ChipGroup - prevent chip from being deselected

Question

This is my code for setting up the chipgroup and chips inside based on list:

val chipGroup = region_list
                val inflator = LayoutInflater.from(chipGroup.context)
                val children = categoryList.map { categoryName ->

                    val chip = inflator.inflate(R.layout.region, chipGroup, false) as Chip
                    chip.text = categoryName.replace('_', ' ')
                    chip.tag = categoryName
                    chip.setOnCheckedChangeListener { button, isChecked ->
                        val s = viewModel.updateFilter(button.tag as String, isChecked)

//s is a string = {"change", "keep"}
//if s is keep that means that the same chip that was selected was pressed again, and in normal chip behaviour in android that chip would then be deselected, I don't want that
                    }

                }

s is a string = {"change", "keep"} if s is keep that means that the same chip that was selected was pressed again, and in normal chip behaviour in android that chip would then be deselected, I don't want that. I can't believe that android team never thought that someone would need a chipgroup where an item can't be deselected, what is the point of chips, to use it as some kind of filter to update view bellow.

Filter and Choice chips, same thing, if you press it once it is selected, if you press it second time it is deselected, I tried also with setting clickListener on chipGroup instead on individual element but it is the same — Alen, Sep 01 '19 at 16:22
You can try yourself some logic if selected chip is selected! — Sumit Shukla, Sep 01 '19 at 16:24
chipGroup.setOnCheckedChangeListener { group, selectedId -> If already selected chip is pressed again, selectedid will be -1, so that tells me that already seelcted chip is pressed, but there is NO way from preventing deselection to happen, I tried to use return statement if selectedid is -1 but it is already deselected here, there must be an easier way to do this or android people who made this are not that smart because it is a common behaviour to have chips which can not be deselected } — Alen, Sep 01 '19 at 16:41

Sumit Shukla · Answer 1 · 2019-09-02T03:17:36.037

Try this logic:

Your Activity:

    int i=0;
    String chipArr[]={"First","Second","Third","Fourth"};
    int selectedChipId=0;

    for (final String chipName : chipArr) {
         Chip chip = (Chip) layoutInflater.inflate(R.layout.cat_chip_group_item_filter, chipGroup, false);
            chip.setText(chipName);
            chip.setId(i);
    }

    for (final String chipName : fileNameChip) {
         LayoutInflater layoutInflater = getLayoutInflater();
         Chip chip = (Chip) layoutInflater.inflate(R.layout.cat_chip_group_item_filter, chipGroup, false);
         chip.setText(chipName);
         chip.setId(i);

        if (i == 0) chip.setSelected(true);

     chip.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
                   selectedChipId=v.getId();
             }
             });
        chipGroup.addView(chip);
        i++;
    }

     chipGroup.setOnCheckedChangeListener(new ChipGroup.OnCheckedChangeListener() {
              @Override
              public void onCheckedChanged(ChipGroup group, int checkedId) {
                     Log.d(TAG, "onCheckedChanged: " + checkedId);

                     if (checkedId == selectedChipId) {
                              chip.setSelected(true);
                     }
               }
    });

Activity layout:

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".activity.ShowCodeActivity">

    <HorizontalScrollView
        android:id="@+id/horScrollView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:scrollbars="none">

        <com.google.android.material.chip.ChipGroup
            android:id="@+id/chip_group_code_files"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="@dimen/margin_4dp"
            android:layout_marginEnd="@dimen/margin_4dp"
            app:singleLine="true"
            app:singleSelection="true" />

    </HorizontalScrollView>


</RelativeLayout>

Your cat_chip_group_item_filter.xml:

<?xml version="1.0" encoding="utf-8"?>
<com.google.android.material.chip.Chip
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    style="@style/Widget.MaterialComponents.Chip.Filter"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"/>

Let me know if it worked for you or not as I haven't tested it!!

ChipGroup - prevent chip from being deselected

1 Answers1