Change expandable indicator in ExpandableListView

Question

Trying to create an ExpandableListView. The initial view with the groups shows up fine. However, when I click the list item, my arrow does not change. See the images below.<

Answer 1

I am a bit late to the party but my requirement was something similar to this but something was different.

I had 3 requirements:

1. if a group have child then show down_arrow (V)
2. if a group doesn't have a child then no arrow/image
3. if a group with child expanded then show up_arrow (^)

To achieve something similar to this:

1. Your ExpandableListView will look something similar to this with android:groupIndicator null

    <ExpandableListView
    android:id="@+id/expandableListView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:divider="@android:color/darker_gray"
    android:dividerHeight="0.5dp"
    android:groupIndicator="@null" />
   

2. Your group/header layout will look something like this with text and image at the end:

<androidx.appcompat.widget.AppCompatImageView
    android:id="@+id/ivDrawerHeaderItemIcon"
    android:layout_width="@dimen/dp_30"
    android:layout_height="@dimen/dp_30"
    android:layout_gravity="center_vertical"
    android:layout_marginStart="@dimen/dp_10"
    android:layout_marginEnd="@dimen/dp_10"
    android:src="@drawable/switch" />

<androidx.appcompat.widget.AppCompatTextView
    android:id="@+id/lblListHeader"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_margin="@dimen/dp_5"
    android:layout_weight="1"
    android:fontFamily="@font/roboto_condensed_regular"
    android:gravity="center_vertical"
    android:padding="@dimen/dp_10"
    android:textAllCaps="true"
    android:textColor="@android:color/white"
    android:textSize="@dimen/sp_16" />

<androidx.appcompat.widget.AppCompatImageView
    android:id="@+id/ivIcon"
    android:layout_width="@dimen/dp_15"
    android:layout_height="@dimen/dp_15"
    android:layout_gravity="center_vertical"
    android:layout_marginStart="@dimen/dp_10"
    android:layout_marginEnd="@dimen/dp_10" />

3. In your BaseExpandableListAdapter's getGroupView() method, use

        if (Objects.requireNonNull(expandableListDetail.get(expandableListTitle.get(listPosition))).size() > 0) {
        if (isExpanded) {
            ivIcon.setImageResource(R.drawable.arrow_up);
        } else {
            ivIcon.setImageResource(R.drawable.arrow_down);
        }
    }
   

Where, expandableListTitle is group and expandableListDetail is its children

Answer 2

Just Create a view/Imageview where ever u want in the xml of group item example:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/parent_group"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:padding="10dp">

<ImageView
    android:id="@+id/expandable_icon"
    android:layout_width="25dp"
    android:layout_height="25dp"
    android:layout_marginTop="6dp"
    android:src="@drawable/group_icon_not_expanded" />

<TextView
    android:id="@+id/group_name"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:layout_marginLeft="10dp"
    android:fontFamily="@font/roboto_thin"
    android:textColor="@android:color/black"
    android:textSize="17sp" />

And then for your ExpandableListView use a GroupClickListener to change the image for ImageView programmatically, example :

listView.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {
        @Override
        public boolean onGroupClick(ExpandableListView parent, View v, int groupPosition, long id) {
            parent.smoothScrollToPosition(groupPosition);

            if (parent.isGroupExpanded(groupPosition)) {
                ImageView imageView = v.findViewById(R.id.expandable_icon);
                imageView.setImageDrawable(getResources().getDrawable(R.drawable.group_icon_not_expanded));
            } else {
                ImageView imageView = v.findViewById(R.id.expandable_icon);
                imageView.setImageDrawable(getResources().getDrawable(R.drawable.group_icon_expanded));
            }
            return false    ;
        }
    });

Answer 3

Try that for your settings_selector.xml:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" >

    <item
        android:drawable="@drawable/arrow_right"
        android:state_expanded="true" />

    <item
        android:drawable="@drawable/arrow_down" />

</selector>

Answer 4

subject:

    int width = getResources().getDisplayMetrics().widthPixels;
    if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.JELLY_BEAN_MR2) {
        listView.setIndicatorBounds(width - getPixelValue(40), width - getPixelValue(10));
    } else {
        listView.setIndicatorBoundsRelative(width - getPixelValue(40), width - getPixelValue(10));
    }

and helper method:

public static int getPixelValue(int dp) {

    final float scale = getResources().getDisplayMetrics().density;
    return (int) (dp * scale + 0.5f);
}

Answer 5

import java.util.ArrayList;

import android.app.Activity;
import android.content.Context;
import android.database.DataSetObserver;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.TextView;

public class MyActivity extends Activity {

    private ExpandableListView mExpandableList;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my);


        mExpandableList = (ExpandableListView)findViewById(R.id.expandable_list);
        mExpandableList.setGroupIndicator(null);
        ArrayList<Parent> arrayParents = new ArrayList<Parent>();
        ArrayList<String> arrayChildren = new ArrayList<String>();

        //here we set the parents and the children
        for (int i = 0; i < 10; i++){
            //for each "i" create a new Parent object to set the title and the children
            Parent parent = new Parent();
            parent.setTitle("Parent " + i);

            arrayChildren = new ArrayList<String>();
            for (int j = 0; j < 10; j++) {
                arrayChildren.add("Child " + j);
            }
            parent.setArrayChildren(arrayChildren);

