Add EditText extension functions

* Text changed TextWatcher

* Validator watcher

Show/hide password

Author: enginebai

base/src/main/java/com/enginebai/base/extensions/EditTextExt.kt

@@ -0,0 +1,80 @@
+package com.enginebai.base.extensions
+
+import android.text.Editable
+import android.text.InputFilter
+import android.text.TextWatcher
+import android.text.method.HideReturnsTransformationMethod
+import android.text.method.PasswordTransformationMethod
+import android.widget.EditText
+import io.reactivex.Observable
+import io.reactivex.Single
+import io.reactivex.subjects.PublishSubject
+
+fun EditText.textChanged(listener: (String) -> Unit): TextWatcher {
+	val textWatcher = object : TextWatcher {
+		override fun afterTextChanged(s: Editable?) {
+			listener.invoke(s?.toString() ?: "")
+		}
+
+		override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {}
+		override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {}
+	}
+	this.addTextChangedListener(textWatcher)
+	return textWatcher
+}
+
+fun EditText.textChanged(): Observable<out CharSequence> {
+	val source: PublishSubject<String> = PublishSubject.create()
+	val textWatcher = TextChangeWatcher(source)
+	addTextChangedListener(textWatcher)
+	return source.doOnDispose {
+		textWatcher.unsubscribe()
+		removeTextChangedListener(textWatcher)
+	}
+}
+
+private class TextChangeWatcher(private var publisher: PublishSubject<String>? = null) :
+	TextWatcher {
+
+	override fun afterTextChanged(s: Editable?) {
+		publisher?.onNext(s?.toString() ?: "")
+	}
+
+	override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {}
+	override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {}
+
+	fun unsubscribe() {
+		publisher = null
+	}
+}
+
+
+fun EditText.validate(errorMessage: String, validator: (String) -> Boolean): TextWatcher {
+	fun showErrorIfInvalid(s: String) {
+		this.error = if (validator(s)) null else errorMessage
+	}
+	// validate original text
+	showErrorIfInvalid(this.text.toString())
+	// validate changed text
+	return this.textChanged { showErrorIfInvalid(it) }
+}
+
+fun EditText.validateEmail(errorMessage: String): TextWatcher {
+	return validate(errorMessage) { it.isValidEmail() }
+}
+
+fun EditText.validateEmail(): Single<Boolean> {
+	return Single.fromObservable(this.textChanged()).flatMap {
+		Single.just(it.toString().isValidEmail())
+	}
+}
+
+fun EditText.showPassword() {
+	transformationMethod = HideReturnsTransformationMethod.getInstance()
+	selectAll()
+}
+
+fun EditText.hidePassword() {
+	transformationMethod = PasswordTransformationMethod.getInstance()
+	selectAll()
+}

base/src/main/java/com/enginebai/base/extensions/StringExt.kt

@@ -0,0 +1,8 @@
+package com.enginebai.base.extensions
+
+import android.util.Patterns
+import androidx.core.util.PatternsCompat
+
+fun String.isValidEmail(): Boolean {
+	return PatternsCompat.EMAIL_ADDRESS.matcher(this).matches()
+}