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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实现类似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根据触摸判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事件跟平常一样，里面针对OnItemClick做了处理，判断触摸距离来判断，如果小于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,根据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) {// 这里根据点击距离来判断是否是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);
}
/**
* 如果一个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开始，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。
* 如果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，如果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，如果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);
}
/**
* 检测是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 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);
}
/**
* 如果一个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开始，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。
* 如果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，如果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，如果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);
}
/**
* 检测是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;
}
}
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="测试数据" />
</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
代码地址：https://github.com/jwzhangjie/-ScrollerDelete
Scroller应用：ListView滑动删除
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