Develop Reference

Tab Indicators Obscured by android:background

Simple TabLayout. No tab indicator. Arggh!
<com.google.android.material.tabs.TabLayout
android:id="#+id/my_tabs"
style="#style/MyTabLayout"
android:theme="#style/MyThemeOverlay"
android:layout_width="match_parent"
android:layout_height="50dp"/>
<style name="MyTabLayout" parent="Widget.MaterialComponents.TabLayout">
<item name="android:background">#color/red</item>
<item name="tabTextAppearance">#style/MyTextAppearance</item>
<item name="tabMinWidth">100dp</item>
<item name="tabMaxWidth">100dp</item>
<item name="tabIndicator">#drawable/tab_indicator_rounded_top_corners</item>
<item name="tabIndicatorColor">#color/color_white</item>
<item name="tabIndicatorHeight">5dp</item>
<item name="tabIndicatorFullWidth">false</item>
<item name="tabTextColor">#color/color_accent_dark</item>
<item name="tabGravity">center</item>
</style>
<style name="MyThemeOverlay">
<item name="android:background">#color/blue</item>
</style>
tab_indicator_rounded_top_corners.xml
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<shape android:shape="rectangle">
<corners
android:topLeftRadius="2dp"
android:topRightRadius="2dp" />
</shape>
</item>
</layer-list>
And this is what pops out. There should be a white bar under the selected tab.
I am almost sure that this relates to this line in the theme overlay:
<item name="android:background">#color/blue</item>
Because when I do not override the background color, I can see the tab indicators. Problem is that I need to change that background color in some cases using theme overlays.

how to change the button style programmatically

I have defined two styles in Style.xml, I want to change the style programmatically for certain conditions, Min SDK version 21
<style name="CheckOutButtonStyle" parent="#style/Widget.AppCompat.Button.Colored">
<item name="android:layout_height">60dp</item>
<item name="android:fontFamily">sans-serif-medium</item>
<item name="android:textSize">16sp</item>
<item name="android:padding">0dp</item>
<item name="android:textColor">#color/white_color</item>
<item name="android:layout_margin">#dimen/general_spacing</item>
</style>
<style name="ScanNextItemSecondaryButtonStyle" parent="#style/Widget.AppCompat.Button.Borderless">
<item name="android:layout_height">wrap_content</item>
<item name="android:fontFamily">sans-serif-medium</item>
<item name="android:stateListAnimator">#null
</item> <!-- remove the shadow, per UI request -->
<item name="android:textSize">16sp</item>
<item name="android:padding">0dp</item>
<item name="android:minHeight">0dp</item>
<item name="android:minWidth">0dp</item>
<item name="android:background">#null</item>
<item name="android:textColor">#color/colorSecondaryAccent</item>
<item name="android:layout_marginBottom">#dimen/general_spacing</item>
</style

1. Create xml in drawable.
\res\drawable\back_button_answer.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle" >
<corners android:radius="10dip" />
<!-- background -->
<gradient
android:startColor="#D6D7D6"
android:centerColor="#E2E2E2"
android:centerY="0.75"
android:endColor="#D6D7D6"
android:angle="270"
/>
<stroke android:width="2dip" android:color="#fff"/>
</shape>
2. Button btn.setBackgroundResource(R.drawable.back_button_answer);

Custom spinner UI with arrow and vertical line

I am trying to implement a spinner with a custom layout (not the spinner item layout), the outer layout. I want it to look like this:
http://imgur.com/a/U6RzU
I searched stackoverflow and google, but couldn't figure out how to come up with this (beside putting the whole picture as a background)
Thanks a lot in advance
Edit
This is what I tried:
styles.xml
<style name="spinner">
<item name="android:layout_marginTop">6dp</item>
<item name="android:layout_marginBottom">6dp</item>
<item name="android:layout_marginLeft">0dp</item>
<item name="android:layout_marginRight">0dp</item>
<item name="android:padding">10dp</item>
<item name="android:background">#drawable/spinner_bg</item>
<item name="android:popupBackground">#color/red</item>
<item name="android:textSize">15sp</item>
</style>
spinner_bg.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<layer-list>
<item>
<shape>
<gradient android:angle="90" android:endColor="#ff0000"
android:startColor="#ff0000" android:type="linear" />
<stroke android:width="0.33dp" android:color="#0fb1fa" />
<corners android:radius="0dp" />
<padding android:bottom="3dp" android:left="3dp" android:right="3dp" android:top="3dp" />
</shape>
</item>
<item android:right="5dp">
<bitmap android:gravity="center_vertical|right" android:src="#drawable/arrow_white_down" />
</item>
</layer-list>
</item>
</selector>
where arrow_white_down is a png of a tiny white arrow (like the one in the link)

I solved it by using a RelativeLayout with the spinner and an image (arrow) beside it, it doesn't look really good in spinnerMode="dropdown" but this is the best I could do
layout
<RelativeLayout
android:id="#+id/spinner_container"
style="#style/spinner_container">
<Spinner
android:id="#+id/spinner"
style="#style/spinner"
android:layout_toLeftOf="#+id/spinner_image"
android:layout_toStartOf="#+id/spinner_image" />
<ImageView
android:id="#+id/spinner_image"
style="#style/spinner_image" />
</RelativeLayout>
styles.xml
<style name="spinner_container">
<item name="android:layout_width">match_parent</item>
<item name="android:layout_height">35dp</item>
<item name="android:orientation">horizontal</item>
<item name="android:layout_marginTop">6dp</item>
<item name="android:layout_marginBottom">6dp</item>
<item name="android:layout_marginLeft">0dp</item>
<item name="android:layout_marginRight">0dp</item>
<item name="android:background">#color/red</item>
</style>
<style name="spinner">
<item name="android:layout_width">match_parent</item>
<item name="android:layout_height">wrap_content</item>
<item name="android:layout_margin">0dp</item>
<item name="android:layout_alignParentLeft">true</item>
<item name="android:layout_alignParentStart">true</item>
<item name="android:padding">5dp</item>
<item name="android:textColor">#color/white</item>
<item name="android:background">#color/red</item>
<item name="android:popupBackground">#color/red</item>
<item name="android:textSize">15sp</item>
</style>
<style name="spinner_image">
<item name="android:layout_width">wrap_content</item>
<item name="android:layout_height">match_parent</item>
<item name="android:layout_margin">5dp</item>
<item name="android:padding">0dp</item>
<item name="android:layout_alignParentRight">true</item>
<item name="android:layout_alignParentEnd">true</item>
<item name="android:adjustViewBounds">true</item>
<item name="android:src">#drawable/bc_spinner_arrow</item>
</style>
where bc_spinner_arrow is a transparent pic of a white arrow and a vertical line (like the one in the question)

What's causing styles to don't work with API level 16?

So I applied a custom style to my buttons, it works ok with API level 22, but when I test it with API level 16 all my custom styles are gone. What's happening here?. I am an android beginner so probably it's a common behavior but I couldn't find any answer.
Styles are split into 4 xml's representing button states: Pressed, focused, disabled and enabled. I grouped them in 1 xml called button.xml and applied it in styles.xml
button_pressed.xml (focused, disabled and enabled are similar)
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<gradient
android:angle="90"
android:endColor="#004B8D"
android:startColor="#0865B7" />
<size
android:height="65dp"
android:width="65dp"/>
<padding
android:bottom="5dp"
android:left="5dp"
android:right="5dp"
android:top="5dp" />
<stroke
android:width="1dp"
android:color="#FFFFFF" />
<corners android:radius="3dp" />
</shape>
button.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:state_enabled="false"
android:drawable="#drawable/button_disabled" />
<item
android:state_pressed="true"
android:state_enabled="true"
android:drawable="#drawable/button_pressed" />
<item
android:state_focused="true"
android:state_enabled="true"
android:drawable="#drawable/button_focused" />
<item
android:state_enabled="true"
android:drawable="#drawable/button_enabled" />
</selector>
styles.xml
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name ="android:buttonStyle">#style/button</item>
</style>
<style name="button" parent="#android:style/Widget.Button">
<item name="android:gravity">center_vertical|center_horizontal</item>
<item name="android:textColor">#FFFFFFFF</item>
<item name="android:shadowColor">#000000</item>
<item name="android:shadowDx">0</item>
<item name="android:shadowDy">-1</item>
<item name="android:shadowRadius">0.4</item>
<item name="android:textSize">20sp</item>
<item name="android:textStyle">bold</item>
<item name="android:background">#drawable/button</item>
<item name="android:focusable">false</item>
<item name="android:clickable">true</item>
<item name="android:fontFamily">sans-serif-condensed</item>
</style>

