Develop Reference

Android override predefined parent style

I use one of the predefined styles for MaterialButton.
<com.google.android.material.button.MaterialButton
style="#style/Widget.MaterialComponents.Button.OutlinedButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Approve" />
And this is the style predefined style which i used.
</style>
<style name="Widget.MaterialComponents.Button.OutlinedButton" parent="Widget.MaterialComponents.Button.TextButton">
<item name="android:paddingLeft">#dimen/mtrl_btn_padding_left</item>
<item name="android:paddingRight">#dimen/mtrl_btn_padding_right</item>
<item name="strokeColor">#color/mtrl_btn_stroke_color_selector</item>
<item name="strokeWidth">#dimen/mtrl_btn_stroke_size</item>
</style>
And this is parent style of Widget.MaterialComponents.Button.OutlinedButton
<style name="Widget.MaterialComponents.Button.TextButton" parent="Widget.MaterialComponents.Button.UnelevatedButton">
<item name="android:textColor">#color/mtrl_text_btn_text_color_selector</item>
<item name="android:paddingLeft">#dimen/mtrl_btn_text_btn_padding_left</item>
<item name="android:paddingRight">#dimen/mtrl_btn_text_btn_padding_right</item>
<item name="iconTint">#color/mtrl_text_btn_text_color_selector</item>
<item name="iconPadding">#dimen/mtrl_btn_text_btn_icon_padding</item>
<item name="backgroundTint">#color/mtrl_btn_text_btn_bg_color_selector</item>
<item name="rippleColor">#color/mtrl_btn_text_btn_ripple_color</item>
</style>
Now i tried to override one of the attributes of Widget.MaterialComponents.Button.TextButton in my styles.xml
<style name="Widget.MaterialComponents.Button.TextButton">
<item name="android:textColor">#color/colorAccent</item>
</style>
I wonder whether this is the right approach or not to override a predefined style and will style Widget.MaterialComponents.Button.OutlinedButton use #color/colorAccent as text color. I think its working but i can not be sure is there any side effect of this approach or is there a better way ?

You can use one of the following:
<style name="MyCustomStyle" parent="Widget.MaterialComponents.Button.OutlinedButton">
<item name="android:textColor">#color/colorAccent</item>
</style>
<style name="Widget.MaterialComponents.Button.OutlinedButton.MyCustomStyle">
<item name="android:textColor">#color/colorAccent</item>
</style>
With these approach, you would inherit all the properties of your parent style and you would be declare only those properties that you like to change/override.
And use this style in your layout file as follow:
<com.google.android.material.button.MaterialButton
style="#style/MyCustomStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Approve" />
or
<com.google.android.material.button.MaterialButton
style="#style/Widget.MaterialComponents.Button.OutlinedButton.MyCustomStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Approve" />

Android Button Theme not applying

I created really simple view. I would like to create default layout for my button and import it via AppTheme, which i added in manifest file.
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="buttonStyle">#style/ButtonStyle</item>
<item name="android:buttonStyle">#style/ButtonStyle</item>
<item name="android:button">#style/ButtonStyle</item>
</style>
<style name="ButtonStyle" >
<item name="android:textSize">20dp</item>
<item name="android:gravity">center</item>
<item name="android:layout_width">150dp</item>
<item name="android:layout_gravity">center</item>
<item name="android:layout_marginTop">10dp</item>
<item name="android:background">#drawable/defaultbutton</item>
</style>
So what I expect is to have all buttons in my app be styled which this settings. Only way i can accomplishe it is to import style inside my button using
style="#style/ButtonStyle"
Button 'Start Test' is styled via inside import.
Funny thing is that some styles are imported for buttons 'Settings' and 'Check Sensors' ( like drawable/deefaultbutton or centered text)
<Button
style="#style/ButtonStyle"
android:id="#+id/test"
android:layout_height="50dp"
android:text="Start Test" />
<Button
android:id="#+id/settings"
android:layout_width="150dp"
android:layout_height="50dp"
android:text="Settings" />
<Button
android:id="#+id/checkSensors"
android:layout_width="150dp"
android:layout_height="50dp"
android:text="Check Sensors" />
My question is, why is this happening and i can't set it as default without importing it via 'Theme' ?
Tried this and read this but it doesn't work for me.

