Android 与RecyclerView+；AppBarLayout
我正在使用AppBarLayout和CollingToolBarLayout的新CoordinatorLayout。在AppBarLayout下面，我有一个包含内容列表的RecyclerView 我已经验证了当我在列表上下滚动时，fling scrolling在RecyclerView上有效。但是，我也希望AppBarLayout在扩展期间平滑滚动 向上滚动以展开CollaspingToolbarLayout时，一旦将手指抬离屏幕，滚动立即停止。如果快速向上滚动，有时折叠工具栏布局也会重新折叠。RecyclerView的这种行为似乎与使用NestedScrollView时的功能大不相同 我曾尝试在recyclerview上设置不同的滚动属性，但我一直无法解决这个问题 下面是一段视频，显示了一些滚动问题。 下面是一个显示RecyclerView（CheeseDetailActivity）问题的示例。 下面是使用Chris Banes的NestedScrollView的原始示例。Android 与RecyclerView+；AppBarLayout,android,android-layout,android-design-library,android-appcompat,Android,Android Layout,Android Design Library,Android Appcompat,我正在使用AppBarLayout和CollingToolBarLayout的新CoordinatorLayout。在AppBarLayout下面，我有一个包含内容列表的RecyclerView 我已经验证了当我在列表上下滚动时，fling scrolling在RecyclerView上有效。但是，我也希望AppBarLayout在扩展期间平滑滚动 向上滚动以展开CollaspingToolbarLayout时，一旦将手指抬离屏幕，滚动立即停止。如果快速向上滚动，有时折叠工具栏布局也会重新折叠。
我在AppBar布局中添加了一个1dp高度的视图，这样效果会更好。这是我的布局
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/white"
tools:context="com.spof.spof.app.UserBeachesActivity">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.Toolbar
android:id="@+id/user_beaches_toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:layout_alignParentTop="true"
android:background="?attr/colorPrimary"
android:minHeight="?attr/actionBarSize"
android:theme="@style/WhiteTextToolBar"
app:layout_scrollFlags="scroll|enterAlways" />
<View
android:layout_width="match_parent"
android:layout_height="1dp" />
</android.support.design.widget.AppBarLayout>
<android.support.v7.widget.RecyclerView
android:id="@+id/user_beaches_rv"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_behavior="@string/appbar_scrolling_view_behavior" />
这是我的布局和滚动条，它正常工作
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
android:id="@+id/container">
<android.support.design.widget.AppBarLayout
android:id="@+id/appbarLayout"
android:layout_height="192dp"
android:layout_width="match_parent">
<android.support.design.widget.CollapsingToolbarLayout
android:id="@+id/ctlLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_scrollFlags="scroll|exitUntilCollapsed"
app:contentScrim="?attr/colorPrimary"
app:layout_collapseMode="parallax">
<android.support.v7.widget.Toolbar
android:id="@+id/appbar"
android:layout_height="?attr/actionBarSize"
android:layout_width="match_parent"
app:layout_scrollFlags="scroll|enterAlways"
app:layout_collapseMode="pin"/>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v7.widget.RecyclerView
android:id="@+id/catalogueRV"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.CoordinatorLayout>
似乎
v23public final class FlingBehavior extends AppBarLayout.Behavior {
public FlingBehavior() {
}
public FlingBehavior(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public boolean onNestedFling(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, float velocityX, float velocityY, boolean consumed) {
if (target instanceof ScrollingView) {
final ScrollingView scrollingView = (ScrollingView) target;
consumed = velocityY > 0 || scrollingView.computeVerticalScrollOffset() > 0;
}
return super.onNestedFling(coordinatorLayout, child, target, velocityX, velocityY, consumed);
}
}
<android.support.design.widget.AppBarLayout