If you are using appcompat-v7 22.2.1 than it will use material design due to this reason it will be not supported in API 16.
for further information see design support library description
may this answer help to solve your issue.

Not all styles are supported out of the box on older android versions.
Thats why you could probably notice folders such as values -14 values-16 values-21
Without you providing actual styles code, we cannot help you further.

Changing button style in the whole application

I'm trying to change all the TextColor of my buttons in my app to white and also trying to make it bold. But that isn't happening, I'm overwriting the android:Widget.Button
I'm developing for Jelly Bean 4.1.2
What am I doing wrong?
Theme definition in manifest
android:theme="#style/spui" >
The theme where I like to
<style name="spui" parent="android:Theme.Holo.Light.DarkActionBar">
<item name="android:buttonStyle">#style/Buttonspui</item>
</style>
The style for the button itself
<style name="Buttonspui" parent="android:Widget.Button">
<item name="android:background">#drawable/btn_default_holo_light</item>
<item name="android:minHeight">48dip</item>
<item name="android:minWidth">64dip</item>
<item name="android:textColor">#ffffff</item>
<item name="android:textStyle">bold</item>
</style>
The button
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="15dp"
android:text="#string/edit"
android:id="#+id/btnEdit"
style="#style/Buttonspui"/>

For styling your Button you can use this:
Go to the drawable folder and make an XML (e.g. button.xml) file called "style" which contains the following:
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<shape>
<gradient android:startColor="#449def" android:endColor="#2f6699" android:angle="270" />
<stroke android:width="1px" android:color="#000000" />
<corners android:bottomLeftRadius="0dp"
android:bottomRightRadius="0dp"
android:topLeftRadius="8dp"
android:topRightRadius="8dp"/>
<padding android:left="10dp" android:top="10dp" android:right="10dp" android:bottom="10dp" />
</shape>
</item>
</selector>
This is my code, you can make the necessary changes you want
Now call it in your layout XML (mainactivity.xml) like this
android:background="#drawable/button.xml"
Now to change the font color and style you can use the following which comes as part of the styles.xml in the values folder
<style name="buttonStyle" parent="#android:style/Widget.Button.Small">
<item name="android:textColor">#FFFFFF</item>
<item name="android:textSize">12sp</item>
<item name="android:textStyle">bold</item>
</style>
Now call this in the layout XML (mainactivity.xml) like this
style="#style/buttonStyle"
The final code is:
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="15dp"
android:text="#string/edit"
android:id="#+id/btnEdit"
android:background="#drawable/button.xml"
style="#style/buttonStyle"
/>
Hope this helps :)

This will change the default button style for the entire app, include alert dialog button. Adjust the style based on yours.
res/values/styles.xml
<resources>
<!-- Your base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Other styles -->
<item name="buttonStyle">#style/MyCustomButton</item>
</style>
<style name="MyCustomButton" parent="Widget.AppCompat.Button">
<item name="android:background">#drawable/selector_button</item>
<item name="android:textColor">#color/buttonText</item>
<item name="android:textStyle">bold</item>
<item name="android:paddingLeft">16dp</item>
<item name="android:paddingRight">16dp</item>
</style>
</resources>
res/drawable/selector_button.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="#drawable/button_selected" android:state_pressed="true"/>
<item android:drawable="#drawable/button_selected" android:state_focused="true"/>
<item android:drawable="#drawable/button_unselected"/>
</selector>
res/drawable/button_selected.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<corners android:radius="1000dp"/>
<solid android:color="#color/buttonSelected"/>
</shape>
res/drawable/button_unselected.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<corners android:radius="1000dp"/>
<solid android:color="#color/buttonUnselected"/>
</shape>