https://stackoverflow.com/questions/41788166/create-an-observable-from-an-edit-text

We can use RxBinding. This example could help you.

https://github.com/JakeWharton/RxBinding

//Validate username field
Observable<Boolean> usernameObservable = RxTextView.textChanges(usernameEditText)
                .map(username -> StringUtils.isNotBlank(username) && Validators.validateUsername(username.toString())).skip(1);

//Validate password field
Observable<CharSequence> passwordObservable = RxTextView.textChanges(passwordEditText).skip(1);

//Validate confirm password field
Observable<CharSequence> confirmPasswordObservable = RxTextView.textChanges(confirmPasswordEditText)
                .skip(1);

//Validate password matches field
Observable<Boolean> passwordMatcherObservable = Observable.combineLatest(passwordObservable, confirmPasswordObservable,
                (password, confirmPassword) -> password.toString().equals(confirmPassword.toString())).skip(1);

Observable.combineLatest(passwordMatcherObservable, usernameObservable,
                (passwordMatch, isUsernameValid) -> passwordMatch && isUsernameValid)
                .distinctUntilChanged()
                .subscribe(valid -> createAccountBtn.setEnabled(valid));

https://medium.com/@goofyahead/debouncing-edittext-with-rxandroid-894e15da1012

Debouncing EditText with RxAndroid

Typical case, several clics on a button, typing fast on a search box… Those are problems that we have to take care on front end for a better smooth UX.

So lets implement it on android, its also a perfect time to start with Rx and observable patterns.

First dependencies needed:

project gradle

...

dependencies {
    classpath 'com.android.tools.build:gradle:2.2.0-rc1'
    classpath 'me.tatarka:gradle-retrolambda:3.2.5'

...

App gradle

//on top of app graddle
apply plugin: 'me.tatarka.retrolambda'

...

compile 'io.reactivex:rxandroid:1.2.1'
compile 'io.reactivex:rxjava:1.1.6'
compile 'com.jakewharton.rxbinding:rxbinding:0.4.0'
compile 'com.jakewharton.rxbinding:rxbinding-design:0.4.0'

// these are for retrolambda and streams api
compile 'com.annimon:stream:1.1.2'

These are retrolambda and stream api for android, Rx java dependencies, Rx for android and UI bindings from jakewharton 🙂

Thats nice but show me the code!

Observable<String> obs = RxTextView.textChanges(searchBox).filter(charSequence -> charSequence.length() > 3).debounce(300, TimeUnit.MILLISECONDS).map(charSequence ->  charSequence.toString());

obs.subscribe(string -> {
    Log.d(TAG, "debounced " + string);
    startIntentService(prefs.getLastLocation().getCountry() + ", " + string);
});

Yay! with just a few lines we got our debounced EditText that will save us some calls to our service and network calls 🙂