I'm having a lot of problems with scrolling and detection of it inside fragments using coordinatorLayout in Android.
I have a "Main Activity" that has inside it 3 fragments. Only on one of those fragments I want to have Appbar that collapses when fragment is scrolled. I've managed to do that, but if i set scrolling beahivour to allow that, my bottomNavigationView (which is found in mainactivity.xml) does NOT react to scrolling. Codes go something like this:
Fragment1.xml
<android.support.design.widget.CoordinatorLayout
...
.../>
<android.support.design.widget.AppBarLayout
...
.../>
<android.support.design.widget.CollapsingToolbarLayout
app:layout_scrollFlags="scroll|exitUntilCollapsed"
...>
<android.support.v7.widget.Toolbar
.../>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.widget.NestedScrollView
app:layout_behavior="#string/appbar_scrolling_view_behavior"
</android.support.v4.widget.NestedScrollView>
</android.support.design.widget.CoordinatorLayout>
MainActivity.xml
<android.support.design.widget.CoordinatorLayout
.../>
<FrameLayout
app:layout_behavior="#string/appbar_scrolling_view_behavior"
.../>
<android.support.design.widget.BottomNavigationView
app:layout_behavior="#string/hide_bottom_view_on_scroll_behavior"
.../>
</android.support.design.widget.CoordinatorLayout>
Now, this works well enough, in the sense that when i scroll inside fragment my AppBar collapses into the title (what i want), BUT my bottomNavigationView does not react to scrolling.
What i found out is that if i add the line
app:layout_behavior="#string/appbar_scrolling_view_behavior"
to the AppBarLyout xml declaration i get the bottomView to collapse on scroll event (when i scroll up it shows again). So basically either i have the ability to collapse appbar inside fragment OR i have the ability to hide BottomNavigationView when i detect a scroll event in fragment.
Any sort of help would be appreciated, I'm losing my mind over this for 3 straight days.
Related
I have an AppBarLayout in my app along with a FrameLayout that I use as a placeholder to load in fragments:
<android.support.design.widget.AppBarLayout
android:layout_height="wrap_content"
android:layout_width="match_parent"
android:theme="#style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="#style/AppTheme.PopupOverlay"/>
<FrameLayout android:id="#+id/main_content_fragment"
android:layout_height="wrap_content"
android:layout_width="match_parent"
android:background="#color/white" />
</android.support.design.widget.AppBarLayout>
The fragment in question looks like this:
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ProgressBar android:id="#+id/loading_downloaded"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<android.support.v7.widget.RecyclerView
android:id = "#+id/items_downloaded"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical"
app:layout_constraintEnd_toEndOf="parent"
/>
</LinearLayout>
The Fragment is substituted in from code as you might anticipate:
val fragMan: FragmentManager = getSupportFragmentManager()
fragMan.beginTransaction().add(R.id.main_content_fragment, fragment).commit()
The problem is that I cannot scroll my RecyclerView when I format it this way. If I move the FrameLayout outside of the AppBarLayout it works perfectly but then the fragment lies behind the app bar, which is very untidy. This confirms for me that the fragment is working correctly, I just can't figure out why the fragment's scroll behaviour changes when it's within the AppBarLayout.
What do I need to do to be able to scroll my content? Or have I misunderstood and I need to display my fragments outside the AppBarLayout where they scroll correctly and shift everything down by the height of the app bar?
Your fragment's content is meant to be placed as a sibling of the AppBarLayout. You should wrap everything inside a CoordinatorLayout and set this attribute in your FrameLayout where your fragment resides: app:layout_behavior="#string/appbar_scrolling_view_behavior".
Here's your XML structure would be:
<CoordinatorLayout>
<FrameLayout
app:layout_behavior="#string/appbar_scrolling_view_behavior" ... >
...
</FrameLayout>
<AppBarLayout> ... </AppBarLayout>
</CoordinatorLayout>
Having this setup would allow your fragment to show all of it's views with your AppBarLayout. CoordinatorLayout will take care of everything for you.
