MiguelHincapieC MiguelHincapieC - 5 months ago 129
Android Question

Sliding up image with Official Support Library 23.x.+ bottomSheet like google maps

Update

I want to accomplish the same behavior that google maps has with Support Library 23.x.+ and without ANY 3rd library



NOTE: this in not a duplicated question because:



  1. I want to use Behaviors, Support Library and without ANY 3rd party library (I added it in question title and above description)

  2. I wanted ALL behaviors that you see in next gif, the other questions are asking for one or two behaviors and using ANY WAY to achieve it.



    like you can see in this gif



I have already the Official bottomSheet working (even inside a tab and view pager).

What is making me going crazy is how to achieve the image behavior that come up from the BottomSheet when sliding up using official bottomSheet?.


I have tried using anchor like FAB with no success.

I read something about using a scroll listener but ppl said its not smooth and faster like google maps.



My XML (I don't think its going to help but anyway):



<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ui.MasterActivity">

<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"
app:layout_scrollFlags="scroll|enterAlways|snap">

<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
style="?android:attr/borderlessButtonStyle"
android:text="Departure"
android:layout_gravity="center"
android:id="@+id/buttonToolBar"
/>


</android.support.v7.widget.Toolbar>

<android.support.design.widget.TabLayout
android:id="@+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabBackground="@android:color/white"
app:tabTextColor="@color/colorAccent"
app:tabSelectedTextColor="@color/colorAccent"/>

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

<android.support.v4.view.ViewPager
android:id="@+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior" />


<android.support.v4.widget.NestedScrollView
android:id="@+id/asdf"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
app:behavior_peekHeight="100dp"
android:fitsSystemWindows="true"
app:layout_behavior="android.support.design.widget.BottomSheetBehavior">

<LinearLayout
android:id="@+id/qwert"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="16dp"
android:background="@android:color/white"
android:padding="15dp">

<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="BOOTOMSHEET TITLE"
android:textAppearance="@style/TextAppearance.AppCompat.Title" />

<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Button1"/>

<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="text 2"
android:layout_margin="10dp"/>

<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="text 3"
android:layout_margin="10dp"/>

<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="text 4"
android:layout_margin="10dp"/>


<FrameLayout
android:layout_width="match_parent"
android:layout_height="320dp"
android:background="@color/colorAccent">

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="Your remaining content here"
android:textColor="@android:color/white" />

</FrameLayout>
</LinearLayout>
</android.support.v4.widget.NestedScrollView>


<android.support.design.widget.FloatingActionButton
android:layout_height="wrap_content"
android:layout_width="wrap_content"
app:layout_anchor="@id/asdf"
app:layout_anchorGravity="top|right|end"
android:src="@drawable/abc_ic_search_api_mtrl_alpha_copy"
android:layout_margin="@dimen/fab_margin"
android:clickable="true"/>

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

Answer

If you want to achieve it using Support Library 23.4.0.+ I will tell you how I got it and how its works.

note: my apologize for my english, I tried to give a programming answer (just short and mixed with useful code) but seem like it was not good enough...

As far I can see that activity/fragment has the followings behaviors:

  1. 2 toolbars with animations that respond to the bottom sheet movements.
  2. A FAB that hides when it is near to the "modal toolbar" (the one that appears when you are sliding up).
  3. A backdrop image behind bottom sheet with some kind of parallax effect.
  4. A Title (TextView) in Toolbar that appears when bottom sheet reach it.
  5. The notification satus bar can turn its background to transparent or full color.
  6. A custom bottom sheet behavior with an "anchor" state.

note2: This answer talk about 6 things not about 1 or 2 like other question, can you see the difference now?

