How to reset the Toolbar position controlled by the CoordinatorLayout?

Question

The app I'm working on consists of a Navigation Drawer which is implemented in an Activity. The activity layout is as follows:

<FrameLayout 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.support.v4.widget.DrawerLayout
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.design.widget.CoordinatorLayout
        android:id="@+id/coordinator"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <FrameLayout
            android:id="@+id/container"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior">

        <include
            android:id="@+id/appbar"
            layout="@layout/appbar" />

    </android.support.design.widget.CoordinatorLayout>

    <android.support.design.widget.NavigationView
        android:id="@+id/navigation_drawer"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        app:headerLayout="@layout/header_drawer"
        app:menu="@menu/menu_nav">
    </android.support.design.widget.NavigationView>

</android.support.v4.widget.DrawerLayout>

</FrameLayout>

This is a very common pattern, only thing that changes frequently is the Fragment inside the container layout.

If any of the Fragment has a scrolling element, upon scrolling, the CoordinatorLayout will happily make position translations, including the Toolbar/AppBarLayout.

The real problem here is, when the Fragment gets replaced, the position for the Toolbar remains the same, i.e., if the Toolbar is hidden, it will stay so which isn't intended.

Result is this:

This:

After scroll

Gets stuck:

Then change

How can one reset the Toolbar position for this case?

EDIT: A bug is probable, the AppBarLayout offset change listener gets called only when relaunching the app (press back button and open the app), and stops getting called again after an intense fling.

no not yet, a kind person had answered here, he deleted his post before even I had chance to discuss, he said that he used setTranslationY() on AppBarLayout to manipulate it rather than reset, and mentioned that it should work, which didn't for me, still looking for answers to this. I'll definitely post a solution once I find it. — razzledazzle, Jun 04 '15 at 16:34
Hey, @razzledazzle, I am trying to put a fragment with recyclerview in a FrameLayout which is part of the CoordinatorLayout. I specified layout_behavior in FrameLayout, but the AppBarLayout does not scroll. Anything you are doing differently? Do I have to initialize views in my activity? — Froyo, Jun 10 '15 at 10:42
fixed it. Forgot to add `app:layout_scrollFlags="scroll"` to toolbar. — Froyo, Jun 10 '15 at 11:51
One more thing. Even if I have no items in the recyclerview, toolbar still scrolls. Any idea how to fix that? — Froyo, Jun 10 '15 at 12:21
@Froyo Make your Activity or Fragment implement AppBarLayout.OnOffsetChangedListener then, `mAppBar.addOnOffsetChangedListener(this);` and `@Override public void onOffsetChanged(AppBarLayout appBarLayout, int offset) { if(recycler.canScrollVertically(1)) { appBarLayout.setTranslationY(0); } }` Basically check if your scrolling view can scroll and lock the AppBarLayout. — razzledazzle, Jul 24 '15 at 08:38
maybe the problem is related to: http://stackoverflow.com/a/35142898/755804 — 18446744073709551615, Feb 02 '16 at 01:03

score 48 · Accepted Answer · answered Jun 09 '15 at 10:25

48

To reset the scroll state, just get the AppBarLayout.Behavior object

CoordinatorLayout coordinator = (CoordinatorLayout) findViewById(R.id.coordinator);
AppBarLayout appbar = (AppBarLayout) findViewById(R.id.appbar);
CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) appbar.getLayoutParams();
AppBarLayout.Behavior behavior = (AppBarLayout.Behavior) params.getBehavior();

and call onNestedPreScroll method manually:

int[] consumed = new int[2];
behavior.onNestedPreScroll(coordinator, appbar, null, 0, -1000, consumed);

If you would like to reset smoothly with an animation, you can try calling onNestedFling instead:

behavior.onNestedFling(coordinator, appbar, null, 0, -1000, true);

answered Jun 09 '15 at 10:25

MattSkala

1,069
1
10
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1

For me it only works for collapsing `AppBarLayout` by setting positive 'velocityY' value. Above code with negative 'velocityY' value has no effect. I'm calling it from `NestedScrollView's onTouchListener` after `ACTION_UP` action. I want to implement snap behavior - to always collapse or expand `AppBarLayout`. – theb1uro Jun 09 '15 at 14:53
Thanks for the answer, this is a good solution, I used the onNestedFling() inside the drawer open callback and it works pretty nicely. – razzledazzle Jun 10 '15 at 13:28
I have exactly the same experience like @theb1uro. Only work for collapse with positive 'velocityY' value. Expand with negative 'velocityY' value has no effect... – Tomas Jun 10 '15 at 16:54
I tested it also on cheesesquare and the same result, any idea why this work only when collapsing AppBarLayout? – Tomas Jun 10 '15 at 21:37
1

params.getBehavior() is returning null. In xml, layout_behaviour tag is set on sibling NestedScrollView, not the AppBarLayout. Please help! – User31689 Jun 26 '15 at 06:55
Works nicely with ViewPager+TabLayout inside CoordinatorLayout – Nati Dykstein Aug 11 '15 at 10:58
negative 'velocityY' value will have effect, when you set app:layout_scrollFlags="scroll|enterAlways" , – xiaoyee Jan 14 '16 at 12:08

score 40 · Answer 2 · answered Oct 23 '15 at 11:59

40

First get a AppBarLayout refrence in you MainActivity, then in the pause state of the fragment that is being replaced, use the method below to expand toolbar :