Here's the official documentation:
AppBarLayout also requires a separate scrolling sibling in order to
know when to scroll. The binding is done through the
AppBarLayout.ScrollingViewBehavior behavior class, meaning that you
should set your scrolling view's behavior to be an instance of
AppBarLayout.ScrollingViewBehavior. A string resource containing the
full class name is available.
See this link for more details: https://developer.android.com/reference/android/support/design/widget/AppBarLayout.html
I have a screen where i need to display a toolbar at the top, a slideshow below the toolbar and a recyclerview below the slideshow.
For displaying the slideshow I am using a viewPager which slides images horizontally.
The problem I am currently facing is that when the recyclerview is scrolled the viewPager needs to scroll with it and the toolbar should stay pinned.
I tried putting the viewPager and the recyclerview inside a nested Scroll but since a nested scroll requires a single child i had to put both the viewpager and recyclerview inside a linear layout because of which the scrolling behaviour of the recyclerview went for a toss ( i am monitoring the recyclerview scroll so i can load more results when it reaches the bottom ).
You can solve this problem by using CoordinatorLayout, AppBarLayout, and CollapsingToolbarLayout. You put your Toolbar and ViewPager in the CollapsingToolbarLayout, and you use the RecyclerView as the scrolling sibling to the AppBarLayout so that it can correctly collapse the ViewPager.
Here's some example XML I used to achieve what I think you described:
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.design.widget.CollapsingToolbarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<android.support.v4.view.ViewPager
android:layout_width="match_parent"
android:layout_height="200dp"
android:layout_marginTop="?attr/actionBarSize"/>
<android.support.v7.widget.Toolbar
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_collapseMode="pin"/>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v7.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
app:layoutManager="LinearLayoutManager"/>
</android.support.design.widget.CoordinatorLayout>
The only tricky bit is that the <Toolbar> tag has to come after the <ViewPager> tag, since they're both inside a view that derives from FrameLayout. Normally, this would mean that the toolbar obscures the top portion of the viewpager, but the viewpager's marginTop attribute stops that from happening.
I am following this guide CodePath trying to achieve this. I don't want a Expandable and Collapsible Toolbar. I just want a simple Toolbar that scrolls up with the Layout and then shows up as soon as one starts going up (not when it reaches all the way to the top).
I followed the Codepath guide and created this Layout. But the scrolling of the NestedScrollView doesn't work here.
So I found an answer on StackOverflow that suggested enclosing the contents of the CoordinatorLayout in a LinearLayout and the scrolling worked (NewLayout). But the Toolbar doesn't scroll with the rest of the Layout and stays fixed at the top and I was hoping like something that was mentioned on the Codepath guide,like this.
What am I doing wrong here ? Thanks
NestedScrollView should be outside appbarlayout, see the example code below :
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<!-- Your scrolling content -->
</android.support.v4.widget.NestedScrollView>
<android.support.design.widget.AppBarLayout
android:layout_height="wrap_content"
android:layout_width="match_parent">
<android.support.v7.widget.Toolbar
...
app:layout_scrollFlags="scroll|enterAlways"/>
<android.support.design.widget.TabLayout
...
app:layout_scrollFlags="scroll|enterAlways"/>
</android.support.design.widget.AppBarLayout>
Reference : https://developer.android.com/reference/android/support/design/widget/AppBarLayout.html
Hope it works !
I tend to further elaborate from this
Android - footer scrolls off screen when used in CoordinatorLayout
and
https://code.google.com/p/android/issues/detail?id=177195
I wish to hide TabLayout while performing scrolling on RecyclerView. That's why I have the following layout.
<CoordinatorLayout>
<CollapsingToolbarLayout>
<TabLayout>
<ViewPager>
<RecyclerView>
<Footer>
For my situation, I have a ViewPager which contains multiple fragments.
Most of the fragments, contains RecyclerView and footer. They look like the following
<LinearLayout>
<RecyclerView />
<LinearLayout id="#+id/footer" />
</LinearLayout>
Unfortunately, the footer is movable when scrolling, although I would like it to be static.
Note, it is important to have app:layout_behavior to place in ViewPager instead of RecyclerView. If not, TabLayout will not appear.