android:id="@+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_behavior="your.package.FlingBehavior">
<!--your views here-->
</android.support.design.widget.AppBarLayout>
verticalScrollOffsetRecyclerViewScrollingViewRecyclerViewRecyclerViewNestedScrollingViewpublic final class FlingBehavior extends AppBarLayout.Behavior {
private static final int TOP_CHILD_FLING_THRESHOLD = 3;
private boolean isPositive;
public FlingBehavior() {
}
public FlingBehavior(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public boolean onNestedFling(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, float velocityX, float velocityY, boolean consumed) {
if (velocityY > 0 && !isPositive || velocityY < 0 && isPositive) {
velocityY = velocityY * -1;
}
if (target instanceof RecyclerView && velocityY < 0) {
final RecyclerView recyclerView = (RecyclerView) target;
final View firstChild = recyclerView.getChildAt(0);
final int childAdapterPosition = recyclerView.getChildAdapterPosition(firstChild);
consumed = childAdapterPosition > TOP_CHILD_FLING_THRESHOLD;
}
return super.onNestedFling(coordinatorLayout, child, target, velocityX, velocityY, consumed);
}
@Override
public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, int dx, int dy, int[] consumed) {
super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed);
isPositive = dy > 0;
}
}
public final类FlingBehavior扩展了AppBarLayout.Behavior{
私有静态最终int TOP\u CHILD\u FLING\u阈值=3；
私有布尔正；
公共FlingBehavior（）{
}
公共FlingBehavior（上下文、属性集属性）{
超级（上下文，attrs）；
}
@凌驾
公共布尔onNestedFling（CoordinatorLayout CoordinatorLayout，AppBarLayout子级，视图目标，浮点速度yx，浮点速度yy，布尔消耗）{
如果（速度y>0&&isPositive | |速度y<0&&isPositive）{
velocityY=velocityY*-1；
}
if（RecyclerView和velocityY的目标实例<0）{
最终RecyclerView RecyclerView=（RecyclerView）目标；
最终视图firstChild=recyclerView.getChildAt（0）；
final int childAdapterPosition=recyclerView.getChildAdapterPosition（firstChild）；
消费=儿童适配器位置>顶部儿童投掷阈值；
}
返回super.onNestedFling（coordinatorLayout、child、target、velocityX、velocityY、consumed）；
}
@凌驾
public void onNestedPreScroll（CoordinatorLayout CoordinatorLayout，AppBarLayout子级，视图目标，int-dx，int-dy，int[]已消耗）{
super.onNestedPreScroll（协调布局、子项、目标、dx、dy、消耗）；
isPositive=dy>0；
}
}
我希望这会有所帮助。这是一个recyclerview错误。它应该在v23.1.0中修复 看
这是谷歌支持设计AppBarLayout的平滑版本。如果您正在使用AppBarLayout，您将知道它与fling有问题
compile "me.henrytao:smooth-app-bar-layout:<latest-version>"
编译“me.henrytao:平滑的应用程序栏布局：”
请看这里的图书馆 我通过将onCrollinglistener应用于recyclerView找到了修复方法。现在它工作得很好。问题是recyclerview提供了错误的消费值，行为不知道何时将recyclerview滚动到顶部
package com.singmak.uitechniques.util.coordinatorlayout;
import android.content.Context;
import android.support.design.widget.AppBarLayout;
import android.support.design.widget.CoordinatorLayout;
import android.support.v7.widget.RecyclerView;
import android.util.AttributeSet;
import android.view.View;
import java.lang.ref.WeakReference;
import java.util.HashMap;
import java.util.Map;
/**
* Created by maksing on 26/3/2016.
*/
public final class RecyclerViewAppBarBehavior extends AppBarLayout.Behavior {
private Map<RecyclerView, RecyclerViewScrollListener> scrollListenerMap = new HashMap<>(); //keep scroll listener map, the custom scroll listener also keep the current scroll Y position.
public RecyclerViewAppBarBehavior() {
}
public RecyclerViewAppBarBehavior(Context context, AttributeSet attrs) {
super(context, attrs);
}
/**
*
* @param coordinatorLayout
* @param child The child that attached the behavior (AppBarLayout)
* @param target The scrolling target e.g. a recyclerView or NestedScrollView
* @param velocityX
* @param velocityY
* @param consumed The fling should be consumed by the scrolling target or not
* @return
*/
@Override
public boolean onNestedFling(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, float velocityX, float velocityY, boolean consumed) {
if (target instanceof RecyclerView) {
final RecyclerView recyclerView = (RecyclerView) target;
if (scrollListenerMap.get(recyclerView) == null) {
RecyclerViewScrollListener recyclerViewScrollListener = new RecyclerViewScrollListener(coordinatorLayout, child, this);
scrollListenerMap.put(recyclerView, recyclerViewScrollListener);
recyclerView.addOnScrollListener(recyclerViewScrollListener);
}
scrollListenerMap.get(recyclerView).setVelocity(velocityY);
consumed = scrollListenerMap.get(recyclerView).getScrolledY() > 0; //recyclerView only consume the fling when it's not scrolled to the top
}
return super.onNestedFling(coordinatorLayout, child, target, velocityX, velocityY, consumed);
}
private static class RecyclerViewScrollListener extends RecyclerView.OnScrollListener {
private int scrolledY;
private boolean dragging;
private float velocity;
private WeakReference<CoordinatorLayout> coordinatorLayoutRef;
private WeakReference<AppBarLayout> childRef;
private WeakReference<RecyclerViewAppBarBehavior> behaviorWeakReference;
public RecyclerViewScrollListener(CoordinatorLayout coordinatorLayout, AppBarLayout child, RecyclerViewAppBarBehavior barBehavior) {
coordinatorLayoutRef = new WeakReference<CoordinatorLayout>(coordinatorLayout);
childRef = new WeakReference<AppBarLayout>(child);
behaviorWeakReference = new WeakReference<RecyclerViewAppBarBehavior>(barBehavior);
}
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
dragging = newState == RecyclerView.SCROLL_STATE_DRAGGING;
}
public void setVelocity(float velocity) {
this.velocity = velocity;
}
public int getScrolledY() {
return scrolledY;
}
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
scrolledY += dy;
if (scrolledY <= 0 && !dragging && childRef.get() != null && coordinatorLayoutRef.get() != null && behaviorWeakReference.get() != null) {
//manually trigger the fling when it's scrolled at the top
behaviorWeakReference.get().onNestedFling(coordinatorLayoutRef.get(), childRef.get(), recyclerView, 0, velocity, false);
}
}
}
}
包com.singmak.uitechniques.util.coordinatorlayout；
导入android.content.Context；
导入android.support.design.widget.AppBarLayout；
导入android.support.design.widget.CoordinatorLayout；
导入android.support.v7.widget.RecyclerView；
导入android.util.AttributeSet；
导入android.view.view；
导入java.lang.ref.WeakReference；
导入java.util.HashMap；
导入java.util.Map；
/**
*由maksing于2016年3月26日创建。
*/
公共最终类RecycleWebAppBarbeHavior扩展AppBarLayout.Behavior{
私有映射scrollListenerMap=new HashMap（）；//保留滚动侦听器映射，自定义滚动侦听器也保留当前滚动Y位置。
公共回收服务AppBarbehavior（）{
}
公共RecycleWebAppBarbeHavior（上下文、属性集属性）{
超级（上下文，attrs）；
}
/**
*
*@param-coordinatorLayout
*@param child附加行为的子级（AppBarLayout）
*@param target滚动目标，如recyclerView或NestedScrollView
*@param-velocityX
*@param-velocityY
*@param已消耗投掷物是否应被滚动目标消耗
*@返回
*/
@凌驾
公共布尔onNestedFling（CoordinatorLayout CoordinatorLayout，AppBarLayout子级，视图目标，浮点速度yx，浮点速度yy，布尔消耗）{
if（RecyclerView的目标实例）{
最终RecyclerView RecyclerView=（RecyclerView）目标；
if（scrollListenerMap.get（recyclerView）==null）{
RecyclerViewScrollListener RecyclerViewScrollListener=新的RecyclerViewScrollListener（coordinatorLayout，child，this）；
scrollListenerMap.put（recyclerView，recyclerViewScrollListener）；
addOnScrollListener（recyclerViewScrollListener）；
import android.content.Context;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.design.widget.AppBarLayout;
import android.support.design.widget.CoordinatorLayout;
import android.support.v7.widget.RecyclerView;
import android.util.AttributeSet;
import android.view.View;
import java.lang.ref.WeakReference;
public class FlingAppBarLayoutBehavior
extends AppBarLayout.Behavior {
// The minimum I have seen for a dy, after the recycler view stopped.
private static final int MINIMUM_DELTA_Y = -4;
@Nullable
RecyclerViewScrollListener mScrollListener;
private boolean isPositive;
public FlingAppBarLayoutBehavior() {
}
public FlingAppBarLayoutBehavior(Context context, AttributeSet attrs) {
super(context, attrs);
}
public boolean callSuperOnNestedFling(
CoordinatorLayout coordinatorLayout,
AppBarLayout child,
View target,
float velocityX,
float velocityY,
boolean consumed) {
return super.onNestedFling(
coordinatorLayout,
child,
target,
velocityX,
velocityY,
consumed
);
}
@Override
public boolean onNestedFling(
CoordinatorLayout coordinatorLayout,
AppBarLayout child,
View target,
float velocityX,
float velocityY,
boolean consumed) {
if (velocityY > 0 && !isPositive || velocityY < 0 && isPositive) {
velocityY = velocityY * -1;
}
if (target instanceof RecyclerView) {
RecyclerView recyclerView = (RecyclerView) target;
if (mScrollListener == null) {
mScrollListener = new RecyclerViewScrollListener(
coordinatorLayout,
child,
this
);
recyclerView.addOnScrollListener(mScrollListener);
}
mScrollListener.setVelocity(velocityY);
}
return super.onNestedFling(
coordinatorLayout,
child,
target,
velocityX,
velocityY,
consumed
);
}
@Override
public void onNestedPreScroll(
CoordinatorLayout coordinatorLayout,
AppBarLayout child,
View target,
int dx,
int dy,
int[] consumed) {
super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed);
isPositive = dy > 0;
}
private static class RecyclerViewScrollListener
extends RecyclerView.OnScrollListener {
@NonNull
private final WeakReference<AppBarLayout> mAppBarLayoutWeakReference;
@NonNull
private final WeakReference<FlingAppBarLayoutBehavior> mBehaviorWeakReference;
@NonNull
private final WeakReference<CoordinatorLayout> mCoordinatorLayoutWeakReference;
private int mDy;
private float mVelocity;
public RecyclerViewScrollListener(
@NonNull CoordinatorLayout coordinatorLayout,
@NonNull AppBarLayout child,
@NonNull FlingAppBarLayoutBehavior barBehavior) {
mCoordinatorLayoutWeakReference = new WeakReference<>(coordinatorLayout);
mAppBarLayoutWeakReference = new WeakReference<>(child);
mBehaviorWeakReference = new WeakReference<>(barBehavior);
}
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
if (newState == RecyclerView.SCROLL_STATE_IDLE) {
if (mDy < MINIMUM_DELTA_Y
&& mAppBarLayoutWeakReference.get() != null
&& mCoordinatorLayoutWeakReference.get() != null
&& mBehaviorWeakReference.get() != null) {
// manually trigger the fling when it's scrolled at the top
mBehaviorWeakReference.get()
.callSuperOnNestedFling(
mCoordinatorLayoutWeakReference.get(),
mAppBarLayoutWeakReference.get(),
recyclerView,
0,
mVelocity, // TODO find a way to recalculate a correct velocity.
false
);
}
}
}
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
mDy = dy;
}
public void setVelocity(float velocity) {
mVelocity = velocity;
}
}
}
private int mScrolled;
private int mPreviousDy;
private AppBarLayout mAppBar;
myRecyclerView.addOnScrollListener(new OnScrollListener() {
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
mScrolled += dy;
// scrolled to the top with a little more velocity than a slow scroll e.g. flick/fling.
// Adjust 10 (vertical change of event) as you feel fit for you requirement
if(mScrolled == 0 && dy < -10 && mPrevDy < 0) {
mAppBar.setExpanded(true, true);
}
mPreviousDy = dy;
});
public final class FlingBehavior extends AppBarLayout.Behavior {
private static final int TOP_CHILD_FLING_THRESHOLD = 3;
private boolean isPositive;
public FlingBehavior() {
}
public FlingBehavior(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public boolean onNestedFling(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, float velocityX, float velocityY, boolean consumed) {
if (velocityY > 0 && !isPositive || velocityY < 0 && isPositive) {
velocityY = velocityY * -1;
}
if (!(target instanceof RecyclerView) && velocityY < 0) {
RecyclerView recycler = findRecycler((ViewGroup) target);
if (recycler != null){
target = recycler;
}
}
if (target instanceof RecyclerView && velocityY < 0) {
final RecyclerView recyclerView = (RecyclerView) target;
final View firstChild = recyclerView.getChildAt(0);
final int childAdapterPosition = recyclerView.getChildAdapterPosition(firstChild);
consumed = childAdapterPosition > TOP_CHILD_FLING_THRESHOLD;
}
return super.onNestedFling(coordinatorLayout, child, target, velocityX, velocityY, consumed);
