Scroller应用：ListView滑动删除
1、设计思路
在Scroller的应用--滑屏实现中使用Scroller实现滑屏效果，这里使用Scroller与ListView实现相似QQ滑动。然后点击删除功能。设计思路是Item使用Scroller实现滑动，ListView依据触摸推断是横向滑动还是竖直滑动。关于点击事件处理思路：对于View的onClick事件跟寻常一样，里面针对OnItemClick做了处理，推断触摸距离来推断。假设小于5的话，在Item的onTouchEvent方法中的MotionEvent.ACTION_UP里面返回false，这样ListView里面的dispatchTouchEvent的super.dispatchTouchEvent(event)就会返回false,依据x,y获取当前position以及点击的view。调用super.performItemClick(view, position, view.getId());来告诉ListView出发onItemClick事件。
2、Item的代码
package com.jwzhangjie.scrollview;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.Scroller;
public class ListItemDelete extends LinearLayout {
private Scroller mScroller;// 滑动控制
private float mLastMotionX;// 记住上次触摸屏的位置
private int deltaX;
private int back_width;
private float downX;
public ListItemDelete(Context context) {
this(context, null);
}
public ListItemDelete(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
private void init(Context context) {
mScroller = new Scroller(context);
}
@Override
public void computeScroll() {
if (mScroller.computeScrollOffset()) {// 会更新Scroller中的当前x,y位置
scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
postInvalidate();
}
}
@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();
}
}
}
@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) {
scrollTo(0, 0);
}
break;
case MotionEvent.ACTION_UP:
Log.e("test", "item ACTION_UP");
int scroll = getScrollX();
if (scroll > back_width / 2) {
scrollTo(back_width, 0);
} else {
scrollTo(0, 0);
}
if (Math.abs(x - downX) < 5) {// 这里依据点击距离来推断是否是itemClick
return false;
}
break;
case MotionEvent.ACTION_CANCEL:
scrollTo(0, 0);
break;
}
return true;
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int 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;
}
}
}
}
3、ListView的代码
package com.jwzhangjie.scrollview;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ListView;
public class ScrollListviewDelete extends ListView {
private float minDis = 10;
private float mLastMotionX;// 记住上次X触摸屏的位置
private float mLastMotionY;// 记住上次Y触摸屏的位置
private boolean isLock = false;
public ScrollListviewDelete(Context context, AttributeSet attrs) {
super(context, attrs);
}
/**
* 假设一个ViewGroup的onInterceptTouchEvent()方法返回true。说明Touch事件被截获，
* 子View不再接收到Touch事件。而是转向本ViewGroup的
* onTouchEvent()方法处理。从Down開始，之后的Move，Up都会直接在onTouchEvent()方法中处理。
* 先前还在处理touch event的child view将会接收到一个 ACTION_CANCEL。
* 假设onInterceptTouchEvent()返回false。则事件会交给child view处理。
*/
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
if (!isIntercept(ev)) {
return false;
}
return super.onInterceptTouchEvent(ev);
}
@Override
public boolean dispatchTouchEvent(MotionEvent event) {
boolean dte = super.dispatchTouchEvent(event);
if (MotionEvent.ACTION_UP == event.getAction() && !dte) {//onItemClick
int position = pointToPosition((int)event.getX(), (int)event.getY());
View view = getChildAt(position);
super.performItemClick(view, position, view.getId());
}
return dte;
}
@Override
// 处理点击事件，假设是手势的事件则不作点击事件 普通View
public boolean performClick() {
return super.performClick();
}
@Override
// 处理点击事件。假设是手势的事件则不作点击事件 ListView
public boolean performItemClick(View view, int position, long id) {
return super.performItemClick(view, position, id);
}
/**
* 检測是ListView滑动还是item滑动 isLock 一旦判读是item滑动。则在up之前都是返回false
*/
private boolean isIntercept(MotionEvent ev) {
float x = ev.getX();
float y = ev.getY();
int action = ev.getAction();
switch (action) {
case MotionEvent.ACTION_DOWN:
Log.e("test", "isIntercept ACTION_DOWN "+isLock);
mLastMotionX = x;
mLastMotionY = y;
break;
case MotionEvent.ACTION_MOVE:
Log.e("test", "isIntercept ACTION_MOVE "+isLock);
if (!isLock) {
float deltaX = Math.abs(mLastMotionX - x);
float deltay = Math.abs(mLastMotionY - y);
mLastMotionX = x;
mLastMotionY = y;
if (deltaX > deltay && deltaX > minDis) {
