Android实现滑动刻度尺效果

package net.loonggg.rulerdemo;
 
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
 
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.ViewGroup.LayoutParams;
import android.widget.HorizontalScrollView;
import android.widget.LinearLayout;
import android.widget.TextView;
 
public class MainActivity extends Activity {
private HorizontalScrollView ruler;
private LinearLayout rulerlayout, all_layout;
private TextView user_birth_value;
private int beginYear;
 
private String birthyear = "1970";
private long time = 0;
private int screenWidth;
private boolean isFirst = true;
 
@Override
protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 user_birth_value = (TextView) findViewById(R.id.user_birth_value);
 user_birth_value.setText("1970");
 ruler = (HorizontalScrollView) findViewById(R.id.birthruler);
 rulerlayout = (LinearLayout) findViewById(R.id.ruler_layout);
 ruler.setOnTouchListener(new OnTouchListener() {
  @Override
  public boolean onTouch(View v, MotionEvent event) {
   int action = event.getAction();
   user_birth_value.setText(String.valueOf(beginYear
     + (int) Math.ceil((ruler.getScrollX()) / 20)));
   switch (action) {
   case MotionEvent.ACTION_DOWN:
   case MotionEvent.ACTION_MOVE:
    break;
   case MotionEvent.ACTION_UP:
    new Handler().postDelayed(new Runnable() {
     @Override
     public void run() {
      user_birth_value.setText(String.valueOf(beginYear
        + (int) Math.ceil((ruler.getScrollX()) / 20)));
      birthyear = String.valueOf((int) (beginYear + Math
        .ceil((ruler.getScrollX()) / 20)));
      try {
       time = (new SimpleDateFormat("yyyy")
         .parse(String.valueOf(birthyear)))
         .getTime();
      } catch (ParseException e) {
       e.printStackTrace();
      }
     }
    }, 1000);
    break;
   }
   return false;
  }
 });
}
@Override
public void onWindowFocusChanged(boolean hasFocus) {
 super.onWindowFocusChanged(hasFocus);
 if (isFirst) {
  screenWidth = ruler.getWidth();
  constructRuler();
  isFirst = false;
 }
}
@Override
protected void onResume() {
 super.onResume();
 new Handler().postDelayed(new Runnable() {
  @Override
  public void run() {
   scroll();
  }
 }, 100);
}
private void scroll() {
 ruler.smoothScrollTo((1970 - beginYear) * 20, 0);
}
@SuppressWarnings("deprecation")
private void constructRuler() {
 int year = new Date().getYear();
 if (year <2015)
  year = 2010;
 beginYear = year / 10 * 10 - 150;
 View leftview = (View) LayoutInflater.from(this).inflate(
   R.layout.blankhrulerunit, null);
 leftview.setLayoutParams(new LayoutParams(screenWidth / 2,
   LayoutParams.MATCH_PARENT));
 rulerlayout.addView(leftview);
 for (int i = 0; i <16; i++) {
  View view = (View) LayoutInflater.from(this).inflate(
    R.layout.hrulerunit, null);
  view.setLayoutParams(new LayoutParams(200,
    LayoutParams.MATCH_PARENT));
  TextView tv = (TextView) view.findViewById(R.id.hrulerunit);
  tv.setText(String.valueOf(beginYear + i * 10));
  rulerlayout.addView(view);
 }
 View rightview = (View) LayoutInflater.from(this).inflate(
   R.layout.blankhrulerunit, null);
 rightview.setLayoutParams(new LayoutParams(screenWidth / 2,
   LayoutParams.MATCH_PARENT));
 rulerlayout.addView(rightview);
}
}