Develop Reference

How to get Transparent android activity over the lockscreen?

I want my activity to show up on lockscreen(which is working fine). but i want to get that activity transparent..
I tried 2 methods both are not allowing my activity to show on lockscreen.
Method 1
android:theme="#android:style/Theme.Translucent.NoTitleBar"
Method 2
<style name="Theme.Transparent" parent="android:Theme">
<item name="android:windowIsTranslucent">true</item>
<item name="android:windowBackground">#android:color/transparent</item>
<item name="android:windowContentOverlay">#null</item>
<item name="android:windowNoTitle">true</item>
<item name="android:windowIsFloating">true</item>
<item name="android:backgroundDimEnabled">false</item>
</style>
Both are not allowing to show the activity on lockscreen.
Is there any method you know?

Try setting following codes in your activity.I have not tried it, it may work.
getWindow().addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD);

This is because you defined windowIsFloating to be true. An activity won't show in front of a lockscreen if the width or height are modified, or if it is set to be floating.
You should set windowIsFloating to false, windowBackground to transparent and if you would still like the dialog-effect, create a dialogfragment, and show that in your onCreate of the activity. And of course, remove the ActionBar from the activity:
<item name="android:windowActionBar">false</item>
<item name="android:windowNoTitle">true</item>

Transparent Android activity trouble

I have an application where the theme can be changed between three different ones. I have two activities that are supposed to have a transparent background and look like a dialog above the previous activity.
I've searched alot for transparent activities here on stack and most of them have the same awnsers. A custom theme with a few properties to enable a transparent background for the activity in question.
The issue for me is that i need to set this custom transparent theme on the parent activity as well to achieve any transparency at all. If i only set a transparent theme on the activity i want to be transparent, it will be a solid background. I've tried everything i could think of but it all boils down to this and im not sure what im doing wrong.
This is my two different parent themes (slimmed down to the neccesary parts):
<style name="StyledActionbar" parent="Theme.Sherlock.Light.ForceOverflow">
<item name="android:textViewStyle">#style/Iksu.TextView</item>
<item name="windowContentOverlay">#null</item>
<item name="android:windowContentOverlay">#null</item>
</style>
<style name="Transparent" parent="Theme.Sherlock.Light.ForceOverflow">
<item name="android:textViewStyle">#style/TextView</item>
<item name="windowContentOverlay">#null</item>
<item name="android:windowContentOverlay">#null</item>
<item name="android:windowIsTranslucent">true</item>
</style>
StyledActionBar is the parent for my three different main themes that is used for all activities that are not supposed to have a transparent background (which is all but two).
Transparent is the parent for three themes that can be used on an activity where the background needs to be transparent.
So the parent activity has a theme based on the StyledActionBar theme. The activity i need to have transparent is based on the Transparent theme.
The background is solid in this state.
If i move:
<item name="android:windowIsTranslucent">true</item>
to StyledActionBar, almost everything works as a charm except a nasty bug in Android 4.4.2 causing the main activity to "fall behind" the OS view when using NavUtils for up-navigation to the main activity.
Any ideas?

in your manigest file
<activity
android:theme="#android:style/Theme.Translucent.NoTitleBar">
</activity>
and in your xml set
android:background="#android/transperent"
also you can use
android:alpha="0.50"

try this one more time :
<style name="Theme.Transparent" parent="android:Theme">
<item name="android:windowIsTranslucent">true</item>
<item name="android:windowBackground">#android:color/transparent</item>
<item name="android:windowContentOverlay">#null</item>
<item name="android:windowNoTitle">true</item>
<item name="android:windowIsFloating">true</item>
<item name="android:backgroundDimEnabled">false</item>
</style>
and in the manifest file
<activity android:name=".AlertActivity"
android:theme="#style/Theme.Transparent"/>
Hope it will work for u.

Android how to get AppCompat.Translucent type theme with support actionbar?

I would like to add the support actionbar to one of my activities, I previously had been using the theme.translucent with this activity but in order to make the support actionbar work I needed to inherit the Theme.AppCompat, I need to maintain a translucent theme in this activity but unfortunately there isnt a Theme.AppCompat.translucent that i can see by default, is there any way that this can be done?

You can create a new set of styles to use which have the same properties as Theme.Translucent from themes.xml.
Add the following to your styles.xml file:
<style name="Theme.AppCompat.Translucent">
<item name="android:windowNoTitle">true</item>
<item name="android:windowBackground">#android:color/transparent</item>
<item name="android:colorBackgroundCacheHint">#null</item>
<item name="android:windowIsTranslucent">true</item>
<item name="android:windowAnimationStyle">#android:style/Animation</item>
</style>
You can change the prefix Theme.AppCompat to something else if you want to inherit other things from the theme such as dialog styles etc. For example, a name like Theme.AppCompat.Light.Translucent would have the properties of the Light theme.
To use the new style, set the theme property to #style/Theme.AppCompat.Translucent
<activity
android:name=".TranslucentActivity"
android:theme="#style/Theme.AppCompat.Translucent" >
</activity>

Parama ,
<style name="Theme.AppCompat.Translucent" parent="Theme.AppCompat.NoActionBar">
<item name="android:windowNoTitle">true</item>
<item name="android:windowBackground">#android:color/transparent</item>
<item name="android:colorBackgroundCacheHint">#null</item>
<item name="android:windowIsTranslucent">true</item>
<item name="android:windowAnimationStyle">#android:style/Animation</item>
</style>
This should be the style header if you want the toolbar to disappear.you can use any parent theme which has NoActionBar for other effects.
Hope this helps

If we use Translucent for transparent activity.
It raises other issues - the color of Msgbox (now white previously black), Default dialog color, the spinners do drop down but do not show the underline and drop-down arrow. The spinners are color black text black; drop-down white drop-down text black and etc.
To overcome this problem, you can just use below code
In style
<style name="Theme.AppCompat.Transparent.NoActionBar" parent="Theme.AppCompat.Light.NoActionBar">
<item name="android:windowIsTranslucent">true</item>
<item name="android:windowBackground">#android:color/transparent</item>
<item name="android:windowContentOverlay">#null</item>
<item name="android:windowNoTitle">true</item>
<item name="android:windowIsFloating">false</item>
<item name="android:backgroundDimEnabled">false</item>
</style>
In manifest file
<activity
android:name=".activity.YourActivityName"
android:theme="#style/Theme.AppCompat.Transparent.NoActionBar" />
I hope it will help
Thanks

Cameron's answer is a nice hack , but it produced a floating action bar and tinted my status bar, which i didn't wanted . So i added more xml attributes for making status bar transparent(for sdk >=19) and used java code for making action bar invisible.
mainActivity.java :
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getSupportActionBar().hide();
...
}
...
}
styles.xml
<style name="AppTheme.TranslucentBG">
<item name="android:windowNoTitle">true</item>
<item name="android:windowBackground">#android:color/transparent</item>
<item name="android:colorBackgroundCacheHint">#null</item>
<item name="android:windowIsTranslucent">true</item>
<item name="android:windowAnimationStyle">#android:style/Animation</item>
<item name="android:windowTranslucentStatus">true</item>
<item name="android:windowTranslucentNavigation">true</item>
</style>
manifest.xml
<application
android:icon="#mipmap/ic_launcher"
...
android:theme="#style/AppTheme"
...
>
<activity android:name=".MainActivity"
android:theme="#style/AppTheme.TranslucentBG"
...
>
...
</activity>
</application>

Set custom theme in Android List Preference

In my Android app, I am using various custom themes in different activities, all of which work fine. All these themes use the same custom styles for buttons, edit controls etc.
My preferences use standard Preference activities, which I define in XML and style via the manifest.
However, when I have a preference that causes an alert dialog to get launched, for example a ListPreference, the dialog uses the standard buttons. It does seem to use my custom EditText style in the EditTextPreference... but not my background or text colour.
Anyone have any idea why this is happening ?
Some of the code:
Styles:
<style name="Theme.Prefs" parent="#android:style/Theme.Holo.Light">
<item name="android:windowBackground">#drawable/background</item>
<item name="android:buttonStyle">#style/CustomButtonStyle</item>
<item name="android:editTextStyle">#style/CustomEditTextStyle</item>
</style>
<style name="CustomButtonStyle" parent="#android:style/Widget.Holo.Button">
<item name="android:background">#drawable/custom_button</item>
<item name="android:textSize">#dimen/dialog_text_size_normal</item>
<item name="android:textColor">#color/dialog_control_colour</item>
</style>
<style name="CustomEditTextStyle" parent="#android:style/Widget.Holo.EditText">
<item name="android:background">#drawable/custom_textfield</item>
<item name="android:textColor">#color/dialog_control_colour</item>
<item name="android:textSize">#dimen/dialog_text_size_normal</item>
</style>
And in the manifest:
<activity
android:name="com.breadbun.prefs.MainPreferencesActivity"
android:theme="#style/Theme.Prefs"
android:screenOrientation="portrait">
</activity>

To customize the alertDialog you need to add the second row to your main theme, and then customize the DialogStyle the way you want it.
<style name="AppTheme" parent="android:Theme.Material">
<item name="android:alertDialogTheme">#style/DialogStyle</item>
</style>
<style name="DialogStyle" parent="android:Theme.Material.Dialog.Alert">
</style>

Android Activity Invisible by Default

I have an activity defined like this
<activity android:name=".queue.ItemDetailActivity"
android:theme="#android:style/Theme.Dialog"></activity>
This activity implements runnable and shows a progress bar while data is retrieved from the server. I would like to have the dialog invisible until the data is loaded. Is there a way for the activity to start invisible and then later use setVisible(true); to make it appear?

Try this style for the activity.
<style name="Invisible" parent="#android:style/Theme.Dialog">
<item name="android:windowBackground">#android:color/transparent</item>
<item name="android:windowIsFloating">true</item>
<item name="android:windowNoTitle">true</item>
<item name="android:windowContentOverlay">#null</item>
</style>