Custom style should extend Widget styles to use with buttonStyle attribute.
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="buttonStyle">#style/Widget.AppCompat.Button.ButtonStyle</item>
</style>
<style name="Widget.AppCompat.Button.ButtonStyle">
<item name="android:textSize">20dp</item>
<item name="android:gravity">center</item>
<item name="android:layout_width">150dp</item>
<item name="android:layout_gravity">center</item>
<item name="android:layout_marginTop">10dp</item>
<item name="android:background">#drawable/defaultbutton</item>
</style>

set a custom font for a button text in Xamarin Android

I have a button and I want to set a custom font to the text but I have trouble doing that.
The code is the following :
In .xml file :
<Button
android:id="#+id/button"
style="#style/ButtonStyle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
tools:text="Sample Text"/>
and in styles.xml
<style name="ButtonStyle" parent="#style/Widget.AppCompat.Button.Borderless">
<item name="android:textSize">#dimen/button_text_size</item>
<item name="android:background">#drawable/button_background</item>
<item name="android:textAppearanceButton">#style/ButtonTextStyle</item>
<item name="android:textColor">?android:textColorPrimaryInverse</item>
</style>
<style name="ButtonTextStyle" parent="TextAppearance.AppCompat">
<item name="android:fontFamily">#font/my_custom_font</item>
</style>

Instead of of creating a different style fontFamily should be used in the button style and the code should look like this.
<style name="ButtonStyle" parent="#style/Widget.AppCompat.Button.Borderless">
<item name="android:textSize">#dimen/button_text_size</item>
<item name="android:background">#drawable/button_background</item>
<item name="android:fontFamily">#font/my_custom_font</item>
<item name="android:textColor">?android:textColorPrimaryInverse</item>
</style>

Android style inheritance not working

styles.xml
<style name="Red" parent="android:TextAppearance.DeviceDefault.Medium.Inverse">
<item name="android:textColor">#f00</item>
</style>
<style name="Red.LARGE">
<item name="android:textSize">30sp</item>
</style>
When i use this;
<Button
android:id="#+id/save"
android:text="#string/save"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="#dimen/save_marginTop"
android:gravity="center"
style="#style/Red.LARGE"/>
This button attribute only Large and doest painting to Red. Why?

Your Red.LARGE style needs to use the parent attribute. Red.LARGE will inherit Red if it is changed to:
<style name="Red.LARGE" parent="Red">
<item name="android:textSize">30sp</item>
</style>

applying style to textview drawable

I have a layout for a TextView and drawable as such...
<LinearLayout style="#style/dashboard_content_horizontal" >
<ImageView
style="#style/dashboard_imageview"
android:src="#drawable/menu6" />
<TextView
style="#style/dashboard_textview"
android:text="#string/menu6_text />
</LinearLayout>
as you can see the image uses a style attribute which looks like this
<style name="dashboard_imageview">
<item name="android:layout_width">fill_parent</item>
<item name="android:layout_height">fill_parent</item>
<item name="android:layout_weight">1</item>
<item name="android:scaleType">fitCenter</item>
</style>
the linear layout's style surrounding it looks like this
<style name="dashboard_content_horizontal">
<item name="android:layout_width">0px</item>
<item name="android:layout_height">fill_parent</item>
<item name="android:layout_weight">3</item>
<item name="android:orientation">vertical</item>
<item name="android:layout_gravity">center</item>
<item name="android:gravity">center</item>
</style>
and TextView's style
<style name="dashboard_textview">
<item name="android:layout_width">fill_parent</item>
<item name="android:layout_height">wrap_content</item>
<item name="android:gravity">center</item>
<item name="android:textSize">20sp</item>
<item name="android:textStyle">bold</item>
<item name="android:textColor">#color/black</item>
</style>
this all works and looks exactly how I want it to look. however, because of this eclipse warning
"This tag and its children can be replaced by one
and a compound drawable" I decide to try to do this with just a TextView and drawable
like such..
<TextView
android:layout_marginTop="10dp"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Menu6"
android:drawableBottom="#drawable/my_drawable"
android:padding="5dp" />
this renders the image too small.. I don't see a way to apply a style to the image to get it like I want it.. anyone know the answer? is even possible?