BTDPInterpreterActivity.java

package com.cheng.bigtalkdesignpatterns.interpreter;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import com.cheng.designpatternstudy.R;

public class BTDPInterpreterActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_btdp_interpreter);
    }

    public void onClick(View v) {
        PlayContext context = new PlayContext();
        // 音乐-上海滩
        System.out.println("上海滩：");
        context.setPlayText("T 500 O 2 E 0.5 G 0.5 A 3 E 0.5 G 0.5 D 3 E 0.5 G 0.5 A 0.5 O 3 C 1 O 2 A 0.5 G 1 C 0.5 E 0.5 D 3 ");
        Expression expression = null;
        try {
            while (context.getPlayText().length() > 0) {
                String str = context.getPlayText().substring(0, 1);
                switch (str) {
                    case "O":
                        expression = new Scale();
                        break;
                    case "T":
                        expression = new Speed();
                        break;
                    case "C":
                    case "D":
                    case "E":
                    case "F":
                    case "G":
                    case "A":
                    case "B":
                    case "P":
                        expression = new Note();
                        break;
                }
                expression.interpret(context);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}