Ok, now let's check one bye one:

ToolBars
When you open that view in google maps u can see a toolbar in where you can search, it's the only one that I'm not doing equals like google maps, because I wanted to do it more generic. Anyway that ToolBar is inside an AppBarLayout and it got hidden when you start dragging the BottomSheet and it appears again when the BottomSheet reach the COLLAPSED state.
To achieve it you need:

  • create a Behavior and extend it from AppBarLayout.ScrollingViewBehavior
  • override layoutDependsOn and onDependentViewChanged methods. Doing it you will listen for bottomSheet movements.
  • create some methods to hide and unhide the AppBarLayout/ToolBar with animations.

This is how I did it for first toolbar or ActionBar:

@Override
public boolean layoutDependsOn(CoordinatorLayout parent, View child, View dependency) {
    return dependency instanceof NestedScrollView;
}

@Override
public boolean onDependentViewChanged(CoordinatorLayout parent, View child,
                                      View dependency) {

    if (mChild == null) {
        initValues(child, dependency);
        return false;
    }

    float dVerticalScroll = dependency.getY() - mPreviousY;
    mPreviousY = dependency.getY();

    //going up
    if (dVerticalScroll <= 0 && !hidden) {
        dismissAppBar(child);
        return true;
    }

    return false;
}

private void initValues(final View child, View dependency) {

    mChild = child;
    mInitialY = child.getY();

    BottomSheetBehaviorGoogleMapsLike bottomSheetBehavior = BottomSheetBehaviorGoogleMapsLike.from(dependency);
    bottomSheetBehavior.addBottomSheetCallback(new BottomSheetBehaviorGoogleMapsLike.BottomSheetCallback() {
        @Override
        public void onStateChanged(@NonNull View bottomSheet, @BottomSheetBehaviorGoogleMapsLike.State int newState) {
            if (newState == BottomSheetBehaviorGoogleMapsLike.STATE_COLLAPSED ||
                    newState == BottomSheetBehaviorGoogleMapsLike.STATE_HIDDEN)
                showAppBar(child);
        }

        @Override
        public void onSlide(@NonNull View bottomSheet, float slideOffset) {

        }
    });
}

private void dismissAppBar(View child){
    hidden = true;
    AppBarLayout appBarLayout = (AppBarLayout)child;
    mToolbarAnimation = appBarLayout.animate().setDuration(mContext.getResources().getInteger(android.R.integer.config_shortAnimTime));
    mToolbarAnimation.y(-(mChild.getHeight()+25)).start();
}

private void showAppBar(View child) {
    hidden = false;
    AppBarLayout appBarLayout = (AppBarLayout)child;
    mToolbarAnimation = appBarLayout.animate().setDuration(mContext.getResources().getInteger(android.R.integer.config_mediumAnimTime));
    mToolbarAnimation.y(mInitialY).start();
}

the complete file if you need it

The second Toolbar or "Modal" toolbar:
You have to override same methods but in this one you have to take care about more behaviors:

  • show/hide the ToolBar with animations
  • change statur bar color/background
  • show/hide the BottomSheet title in the ToolBar
  • close the bottomSheet or send it to collapsed state

The code for this one is a little extensive so I will let the link

The FAB

This is a Custom Behavior too but extends from FloatingActionButton.Behavior. In onDependentViewChanged you have to look when it reach the "offSet" or point in where you want to hide it. In my case I want hide it when its near to the second toolbar, so I dig into FAB parent (a CoordiantorLayout) looking for the AppBarLayout that contains the ToolBar, then I use the ToolBar position like OffSet:

@Override
public boolean onDependentViewChanged(CoordinatorLayout parent, FloatingActionButton child, View dependency) {

    if (offset == 0)
        setOffsetValue(parent);

    if (dependency.getY() <=0)
        return false;

    if (child.getY() <= (offset + child.getHeight()) && child.getVisibility() == View.VISIBLE)
        child.hide();
    else if (child.getY() > offset && child.getVisibility() != View.VISIBLE)
        child.show();

    return false;
}

Complete Custom FAB Behavior link

The Image behind the BottomSheet with parallax effect:
Like the others its a custom behavior, the only "complicated" thing in this one is the little algorithm that keeps the Image anchored to the BottomSheet and avoid the image collapse like default parallax effect:

