Saturday, February 29, 2020

android kotlin - Spinner selected item background color

MainActivity.kt

package com.cfsuman.kotlintutorials

import android.graphics.Color
import android.graphics.Typeface
import android.graphics.drawable.ColorDrawable
import android.os.Bundle
import android.view.View
import android.view.ViewGroup
import android.widget.*
import androidx.appcompat.app.AppCompatActivity


class MainActivity : AppCompatActivity() {
    private lateinit var context:MainActivity

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Get the context
        context = this

        // Get the widgets reference from XML layout
        val spinner = findViewById<Spinner>(R.id.spinner)

        // list of spinner items
        val list = listOf(
            "Honeydew",
            "Laurel green",
            "Light salmon",
            "Bright maroon",
            "Cherry blossom pink",
            "Moss green",
            "Antique bronze"
        )

        // initialize an array adapter for spinner
        val adapter:ArrayAdapter<String> = object: ArrayAdapter<String>(
            context,
            android.R.layout.simple_spinner_dropdown_item,
            list
        ){
            override fun getDropDownView(
                position: Int,
                convertView: View?,
                parent: ViewGroup
            ): View {
                val view:TextView = super.getDropDownView(
                    position,
                    convertView,
                    parent
                ) as TextView
                // set item font family
                view.setTypeface(Typeface.SANS_SERIF,Typeface.BOLD)

                // set item padding
                view.setPaddingRelative(48,0,48,0)

                // set selected item style
                if (position == spinner.selectedItemPosition){
                    // selected item background color
                    view.background = ColorDrawable(
                        Color.parseColor("#FFF600")
                    )
                    // selected item text color
                    view.setTextColor(Color.parseColor("#2E2D88"))
                }

                return view
            }
        }

        // finally, data bind spinner with adapter
        spinner.adapter = adapter

        // set up initial selection
        spinner.setSelection(2)
    }
}
activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/rootLayout"
    android:background="#DCDCDC"
    android:padding="24dp">

    <Spinner
        android:id="@+id/spinner"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>
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