CODEWITHSUNDEEP
androidandroid-design-libraryandroid-collapsingtoolbarlayout
d0pestar
d0pestar

Reputation: 575

How can I determine that CollapsingToolbar is collapsed?

I need to know when CollapsingToolbar from material design library is collapsed.

Upvotes: 47

Views: 43593

Answers (5)

qianlv
qianlv

Reputation: 550

 appBarLayout.addOnOffsetChangedListener(AppBarLayout.OnOffsetChangedListener { appBarLayout, verticalOffset ->

        if (Math.abs(verticalOffset)  >= appBarLayout.totalScrollRange) { // collapse
        } else if (verticalOffset == 0) { // fully expand

        } else { // scolling

        }
    })

appBarLayout.totalScrollRange is not always equal to verticalOffset in some case, better check verticalOffset larger than totoalScrollRange

Upvotes: 2

dileep krishnan
dileep krishnan

Reputation: 344

appBarLayout.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() 
{
        @Override
        public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset)
 {

            if (Math.abs(verticalOffset)-appBarLayout.getTotalScrollRange() == 0)
            {
                //  on Collapse
            }
            else
            {
               //  on expand
            }
        }
    });

Upvotes: 0

Marko
Marko

Reputation: 20513

UPDATE: Since support versions of 23.1.1+ the issue is no longer there, no need to use the listener and disable the swipe refresh layout, it will work as it should (link).

Implement AppBarLayout.OnOffsetChangedListener listener on your AppBarLayout

AppBarLayout appBarLayout = (AppBarLayout) view.findViewById(R.id.app_bar_layout);
appBarLayout.addOnOffsetChangedListener(this);

And check if offset is 0, meaning the toolbar is fully expanded.

@Override
public void onOffsetChanged(AppBarLayout appBarLayout, int offset)
{
    if (offset == 0)
    {
        // Fully expanded
    }
    else
    {
        // Not fully expanded or collapsed
    }
}

Upvotes: 81

chrlaura
chrlaura

Reputation: 1317

As Marko said, this can be achieved using your own implementation of a OnOffsetChangedListener.

AppBarLayout appBarLayout = (AppBarLayout) view.findViewById(R.id.app_bar_layout);
appBarLayout.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
        @Override
        public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
            if (Math.abs(verticalOffset) == appBarLayout.getTotalScrollRange()) {
                // Collapsed
            } else if (verticalOffset == 0) {
                // Expanded
            } else {
                // Somewhere in between
            }
        }
    }););

Upvotes: 102

Eduard B.
Eduard B.

Reputation: 6803

Take a look over this github gist

public class MyAppBarLayout extends AppBarLayout
        implements AppBarLayout.OnOffsetChangedListener {

    private State state;
    private OnStateChangeListener onStateChangeListener;

    public MyAppBarLayout(Context context) {
        super(context);
    }

    public MyAppBarLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();
        if (!(getLayoutParams() instanceof CoordinatorLayout.LayoutParams)
                || !(getParent() instanceof CoordinatorLayout)) {
            throw new IllegalStateException(
                    "MyAppBarLayout must be a direct child of CoordinatorLayout.");
        }
        addOnOffsetChangedListener(this);
    }

    @Override
    public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
        if (verticalOffset == 0) {
            if (onStateChangeListener != null && state != State.EXPANDED) {
                onStateChangeListener.onStateChange(State.EXPANDED);
            }
            state = State.EXPANDED;
        } else if (Math.abs(verticalOffset) >= appBarLayout.getTotalScrollRange()) {
            if (onStateChangeListener != null && state != State.COLLAPSED) {
                onStateChangeListener.onStateChange(State.COLLAPSED);
            }
            state = State.COLLAPSED;
        } else {
            if (onStateChangeListener != null && state != State.IDLE) {
                onStateChangeListener.onStateChange(State.IDLE);
            }
            state = State.IDLE;
        }
    }

    public void setOnStateChangeListener(OnStateChangeListener listener) {
        this.onStateChangeListener = listener;
    }

    public interface OnStateChangeListener {
        void onStateChange(State toolbarChange);
    }

    public enum State {
        COLLAPSED,
        EXPANDED,
        IDLE
    }
}

Upvotes: 19

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