@Override
public boolean onDependentViewChanged(CoordinatorLayout parent, View child,
                                      View dependency) {

    if (mYmultiplier == 0) {
        initValues(child, dependency);
        return true;
    }

    float dVerticalScroll = dependency.getY() - mPreviousY;
    mPreviousY = dependency.getY();

    //going up
    if (dVerticalScroll <= 0 && child.getY() <= 0) {
        child.setY(0);
        return true;
    }

    //going down
    if (dVerticalScroll >= 0 && dependency.getY() <= mImageHeight)
        return false;

    child.setY( (int)(child.getY() + (dVerticalScroll * mYmultiplier) ) );

    return true;
}


complete file for backdrop Image with parallax effect

Now for the end: The Custom BottomSheet Behavior
To achieve the 3 steps first you need to understant that default BottomSheetBehavior has 5 states: STATE_DRAGGING, STATE_SETTLING, STATE_EXPANDED, STATE_COLLAPSED, STATE_HIDDEN and for the Google Maps behavior you need to add a middle state between collapsed and expanded: STATE_ANCHOR_POINT.
I tried extends the default bottomSheetBehavior with no success, so I just copy paste all code and modified what I need.
To achieve what I'm talking about follow the next steps:

  1. Create a Java class and extend it from CoordinatorLayout.Behavior<V>
  2. Copy paste code from default BottomSheetBehavior file to your new one.
  3. Modify the method clampViewPositionVertical with the following code:

    @Override public int clampViewPositionVertical(View child, int top, int dy) { return constrain(top, mMinOffset, mHideable ? mParentHeight : mMaxOffset); } int constrain(int amount, int low, int high) { return amount < low ? low : (amount > high ? high : amount); }

  4. Add a new state

    public static final int STATE_ANCHOR_POINT = X;

  5. Modify the next methods: onLayoutChild, onStopNestedScroll, BottomSheetBehavior<V> from(V view) and setState (optional)



public boolean onLayoutChild(CoordinatorLayout parent, V child, int layoutDirection) {
    // First let the parent lay it out
    if (mState != STATE_DRAGGING && mState != STATE_SETTLING) {
        if (ViewCompat.getFitsSystemWindows(parent) &&
                !ViewCompat.getFitsSystemWindows(child)) {
            ViewCompat.setFitsSystemWindows(child, true);
        }
        parent.onLayoutChild(child, layoutDirection);
    }
    // Offset the bottom sheet
    mParentHeight = parent.getHeight();
    mMinOffset = Math.max(0, mParentHeight - child.getHeight());
    mMaxOffset = Math.max(mParentHeight - mPeekHeight, mMinOffset);

    //if (mState == STATE_EXPANDED) {
    //    ViewCompat.offsetTopAndBottom(child, mMinOffset);
    //} else if (mHideable && mState == STATE_HIDDEN...
    if (mState == STATE_ANCHOR_POINT) {
        ViewCompat.offsetTopAndBottom(child, mAnchorPoint);
    } else if (mState == STATE_EXPANDED) {
        ViewCompat.offsetTopAndBottom(child, mMinOffset);
    } else if (mHideable && mState == STATE_HIDDEN) {
        ViewCompat.offsetTopAndBottom(child, mParentHeight);
    } else if (mState == STATE_COLLAPSED) {
        ViewCompat.offsetTopAndBottom(child, mMaxOffset);
    }
    if (mViewDragHelper == null) {
        mViewDragHelper = ViewDragHelper.create(parent, mDragCallback);
    }
    mViewRef = new WeakReference<>(child);
    mNestedScrollingChildRef = new WeakReference<>(findScrollingChild(child));
    return true;
}


