style/Theme.Dialog" to my Activity's manifest declaration. However, as far as I am aware, this displays in the centre of the screen and not such that I can resize it how I require. Correct me if I am wrong 🙏

Answer 1

This is the XML for activities that should be on top of Activity A:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#00000000" >
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="0"
        android:layout_weight="0.6"
        android:background="#000000" >
        //use this for your new activity contents
    </LinearLayout>
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="0"
        android:layout_weight="0.4"
        android:background="#00000000" >
        //this is empty
    </LinearLayout>
</LinearLayout>

Now, in your manifest for Activities B, C etc:

<activity
    android:label="@string/app_name"
    android:name=".ActivityB"
    android:theme="@style/Theme.Transparent"
    android:screenOrientation="portrait" >

In values/styles.xml:

<?xml version="1.0" encoding="utf-8"?>  
<resources>
    <style name="Theme.Transparent" parent="android:Theme.NoTitleBar">  
        <item name="android:windowIsTranslucent">true</item>
        <item name="android:windowBackground">@drawable/theme_transparent</item>
    </style>
</resources>  

Finally, in drawable/theme_transparent.xml:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" >
    <solid android:color="#00000000" ></solid>
</shape>