kotlin custom spinner example in android

 kotlin custom spinner example in android

In this Article today learn kotlin custom spinner example. follow the full source code kotlin custom spinner example

1.MainActivity.kt:

import androidx.appcompat.app.AppCompatActivity

import android.os.Bundle

import com.google.gson.Gson

import kotlinx.android.synthetic.main.activity_main.*

 

class MainActivity : AppCompatActivity() {

 

    override fun onCreate(savedInstanceState: Bundle?) {

        super.onCreate(savedInstanceState)

        setContentView(R.layout.activity_main)

 

        val modelList: List<Model> = readFromAsset()

 

        val customDropDownAdapter = CustomDropDownAdapter(this, modelList)

        spinner04.adapter = customDropDownAdapter

    }

 

    private fun readFromAsset(): List<Model> {

        val file_name = "android_version.json"

 

        val bufferReader = application.assets.open(file_name).bufferedReader()

 

        val json_string = bufferReader.use {

            it.readText()

        }

        val gson = Gson()

        val modelList: List<Model> = gson.fromJson(json_string, Array<Model>::class.java).toList()

        return modelList

    }

 

}

2.activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout

        xmlns:android="http://schemas.android.com/apk/res/android"

        xmlns:tools="http://schemas.android.com/tools"

        xmlns:app="http://schemas.android.com/apk/res-auto"

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        tools:context=".MainActivity"

        android:orientation="vertical">

 

    <TextView android:layout_width="wrap_content"

              android:layout_height="wrap_content"

              android:text="Custom Spinner With Text and Image"

              android:layout_marginTop="20dp"

              android:textSize="20sp"

              android:textStyle="bold"/>

 

    <androidx.appcompat.widget.AppCompatSpinner

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:layout_marginTop="16dp"

            android:id="@+id/spinner04"/>

     

</LinearLayout>

3.Model.kt:

data class Model

(val name: String, val url: String) 

{

}

4.CustomDropDownAdapter.kt:

import android.content.Context

import android.view.LayoutInflater

import android.view.View

import android.view.ViewGroup

import android.widget.BaseAdapter

import android.widget.ImageView

import android.widget.TextView

 

class CustomDropDownAdapter(val context: Context, var dataSource: List<Model>) : BaseAdapter() {

 

    private val inflater: LayoutInflater = context.getSystemService(Context.LAYOUT_INFLATER_SERVICE) as LayoutInflater

 

    override fun getView(position: Int, convertView: View?, parent: ViewGroup?): View {

 

        val view: View

        val vh: ItemHolder

        if (convertView == null) {

            view = inflater.inflate(R.layout.custom_spinner_item, parent, false)

            vh = ItemHolder(view)

            view?.tag = vh

        } else {

            view = convertView

            vh = view.tag as ItemHolder

        }

        vh.label.text = dataSource.get(position).name

 

        val id = context.resources.getIdentifier(dataSource.get(position).url, "drawable", context.packageName)

        vh.img.setBackgroundResource(id)

 

        return view

    }

 

    override fun getItem(position: Int): Any? {

        return dataSource[position];

    }

 

    override fun getCount(): Int {

        return dataSource.size;

    }

 

    override fun getItemId(position: Int): Long {

        return position.toLong();

    }

 

    private class ItemHolder(row: View?) {

        val label: TextView

        val img: ImageView

 

        init {

            label = row?.findViewById(R.id.text) as TextView

            img = row?.findViewById(R.id.img) as ImageView

        }

    }

 

}

5.custom_spinner_item.xml:

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

              android:orientation="horizontal"

              android:layout_width="match_parent"

              android:layout_height="wrap_content"

              android:padding="8dp">

 

    <ImageView android:layout_width="40dp"

               android:layout_height="40dp"

               android:id="@+id/img"

               android:contentDescription="@string/app_name"/>

 

    <TextView android:layout_width="match_parent"

              android:layout_height="wrap_content"

              android:textSize="20sp"

              android:paddingStart="10dp"

              android:layout_gravity="center_vertical"

              android:id="@+id/text"/>

 

</LinearLayout>

6.AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>

<manifest

    package="com.spinner.example"

    xmlns:android="http://schemas.android.com/apk/res/android">

    <application

        android:name=".ui.App"

        android:allowBackup="true"

        android:icon="@mipmap/ic_launcher"

        android:networkSecurityConfig="@xml/network_security_config"

        android:label="@string/app_name"

        android:theme="@style/AppTheme">

        <activity

            android:name=".ui.activities.MainActivity"

            android:label="@string/app_name">

            <intent-filter>

                <action android:name="android.intent.action.MAIN"/>

                <category android:name="android.intent.category.LAUNCHER"/>

            </intent-filter>

        </activity>

        

    </application>

</manifest>