public void onStopNestedScroll(CoordinatorLayout coordinatorLayout, V child, View target) {
    if (child.getTop() == mMinOffset) {
        setStateInternal(STATE_EXPANDED);
        return;
    }
    if (target != mNestedScrollingChildRef.get() || !mNestedScrolled) {
        return;
    }
    int top;
    int targetState;
    if (mLastNestedScrollDy > 0) {
        //top = mMinOffset;
        //targetState = STATE_EXPANDED;
        int currentTop = child.getTop();
        if (currentTop > mAnchorPoint) {
            top = mAnchorPoint;
            targetState = STATE_ANCHOR_POINT;
        }
        else {
            top = mMinOffset;
            targetState = STATE_EXPANDED;
        }
    } else if (mHideable && shouldHide(child, getYVelocity())) {
        top = mParentHeight;
        targetState = STATE_HIDDEN;
    } else if (mLastNestedScrollDy == 0) {
        int currentTop = child.getTop();
        if (Math.abs(currentTop - mMinOffset) < Math.abs(currentTop - mMaxOffset)) {
            top = mMinOffset;
            targetState = STATE_EXPANDED;
        } else {
            top = mMaxOffset;
            targetState = STATE_COLLAPSED;
        }
    } else {
        //top = mMaxOffset;
        //targetState = STATE_COLLAPSED;
        int currentTop = child.getTop();
        if (currentTop > mAnchorPoint) {
            top = mMaxOffset;
            targetState = STATE_COLLAPSED;
        }
        else {
            top = mAnchorPoint;
            targetState = STATE_ANCHOR_POINT;
        }
    }
    if (mViewDragHelper.smoothSlideViewTo(child, child.getLeft(), top)) {
        setStateInternal(STATE_SETTLING);
        ViewCompat.postOnAnimation(child, new SettleRunnable(child, targetState));
    } else {
        setStateInternal(targetState);
    }
    mNestedScrolled = false;
}

public final void setState(@State int state) {
    if (state == mState) {
        return;
    }
    if (mViewRef == null) {
        // The view is not laid out yet; modify mState and let onLayoutChild handle it later
        /**
         * New behavior (added: state == STATE_ANCHOR_POINT ||)
         */
        if (state == STATE_COLLAPSED || state == STATE_EXPANDED ||
                state == STATE_ANCHOR_POINT ||
                (mHideable && state == STATE_HIDDEN)) {
            mState = state;
        }
        return;
    }
    V child = mViewRef.get();
    if (child == null) {
        return;
    }
    int top;
    if (state == STATE_COLLAPSED) {
        top = mMaxOffset;
    } else if (state == STATE_ANCHOR_POINT) {
        top = mAnchorPoint;
    } else if (state == STATE_EXPANDED) {
        top = mMinOffset;
    } else if (mHideable && state == STATE_HIDDEN) {
        top = mParentHeight;
    } else {
        throw new IllegalArgumentException("Illegal state argument: " + state);
    }
    setStateInternal(STATE_SETTLING);
    if (mViewDragHelper.smoothSlideViewTo(child, child.getLeft(), top)) {
        ViewCompat.postOnAnimation(child, new SettleRunnable(child, state));
    }
}


public static <V extends View> BottomSheetBehaviorGoogleMapsLike<V> from(V view) {
    ViewGroup.LayoutParams params = view.getLayoutParams();
    if (!(params instanceof CoordinatorLayout.LayoutParams)) {
        throw new IllegalArgumentException("The view is not a child of CoordinatorLayout");
    }
    CoordinatorLayout.Behavior behavior = ((CoordinatorLayout.LayoutParams) params)
            .getBehavior();
    if (!(behavior instanceof BottomSheetBehaviorGoogleMapsLike)) {
        throw new IllegalArgumentException(
                "The view is not associated with BottomSheetBehaviorGoogleMapsLike");
    }
    return (BottomSheetBehaviorGoogleMapsLike<V>) behavior;
}



link to the hole project in where you can see all Custom Behaviors

note3: next time add a comment asking in a polite way for change of the answer or ask why this answer has SOME equals stuff than others answer of mine about same topic BEFORE close it or mark like duplicated.

And here is how its looks like:
[CustomBottomSheetBehavior]

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