How to toggle the view color in Fast Adapter library

Question

I want to implement multi select adapter for my recycler view. I m using Mike Penz's FastAdapter for the same.

I am not sure on how to toggle the selected item view color.

Here is the code snippet, attaching a ClickEventHook<SimpleItem> to the card view in the item so onClick() is called when clicked on the card view,

private void setupFastAdapter() {
    mFastAdapter = new FastAdapter<>();

    // Configure the FastAdapter.
    mFastAdapter.withSelectable(true);
    mFastAdapter.withMultiSelect(true);
    mFastAdapter.withSelectOnLongClick(false);

    mFastAdapter.withSelectionListener(new ISelectionListener<SimpleItem>() {
        @Override
        public void onSelectionChanged(SimpleItem item, boolean selected) {
            // Toggle the card and text colors.
            if (selected) {
                Logger.i("Selected [%s]", item.getText());
            } else {
                Logger.i("Unselected [%s]", item.getText());
            }
        }
    });

    // Click listeners for views inside the item, add an `EventHook` to the `FastAdapter` by
    // implementing either a `ClickEventHook`, `LongClickEventHook`, `TouchEventHook`, `CustomEventHook`
    mFastAdapter.withEventHook(new ClickEventHook<SimpleItem>() {
        private CardView cardView;
        private TextView textView;

        @Nullable
        @Override
        public View onBind(@NonNull RecyclerView.ViewHolder viewHolder) {
            //return the views on which you want to bind this event
            if (viewHolder instanceof SimpleItem.ViewHolder) {
                cardView = ((SimpleItem.ViewHolder) viewHolder).mCardView;
                textView = ((SimpleItem.ViewHolder) viewHolder).mTextView;
                return cardView;
            } else {
                return null;
            }
        }

        @Override
        public void onClick(View v, int position, FastAdapter<SimpleItem> fastAdapter, SimpleItem item) {
            //react on the click event
            Logger.i("Clicked [%s]", item.getText());
            if (cardView.isSelected()) {
                cardView.setCardBackgroundColor(getActivity().getResources().getColor(R.color.app_green_dark));
                textView.setTextColor(getActivity().getResources().getColor(R.color.app_white));
            } else {
                cardView.setCardBackgroundColor(getActivity().getResources().getColor(R.color.app_light_blue_50));
                textView.setTextColor(getActivity().getResources().getColor(R.color.primary_text));
            }
        }
    });
}

Color of the card view and text color of the text view are not toggling. And I am not sure how it is implemented correctly.

I have observed onSelectionChanged() method is also not called when the card view in the item is clicked.

Can anyone suggest me an approach to toggle the color of the card view and text on selection and deselection?

Thank you in advance,
Mani

score 0 · Answer 1 · edited Feb 10 '22 at 19:33

I would suggest to use a ColorStateList or a StateListDrawable for setting state specific backgrounds.

Something like this is used in the sample application.

You can see a simple implementation of such a StateListDrawable here:

StateListDrawable states = new StateListDrawable();

ColorDrawable clrActive = new ColorDrawable(selected_color);
states.addState(new int[]{android.R.attr.state_selected}, clrActive);

states.addState(new int[]{}, ContextCompat.getDrawable(ctx, getSelectableBackground(ctx)));

This even supports animation:

//if possible we enable animating across states
if (animate) {
    int duration = ctx.getResources().getInteger(android.R.integer.config_shortAnimTime);
    states.setEnterFadeDuration(duration);
    states.setExitFadeDuration(duration);
}

How to toggle the view color in Fast Adapter library

1 Answers1