This example depends on Support Library 23.4.0.+.
BottomSheetBehavior is characterized by :
Now let’s check them one by one:
ToolBars When you open that view in Google Maps, you can see a toolbar in where you can search, it’s the only one that I’m not doing exactly 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 to:
Behavior
and extend it from AppBarLayout.ScrollingViewBehavior
layoutDependsOn
and onDependentViewChanged
methods. Doing it you will listen for bottomSheet movements.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();
}
Here is the complete file if you need it
The second Toolbar or “Modal” toolbar: You have to override the same methods, but in this one you have to take care of more behaviors: