Develop Reference

Understanding styles

I'm trying to set a custom colour for my buttons in Android application but value set for accentColor is always used as button background colour. I am trying to set a global colour for all buttons without having to specify styles or theme for each button individually.
Can you explain please how styling works in Android? I understand the basics, but overriding existing themes is never working for me :(
styles.xml
<resources>
<style name="AppTheme" parent="Theme.MaterialComponents.Light.NoActionBar">
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorAccent</item>
<item name="android:titleTextColor">#ffffff</item>
<item name="android:buttonStyle">#style/AppTheme.Button</item>
</style>
<style name="AppTheme.NoActionBar">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
</style>
<style name="AppTheme.Button" >
<item name="android:backgroundTint">#color/colorPrimaryDark</item>
</style>
<style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />
<style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />

Short answer: Try going to the source code of how the
Theme.MaterialComponents.Light.NoActionBar is defining the style for
the buttons and override those attributes.
Android styling works by merging all the defined attributes in a theme. For example, you have an AppTheme that includes theming for every built-in view. If you create a new theme for your button and your define just a couple of attributes, what android studio does is to merge all the attributes defined in the AppTheme with your new attributes. So if you want to override the buttons, you need to go deep and find out what are exactly the attributes defined in the general AppTheme you set in your application, they may not be the same.
For example, this is how I changed the color of all the buttons in my app since they were using a global attribute for it:
In the general styles.xml file, I put:
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
...
<item name="colorButtonNormal">?myCustomColor</item>
...
</style>
But if I wanted to change the backgroundTint attribute of my buttons, I had to do this:
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
...
<item name="colorButtonNormal">?myCustomColor</item>
<item name="android:buttonStyle">#style/AppButtonStyle</item>
...
</style>
<style name="AppButtonStyle" parent="Widget.AppCompat.Button">
<item name="android:backgroundTint">?attr/colorAccent</item>
</style>
Also, check out this cool Medium post for another developer experience in this topic.

I managed to solve the issue. The main point to notice here is that I am using Theme.MaterialComponents and not AppCompact.
I have defined a new style and I set it to buttonStyle, which refers to style for AppCompact button. In order to set a style for the material button, I had to use "materialButtonStyle" instead of "buttonStyle".
All relevant properties that can be overridden for MaterialComponents can be found in material design documentation: https://www.material.io/develop/android/components/material-button/
So the final code looks like this:
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.MaterialComponents.Light.NoActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorAccent</item>
<item name="colorSecondary">#color/colorAccent</item>
<item name="floatingActionButtonStyle">#style/AppTheme.Test</item>
<item name="materialButtonStyle">#style/AppTheme.Button</item>
<!--<item name="buttonStyle">#style/Widget.MaterialComponents.Button.Icon</item>-->
</style>
<style name="AppTheme.Button" parent="#style/Widget.MaterialComponents.Button">
<item name="android:backgroundTint">#D400EB</item>
</style>
<style name="AppTheme.Test" parent="#style/Widget.MaterialComponents.FloatingActionButton">
<item name="backgroundTint">#A305B1</item>
</style>
<style name="AppTheme.NoActionBar">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
</style>
<style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar"/>
<style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light"/>
</resources>

Change background colour of Activity

I have created an Android project and included Navigation Drawer Activity.
But the backgrounds of the activities are black.
I know I can change the background colour to white using XML or Java. But every time I do that I need to change other views as well. I checked the styles file. But it doesn't contain any tag about the background colour.
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat">
<!-- Customize your theme here. -->
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorAccent</item>
</style>
<style name="AppTheme.NoActionBar">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
</style>
<style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />
<style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />
</resources>
Is there any solution for that? Thank you!

Extend your app Theme from Theme.AppCompat.Light

you can Extend your app Theme from Theme.AppCompat.Light or you can pass background color to the root view of you activity layout.

Get full screen layout in Fragment

I have a main Activity, and I am loading Fragments inside it.
I do not want the ActionBar, so I have hidden it in Manifest as follows
android:theme="#style/NoActionBar"
When I populate a Fragment, the ActionBar is hidden, but it gives a black portion on the bottom of the screen and I can't even use that specific portion in my layout.
Any help?

Replace your style.xml with below code:
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorAccent</item>
</style>
<style name="AppTheme.NoActionBar">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
</style>
</resources>
and then set theme as
android:theme="#style/AppTheme.NoActionBar"

In my project we are using that kind of style:
<style name="NoActionBarTheme" parent="Theme.AppCompat.Light.NoActionBar">
<item name="android:windowActionBarOverlay">true</item>
<item name="android:windowBackground">#color/black</item>
</style>
in AndroidManifest.xml you set it like
<application ...
android:theme="#style/NoActionBarTheme">...

I can't remove the action bar from my application

I am trying to remove the Action Bar from my app, but it just won't leave. Here is what I have done:
styles.xml
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorAccent</item>
</style>
<style name="AppTheme.NoActionBar">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
</style>
<style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />
<style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />
</resources>
styles.xml v21:
<resources>>
<style name="AppTheme.NoActionBar">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
<item name="android:windowDrawsSystemBarBackgrounds">true</item>
<item name="android:statusBarColor">#android:color/transparent</item>
</style>
</resources>
And the app theme is set to No Action Bar.
I also am doing this in the MainActivity.java class:
getActionBar().hide();
But that only removes it when I run the app. I would like it to be gone in the design panel.
How is that done?

But that only removes it when I run the app. I would like it to be
gone in the design panel.
Simply, use a theme without ActionBar on Android Studio's Preview:
I said that because you said it's working after compiling the app and your question was about:
I would like it to be gone in the design panel
Design panel!
But, this will only show you how to remove that ActionBar on Andorid Studio's Preview.
The thing is, it should be like this:
In Manifest:
<android:theme="#android:style/Theme.NoTitleBar">
And if it is still there, You should check if there is a Toolbar in your Layouts

You have missed parent attribute:
<style name="AppTheme.NoActionBar" parent="AppTheme">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
</style>
Similarly:
<style name="AppTheme.NoActionBar" parent="AppTheme">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
<item name="android:windowDrawsSystemBarBackgrounds">true</item>
<item name="android:statusBarColor">#android:color/transparent</item>
</style>
And don't forget to add theme declaration in manifest using:
android:theme="#style/AppTheme.NoActionBar"
Hope this would help!!

Go to your manifest.xml on this line:
android:theme="#style/AppTheme"
delete Apptheme, than typing Theme. with a dot (.) it will show you different options of theme layouts.
follow the pictures:
This will affect only the emulator. In order to see also the effect in the activity_main.xml, just go on that tab activity and press, form the preview window, the button no the top right corner "NoActionBar" as I show in follow picture, choose form the dialog box "manifest theme" and hit OK.
this will change the preview too!
hope this will help ;)

How to make my app with transparrent theme?

I am making my Music player now. I want it to be lightly transparent(Android background barely visable). Structure: One activity with 4 fragments (viewPager with tabs). Any ideas?
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorAccent</item>
</style>
<style name="AppTheme.NoActionBar">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
</style>
<style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />
<style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />

Just use this theme in your Activity's theme
android:theme="#android:style/Theme.Translucent.NoTitleBar"
This will make the background of your ACtivity completely transparent. You can also extend that theme and set a custom windowBackground
In your styles.xml
<style name="MyTransparentTheme" parent="#android:style/Theme.Translucent.NoTitleBar">
<item name="windowBackground">#color/my_transparent_color</item>
</style>
In case you are using AppCompat you should change the parent theme to
<style name="MyTransparentTheme" parent="#style/Theme.AppCompat.Translucent.NoTitleBar">
<item name="windowBackground">#color/my_transparent_color</item>
</style>