David Seroussi David Seroussi - 3 months ago 77
Android Question

BottomSheetDialog remains hidden after dismiss by dragging down

I am pretty curious about the behavior of the

BottomSheetDialog
when it is dismissed : when the user draggs it down to hide it, it will remain hidden, even if
bottomSheetDialog#show()
is called after. This only happens when it is dragged down, not when the user touches outside or when
bottomSheetDialog#dismiss()
is called programatically.

It is really annoying because I have a pretty big
bottomSheetDialog
with a recyclerview inside, and I have to create a new one every time I want to show the
bottomSheetDialog
.

So instead of just doing this :

if(bottomSheetDialog != null){
bottomSheetDialog.show();
else{
createNewBottomSheetDialog();
}


I have to create one every time.

Am I missing something or is it the normal behavior ? (Btw I use
appcompat-v7:23.2.1
)

Answer

So I finally managed to solve this problem by looking directly into the BottomSheetDialog implementation, and I discovered it was nothing but a simple Dialog wrapped into a regular BottomSheet.
The problem was in the BottomSheetCallBack :

@Override
    public void onStateChanged(@NonNull View bottomSheet,
            @BottomSheetBehavior.State int newState) {
        if (newState == BottomSheetBehavior.STATE_HIDDEN) {
            dismiss();
        }
    }

The problem occurs when the state HIDDEN is reached which happens when the dialog is dismissed by being dragged down. After that the dialog stays hidden even if bottomSheetDialog.show() is called. The most simple fix I found was to remove this state and replace it by the COLLAPSED state.

I create a classCustomBottomSheetDialog, copied the entire BottomSheetDialog class and added a single line to fix the problem :

@Override
    public void onStateChanged(@NonNull View bottomSheet,
                               @BottomSheetBehavior.State int newState) {

        if (newState == CustomBottomSheetBehavior.STATE_HIDDEN) {

            dismiss();
            bottomSheetBehavior.setState(CustomBottomSheetBehavior.STATE_COLLAPSED);
        }
    }

Here is the final code:

public class CustomBottomSheetDialog extends AppCompatDialog {

    public CustomBottomSheetDialog (@NonNull Context context) {
        this(context, 0);
    }

    public CustomBottomSheetDialog (@NonNull Context context, @StyleRes int theme) {
        super(context, getThemeResId(context, theme));
        // We hide the title bar for any style configuration. Otherwise, there will be a gap
        // above the bottom sheet when it is expanded.
        supportRequestWindowFeature(Window.FEATURE_NO_TITLE);
    }

    protected CustomBottomSheetDialog (@NonNull Context context, boolean cancelable,
            OnCancelListener cancelListener) {
        super(context, cancelable, cancelListener);
        supportRequestWindowFeature(Window.FEATURE_NO_TITLE);
    }

    @Override
    public void setContentView(@LayoutRes int layoutResId) {
        super.setContentView(wrapInBottomSheet(layoutResId, null, null));
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().setLayout(
                ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
    }

    @Override
    public void setContentView(View view) {
        super.setContentView(wrapInBottomSheet(0, view, null));
    }

    @Override
    public void setContentView(View view, ViewGroup.LayoutParams params) {
        super.setContentView(wrapInBottomSheet(0, view, params));
    }

    private View wrapInBottomSheet(int layoutResId, View view, ViewGroup.LayoutParams params) {
        final CoordinatorLayout coordinator = (CoordinatorLayout) View.inflate(getContext(),
                R.layout.design_bottom_sheet_dialog, null);
        if (layoutResId != 0 && view == null) {
            view = getLayoutInflater().inflate(layoutResId, coordinator, false);
        }
        FrameLayout bottomSheet = (FrameLayout) coordinator.findViewById(R.id.design_bottom_sheet);
        BottomSheetBehavior.from(bottomSheet).setBottomSheetCallback(mBottomSheetCallback);
        if (params == null) {
            bottomSheet.addView(view);
        } else {
            bottomSheet.addView(view, params);
        }
        // We treat the CoordinatorLayout as outside the dialog though it is technically inside
        if (shouldWindowCloseOnTouchOutside()) {
            coordinator.findViewById(R.id.touch_outside).setOnClickListener(
                    new View.OnClickListener() {
                        @Override
                        public void onClick(View view) {
                            if (isShowing()) {
                                cancel();
                            }
                        }
                    });
        }
        return coordinator;
    }

    private boolean shouldWindowCloseOnTouchOutside() {
        if (Build.VERSION.SDK_INT < 11) {
            return true;
        }
        TypedValue value = new TypedValue();
        //noinspection SimplifiableIfStatement
        if (getContext().getTheme()
                .resolveAttribute(android.R.attr.windowCloseOnTouchOutside, value, true)) {
            return value.data != 0;
        }
        return false;
    }

    private static int getThemeResId(Context context, int themeId) {
        if (themeId == 0) {
            // If the provided theme is 0, then retrieve the dialogTheme from our theme
            TypedValue outValue = new TypedValue();
            if (context.getTheme().resolveAttribute(
                    R.attr.bottomSheetDialogTheme, outValue, true)) {
                themeId = outValue.resourceId;
            } else {
                // bottomSheetDialogTheme is not provided; we default to our light theme
                themeId = R.style.Theme_Design_Light_BottomSheetDialog;
            }
        }
        return themeId;
    }

    private BottomSheetBehavior.BottomSheetCallback mBottomSheetCallback
            = new BottomSheetBehavior.BottomSheetCallback() {
        @Override
        public void onStateChanged(@NonNull View bottomSheet,
                @BottomSheetBehavior.State int newState) {
            if (newState == BottomSheetBehavior.STATE_HIDDEN) {
                dismiss();
                bottomSheetBehavior.setState(CustomBottomSheetBehavior.STATE_COLLAPSED);
            }
        }

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

}
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