Android Multilevel expandable list view set third level child item clicked

Issue

i have codes from this project, and i want to implement expandable third level child OnItemClick, i tried to use concept from this 2 level expandablelistview child click listener but it did not work. SO how can i make user know has selected certain parent/group level, second level and third level items.

here is my codes:

MainPageActivity.java

  public class MainPageActivity extends AppCompatActivity {

private ExpandableListView expandableListView;

String[] parent = new String[]{"group 1", "group 2"};
String[] q1 = new String[]{"Child Level 1", "Child level 2"};
String[] q2 = new String[]{"Child Level 1B", "Child Level 2B"};
String[] q3 = new String[]{"Child Level 1C"};
String[] des1 = new String[]{"A","B","C"};
String[] des2 = new String[]{"D","E","F"};
String[] des3 = new String[]{"G"};
String[] des4 = new String[]{"H","J"};
String[] des5 = new String[]{"U."," R"," V"};

LinkedHashMap<String, String[]> thirdLevelq1 = new LinkedHashMap<>();
LinkedHashMap<String, String[]> thirdLevelq2 = new LinkedHashMap<>();
LinkedHashMap<String, String[]> thirdLevelq3 = new LinkedHashMap<>();
/**
 * Second level array list
 */
List<String[]> secondLevel = new ArrayList<>();
/**
 * Inner level data
 */
List<LinkedHashMap<String, String[]>> data = new ArrayList<>();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main_page);
    setUpAdapter();
}

private void setUpAdapter() {
    secondLevel.add(q1);
    secondLevel.add(q2);
    secondLevel.add(q3);
    thirdLevelq1.put(q1[0], des1);
    thirdLevelq1.put(q1[1], des2);
    thirdLevelq2.put(q2[0], des3);
    thirdLevelq2.put(q2[1], des4);
    thirdLevelq3.put(q3[0], des5);

    data.add(thirdLevelq1);
    data.add(thirdLevelq2);
    data.add(thirdLevelq3);
    expandableListView = (ExpandableListView) findViewById(R.id.expandible_listview);
    //passing three level of information to constructor
    ThreeLevelListAdapter threeLevelListAdapterAdapter = new ThreeLevelListAdapter(this, parent, secondLevel, data);
    expandableListView.setAdapter(threeLevelListAdapterAdapter);
    expandableListView.setOnGroupExpandListener(new ExpandableListView.OnGroupExpandListener() {
        int previousGroup = -1;

        @Override
        public void onGroupExpand(int groupPosition) {
            if (groupPosition != previousGroup)
                expandableListView.collapseGroup(previousGroup);
            previousGroup = groupPosition;
        }
    });

    // ExpandableListView on child click listener

    expandableListView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {

        @Override
        public boolean onChildClick(ExpandableListView parent, View v,
                                    int groupPosition, int childPosition, long id) {
            String[] value=  secondLevel.get(groupPosition);
                Toast.makeText(
                        getApplicationContext(),
                        secondLevel.get(groupPosition)
                                + " : ", Toast.LENGTH_SHORT)
                        .show();
            return false;
        }
    });  }}

SecondLevelExpandableListView.java

            public class SecondLevelExpandableListView extends ExpandableListView {

        public SecondLevelExpandableListView(Context context) {
    super(context);
}

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    heightMeasureSpec = MeasureSpec.makeMeasureSpec(999999, MeasureSpec.AT_MOST);
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
  }

SecondLevelAdapter.java

public class SecondLevelAdapter extends BaseExpandableListAdapter {

   private Context context;


List<String[]> data;

String[] headers;

ImageView ivGroupIndicator;


public SecondLevelAdapter(Context context, String[] headers, List<String[]> data) {
    this.context = context;
    this.data = data;
    this.headers = headers;

}

@Override
public Object getGroup(int groupPosition) {

    return headers[groupPosition];
}

@Override
public int getGroupCount() {

    return headers.length;
}

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

@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
    LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    convertView = inflater.inflate(R.layout.row_second, null);
    TextView text = (TextView) convertView.findViewById(R.id.rowSecondText);
    String groupText = getGroup(groupPosition).toString();
    text.setText(groupText);
    return convertView;
}

@Override
public Object getChild(int groupPosition, int childPosition) {

    String[] childData;

    childData = data.get(groupPosition);


    return childData[childPosition];
}

@Override
public long getChildId(int groupPosition, int childPosition) {
    return childPosition;
}

@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {

    LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    convertView = inflater.inflate(R.layout.row_third, null);

    TextView textView = (TextView) convertView.findViewById(R.id.rowThirdText);

    String[] childArray = data.get(groupPosition);

    String text = childArray[childPosition];

    textView.setText(text);

    return convertView;
}

@Override
public int getChildrenCount(int groupPosition) {
    String[] children = data.get(groupPosition);


    return children.length;
}

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

@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
    return true;
}

}

ThreeLevelListAdapter .java

 public class ThreeLevelListAdapter extends BaseExpandableListAdapter {

String[] parentHeaders;
List<String[]> secondLevel;
private Context context;
List<LinkedHashMap<String, String[]>> data;

/**
 * Constructor
 * @param context
 * @param parentHeader
 * @param secondLevel
 * @param data
 */
public ThreeLevelListAdapter(Context context, String[] parentHeader, List<String[]> secondLevel, List<LinkedHashMap<String, String[]>> data) {
    this.context = context;

    this.parentHeaders = parentHeader;

    this.secondLevel = secondLevel;

    this.data = data;
}

@Override
public int getGroupCount() {
    return parentHeaders.length;
}

@Override
public int getChildrenCount(int groupPosition) {


    // no idea why this code is working

    return 1;

