Android自定义View的学习(四)

MainActivity如下:

package cc.testviewstudy4;

import java.util.ArrayList;
import java.util.HashMap;
import cc.testviewstudy4.ListViewSubClass.OnDeleteListener;
import android.os.Bundle;
import android.widget.SimpleAdapter;
import android.app.Activity;
/**
 * Demo描述:
 * 关于自定义View的学习(四)
 * 
 * 自定义View的实现方式大概可以分为三种:
 * 自绘控件、组合控件、以及继承控件
 * 在此Demo中实现继承控件:
 * 自定义ListView.在ListView的Item上滑动时可出现一个
 * 删除View.点击它,可删除ListView中的该条数据
 * 
 * 学习资料:
 * http://blog.csdn.net/guolin_blog/article/details/17357967
 * Thank you very much
 * 
 */
public class MainActivity extends Activity {
    private ListViewSubClass mListView;
    private SimpleAdapter mSimpleAdapter;
    private ArrayList<HashMap<String, Object>> mArrayList;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		init();
	}
	
	private void init(){
		mListView=(ListViewSubClass) findViewById(R.id.listView);
		mArrayList=new ArrayList<HashMap<String,Object>>();
      	HashMap<String, Object> hashMap=null;
      	for (int i = 0; i <12; i++) {
      		hashMap=new HashMap<String, Object>();
      		hashMap.put("name", "小明"+i);
        	mArrayList.add(hashMap);
		}
      mSimpleAdapter=new SimpleAdapter(this, mArrayList, R.layout.listviewitem, 
    		                           new String []{"name"}, new int[]{R.id.name});
      mListView.setAdapter(mSimpleAdapter);
      mListView.setOnDeleteListener(new OnDeleteListener() {
		@Override
		public void onDelete(int index) {
			mArrayList.remove(index);
			mSimpleAdapter.notifyDataSetChanged();
		}
	});
	}
}

ListViewSubClass如下:

package cc.testviewstudy4;

import android.content.Context;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.GestureDetector.OnGestureListener;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.ViewGroup;
import android.widget.ListView;
import android.widget.RelativeLayout;

public class ListViewSubClass extends ListView implements OnGestureListener,OnTouchListener {
	private GestureDetector mGestureDetector;
	private OnDeleteListener mDeleteListener;
	private View mDeleteView;
	private ViewGroup mListViewItemViewGroup;
	private int selectedItem;
	private boolean isDeleteShowing;
	
	public ListViewSubClass(Context context) {
		super(context);
	}
	
	public ListViewSubClass(Context context, AttributeSet attrs) {
		super(context, attrs);
		// 监听Touch
		setOnTouchListener(this);
		// 手势
		mGestureDetector = new GestureDetector(context, this);
	}
	
	public ListViewSubClass(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
	}

	
	public void setOnDeleteListener(OnDeleteListener onDeleteListener){
		mDeleteListener=onDeleteListener;
	}

	//定义一个接口
	public interface OnDeleteListener {
		void onDelete(int index);
	}
	
	//------>以下方法为OnTouchListener接口的实现
	@Override
	public boolean onTouch(View v, MotionEvent event) {
		//if-->当有删除View的时候.我们触摸该ListView时将其消失
		if (isDeleteShowing) {
			mListViewItemViewGroup.removeView(mDeleteView);
			mDeleteView = null;
			isDeleteShowing = false;
			return false;
	    //else-->其余时候交给GestureDetector处理
		} else {
			return mGestureDetector.onTouchEvent(event);
		}

	}
	//------>以下方法为OnTouchListener接口的实现
	
	

	
	//------>以下方法为OnGestureListener接口的实现
	@Override
	public boolean onDown(MotionEvent e) {
		if (!isDeleteShowing) {
			selectedItem = pointToPosition((int) e.getX(), (int) e.getY());
		}
		return false;
	}

	@Override
	public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,float velocityY) {
		//当删除View没有显示并且是水平滑动时我们显示删除View
		if (!isDeleteShowing && Math.abs(velocityX) > Math.abs(velocityY)) {
			mDeleteView = LayoutInflater.from(getContext()).inflate(R.layout.delete, null);
			mDeleteView.setOnClickListener(new OnClickListener() {
				@Override
				public void onClick(View v) {
					mListViewItemViewGroup.removeView(mDeleteView);
					mDeleteView = null;
					isDeleteShowing = false;
					mDeleteListener.onDelete(selectedItem);
				}
			});
			//找到当前的Item
			mListViewItemViewGroup = (ViewGroup) getChildAt(selectedItem-getFirstVisiblePosition());
			RelativeLayout.LayoutParams params = new 
			RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
			params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
			params.addRule(RelativeLayout.CENTER_VERTICAL);
			mListViewItemViewGroup.addView(mDeleteView, params);
			isDeleteShowing = true;
		}
		
		return false;

	}

	@Override
	public void onLongPress(MotionEvent e) {

	}

	@Override
	public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,float distanceY) {
		return false;
	}

	@Override
	public void onShowPress(MotionEvent e) {

	}

	@Override
	public boolean onSingleTapUp(MotionEvent e) {
		return false;
	}
	//------>以上方法为OnGestureListener接口的实现

}

main.xml如下:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
     >

    <cc.testviewstudy4.ListViewSubClass
        android:id="@+id/listView"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
     />
</RelativeLayout>

delete.xml如下:

<?xml version="1.0" encoding="utf-8"?>
<Button xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/deleteButton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@drawable/deletebutton" >
</Button>

listviewitem如下:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="70dip"
     >

    <TextView
        android:id="@+id/name"
        android:layout_width="100dip"
        android:layout_height="wrap_content"
        android:textSize="25sp"
        android:layout_centerVertical="true"
     />

</RelativeLayout>