compileSdkVersion 28

implementation 'com.google.android.material:material:1.0.0-rc01'

    <com.google.android.material.textfield.TextInputLayout
        android:id="@+id/textInputLayout"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        android:hint="@string/enter_chip_txt"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <!--Horizontal ScrollView to accomodate chips overflow by making them scroll-->

        <HorizontalScrollView
            android:id="@+id/horizontal_scroll_view"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:scrollbars="none">

            <androidx.constraintlayout.widget.ConstraintLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                tools:layout_editor_absoluteX="8dp"
                tools:layout_editor_absoluteY="503dp">

                <!--ChipGroup to hold multiple chips and help in removal by getting child elements-->

                <com.google.android.material.chip.ChipGroup
                    android:id="@+id/chipGroup"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    app:layout_constraintBottom_toBottomOf="@+id/textInputEditText"
                    app:layout_constraintEnd_toStartOf="@+id/textInputEditText"
                    app:layout_constraintStart_toStartOf="parent"
                    app:layout_constraintTop_toTopOf="@+id/textInputEditText" />

                <!--Entering chip generation text and using commas to detect when a new chip is to be generated-->

                <com.google.android.material.textfield.TextInputEditText
                    android:id="@+id/textInputEditText"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:hint="@string/enter_chip_txt"
                    app:layout_constraintBottom_toBottomOf="parent"
                    app:layout_constraintEnd_toEndOf="parent"
                    app:layout_constraintStart_toEndOf="@+id/chipGroup"
                    app:layout_constraintTop_toTopOf="parent" />

            </androidx.constraintlayout.widget.ConstraintLayout>

        </HorizontalScrollView>
    </com.google.android.material.textfield.TextInputLayout>
    

override fun afterTextChanged(s: Editable?) {
                val trimmed = s.toString().trim { it <= ' ' }
                if (trimmed.length > 1 && trimmed.endsWith(",")) {
                    val chip = Chip(this@MainActivity)
                    chip.text = trimmed.substring(0, trimmed.length - 1)
                    chip.isCloseIconVisible = true
                    
                    //Callback fired when chip close icon is clicked 
                    chip.setOnCloseIconClickListener {
                        chipGroup.removeView(chip)
                    }
                    
                    chipGroup.addView(chip)
                    s?.clear()
                }
            }
            

textInputEditText.setOnKeyListener { _, _, event ->
            if (event != null && event.action == KeyEvent.ACTION_DOWN && event.keyCode == KeyEvent.KEYCODE_DEL) {
                if (textInputEditText.length() == 0 && chipGroup.childCount > 0) {
                    val chip = chipGroup.getChildAt(chipGroup.childCount - 1) as Chip
                    chipGroup.removeView(chip)
                }
            }
            false
        }