CODEWITHSUNDEEP
androidandroid-toolbarandroid-appbarlayout
Cilenco
Cilenco

Reputation: 7179

Toolbar expands on swipe down

In my application I have a collapsing Toolbar. If I start a specific Fragment I want to collapse the Toolbar so it behaves like a "normal" one and that the user can not expend it by himself. Here is my layout which I use for my Toolbar:

<android.support.design.widget.AppBarLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/appBarLayout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/collapsing_toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:contentScrim="?attr/colorPrimary"
        app:expandedTitleMarginEnd="64dp"
        app:expandedTitleMarginStart="48dp"
        app:titleEnabled="false"
        app:layout_scrollFlags="scroll|exitUntilCollapsed">

        <ImageView
            android:src="@drawable/drawer_background"
            app:layout_scrollFlags="scroll|enterAlways|enterAlwaysCollapsed"
            android:layout_width="match_parent"
            android:layout_height="172dp"
            android:scaleType="centerCrop"
            app:layout_collapseMode="parallax"
            android:minHeight="100dp" />

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolBar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:layout_collapseMode="pin"
            app:layout_scrollFlags="scroll|enterAlways" />

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

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

I also can collapse the layout from code like so:

appBarLayout.setExpanded(false, false);

final AppBarLayout.LayoutParams params = (AppBarLayout.LayoutParams) collapsingToolbarLayout.getLayoutParams();
params.setScrollFlags(0);
collapsingToolbarLayout.setLayoutParams(params);

But this does not help. If the user swipes down from the Toolbar it will expand.

Do you have any ideas why?

Upvotes: 16

Views: 6585

Answers (7)

Finch
Finch

Reputation: 1

the simplest thing to do is to extend the class AppBarLayout.Behavior

public class AppBarBehavior extends AppBarLayout.Behavior {
  private boolean locked;

  public AppBarBehavior() {
    super();
  }

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

  @Override
  public boolean onStartNestedScroll(@NonNull CoordinatorLayout parent, @NonNull AppBarLayout child, @NonNull View directTargetChild, View target, int nestedScrollAxes, int type) {
    if (locked) return false;       // Lock when content scrolled
    else return super.onStartNestedScroll(parent, child, directTargetChild, target, nestedScrollAxes, type);
  }

  @Override
  public boolean onTouchEvent(@NonNull CoordinatorLayout parent, @NonNull AppBarLayout child, @NonNull MotionEvent ev) {
    if (locked) return false;       // Lock when appBar swiped
    else return super.onTouchEvent(parent, child, ev);
  }

  public void lock(boolean locked) {
    this.locked = locked;
  }
}

Then set new layout_behavior in XML

<com.google.android.material.appbar.AppBarLayout
    android:id="@+id/main.appbar"
    android:layout_width="match_parent"
    android:layout_height="200dp"
    android:fitsSystemWindows="false"
    app:layout_behavior="<full path to package>.AppBarBehavior">

And now you can manage locking with:

AppBarLayout appBar = findViewById(R.id.main_appbar);
appBar.setExpanded(false, true);   // collapse appBar
CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) appBar.getLayoutParams();
AppBarBehavior behavior = (AppBarBehavior) params.getBehavior();
behavior.lock(true);   // lock appBar

Upvotes: 0

Bharatesh
Bharatesh

Reputation: 9009

Well try setting some parameters to toolBar, tabLayout programatically, I have ViewPager changing flags on onPageSelected(int)

        @Override
        public void onPageSelected(int position) {
            AppBarLayout.LayoutParams params = new AppBarLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
            if (position == 3) {//listen for scrolls only for Fragment 3
                params.setScrollFlags(AppBarLayout.LayoutParams.SCROLL_FLAG_SCROLL | AppBarLayout.LayoutParams.SCROLL_FLAG_ENTER_ALWAYS);
                toolBar.setLayoutParams(params);//hide as per scroll
                params = new AppBarLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
                params.setScrollFlags(AppBarLayout.LayoutParams.SCROLL_FLAG_ENTER_ALWAYS);
                tabLayout.setLayoutParams(params);//always visible
            } else {
                appBarLayout.setExpanded(false, true);
                params.setScrollFlags(AppBarLayout.LayoutParams.SCROLL_FLAG_ENTER_ALWAYS | AppBarLayout.LayoutParams.SCROLL_FLAG_ENTER_ALWAYS_COLLAPSED);
                toolBar.setLayoutParams(params);//don't listen to scrolls
                tabLayout.setLayoutParams(params);//dont listen to scrolls
            }
        }

Use/Set above flags as you required. AppBarLayout.LayoutParams

Upvotes: 1

Kemal
Kemal

Reputation: 96

None of the provided solutions worked for me except this one. With this solution, i can easily manage the state of collapsing toolbar. This will prevent expanding/enable collapsing of collapsing toolbar and set title for it.