isLock = true;
return false;
}
} else {
return false;
}
break;
case MotionEvent.ACTION_UP:
Log.e("test", "isIntercept ACTION_UP "+isLock);
isLock = false;
break;
case MotionEvent.ACTION_CANCEL:
Log.e("test", "isIntercept ACTION_CANCEL "+isLock);
isLock = false;
break;
}
return true;
}
}
4、Activity代码
package com.jwzhangjie.scrollview;
import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class ScrollerDeleteActivity extends FragmentActivity implements
OnItemClickListener {
private Toast mToast;
private ScrollListviewDelete listviewDelete;
private DeleteAdapter adapter;
private String[] datas = { "第一项", "第二项", "第三项", "第四项", "第五项", "第六项", "第七项",
"第八项", "第九项", "第十项" };
private List<String> listDatas = new ArrayList<String>();
@Override
protected void onCreate(Bundle bundle) {
super.onCreate(bundle);
setContentView(R.layout.activity_scroller_delete);
int len = datas.length;
for (int i = 0; i < len; i++) {
listDatas.add(datas[i]);
}
listviewDelete = (ScrollListviewDelete) findViewById(android.R.id.list);
adapter = new DeleteAdapter();
listviewDelete.setAdapter(adapter);
listviewDelete.setOnItemClickListener(this);
}
class DeleteAdapter extends BaseAdapter {
@Override
public int getCount() {
return listDatas.size();
}
@Override
public Object getItem(int position) {
return listDatas.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(final int position, View convertView,
ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
holder = new ViewHolder();
convertView = LayoutInflater.from(getApplicationContext())
.inflate(R.layout.item_delete, null);
holder.itemData = (TextView) convertView
.findViewById(R.id.itemData);
holder.btnDelete = (Button) convertView
.findViewById(R.id.btnDelete);
holder.btnNao = (Button) convertView.findViewById(R.id.btnNao);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.btnDelete.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
showInfo("点击删除了");
}
});
holder.itemData.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
showInfo("点击了数据： " + listDatas.get(position));
}
});
holder.btnNao.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
showInfo("点击了闹铃");
}
});
holder.itemData.setText(listDatas.get(position));
return convertView;
}
class ViewHolder {
TextView itemData;
Button btnDelete;
Button btnNao;
}
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
showInfo("onItemClick : " + position);
}
public void showInfo(String text) {
if (mToast == null) {
mToast = Toast.makeText(this, text, Toast.LENGTH_SHORT);
} else {
mToast.setText(text);
mToast.setDuration(Toast.LENGTH_SHORT);
}
mToast.show();
}
}
5、XML代码
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<com.jwzhangjie.scrollview.ScrollListviewDelete
android:id="@android:id/list"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
<?xml version="1.0" encoding="utf-8"?>
<com.jwzhangjie.scrollview.ListItemDelete xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<LinearLayout
android:id="@+id/front"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/bg_item_list_8"
android:gravity="center"
android:orientation="horizontal" >
<TextView
android:id="@+id/itemData"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="測试数据" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:orientation="horizontal" >
<Button
android:id="@+id/btnNao"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:background="@drawable/bg_item_list_4"
android:text="闹铃" />
<Button
android:id="@+id/btnDelete"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:background="@drawable/bg_item_list_5"
android:text="删除" />
</LinearLayout>
</com.jwzhangjie.scrollview.ListItemDelete>6、界面效果
不保证上面的代码是最新的。更新代码地址：https://github.com/jwzhangjie/-ScrollerDelete
V1.0版本号：解决
地址：https://github.com/jwzhangjie/-ScrollerDelete 里面有编译好的apk
