Material Chip the selection behavior doesn't work

Question

I can't understand how the Chip works. I want to do a a view which contains dynamic filters to select. When I select a chip, there is a press effect (OK), but the chip doesn't stay in the selected state...

I did this quick example in XML. The result is the same...

<com.google.android.material.chip.ChipGroup
        android:id="@+id/tags"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        style="@style/Widget.MaterialComponents.Chip.Choice"
        android:layout_marginTop="@dimen/keyline_0"
        app:chipSpacingHorizontal="8dp"
        app:lineSpacing="8dp">

        <com.google.android.material.chip.Chip
            android:id="@+id/chip"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="test"/>

        <com.google.android.material.chip.Chip
            android:id="@+id/chip2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="test2"/>

        <com.google.android.material.chip.Chip
            android:id="@+id/chip3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="test3"/>

        <com.google.android.material.chip.Chip
            android:id="@+id/chip4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="test4"/>

    </com.google.android.material.chip.ChipGroup>

Answer 1

To style a chip view you need to apply @style/Widget.MaterialComponents.Chip.Choice style to the Chip element. (It is not for ChipGroup).

Take a look at https://material.io/components/chips/android#choice-chip,

Answer 2

Do this

    chips.isCheckable = true

and then set this

    chips.setOnCheckedChangeListener { compoundButton, b ->
              
    }