My implementation is as follow
my_fragment.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"
android:id="#+id/coordinator_layout"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<android.support.design.widget.AppBarLayout
android:id="#+id/app_bar_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar" >
<android.support.design.widget.CollapsingToolbarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_scrollFlags="scroll|enterAlways|snap">
<android.support.design.widget.TabLayout
android:id="#+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabIndicatorColor="?attr/portfolioTabIndicatorColor" />
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="org.yccheok.xxx.CustomScrollingViewBehavior"
/>
</android.support.design.widget.CoordinatorLayout>
The very key class is org.yccheok.xxx.CustomScrollingViewBehavior, which is copied and pasted from https://stackoverflow.com/a/33396965/72437
org.yccheok.xxx.CustomScrollingViewBehavior is the best solution I can find so far. However, it is far from perfect, as it yields the following behavior.
It causes flickering, when you scroll up a little, and release your finger. Please refer to the following video.
https://youtu.be/8RvCZJeQvS0
I was wondering, based on proposed solution at https://stackoverflow.com/a/33396965/72437, is there any further improvement I can done on CustomScrollingViewBehavior class, to avoid flickering effect?
I was able to achieve what I want, by following tutorial at
https://mzgreen.github.io/2015/02/15/How-to-hideshow-Toolbar-when-list-is-scroling%28part1%29/
http://mzgreen.github.io/2015/02/28/How-to-hideshow-Toolbar-when-list-is-scrolling%28part2%29/
The key ideas are
Don't use CoordinatorLayout
Place TabLayout and RecyclerView within FrameLayout, so that TabLayout will overlay on the top of RecyclerView
Add top padding on RecyclerView. Having android:clipToPadding="false" is important as well.
To hide/ show TabLayout during scrolling, attach HidingScrollListener to RecyclerView.
The shortcoming for this solution is that, requiresFadingEdge will no longer work on RecyclerView, due to the top padding.
I encountered a strange problem with the new Android Design Support Librar (http://android-developers.blogspot.com.ar/2015/05/android-design-support-library.html). If I place additional content (like a LinearLayout) in an AppBarLayout along with the ToolBar and toggle the visibility of that content then switching fragments will have show a dead space at the top of the fragment content.
It appears that AppBarLayout isn't resizing the parent CoordinatorLayout correctly when visibility of the content is toggled. I have my CoordinatorLayout wrapped in the DrawerLayout. I want to toggle the visibility of the extra LinearLayout in the AppBarLayout depending on the which fragment shown.
Here is my main.xml file for the MainActivity:
<android.support.v4.widget.DrawerLayout
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/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<android.support.design.widget.CoordinatorLayout
android:layout_height="match_parent"
android:layout_width="match_parent">
<android.support.design.widget.AppBarLayout
android:id="#+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:gravity="center_vertical"">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="start"
android:text="Hello"/>
</LinearLayout>
</android.support.design.widget.AppBarLayout>
<FrameLayout
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:id="#+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</android.support.design.widget.CoordinatorLayout>
<android.support.design.widget.NavigationView
android:id="#+id/navigation"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
app:menu="#menu/drawer"/>
</android.support.v4.widget.DrawerLayout>
I had a similar problem using the support design widget. I had a CoordinatorLayout inside a DrawerLayout and an AppBarLayout inside the CoordinatorLayout. I had two toolbars inside the AppBarLayout. My aim was to display a toolbar with a ViewPager displaying a recyclerview content. I wanted to swop between the toolbars when selecting items. In other words, I made one toolbar GONE while the other was visible and vise versa. Scrolling the content up would push the toolbar up off the top of the screen. Everything worked perfectly except that changing orientation would show a space for the toolbar that should be gone. I tried every hack I could think of to get rid of it but did not succeed. I then came across this post and realized that it was a bug in the support library. I then tried putting a FrameLayout in the AppBarLayout and then put the two toolbars inside the FrameLayout and NO MORE SPACE! everything now works as I intend it to work. GONE toolbars are GONE and only the visible toolbar shows, even when changing the orientation.
Hope this helps someone.