android - layout_collapsemode - Cómo expandir AppBarLayout cuando se desplaza hacia abajo se encuentra en la parte superior de RecyclerView
coordinatorlayout example (1)
Acabo de armar una aplicación de muestra que parece demostrar el comportamiento que está buscando. La AppBar se expandirá automáticamente cada vez que el RecyclerView debajo se desplace hacia la parte superior, en lugar de detenerse y esperar a que otro golpe para abrir la AppBar .
Los componentes más relevantes residen en una clase personalizada RecyclerView . He añadido algunos comentarios explicativos:
public class ScrollFeedbackRecyclerView extends RecyclerView {
private WeakReference<Callbacks> mCallbacks;
public ScrollFeedbackRecyclerView(Context context) {
super(context);
attachCallbacks(context);
}
public ScrollFeedbackRecyclerView(Context context, AttributeSet attrs) {
super(context, attrs);
attachCallbacks(context);
}
/*If the first completely visible item in the RecyclerView is at
index 0, then we''re at the top of the list, so we want the AppBar to expand
**if the AppBar is also collapsed** (otherwise the AppBar will constantly
attempt to expand).
*/
@Override
public void onScrolled(int dx, int dy) {
if(((LinearLayoutManager)getLayoutManager()).findFirstCompletelyVisibleItemPosition() == 0) {
Log.e(getClass().getSimpleName(), "index 0 visible");
if(mCallbacks.get().isAppBarCollapsed()) {
mCallbacks.get().setExpanded(true);
}
}
super.onScrolled(dx, dy);
}
/* the findFirstCompletelyVisibleItem() method is only available with
LinearLayoutManager and its subclasses, so test for it when setting the
LayoutManager
*/
@Override
public void setLayoutManager(LayoutManager layout) {
if(!(layout instanceof LinearLayoutManager)) {
throw new IllegalArgumentException(layout.toString() + " must be of type LinearLayoutManager");
}
super.setLayoutManager(layout);
}
private void attachCallbacks(Context context) {
try {
mCallbacks = new WeakReference<>((Callbacks)context);
} catch (ClassCastException e) {
throw new ClassCastException(context.toString() + " must implement " +
"ScrollFeedbackRecyclerView.Callbacks");
}
}
/* Necessary to interact with the AppBarLayout in the hosting Activity
*/
interface Callbacks {
boolean isAppBarCollapsed();
void setExpanded(boolean expanded);
}
}
MainActivity.java
public class MainActivity extends AppCompatActivity implements ScrollFeedbackRecyclerView.Callbacks{
private AppBarLayout mAppBarLayout;
private Toolbar mToolbar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ScrollFeedbackRecyclerView mRecyclerView = (ScrollFeedbackRecyclerView) findViewById(R.id.rv_container);
RecyclerViewAdapter mAdapter = new RecyclerViewAdapter();
mRecyclerView.setAdapter(mAdapter);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
mAppBarLayout = (AppBarLayout) findViewById(R.id.app_bar);
mToolbar = (Toolbar) findViewById(R.id.toolbar);
}
/* When collapsed, calling getY() on the AppBar will return a negative number.
Adding this number to getHeight() will return the same value as the toolbar''s
height if the AppBar is fully collapsed.
*/
@Override
public boolean isAppBarCollapsed() {
final int appBarVisibleHeight = (int) (mAppBarLayout.getY() + mAppBarLayout.getHeight());
final int toolbarHeight = mToolbar.getHeight();
return (appBarVisibleHeight == toolbarHeight);
}
@Override
public void setExpanded(boolean expanded) {
mAppBarLayout.setExpanded(expanded, true);
}
}
Estoy trabajando en una aplicación de Android en la que estoy usando CoordinatorLayout , AppBarLayout y CollapsingToolbarLayout para usar la funcionalidad de barra de contracción avanzada.
Estoy utilizando recyclerview para mostrar el número de elementos en el fragmento. Cuando me AppBarLayout hacia arriba, recyclerview colapsa suavemente AppBarLayout pero cuando me AppBarLayout hacia abajo y AppBarLayout el primer elemento de recyclerview , detiene automáticamente el desplazamiento sin expandir "AppBarLayout".
Entonces otra vez necesito desplazarme hacia abajo nuevamente para hacer que AppBarLayout visible. Por lo tanto, mi requisito es que al desplazarme hacia abajo cuando alcance la parte superior de recyclerview, deba expandir "AppBarLayout".
