Material-components-android: How to get selected chips from a chipgroup?

[rexdarel]

I have a chip group for post tags. The chip group contains chips for tags, example: "Announcement", "Meeting", "Question". The problem is I can't find a way to get checked chips from the chip group. A user, can select multiple chips in a one post. But according to the docs,

Call setOnCheckedChangeListener(OnCheckedChangeListener) to register a callback to be invoked when the checked chip changes in this group. This callback is only invoked in single selection mode.

[rexdarel]

Here is my xml;

` android:id="@+id/chipGroup"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:singleLine="true"
android:layout_marginTop="@dimen/margin_small"
android:layout_marginBottom="@dimen/margin_small">

            <com.google.android.material.chip.Chip
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                style="@style/Widget.MaterialComponents.Chip.Entry"
                app:closeIconEnabled="false"
                android:textColor="@color/colorWhite"
                app:chipBackgroundColor="@color/light_blue_500"
                android:text="Announcement"/>

            <com.google.android.material.chip.Chip
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                style="@style/Widget.MaterialComponents.Chip.Entry"
                app:closeIconEnabled="false"
                android:textColor="@color/colorWhite"
                app:chipBackgroundColor="@color/pink_500"
                android:text="Meeting"/>

            <com.google.android.material.chip.Chip
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                style="@style/Widget.MaterialComponents.Chip.Entry"
                app:closeIconEnabled="false"
                android:textColor="@color/colorWhite"
                app:chipBackgroundColor="@color/lime_500"
                android:text="General"/>

            <com.google.android.material.chip.Chip
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                style="@style/Widget.MaterialComponents.Chip.Entry"
                app:closeIconEnabled="false"
                android:textColor="@color/colorWhite"
                app:chipBackgroundColor="@color/indigo_500"
                android:text="Feedback"/>

            <com.google.android.material.chip.Chip
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                style="@style/Widget.MaterialComponents.Chip.Entry"
                app:closeIconEnabled="false"
                android:textColor="@color/colorWhite"
                app:chipBackgroundColor="@color/blue_grey_500"
                android:text="Question"/>
        </com.google.android.material.chip.ChipGroup>`

[shivam2702]

private fun getSelectedText(chipGroup: ChipGroup, id: Int): String {
val mySelection = chipGroup.findViewById(id)
return mySelection?.text?.toString() ?: ""
}

You can use this val mySelection = chipGroup.findViewById<Chip>(id) to get the selectedChip and the complete fuction will look like

filterChips.setOnCheckedChangeListener { chipGroup, i ->
getSelectedText(chipGroup, i)
}

[dsn5ft]

You should be able to iterate through the children of the ChipGroup and check chip.isChecked().

[algrid]

Wouldn't it be nice if the API exposed it in a more direct way?

[gabrielemariotti]

To be honest it is not clear why we should have this method (which works only in a single selection mode):

```
@IdRes
public int getCheckedChipId() {
return singleSelection ? checkedId : View.NO_ID;
}

and we don't have a method like:

/**

• Returns the identifiers of the selected {@link Chip}s in this group. Upon empty
• selection, the returned value is an empty list.
  *
• @return The unique IDs of the selected {@link Chip}s in this group. When in {@link
• #isSingleSelection() single selection mode}, returns a list with a single ID. When no
• {@link Chip}s are selected, returns an empty list.
  */
  @NonNull
  public List getCheckedChipIds() {
  ArrayList checkedIds = new ArrayList<>();
  for (int i = 0; i < getChildCount(); i++) {
  View child = getChildAt(i);
  if (child instanceof Chip) {
  if (((Chip) child).isChecked()) {
  checkedIds.add(child.getId());
  }
  }
  }

return checkedIds;

}
```

I could make a PR but before that I would like to understand if there are some reasons to avoid this kind of method.