I ran into a problem where I had a simple ListView
in a BottomSheet
and ListView
had enough items to fill the screen and scroll even m
The solution is to extend the ListView
like this:
public class BottomSheetListView extends ListView {
public BottomSheetListView (Context context, AttributeSet p_attrs) {
super (context, p_attrs);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
return true;
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
if (canScrollVertically(this)) {
getParent().requestDisallowInterceptTouchEvent(true);
}
return super.onTouchEvent(ev);
}
public boolean canScrollVertically (AbsListView view) {
boolean canScroll = false;
if (view !=null && view.getChildCount ()> 0) {
boolean isOnTop = view.getFirstVisiblePosition() != 0 || view.getChildAt(0).getTop() != 0;
boolean isAllItemsVisible = isOnTop && view.getLastVisiblePosition() == view.getChildCount();
if (isOnTop || isAllItemsVisible) {
canScroll = true;
}
}
return canScroll;
}
}
Then in your layout file bottom_sheet_view.xml
:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.mypackage.name.BottomSheetListView
android:id="@+id/listViewBtmSheet"
android:divider="@color/colorPrimary"
android:dividerHeight="1dp"
android:layout_weight="1"
android:layout_width="match_parent"
android:layout_height="0dp" />
</LinearLayout>
Then finally, in your Activity
/Fragment
:
BottomSheetDialog dialog = new BottomSheetDialog(context);
dialog.setContentView(R.layout.bottom_sheet_view);
BottomSheetListView listView = (BottomSheetListView) dialog.findViewById(R.id.listViewBtmSheet);
// apply some adapter - add some data to listview
dialog.show();
This will provide a BottomSheet
that is fully working with ListView
scroll.
This is the correct list view custom class with touch event hadnling
public class BottomSheetListView extends ListView
{
public BottomSheetListView(Context context, AttributeSet p_attrs)
{
super(context, p_attrs);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev)
{
if (canScrollVertically(this))
{
getParent().requestDisallowInterceptTouchEvent(true);
}
return super.onInterceptTouchEvent(ev);
}
@Override
public boolean onTouchEvent(MotionEvent ev)
{
if (canScrollVertically(this))
{
getParent().requestDisallowInterceptTouchEvent(true);
}
return super.onTouchEvent(ev);
}
public boolean canScrollVertically(AbsListView view)
{
boolean canScroll = false;
if (view != null && view.getChildCount() > 0)
{
boolean isOnTop = view.getFirstVisiblePosition() != 0 || view.getChildAt(0).getTop() != 0;
boolean isAllItemsVisible = isOnTop && view.getLastVisiblePosition() == view.getChildCount();
if (isOnTop || isAllItemsVisible)
{
canScroll = true;
}
}
return canScroll;
}
}
There is a better approach if you don't want to extend the ListView
:
//in onCreate
_listView.setOnTouchListener(new ListView.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
int action = event.getAction();
switch (action) {
case MotionEvent.ACTION_DOWN:
// Disallow NestedScrollView to intercept touch events.
v.getParent().requestDisallowInterceptTouchEvent(true);
break;
case MotionEvent.ACTION_UP:
// Allow NestedScrollView to intercept touch events.
v.getParent().requestDisallowInterceptTouchEvent(false);
break;
}
// Handle ListView touch events.
v.onTouchEvent(event);
return true;
}
});
Just set android:nestedScrollingEnabled
to true
inside your
layout as ListView
attribute or listView.setNestedScrollingEnabled(true)
in java.
I know it's a bit hack but it worked for me, and even listview is selectable. As we know that when ever bottom sheet change its state it can be caught in it's listener so don't let it change the state if listview is not touching top, henceforth touch event will be passed to listview and will work as it does.
mBottomSheetBehavior.setBottomSheetCallback(new BottomSheetBehavior.BottomSheetCallback(){
@Override
public void onStateChanged(View bottomSheet, int newState) {
if (newState == BottomSheetBehavior.STATE_DRAGGING && !listIsAtTop()){
mBottomSheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);
}
}
@Override
public void onSlide(View bottomSheet, float slideOffset) {}});
public boolean listIsAtTop() {
if(tripListView.getChildCount() == 0) return true;
return (tripListView.getChildAt(0).getTop() == 0 && tripListView.getFirstVisiblePosition() ==0);
}
public class BottomSheetListView extends ListView {
public BottomSheetListView(Context context, AttributeSet attributeSet) {
super(context, attributeSet);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent motionEvent) {
View view = (View) getChildAt(getChildCount() - 1);
int diffBottom = (view.getBottom() - (getHeight() + getScrollY()));
if (motionEvent.getAction() == MotionEvent.ACTION_DOWN) {
if (diffBottom == 0) {
return false;
}
}
/*//Need more improvement on this logic. Do not uncomment
int diffTop = (view.getTop() - (getHeight() + getScrollY()));
if (motionEvent.getAction() == MotionEvent.ACTION_DOWN) {
if (diffTop < 0) {
return true;
}
}*/
return super.onInterceptTouchEvent(motionEvent);
}
@Override
public boolean onTouchEvent(MotionEvent motionEvent) {
if (canScrollVertically(this)) {
getParent().requestDisallowInterceptTouchEvent(true);
}
return super.onTouchEvent(motionEvent);
}
public boolean canScrollVertically(AbsListView absListView) {
boolean canScroll = false;
if (absListView != null && absListView.getChildCount() > 0) {
boolean isOnTop = absListView.getFirstVisiblePosition() != 0 || absListView.getChildAt(0).getTop() != 0;
boolean isAllItemsVisible = isOnTop && getLastVisiblePosition() == absListView.getChildCount();
if (isOnTop || isAllItemsVisible)
canScroll = true;
}
return canScroll;
}
}