Cómo podemos hacer esto. Alguna idea ? Por favor vea el video de https://www.dropbox.com/s/va5jk27ikytk5ax/app_collapsebar_issue.mp4?dl=0
Aquí está mi diseño de la misma:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/drawerLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<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:id="@+id/coordinator"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:adjustViewBounds="true"
android:fitsSystemWindows="true"
app:layout_scrollFlags="scroll|exitUntilCollapsed"
>
<android.support.design.widget.AppBarLayout
android:id="@+id/app_bar"
android:layout_width="match_parent"
android:layout_height="220dp"
android:background="@drawable/offer_image"
android:fitsSystemWindows="true"
android:theme="@style/AppTheme.AppBarOverlay"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<!-- <com.flaviofaria.kenburnsview.KenBurnsView
android:id="@+id/image"
android:layout_width="match_parent"
android:layout_height="220dp"
android:src="@drawable/offer_image" />-->
<android.support.design.widget.CollapsingToolbarLayout
android:id="@+id/toolbar_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:expandedTitleMarginEnd="64dp"
app:expandedTitleMarginStart="48dp"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<com.flaviofaria.kenburnsview.KenBurnsView
android:id="@+id/image"
android:layout_width="match_parent"
android:layout_height="220dp"
android:src="@drawable/offer_image" />
<FrameLayout
android:id="@+id/collapse_frame"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#B3c85a00">
</FrameLayout>
<FrameLayout
android:id="@+id/centerCircle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center">
<ImageView
android:id="@+id/imageViewCenter"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:src="@drawable/offer" />
</FrameLayout>
<include
android:id="@+id/toolbar"
layout="@layout/toolbar" />
<android.support.design.widget.TabLayout
android:id="@+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:layout_marginBottom="15dp"
app:tabIndicatorColor="#FFFFFF"
app:tabMode="scrollable" />
<!--</FrameLayout>-->
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<!--<FrameLayout-->
<!--android:layout_width="match_parent"-->
<!--android:layout_height="match_parent"-->
<!-- -->
<!--android:visibility="visible">-->
<android.support.design.widget.FloatingActionButton
android:id="@+id/fab"
style="@style/floating_action_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:src="@drawable/ic_share_white_24dp"
android:visibility="gone"
app:backgroundTint="#FF9800"
app:elevation="6dp"
app:pressedTranslationZ="12dp" />
<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="left|bottom|fill_vertical"
android:layout_marginTop="0dp"
app:layout_behavior="@string/appbar_scrolling_view_behavior"></android.support.v4.view.ViewPager>
<!--</FrameLayout>-->
<!--<include layout="@layout/content_scrolling" />-->
</android.support.design.widget.CoordinatorLayout>
<RelativeLayout
android:id="@+id/bannerView"
android:layout_width="match_parent"
android:layout_height="58dp"
android:layout_gravity="bottom|center"
android:background="@drawable/curved_white_with_blue_border"
android:visibility="gone">
<TextView
android:id="@+id/bannerText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerInParent="true"
android:layout_centerVertical="true"
android:gravity="center"
android:padding="3dp"
android:text="Banner"
android:visibility="gone" />
<ImageView
android:id="@+id/bannerImage"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:gravity="center"
android:padding="3dp"
android:scaleType="fitXY"
android:visibility="gone" />
<ImageView
android:id="@+id/bannerClose"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:layout_centerVertical="true"
android:src="@drawable/cross_icon" />
</RelativeLayout>
<LinearLayout
android:id="@+id/socialTabs"
android:layout_width="match_parent"
android:layout_height="46dp"
android:layout_gravity="bottom|center"
android:layout_marginBottom="5dp"
android:background="@color/White"
android:orientation="horizontal"
android:visibility="gone">
<ImageView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:adjustViewBounds="true"
android:src="@drawable/follow" />
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:background="@color/White">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="46dp"
android:layout_gravity="center"
android:gravity="center"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:weightSum="3">
<ImageView
android:id="@+id/facebookImageView"
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_weight="1"
android:src="@drawable/fb_follow" />
<ImageView
android:id="@+id/googlePlusImageView"
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_marginLeft="5dp"
android:layout_marginRight="5dp"
android:layout_weight="1"
android:adjustViewBounds="true"
android:src="@drawable/google_follow" />
<ImageView
android:id="@+id/twitterImageView"
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_weight="1"
android:adjustViewBounds="true"
android:src="@drawable/twitter_follow" />
</LinearLayout>
</FrameLayout>
</LinearLayout>
</FrameLayout>
<ExpandableListView
android:id="@+id/left_drawer"
android:layout_width="265dp"
android:layout_height="match_parent"
android:layout_gravity="start"
android:background="#fff"
android:choiceMode="singleChoice"
android:divider="@null"
android:dividerHeight="0dp"
android:drawSelectorOnTop="true"
android:groupIndicator="@null"
android:scrollbars="@null" />
</android.support.v4.widget.DrawerLayout>