public void lockAppBar(boolean locked,String title) {
    if(locked){
        appBarLayout.setExpanded(false, true);
        int px = (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 80, getResources().getDisplayMetrics());
        CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams)appBarLayout.getLayoutParams();
        lp.height = px;
        appBarLayout.setLayoutParams(lp);
        collapsingToolbarLayout.setTitleEnabled(false);
        toolbar.setTitle(title);
    }else{
        appBarLayout.setExpanded(true, false);
        appBarLayout.setActivated(true);
        CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams) appBarLayout.getLayoutParams();
        lp.height = (int) getResources().getDimension(R.dimen.toolbarExpandHeight);
        collapsingToolbarLayout.setTitleEnabled(true);
        collapsingToolbarLayout.setTitle(title);
    }

}

Upvotes: 2

Sevle
Sevle

Reputation: 3119

The core problem is that there is no CollapsingToolbarLayout.lock(); method up until now (v23.2.1 of support design). Hopefully, this feature will be included in a future version. Until then, I'm suggesting the following workaround:

You can collapse and lock your toolbar with:

appbar.setExpanded(false,false);
CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams)appbar.getLayoutParams();
lp.height = (int) getResources().getDimension(R.dimen.toolbar_height);

and unlock it with:

 CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams)appbar.getLayoutParams();
 lp.height = (int) getResources().getDimension(R.dimen.nav_header_height);

However, with the above code a problem occurs:

when forcefully collapsing CoordinatorLayout the title of our Toolbar is gone and CollapsingToolbarLayout.setTitle(CharSequence title); no longer works. To fix that we add a TextView in our Toolbar and manipulate its visibility accordingly. (we want it "gone" in a fragment that has its toolbar 'unlocked' and "visible" in a fragment that has its toolbar 'locked'.

We have to set TextView's android:textAppearance to be the same with CollapsingToolbarLayout's app:collapsedTitleTextAppearance to be consistent and avoid disrupting the user with different toolbar text sizes and colors.

In summary, with an interface like this:

public interface ToolbarManipulation {
    void collapseToolbar();
    void expandToolbar();
    void setTitle(String s);
}

implemantations like these: 

@Override
    public void collapseToolbar(){
        appbar.setExpanded(false,false);
        CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams)appbar.getLayoutParams();
        lp.height = (int) getResources().getDimension(R.dimen.toolbar_height);
        toolbarCollapsedTitle.setVisibility(View.VISIBLE);
    }

    @Override
    public void expandToolbar() {
        CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams)appbar.getLayoutParams();
        lp.height = (int) getResources().getDimension(R.dimen.nav_header_height);
        toolbarCollapsedTitle.setVisibility(View.GONE);
    }

    @Override
    public void setTitle(String s) {
        collapsingToolbarLayout.setTitle(s);
        toolbarCollapsedTitle.setText(s);
        collapsingToolbarLayout.invalidate();
        toolbarCollapsedTitle.invalidate();
    }

and main xml like this:

....
  <android.support.design.widget.CollapsingToolbarLayout
            android:id="@+id/collapsing_toolbar"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:fitsSystemWindows="true"
            app:contentScrim="?attr/colorPrimary"
            app:layout_scrollFlags="scroll|exitUntilCollapsed"
            app:collapsedTitleTextAppearance="@style/CollapsedAppBar"

            >
                <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_collapseMode="pin"
                    app:popupTheme="@style/AppTheme.PopupOverlay"
                    >
                    <TextView
                        android:layout_width="match_parent"
                        android:layout_height="?attr/actionBarSize"
                        android:visibility="gone"
                        android:layout_gravity="center_vertical|start"
                        android:gravity="center_vertical|start"
                        android:id="@+id/toolbar_collapsed_title"
                        android:textAppearance="@style/CollapsedAppBar"
                        />
                </android.support.v7.widget.Toolbar>
        </android.support.design.widget.CollapsingToolbarLayout>
......

you can lock and unlock your Toolbar as you like. Your fragments should call these functions in their onResume();

I've uploaded an example implementation here.

Note: This is just a workaround and obviously not the cleanest solution. We're waiting for a newer version of com.android.support to resolve this.

Upvotes: 21

Vaibhav Sharma
Vaibhav Sharma

Reputation: 2319

Do findViewById(R.id.image_view).setVisibility(View.GONE); where image_view is the id of the imageView in the collapsing toolbar. But if you want to do it for a specific fragment I suggest calling the same using fragment- activity communication.

Upvotes: 2

arsent
arsent

Reputation: 7183

Try to change the height of the AppBar. It works for me.

public void lockAppBar() {
    int appbarHeight = (int)getResources().getDimension(R.dimen.your_fixed_appbar_height);
    getView().findViewById(R.id.my_appbar).getLayoutParams().height = appbarHeight; 
}

Upvotes: 2

gaara87
gaara87

Reputation: 2077

I'm not exactly sure if this is what you are looking for

CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) appBarLayout.getLayoutParams(); 
AppBarLayout.Behavior behavior = (AppBarLayout.Behavior) params.getBehavior(); 
behavior.setDragCallback(new AppBarLayout.Behavior.DragCallback() {
    @Override
    public boolean canDrag(@NonNull AppBarLayout appBarLayout) {
        return false;
    } 
});

Upvotes: 13

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