Android 中RxBinding的使用

Jake Wharton的RxBinding
RxBinding系列之RxView(一)

RxBinding可将Android中各类UI控件的动作事件转换为RxJava中的数据流。也就是说可以使用RxBinding以RxJava的形式来处理UI事件。本篇主要讲解其中RxView的相关View事件如何绑定。
RxBinding中主要包含RxView、RxTextView、RxAdapterView、RxCompoundButton等等。

Platform bindings:

implementation 'com.jakewharton.rxbinding3:rxbinding:3.0.0-alpha2'

AndroidX library bindings:

implementation 'com.jakewharton.rxbinding3:rxbinding-core:3.0.0-alpha2'
implementation 'com.jakewharton.rxbinding3:rxbinding-appcompat:3.0.0-alpha2'
implementation 'com.jakewharton.rxbinding3:rxbinding-drawerlayout:3.0.0-alpha2'
implementation 'com.jakewharton.rxbinding3:rxbinding-leanback:3.0.0-alpha2'
implementation 'com.jakewharton.rxbinding3:rxbinding-recyclerview:3.0.0-alpha2'
implementation 'com.jakewharton.rxbinding3:rxbinding-slidingpanelayout:3.0.0-alpha2'
implementation 'com.jakewharton.rxbinding3:rxbinding-swiperefreshlayout:3.0.0-alpha2'
implementation 'com.jakewharton.rxbinding3:rxbinding-viewpager:3.0.0-alpha2'

Google 'material' library bindings:

implementation 'com.jakewharton.rxbinding3:rxbinding-material:3.0.0-alpha2'

click点击事件

clicks
throttleFirst(long windowDuration, TimeUnit unit)，设置一定时间内只响应首次(throttleFirst)或者末次(throttleLast)的点击事件。windowDuration为防抖时间，unit为时间单位。调用这个方法便可防止短时间内对View的重复点击，本例中设置的防抖时间为 1s。

 RxView.clicks(mLoginButton)
                //1秒钟之内只取一个点击事件，防抖操作
                .throttleFirst(1, TimeUnit.SECONDS)
                .subscribe(new Consumer<Unit>() {
                    @Override
                    public void accept(Unit unit) throws Exception {

                    }
                }, new Consumer<Throwable>() {
                    @Override
                    public void accept(Throwable throwable) throws Exception {

                    }
                });

longClicks
RxView.longClicks(View view)，内部封装了View.OnLongClickListener长按监听，原理同上。

   RxView.longClicks(mLoginButton)
                .subscribe(new Consumer<Unit>() {
                    @Override
                    public void accept(Unit unit) throws Exception {
                        Log.i(TAG, "accept: longClicks-test");
                    }
                });

RxTextView

  /**
         * accept: rxbindg_test before0-start-0-textxx
         * accept: rxbindg_test before12-start-12-textxx
         */
        RxTextView.textChangeEvents(mPswEditText)
                .subscribe(new Consumer<TextViewTextChangeEvent>() {
                    @Override
                    public void accept(TextViewTextChangeEvent textViewTextChangeEvent) throws Exception {
                        Log.i(TAG, "accept: rxbindg_test before"+textViewTextChangeEvent.getStart()
                                +"-start-"+textViewTextChangeEvent.getStart()
                                +"-text"+textViewTextChangeEvent.getText()+"count"+textViewTextChangeEvent.getCount());

                    }
                });

RxTextView结合combineLatest操作符：
应用场景：登录时满足所有条件下，登录按钮才可以点击
说明：监听多个被观察者是否变化，在一个地方进行统一验证，如果验证成功，那么允许用户进行下一步的操作，否则提示用户输入不正确，有任意一个被观察者发生改变时，会去取 其它 Observable 最近一次发射的数据，回调到函数当中。combineLatest就被触发连接几个被观察者进行校验。
比如以下的两个被观察者，启动APP并没有再用户名和密码输入框中输入数据，但是此时这两个控件已被监听，相当于所有的Observable都至少发射过一个数据项，监听结果为空直接触发apply事件，输入用户名时被观察者nameObservable发生变化，也直接触发apply事件。

 private void initFilter() {
        InitialValueObservable<CharSequence> nameObservable = RxTextView.textChanges(userNameEditText);
        InitialValueObservable<CharSequence> pwdObservable = RxTextView.textChanges(userPwdEditText);
        InitialValueObservable<CharSequence> checkBoxObservable = RxTextView.textChanges(userPwdEditText);
        nameObservable.subscribe(new Consumer<CharSequence>() {
            @Override
            public void accept(CharSequence charSequence) throws Exception {
                String txt = charSequence.toString();
            }
        }, new Consumer<Throwable>() {
            @Override
            public void accept(Throwable throwable) throws Exception {

            }
        });

        Observable.combineLatest(nameObservable, pwdObservable, new BiFunction<CharSequence, CharSequence, Boolean>() {
            @Override
            public Boolean apply(CharSequence charSequence, CharSequence charSequence2) throws Exception {
                boolean isEnnable = !TextUtils.isEmpty(userNameEditText.getText().toString()) && !TextUtils.isEmpty(userPwdEditText.getText().toString());
                Log.i(TAG, "apply: " + isEnnable);

                return isEnnable;
            }
        }).subscribe(new Consumer<Boolean>() {
            @Override
            public void accept(Boolean aBoolean) throws Exception {
                Log.i(TAG, "accept: " + aBoolean);
                if (aBoolean) {
                    loginButton.setBackgroundColor(0xffFF0000);
                    loginButton.setClickable(true);
                } else {
                    loginButton.setBackgroundColor(0xff00FF00);
                    loginButton.setClickable(false);

                }
            }
        });

 Observable.combineLatest(mobileObservable, passwordObservable, new BiFunction<CharSequence, CharSequence, Object>() {
            @Override
            public Object apply(CharSequence mobile, CharSequence password) throws Exception {
                Log.d(TAG,"合并事件订阅 "+mobile+"  "+password);
                //手机号、短信验证码、勾选框 都符合条件时，才允许点击登录
                if(!TextUtils.isEmpty(mobile) && !TextUtils.isEmpty(password)){
                    loginButton.setClickable(true);
                    loginButton.setBackgroundResource(R.drawable.basic_login_bg02);
                }else{
                    loginButton.setClickable(false);
                    loginButton.setBackgroundResource(R.drawable.basic_login_bg01);
                }

                return new Object();
            }
        }).subscribeOn(AndroidSchedulers.mainThread())
                .observeOn(AndroidSchedulers.mainThread())
                .as(AutoDispose.autoDisposable(AndroidLifecycleScopeProvider.from(activityContext, Lifecycle.Event.ON_DESTROY)))
                .subscribe(new Consumer<Object>() {
                    @Override
                    public void accept(Object o) throws Exception {}
                });