material checkbox style after customize

Question

My customized checkbox (MyCheckbox) has extended from androidx.appcompat.widget.AppCompatCheckBox, but the default styles don\'t apply to it.

Answer 1

According to this answer, I tried using ContextThemeWrapper to apply the style:

class MyCheckbox @JvmOverloads constructor(context: Context,
                                        attrs: AttributeSet? = null,
                                        defStyle: Int = 0)
: MaterialCheckBox(ContextThemeWrapper(context, R.style.CheckboxTheme), attrs, defStyle)

Answer 2

The MaterialCheckBox provided by the Material Components library uses the checkboxStyle attribute defined in the theme.
Just override this attribute to define globally the style in your app:

<style name="AppTheme" parent="Theme.MaterialComponents.DayNight">
   <!-- .... -->
   <item name="checkboxStyle">@style/MyCheckBox</item>
</style>

If you want to customize the color you can use the materialThemeOverlay attribute in the style:

<style name="MyCheckBox" parent="@style/Widget.MaterialComponents.CompoundButton.CheckBox">
   <item name="materialThemeOverlay">@style/ThemeOverlay.CheckBox</item>
</style>

with:

  <style name="ThemeOverlay.CheckBox" parent="">
    <item name="colorSecondary">@color/....</item>   <!-- checked -->
    <item name="colorOnSurface">@color/.....</item>  <!-- unchecked -->
  </style>

You can also apply the style to the single checkbox using:

<com.google.android.material.checkbox.MaterialCheckBox
    style="@style/MyCheckBox"
    ..>

As alternative you can also use the android:theme in the layout, but it doesn't work globally.

<com.google.android.material.checkbox.MaterialCheckBox
    ...
    android:theme="@style/ThemeOverlay.CheckBox"/>

Just a note.
The colorTint selector is defined programmatically in the MaterialCheckBox code. You can also define a custom colorTint selector adding the buttonTint attribute in your custom style. In this case the colors defined above are ignored.