Programmatically set android:windowIsTranslucent

Question

I was able to create a floating activity after following this tutorial http://cases.azoft.com/android-tutorial-floating-activity/

However, to do so, I had to add this line in styles.xml :

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

Is it possible to have the same effect using only Android/Java code ? (e.g. in Activity.onAttachedToWindow() or so...)

Thanks in advance for your help.

[EDIT 01] styles.xml must not be changed (and I'm not supposed to know what's in it...). But for testing purposes, I'm using the default one:

<resources>
    <style name="AppBaseTheme" parent="Theme.AppCompat.Light">
    </style>
    <style name="AppTheme" parent="AppBaseTheme">
    </style>
</resources>

[EDIT 02] Resources.Theme.applyStyle() seems to do what I want (according to the API description: "Place new attribute values into the theme" ). So I created the following custom_style.xml :

<resources>
    <style name="MyCustomStyle" >
        <item name="android:windowIsTranslucent">true</item>
    </style>
</resources>

Then, in onAttachedToWindow() , I called:

getTheme().applyStyle(R.style.MyCustomStyle, true);

But it didn't have any effect...

Answer 1

Is it possible to have the same effect using only Android/Java code ?

I am afraid, No. You will have to do it in styles.xml only. AFAIK value of android:windowIsTranslucent alone can't be changed programatically.

When we call super.onCreate(savedInstanceState); the Activity class provides empty graphical window on which we set our content ie.views. And a theme is applied to this window and then the content are loaded on this view.

Hence the sequence will be,

1. call to super.onCreate()
2. setting theme for the activty.
3. seting the content views for that activity.

eg.

styles.xml

<style name="AppTheme" parent="AppBaseTheme">

<!-- All customizations that are NOT specific to a particular API-level can go here. -->

    <item name="android:windowBackground">@drawable/background</item>
    <item name="android:windowNoTitle">true</item>
</style>

<!-- Application theme.without title bar -->
<style name="AppTheme.NoTitleBar" parent="AppBaseTheme">

<!-- All customizations that are NOT specific to a particular API-level can go here. -->
    <item name="android:windowBackground">@drawable/background</item>
    <item name="android:windowNoTitle">true</item>
</style>

<!--Floating activity theme -->
<style name="Theme_Translucent" parent="android:style/Theme.NoTitleBar.Fullscreen">
    <item name="android:windowBackground">@android:color/transparent</item>
    <item name="android:windowFrame">@null</item>
    <item name="android:windowContentOverlay">@null</item>
    <item name="android:windowIsFloating">true</item>
    <item name="android:backgroundDimEnabled">true</item>
    <item name="android:windowIsTranslucent">true</item>
    <item name="android:windowNoTitle">true</item>
    <item name="android:windowAnimationStyle">@android:style/Animation.Dialog</item>
    <item name="android:windowFullscreen">true</item>
</style>

Then set your theme for Floating activity as follows:

public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setTheme(R.style.Theme_Translucent); // Set here
    setContentView(...)
}