I encountered a problem the first time I ran a fragment. It looks like CoordinatorLayout is adding a negative margin to the NestedScrollView, which is equal to CollapsingToolbarLayout height in the collapsed state (I tested it by changing the height value). As a result, the RecyclerView, which lives in the NestedScrollView, cannot scroll to display several of its lower elements.
There are the same questions about SO (like this , this, and this ), but they do not provide a solution that worked for me, and moreover, they do not give any explanation what might cause the problem.
It is interesting to note that if I turn or turn off the screen and the layout and afterword are restored on it, it will be displayed correctly. Also, if I click on an element, it will call something, and then I can scroll through these hidden elements. As a workaround, it would be nice to call a function that correctly rebuilds the layout manually, but I couldn't figure out what it was (see What I tried to do below)
What I tried to do:
Add a bottom margin equal to the height of the toolbar for NestedScrollView. Although this helped on the first start, but after I clicked on an element or rotated the screen, an extra edge would push the look up from the bottom of the screen.
I could not find any problem in my code while debugging.
calling getView.invalidate () also did not help.
Can someone help me figure out what might be causing the problem, please?
fragment_player.xml
<?xml version="1.0" encoding="utf-8"?> <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:fitsSystemWindows="true" tools:context="ru.orgin.glagol.MainActivity"> <android.support.design.widget.AppBarLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:theme="@style/AppTheme.AppBarOverlay" android:stateListAnimator="@animator/appbar_always_elevated"> <android.support.design.widget.CollapsingToolbarLayout android:id="@+id/toolbar_layout" android:layout_width="match_parent" android:layout_height="match_parent" android:fitsSystemWindows="true" app:layout_scrollFlags="scroll|exitUntilCollapsed" app:titleEnabled="false"> <include layout="@layout/player_view"/> <android.support.v7.widget.Toolbar android:id="@+id/toolbar" android:layout_width="match_parent" android:layout_height="@dimen/player_toolbar_height" app:layout_collapseMode="none" app:popupTheme="@style/AppTheme.PopupOverlay" /> </android.support.design.widget.CollapsingToolbarLayout> </android.support.design.widget.AppBarLayout> <android.support.v4.widget.NestedScrollView android:id="@+id/scrollView" android:layout_width="match_parent" android:layout_height="wrap_content" app:layout_behavior="@string/appbar_scrolling_view_behavior" > <ViewAnimator android:id="@+id/viewAnimator" android:layout_width="match_parent" android:layout_height="wrap_content" android:inAnimation="@android:anim/fade_in" android:outAnimation="@android:anim/fade_out"> <ProgressBar android:layout_width="wrap_content" android:layout_height="64dp" android:layout_gravity="center" style="?android:attr/progressBarStyle"/> <android.support.v7.widget.RecyclerView android:id="@+id/recyclerView" android:nestedScrollingEnabled="false" android:layout_width="match_parent" android:layout_height="match_parent"/> <TextView android:layout_width="match_parent" android:layout_height="64dp" android:gravity="center" android:layout_gravity="center" android:text="@string/empty_history_books" /> <TextView android:layout_width="match_parent" android:layout_height="64dp" android:gravity="center" android:layout_gravity="center" android:text="@string/error_loading_data" /> </ViewAnimator> </android.support.v4.widget.NestedScrollView> </android.support.design.widget.CoordinatorLayout>
Update: I still don’t know the reason, but it seems that adding the minHeight attribute to CollapsingToolbarLayout does the trick.
android
AlexKost
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