ListItemDelete.java

package com.jwzhangjie.scrollview;

import android.annotation.SuppressLint;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.LinearLayout;

public class ListItemDelete extends LinearLayout {

	private float mLastMotionX;// 记住上次触摸屏的位置
	private int deltaX;
	private int back_width;//滑动显示组件的宽度
	private float downX;
	private int itemClickMin = 5;//判断onItemClick的最大距离
	
	public ListItemDelete(Context context) {
		this(context, null);
	}

	public ListItemDelete(Context context, AttributeSet attrs) {
		super(context, attrs);
		init(context);
	}

	private void init(Context context) {
		
	}


	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
		super.onMeasure(widthMeasureSpec, heightMeasureSpec);
		int count = getChildCount();
		for (int i = 0; i < count; i++) {
			measureChild(getChildAt(i), widthMeasureSpec, heightMeasureSpec);
			if (i == 1) {
				back_width = getChildAt(i).getMeasuredWidth();
			}
		}
	}
	
	public void reSet(){
		scrollTo(0, 0);
		DeleteAdapter.itemDelete = null;
	}

	@SuppressLint("ClickableViewAccessibility")
	@Override
	public boolean onTouchEvent(MotionEvent event) {
		int action = event.getAction();
		float x = event.getX();
		switch (action) {
		case MotionEvent.ACTION_DOWN:
			Log.e("test", "item  ACTION_DOWN");
			mLastMotionX = x;
			downX = x;
			break;
		case MotionEvent.ACTION_MOVE:
			Log.e("test", back_width + "  item  ACTION_MOVE  " + getScrollX());
			deltaX = (int) (mLastMotionX - x);
			mLastMotionX = x;
			int scrollx = getScrollX() + deltaX;
			if (scrollx > 0 && scrollx < back_width) {
				scrollBy(deltaX, 0);
			} else if (scrollx > back_width) {
				scrollTo(back_width, 0);
			} else if (scrollx < 0) {
				reSet();
			}
			break;
		case MotionEvent.ACTION_UP:
			Log.e("test", "item  ACTION_UP");
			int scroll = getScrollX();
			if (Math.abs(x - downX) < itemClickMin) {// 这里根据点击距离来判断是否是itemClick
				DeleteAdapter.ItemDeleteReset();
				return false;
			}
			if (deltaX > 0) {
				if (scroll > back_width / 4) {
					scrollTo(back_width, 0);
					DeleteAdapter.itemDelete = this;
				} else {
					reSet();
				}
			} else {
				if (scroll > back_width * 3 / 4) {
					scrollTo(back_width, 0);
					DeleteAdapter.itemDelete = this;
				} else {
					reSet();
				}
			}
			break;
		case MotionEvent.ACTION_CANCEL:
			reSet();
			break;
		}
		return true;
	}

	@Override
	protected void onLayout(boolean changed, int l, int t, int r, int b) {
		super.onLayout(changed, l, t, r, b);
		int margeLeft = 0;
		int size = getChildCount();
		for (int i = 0; i < size; i++) {
			View view = getChildAt(i);
			if (view.getVisibility() != View.GONE) {
				int childWidth = view.getMeasuredWidth();
				// 将内部子孩子横排排列
				view.layout(margeLeft, 0, margeLeft + childWidth,
						view.getMeasuredHeight());
				margeLeft += childWidth;
			}
		}
	}
}