Wednesday, March 11, 2020

android kotlin - ListView disable item programmatically

MainActivity.kt 

package com.cfsuman.kotlintutorials

import android.app.Activity
import android.os.Bundle
import android.view.View
import android.view.ViewGroup
import android.widget.*


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

        // get the widgets reference from XML layout
        val button = findViewById<Button>(R.id.button)
        val listView = findViewById<ListView>(R.id.listView)
        val textView = findViewById<TextView>(R.id.textView)


        // list to populate list view
        val list = mutableListOf(
            "Golden yellow",
            "Han purple",
            "Hansa yellow",
            "Jazzberry jam",
            "Jungle green",
            "Lavender blush",
            "Lawn green"
        )


        // initialize an array adapter
        val adapter:ArrayAdapter<String> = object: ArrayAdapter<String>(
            this,
            android.R.layout.simple_dropdown_item_1line,
            list
        ){
            override fun isEnabled(position: Int): Boolean {
                // disable adapter fifth item at array adapter initialization
                // this actually disable list view item click
                return position != 4
            }

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

                val tv =  super.getView(position,
                    convertView, parent) as TextView

                // show the disable text color for fifth item
                // this actually not disable the list view item click
                tv.isEnabled = position != 4

                return tv
            }
        }


        // attach the array adapter with list view
        listView.adapter = adapter


        // list view item click listener
        listView.onItemClickListener = AdapterView.OnItemClickListener {
                parent, view, position, id ->

            val selectedItem = parent?.getItemAtPosition(position)
                .toString()
            textView.text = selectedItem
        }


        // disable list view third item on button click
        button.setOnClickListener {
            // disable the button itself
            it.isEnabled = false

            // disable the third item of list view
            val view = listView.getChildAt(2)
            view.setOnClickListener { }
            view.isEnabled = false
        }
    }
}
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">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Disable Third Item"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ListView
        android:id="@+id/listView"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginBottom="24dp"
        app:layout_constraintBottom_toTopOf="@+id/textView"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/button" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="Select your favorite color"
        android:fontFamily="sans-serif"
        android:gravity="center"
        android:textColor="#333399"
        android:textSize="24sp"
        android:textStyle="italic"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>
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