SOLID -界面分离原则

Question

我想知道如何在TextWatcher上实现SOLID中的接口隔离原则。

更具体地说:如何删除不需要的函数：

beforeTextChanged()、afterTextChanged()

因为我只需要：

onTextChanged()

    passwordinput.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            presenter.validateCredentials(emailinput.getText().toString(), passwordinput.getText().toString());
        }

        @Override
        public void afterTextChanged(Editable s) {

        }
    });

Answer 1

创建一个从MyTextWatcher继承的类NewClass，并

passwordinput.addTextChangedListener(new New Class() {

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
        presenter.validateCredentials(emailinput.getText().toString(), passwordinput.getText().toString());
    }

    });

Answer 2

您可以通过实现TextWatcher来创建自己的TextWatcher类，并保留默认实现为空。然后，在您的匿名实现中，只覆盖onTextChanged()。

class MyTextWatcher implements TextWatcher {
@Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {

    }

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {

    }

    @Override
    public void afterTextChanged(Editable s) {

    }
}

用法：

passwordinput.addTextChangedListener(new MyTextWatcher() {

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            presenter.validateCredentials(emailinput.getText().toString(), passwordinput.getText().toString());
        }

    });