MainActivity.appbar.setExpanded(true,true);

And or to close the toolbar :

MainActivity.appbar.setExpanded(false,true);

The second parameter is used to scroll the toolbar smoothly.

answered Oct 23 '15 at 11:59

Shayan Shafiee

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5
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This does not cover the use case when you would want to lock the `AppBarLayout`. – razzledazzle Dec 04 '15 at 03:12
1

AppBarLayout has no such method `setExpanded`? – Muhammad Babar Jan 22 '16 at 11:06
3

@MuhammadBabar Update your dependencies, bro. – Pkmmte Feb 04 '16 at 01:01

score 14 · Answer 3 · answered Dec 03 '15 at 14:57

14

Update your support lib to v23 then you can use:

appBarLayout.setExpanded(true/false);

public void setExpanded (boolean expanded)

Sets whether this AppBarLayout is expanded or not, animating if it has already been laid out.

As with AppBarLayout's scrolling, this method relies on this layout being a direct child of a CoordinatorLayout.

expanded true if the layout should be fully expanded, false if it should be fully collapsed

answered Dec 03 '15 at 14:57

Context

1,873
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24

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This fails to lock the `AppBarLayout` in place. It however does work for regular cases. – razzledazzle Dec 04 '15 at 03:14

score 3 · Answer 4 · answered Jun 10 '15 at 14:26

3

@razzledazzle The AppBarLayout stores onOffsetChangedListeners as WeakReferences, which means they are garbage collected when needed, for instance when you do a intense fling. See solution here:

https://code.google.com/p/android/issues/detail?id=176328

answered Jun 10 '15 at 14:26

freebiefalk

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Ah, this was definitely the case, I did see WeakReferences in the source but never thought how easily they could get GCed. This also explains why referencing the listeners as field under onResume() worked better as opposed to initializing anonymous classed during onCreate(). Implementing the listener as a class is a guaranteed solution as mentioned in the link. Thank you very much for your input! – razzledazzle Jun 10 '15 at 14:56
According to that post is has been fixed. – Michael Dec 06 '15 at 21:51

score 2 · Answer 5 · answered Jun 07 '15 at 16:43

2

I'm using this codes before fragment changes.

scrollingElement.startNestedScroll(ViewCompat.SCROLL_AXIS_VERTICAL);
scrollingElement.dispatchNestedPreScroll(0, -Integer.MAX_VALUE, null, null);
scrollingElement.stopNestedScroll();

answered Jun 07 '15 at 16:43

weumj

29
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3

Can you add some explanations? – Peanut Jun 07 '15 at 16:56
Idea appears to be coming from the doc for startNestedScroll(), see https://developer.android.com/reference/android/view/View.html#startNestedScroll%28int%29 – Dan Dar3 Oct 17 '15 at 08:59

score 2 · Answer 6 · answered May 08 '17 at 15:08

Replace or Wrap the FrameLayout inside the android.support.design.widget.CoordinatorLayout with a android.support.v4.widget.NestedScrollView and that will do the job automatically without having to any other hacks....so it would look like this:

<android.support.design.widget.CoordinatorLayout
    android:id="@+id/coordinator"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v4.widget.NestedScrollView
        android:id="@+id/container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">

    <include
        android:id="@+id/appbar"
        layout="@layout/appbar" />

</android.support.design.widget.CoordinatorLayout>

hassan moradnezhad · Answer 7 · 2019-08-07T09:00:45.863

As document said

AppBarLayout supports
void setExpanded (boolean expanded, boolean animate);
Sets whether this AppBarLayout is expanded or not.

expanded boolean: true if the layout should be fully expanded, false if it should be fully collapsed

animate boolean: Whether to animate to the new state

So first, you need

AppBarLayout appBarLayout = findViewById(R.id.appBarLayout);

then to expand layout

appBarLayout.setExpanded(true, true); // with animation
appBarLayout.setExpanded(true, false); // without animation

and to collapse layout

appBarLayout.setExpanded(false, true); // with animation
appBarLayout.setExpanded(false, false); // without animation

score 0 · Answer 8 · answered Dec 20 '19 at 03:35

0

// Get the reference for appbar from layout
AppBarLayout appbar = rootView.findViewById(R.id.appbar);
//boolean expanded, boolean animate
appbar.setExpanded(true, true);

answered Dec 20 '19 at 03:35

Shashank Degloorkar

3,151
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score 0 · Answer 9 · answered Apr 23 '21 at 15:21

I had a similar problem. My layout was placed either higher than needed (like here), or lower, when I dynamically resized it. It was a Fragment that was replaced in FrameLayout programmatically. What I did: I began to re-creating my Fragment on change the FrameLayout size.

myFragment = new MyFragment();
getSupportFragmentManager().beginTransaction()
                .replace(R.id.frame_layout, myFragment)
                .commit();

How to reset the Toolbar position controlled by the CoordinatorLayout?

9 Answers9

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