package com.example.popupwindowdemo;
import android.app.Activity;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout.LayoutParams;
import android.widget.PopupWindow;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener
{
    private PopupWindow pw = null;
    private Button but_pos = null;
    private Button but_neg = null;
    
    private Button but_show = null;
    
    private int screenWidth = 0;
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        screenWidth = getWindowManager().getDefaultDisplay().getWidth();
        but_show = (Button) findViewById(R.id.but_show);
        but_show.setOnClickListener(this);
    }
    
    public void initPopupWindow()
    {
        View view = getLayoutInflater().inflate(R.layout.layout_popup_window,null);
        but_pos = (Button) view.findViewById(R.id.but_pos);
        but_neg = (Button) view.findViewById(R.id.but_neg);
        but_neg.setOnClickListener(this);
        but_pos.setOnClickListener(this);
        
        pw = new PopupWindow(view, LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT,true);
        pw.setWidth(screenWidth*3/4);
        pw.setBackgroundDrawable(new BitmapDrawable());
    }
    @Override
    public void onClick(View v)
    {
        switch (v.getId())
        {
        case R.id.but_neg:
            Toast.makeText(this,"取消", 0).show();
            pw.dismiss();
            break;
        case R.id.but_pos:
            Toast.makeText(this,"開始下載", 0).show();
            pw.dismiss();
            break;
        case R.id.but_show:
            initPopupWindow();
            //顯示在指定位置
            pw.showAtLocation(findViewById(R.id.root),Gravity.CENTER,0,0);
            //預設顯示在指定的view左下,可以指定偏移量,這裡讓其顯示在中間
//            pw.showAsDropDown(but_show,(screenWidth-pw.getWidth())/2,0);
            break;
        }
    }
}