Can't change backgroundTint programmatically

Question

Android Studio 3.6

in my styles. xml

 <style name="buttonStyle">
        <item name="android:textColor">@color/default_button_textColor</item>
        <item name="android:backgroundTint">@color/button_bg_color</item>
        <item name="android:textSize">18sp</item>
        <item name="android:textAllCaps">true</item>
    </style>

    <style name="buttonClickStyle">
        <item name="android:textColor">@color/button_bg_color</item>
        <item name="android:backgroundTint">@color/button_click_bg_color</item>
        <item name="android:textSize">18sp</item>
        <item name="android:textAllCaps">true</item>
    </style>

in xml layout:

 <com.google.android.material.button.MaterialButton
            android:id="@+id/buttonStartSearchBluetooth"
            style="@style/buttonStyle"
            android:layout_width="0dp"
            android:layout_height="@dimen/button_height"
            android:layout_margin="@dimen/button_margin"
            android:onClick="onClickButtonStartSearch"
            android:text="@string/start_search"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent" />

When click button I try to change style like this:

dataBinding.buttonStartSearchBluetooth.setTextAppearance(R.style.buttonClickStyle)

But it change only text color. Not change backgroundTint

Why?

Answer 1

To change programmatically the text color and the background color use:

• the method setBackgroundTintList to change the background color selector.
• the method setTextColor to change the text color

Something like:

    button.setBackgroundTintList(ContextCompat.getColorStateList(this,R.color.button_selector));
    button.setTextColor(ContextCompat.getColor(this, R.color....));

In any case there are some issues in your style.

• use a MaterialComponents.Button.* style as parent
• use backgroundTint instead of android:backgroundTint
• use android:textAppearance to define your text style

Something like:

<style name="buttonStyle" parent="@style/Widget.MaterialComponents.Button">
  <item name="android:textColor">@color/default_button_textColor</item>
  <item name="backgroundTint">@color/my_selector</item>
  <item name="android:textAppearance">@style/my_textAppearance</item>
</style>
<style name="my_textAppearance" parent="@style/TextAppearance.MaterialComponents.Button">
    <item name="android:textSize">18sp</item>
    <item name="android:textAllCaps">true</item>
</style>