            //in this array we add the Parent object. We will use the arrayParents at the setAdapter
            arrayParents.add(parent);
        }

        //sets the adapter that provides data to the list.
        mExpandableList.setAdapter(new MyCustomAdapter(MyActivity.this,arrayParents));

    }

    public class Parent {
        private String mTitle;
        private ArrayList<String> mArrayChildren;

        public String getTitle() {
            return mTitle;
        }

        public void setTitle(String mTitle) {
            this.mTitle = mTitle;
        }

        public ArrayList<String> getArrayChildren() {
            return mArrayChildren;
        }

        public void setArrayChildren(ArrayList<String> mArrayChildren) {
            this.mArrayChildren = mArrayChildren;
        }
    }




    public class MyCustomAdapter extends BaseExpandableListAdapter implements OnClickListener{


        private LayoutInflater inflater;
        private ArrayList<Parent> mParent;

        public MyCustomAdapter(Context context, ArrayList<Parent> parent){
            mParent = parent;
            inflater = LayoutInflater.from(context);
        }


        @Override
        //counts the number of group/parent items so the list knows how many times calls getGroupView() method
        public int getGroupCount() {
            return mParent.size();
        }

        @Override
        //counts the number of children items so the list knows how many times calls getChildView() method
        public int getChildrenCount(int i) {
            return mParent.get(i).getArrayChildren().size();
        }

        @Override
        //gets the title of each parent/group
        public Object getGroup(int i) {
            return mParent.get(i).getTitle();
        }

        @Override
        //gets the name of each item
        public Object getChild(int i, int i1) {
            return mParent.get(i).getArrayChildren().get(i1);
        }

        @Override
        public long getGroupId(int i) {
            return i;
        }

        @Override
        public long getChildId(int i, int i1) {
            return i1;
        }

        @Override
        public boolean hasStableIds() {
            return true;
        }

        @Override
        //in this method you must set the text to see the parent/group on the list
        public View getGroupView(int i, boolean b, View view, ViewGroup viewGroup) {

            if (view == null) {
                view = inflater.inflate(R.layout.list_item_parent, viewGroup,false);
            }
            view.findViewById(R.id.button).setTag(i);
            view.findViewById(R.id.button).setOnClickListener(this);
            TextView textView = (TextView) view.findViewById(R.id.list_item_text_view);
            //"i" is the position of the parent/group in the list
            textView.setText(getGroup(i).toString());

            //return the entire view
            return view;
        }

        @Override
        //in this method you must set the text to see the children on the list
        public View getChildView(int i, int i1, boolean b, View view, ViewGroup viewGroup) {
            if (view == null) {
                view = inflater.inflate(R.layout.list_item_child, viewGroup,false);
            }

            TextView textView = (TextView) view.findViewById(R.id.list_item_text_child);
            //"i" is the position of the parent/group in the list and
            //"i1" is the position of the child
            textView.setText(mParent.get(i).getArrayChildren().get(i1));

            //return the entire view
            return view;
        }

        @Override
        public boolean isChildSelectable(int i, int i1) {
            return true;
        }

        @Override
        public void registerDataSetObserver(DataSetObserver observer) {
            /* used to make the notifyDataSetChanged() method work */
            super.registerDataSetObserver(observer);
        }


        /* (non-Javadoc)
         * @see android.view.View.OnClickListener#onClick(android.view.View)
         * @since Mar 20, 2013
         * @author rajeshcp 
         */
        @Override
        public void onClick(View v) {
            if(mExpandableList.isGroupExpanded((Integer)v.getTag()))
        {
            mExpandableList.collapseGroup((Integer)v.getTag());
        }else
        {
            mExpandableList.expandGroup((Integer)v.getTag());
        }
        }
    }


}

Change your MyActivity like this and let me know what else you want ?

Answer 6

expandable listview

 <ExpandableListView
    android:id="@+id/expandable_list"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:groupIndicator="@drawable/group_indicator"
    android:transcriptMode="alwaysScroll" />

setindicator here iam useing setindicator code like this this working nice

 DisplayMetrics metrics = new DisplayMetrics();
    getWindowManager().getDefaultDisplay().getMetrics(metrics);
    int width = metrics.widthPixels; 

 mExpandableList = (ExpandableListView)findViewById(R.id.expandable_list);
 mExpandableList.setIndicatorBounds(width - GetPixelFromDips(50), width - GetPixelFromDips(10));  

   public int GetPixelFromDips(float pixels) {
    // Get the screen's density scale 
    final float scale = getResources().getDisplayMetrics().density;
    // Convert the dps to pixels, based on density scale
    return (int) (pixels * scale + 0.5f);
}

res/drawable/group_indicator

  <?xml version="1.0" encoding="utf-8"?>

     <selector xmlns:android="http://schemas.android.com/apk/res/android">            
           <item android:drawable="@drawable/arrow_right" android:state_empty="true">  </item>            
           <item android:drawable="@drawable/arrow_down" android:state_expanded="true"></item>                
           <item android:drawable="@drawable/arrow_right"></item>
     </selector>