}
@Override
public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, int dx, int dy, int[] consumed) {
super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed);
isPositive = dy > 0;
}
@Nullable
private RecyclerView findRecycler(ViewGroup container){
for (int i = 0; i < container.getChildCount(); i++) {
View childAt = container.getChildAt(i);
if (childAt instanceof RecyclerView){
return (RecyclerView) childAt;
}
if (childAt instanceof ViewGroup){
return findRecycler((ViewGroup) childAt);
}
}
return null;
}
}
/*
* Copyright 2017 Julian Ostarek
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.support.v7.widget
import android.support.design.widget.AppBarLayout
import android.support.design.widget.CoordinatorLayout
import android.support.v4.widget.ScrollerCompat
import android.view.View
import android.widget.OverScroller
class SmoothScrollBehavior(recyclerView: RecyclerView) : AppBarLayout.Behavior() {
// We're using this SplineOverScroller from deep inside the RecyclerView to calculate the fling distances
private val splineOverScroller: Any
private var isPositive = false
init {
val scrollerCompat = RecyclerView.ViewFlinger::class.java.getDeclaredField("mScroller").apply {
isAccessible = true
}.get(recyclerView.mViewFlinger)
val overScroller = ScrollerCompat::class.java.getDeclaredField("mScroller").apply {
isAccessible = true
}.get(scrollerCompat)
splineOverScroller = OverScroller::class.java.getDeclaredField("mScrollerY").apply {
isAccessible = true
}.get(overScroller)
}
override fun onNestedFling(coordinatorLayout: CoordinatorLayout?, child: AppBarLayout, target: View?, velocityX: Float, givenVelocity: Float, consumed: Boolean): Boolean {
// Making sure the velocity has the correct sign (seems to be an issue)
var velocityY: Float
if (isPositive != givenVelocity > 0) {
velocityY = givenVelocity * - 1
} else velocityY = givenVelocity
if (velocityY < 0) {
// Decrement the velocity to the maximum velocity if necessary (in a negative sense)
velocityY = Math.max(velocityY, - (target as RecyclerView).maxFlingVelocity.toFloat())
val currentOffset = (target as RecyclerView).computeVerticalScrollOffset()
if (currentOffset == 0) {
super.onNestedFling(coordinatorLayout, child, target, velocityX, velocityY, false)
return true
} else {
val distance = getFlingDistance(velocityY.toInt()).toFloat()
val remainingVelocity = - (distance - currentOffset) * (- velocityY / distance)
if (remainingVelocity < 0) {
(target as RecyclerView).addOnScrollListener(object : RecyclerView.OnScrollListener() {
override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
if (newState == RecyclerView.SCROLL_STATE_IDLE) {
recyclerView.post { recyclerView.removeOnScrollListener(this) }
if (recyclerView.computeVerticalScrollOffset() == 0) {
super@SmoothScrollBehavior.onNestedFling(coordinatorLayout, child, target, velocityX, remainingVelocity, false)
}
}
}
})
}
return false
}
}
// We're not getting here anyway, flings with positive velocity are handled in onNestedPreFling
return false
}
override fun onNestedPreFling(coordinatorLayout: CoordinatorLayout?, child: AppBarLayout, target: View?, velocityX: Float, givenVelocity: Float): Boolean {
// Making sure the velocity has the correct sign (seems to be an issue)
var velocityY: Float
if (isPositive != givenVelocity > 0) {
velocityY = givenVelocity * - 1
} else velocityY = givenVelocity
if (velocityY > 0) {
// Decrement to the maximum velocity if necessary
velocityY = Math.min(velocityY, (target as RecyclerView).maxFlingVelocity.toFloat())
val topBottomOffsetForScrollingSibling = AppBarLayout.Behavior::class.java.getDeclaredMethod("getTopBottomOffsetForScrollingSibling").apply {
isAccessible = true
}.invoke(this) as Int
val isCollapsed = topBottomOffsetForScrollingSibling == - child.totalScrollRange
// The AppBarlayout is collapsed, we'll let the RecyclerView handle the fling on its own
if (isCollapsed)
return false
// The AppbarLayout is not collapsed, we'll calculate the remaining velocity, trigger the appbar to collapse and fling the RecyclerView manually (if necessary) as soon as that is done
val distance = getFlingDistance(velocityY.toInt())
val remainingVelocity = (distance - (child.totalScrollRange + topBottomOffsetForScrollingSibling)) * (velocityY / distance)
if (remainingVelocity > 0) {
