igorwojda

class KotlinViewModelProvider {
    companion object {
        inline fun <reified T : ViewModel> of(fragment: Fragment, crossinline factory: () -> T): T {

            @Suppress("UNCHECKED_CAST")
            val vmFactory = object : ViewModelProvider.Factory {
                override fun <U : ViewModel> create(modelClass: Class<U>): U = factory() as U
            }

            return ViewModelProviders.of(fragment, vmFactory)[T::class.java]

igorwojda

class Person {
    var age: Int = 0
}

//Usage
val person = Person()
person.age = 20
println(person.age) //prints 20

igorwojda

class Person {
    private var age: Int = 0

    fun getAge(): Int {
        return age
    }

    fun setAge(age: Int) {
        this.age = age
    }

igorwojda

val view = View()
view.beforeTextChangedListener = { /* do something */ }

igorwojda

class View {
    var beforeTextChangedListener: (() -> Unit)? = null
    var afterTextChangedListener: (() -> Unit)? = null
    var onTextChangedListener: (() -> Unit)? = null
}

igorwojda

val view = View()
view.setBeforeTextChangedListener ({ /* do something */ })
//...
// later in code we can set another listener
view.setAfterTextChangedListener ({ /* do something */ })
//no need to set 3rd listener

igorwojda

public interface TextWatcher {
    public void beforeTextChanged(CharSequence s, int start,
    public void onTextChanged(CharSequence s, int start, int before, int count);
    public void afterTextChanged(Editable s);
}

igorwojda

val view = View()
view.setBeforeTextChangedListener { /* do something */ }
//...
// later in code we can set another listener
view.setAfterTextChangedListener { /* do something */ }
//no need to set 3rd listener

igorwojda

class View {
    private var beforeTextChangedListener: (() -> Unit)? = null
    private var afterTextChangedListener: (() -> Unit)? = null
    private var onTextChangedListener: (() -> Unit)? = null

    fun setBeforeTextChangedListener(listener: () -> Unit) {
        beforeTextChangedListener = listener
    }

    fun setAfterTextChangedListener(listener: () -> Unit) {

igorwojda

textView.addTextChangedListener(new TextWatcher() {

    public void afterTextChanged(Editable s) {
        //do something
    }

    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        //do something
    }