Scrollable Recycler view and view pager - android

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.

Related

Inconsistent vertical scrolling of a BottomSheetBehavior ViewGroup containing nested RecyclerViews

Abstract
Trying something similar to Google Maps layout behaviour
Detail
I'm trying to implement a BottomSheetBehavior that has a
ViewGroup (any) -> ViewPager(Fragments) -> RecyclerView (Vertical) -> Multiple horizontally scrollable RecyclerView / or any scrollable view.
The horizontally scrollable child RecyclerViews are part of ItemHolders of parent RecyclerView (vertically scrollable)
<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"
tools:context=".bottom.BottomSheetActivity">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
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" />
</android.support.design.widget.AppBarLayout>
<include layout="#layout/content_bottom_sheet" />
<android.support.v4.widget.NestedScrollView
android:id="#+id/frame_bottom"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:behavior_hideable="false"
app:behavior_peekHeight="240dp"
android:background="#android:color/white"
app:layout_behavior="android.support.design.widget.BottomSheetBehavior">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView_bottom"
android:layout_width="match_parent"
android:nestedScrollingEnabled="true"
android:layout_height="match_parent"/>
</FrameLayout>
</android.support.v4.widget.NestedScrollView>
</android.support.design.widget.CoordinatorLayout>
Problem
When a user touches inside the horizontal scrollable element & tries to scroll vertically, the parent RecyclerView is not scrolling up/down.
When the user touches outside the horizontal scrollable element & tries to scroll vertically, the parent RecyclerView is WORKING as usual.
This problem happens only when using BottomSheetBehavior, without BottomSheetBehavior, it works perfectly fine.
I tried with a FrameLayout instead of a NestedScrollView, also tried directly putting ReyclerView as the BottomSheetBehavior viewgroup. It didn't work.
So, how do I pass the vertical scroll touch events from a horizontally scrollable reyclerView which is part of a viewHolder to the parent RecyclerView when using a BottomSheetBehavior?

How to fix footer properly which is inside CoordinatorLayout

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.

Do I have to implement RecyclerView in order to scroll out a view out of screen

I have following layout:
What I would like to achieve is to scroll out the ViewPager out of the screen when you scroll in any of the listviews at the half bottom of the screen. As the ViewPager would be getting out of the screen the ListViews should take up more and more screen. Toolbar should stay pinned.
I was having look at the Support Design Library.
In my case from the examples the most interesting piece of code was this:
<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">
<! -- Your Scrollable View -->
<android.support.v7.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<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>
</android.support.design.widget.CoordinatorLayout>
Do I need to change my ListViews to RecyclerViews in order to achieve scrolling out the ViewPager from the screen - while the ListViews would increase their height as the ViewPager would getting out of the screen? Is that even possible with the Coordinator Layout?

CoordinatorLayout overlapping

Have a look at the following layout. You will see, that the floating button is too far to the bottom. This is because the Toolbar and the Tabs are shown and the height of the ViewPager is wrong. So somehow I'm doing something wrong with the layout_height. But how can I fix that?
Remark: The ViewPager is the main content and it contains a fragment with a ListView and a Google Map V2 in the second tab.
That's the layout 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: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:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways" />
<android.support.design.widget.TabLayout
android:id="#+id/sliding_tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/pager_list_views"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:layout_width="match_parent"
android:layout_height="fill_parent">
</android.support.v4.view.ViewPager>
</android.support.design.widget.CoordinatorLayout>
Here's the layout for the fragment in the first tab (the list):
<?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:layout_width="match_parent"
android:layout_height="match_parent">
<ListView
android:id="#+id/preview_list"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:choiceMode="singleChoice"
android:orientation="vertical" />
<android.support.design.widget.FloatingActionButton
android:id="#+id/action_add"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="end|bottom"
android:layout_margin="16dp"
android:src="#mipmap/ic_add_white_48dp" />
</android.support.design.widget.CoordinatorLayout>
Just to make sure; it's not a problem with the FAB. See this picture. It's a similar layout. A CoordinatorLayout with a ToolBar and a ViewPager which swipes through all detail-entries (therefore no tabs are needed). And again, the inner view seems to be too long (the same height as the ToolBar).
You should use android.support.v7.widget.RecyclerView and not ListView
Although you are already using android.support.v7.widget.RecyclerView be 100% sure that you have declard compile 'com.android.support:recyclerview-v7:23.0.0' in your build.gradle dependencies. I encountered the same issue where the viewpager overlaps the system buttons. I fixed it by simply adding this dependency.
Anything you what to be "coordinate" need to be direct child of CoordinatorLayout, Including the AppBar, RecyclerView (ListView in API21+ or other view support nested scroll is OK), or FAB, etc.
The reason why your FAB is offset out of screen, is that:
ViewPager has a #string/appbar_scrolling_view_behavior, the implement of this behavior will offset view when you scroll.
you put FAB inside ViewPager.
So when the offset of ViewPager changed, anything inside ViewPager will offset together (extra CoordinatorLayout has no help to change offset).
To fix this, don't use CoordinatorLayout outside ViewPager.
Or:
Put your FAB out of ViewPager so it won't scroll with ViewPager.
If the FAB only work with some of your page, hide() it when need.
BTW, there is very good App, Cheesesquare Sample, to demo the design library.

Toggling visibility AppBarLayout views causes spacing issues for loaded Fragments

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.

Categories

Resources