(child as AppBarLayout).addOnOffsetChangedListener(object : AppBarLayout.OnOffsetChangedListener {
override fun onOffsetChanged(appBarLayout: AppBarLayout, verticalOffset: Int) {
// The AppBarLayout is now collapsed
if (verticalOffset == - appBarLayout.totalScrollRange) {
(target as RecyclerView).mViewFlinger.fling(velocityX.toInt(), remainingVelocity.toInt())
appBarLayout.post { appBarLayout.removeOnOffsetChangedListener(this) }
}
}
})
}
// Trigger the expansion of the AppBarLayout
super.onNestedFling(coordinatorLayout, child, target, velocityX, velocityY, false)
// We don't let the RecyclerView fling already
return true
} else return super.onNestedPreFling(coordinatorLayout, child, target, velocityX, velocityY)
}
override fun onNestedPreScroll(coordinatorLayout: CoordinatorLayout?, child: AppBarLayout?, target: View?, dx: Int, dy: Int, consumed: IntArray?) {
super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed)
isPositive = dy > 0
}
private fun getFlingDistance(velocity: Int): Double {
return splineOverScroller::class.java.getDeclaredMethod("getSplineFlingDistance", Int::class.javaPrimitiveType).apply {
isAccessible = true
}.invoke(splineOverScroller, velocity) as Double
}
}
compile 'com.android.support:design:26.0.0'
public final class FlingBehavior extends AppBarLayout.Behavior {
private boolean isPositive;
private float mFlingFriction = ViewConfiguration.getScrollFriction();
private float DECELERATION_RATE = (float) (Math.log(0.78) / Math.log(0.9));
private final float INFLEXION = 0.35f;
private float mPhysicalCoeff;
public FlingBehavior(){
init();
}
public FlingBehavior(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init(){
final float ppi = BaseApplication.getInstance().getResources().getDisplayMetrics().density * 160.0f;
mPhysicalCoeff = SensorManager.GRAVITY_EARTH // g (m/s^2)
* 39.37f // inch/meter
* ppi
* 0.84f; // look and feel tuning
}
@Override
public boolean onNestedFling(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, float velocityX, float velocityY, boolean consumed) {
if (velocityY > 0 && !isPositive || velocityY < 0 && isPositive) {
velocityY = velocityY * -1;
}
if (target instanceof RecyclerView && velocityY < 0) {
RecyclerView recyclerView = (RecyclerView) target;
double distance = getFlingDistance((int) velocityY);
if (distance < recyclerView.computeVerticalScrollOffset()) {
consumed = true;
} else {
consumed = false;
}
}
return super.onNestedFling(coordinatorLayout, child, target, velocityX, velocityY, consumed);
}
@Override
public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, int dx, int dy, int[] consumed) {
super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed);
isPositive = dy > 0;
}
public double getFlingDistance(int velocity){
final double l = getSplineDeceleration(velocity);
final double decelMinusOne = DECELERATION_RATE - 1.0;
return mFlingFriction * mPhysicalCoeff * Math.exp(DECELERATION_RATE / decelMinusOne * l);
}
private double getSplineDeceleration(int velocity) {
return Math.log(INFLEXION * Math.abs(velocity) / (mFlingFriction * mPhysicalCoeff));
}
}
allprojects {
repositories {
jcenter()
maven {
url "https://maven.google.com"
}
}
}
<android.support.design.widget.AppBarLayout
android:id="@+id/smooth_app_bar_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/white"
app:elevation="0dp"
app:layout_behavior="com.sogou.groupwenwen.view.topic.FixAppBarLayoutBehavior">
public boolean onInterceptTouchEvent(CoordinatorLayout parent, AppBarLayout child, MotionEvent ev) {
if (ev.getAction() == ACTION_DOWN) {
Object scroller = getSuperSuperField(this, "mScroller");
if (scroller != null && scroller instanceof OverScroller) {
OverScroller overScroller = (OverScroller) scroller;
overScroller.abortAnimation();
}
}
return super.onInterceptTouchEvent(parent, child, ev);
}
private Object getSuperSuperField(Object paramClass, String paramString) {
Field field = null;
Object object = null;
try {
field = paramClass.getClass().getSuperclass().getSuperclass().getDeclaredField(paramString);
field.setAccessible(true);
object = field.get(paramClass);
} catch (Exception e) {
e.printStackTrace();
}
return object;
}
//or check the raw file:
//https://github.com/shaopx/CoordinatorLayoutExample/blob/master/app/src/main/java/com/spx/coordinatorlayoutexample/util/FixAppBarLayoutBehavior.java