}

@Override
public Object getGroup(int groupPosition) {

    return groupPosition;
}

@Override
public Object getChild(int group, int child) {


    return child;


}

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

@Override
public long getChildId(int groupPosition, int childPosition) {
    return childPosition;
}

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

@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {

    LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    convertView = inflater.inflate(R.layout.row_first, null);
    TextView text = (TextView) convertView.findViewById(R.id.rowParentText);
    text.setText(this.parentHeaders[groupPosition]);

    return convertView;
}

@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {

    final SecondLevelExpandableListView secondLevelELV = new SecondLevelExpandableListView(context);

    String[] headers = secondLevel.get(groupPosition);


    List<String[]> childData = new ArrayList<>();
    HashMap<String, String[]> secondLevelData = data.get(groupPosition);

    for (String key : secondLevelData.keySet()) {


        childData.add(secondLevelData.get(key));

    }


    secondLevelELV.setAdapter(new SecondLevelAdapter(context, headers, childData));

    secondLevelELV.setGroupIndicator(null);


    secondLevelELV.setOnGroupExpandListener(new ExpandableListView.OnGroupExpandListener() {
        int previousGroup = -1;

        @Override
        public void onGroupExpand(int groupPosition) {
            if (groupPosition != previousGroup)
                secondLevelELV.collapseGroup(previousGroup);
            previousGroup = groupPosition;
        }
    });


    return secondLevelELV;
}

@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
    return true;
}

}

Solution

You can get the item clicked at the third level by creating interface in the ThreeLevelListAdapter and implemented in the activity. Try below:

MainPageActivity.java:

public class MainPageActivity extends AppCompatActivity implements ThreeLevelListAdapter.ThreeLevelListViewListener{
private ExpandableListView expandableListView;

String[] parent = new String[]{"group 1", "group 2"};
String[] q1 = new String[]{"Child Level 1", "Child level 2"};
String[] q2 = new String[]{"Child Level 1B", "Child Level 2B"};
String[] q3 = new String[]{"Child Level 1C"};
String[] des1 = new String[]{"A","B","C"};
String[] des2 = new String[]{"D","E","F"};
String[] des3 = new String[]{"G"};
String[] des4 = new String[]{"H","J"};
String[] des5 = new String[]{"U."," R"," V"};

LinkedHashMap<String, String[]> thirdLevelq1 = new LinkedHashMap<>();
LinkedHashMap<String, String[]> thirdLevelq2 = new LinkedHashMap<>();
LinkedHashMap<String, String[]> thirdLevelq3 = new LinkedHashMap<>();
/**
 * Second level array list
 */
List<String[]> secondLevel = new ArrayList<>();
/**
 * Inner level data
 */
List<LinkedHashMap<String, String[]>> data = new ArrayList<>();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main_page);
    setUpAdapter();
}

private void setUpAdapter() {
    secondLevel.add(q1);
    secondLevel.add(q2);
    secondLevel.add(q3);
    thirdLevelq1.put(q1[0], des1);
    thirdLevelq1.put(q1[1], des2);
    thirdLevelq2.put(q2[0], des3);
    thirdLevelq2.put(q2[1], des4);
    thirdLevelq3.put(q3[0], des5);

    data.add(thirdLevelq1);
    data.add(thirdLevelq2);
    data.add(thirdLevelq3);
    expandableListView = (ExpandableListView) findViewById(R.id.expandable_listview);
    //passing three level of information to constructor
    ThreeLevelListAdapter threeLevelListAdapterAdapter = new ThreeLevelListAdapter(this, parent, secondLevel, data, this);
    expandableListView.setAdapter(threeLevelListAdapterAdapter);
    expandableListView.setOnGroupExpandListener(new ExpandableListView.OnGroupExpandListener() {
        int previousGroup = -1;
        @Override
        public void onGroupExpand(int groupPosition) {
            if (groupPosition != previousGroup)
                expandableListView.collapseGroup(previousGroup);
            previousGroup = groupPosition;
        }
    });
}

@Override
public void onFinalChildClick(int plpos, int slpos, int tlpos) {
    Toast.makeText(this, plpos + ", " + slpos + ", " + tlpos, Toast.LENGTH_SHORT).show();
}

@Override
public void onFinalItemClick(String plItem, String slItem, String tlItem) {
    Toast.makeText(this, plItem + ", " + slItem + ", " + tlItem, Toast.LENGTH_SHORT).show();
}
}

ThreeLevelListAdapter .java:

public class ThreeLevelListAdapter extends BaseExpandableListAdapter {
String[] parentHeaders;
List<String[]> secondLevel;
private Context context;
List<LinkedHashMap<String, String[]>> data;
ThreeLevelListViewListener mThreeLevelListViewListener;

/**
 * Constructor
 * @param context
 * @param parentHeader
 * @param secondLevel
 * @param data
 * @param listener
 */
public ThreeLevelListAdapter(Context context, String[] parentHeader, List<String[]> secondLevel,
                             List<LinkedHashMap<String, String[]>> data,
                             ThreeLevelListViewListener listener) {
    this.context = context;
    this.parentHeaders = parentHeader;
    this.secondLevel = secondLevel;
    this.data = data;
    mThreeLevelListViewListener = listener;
}

@Override
public int getGroupCount() {
    return parentHeaders.length;
}

@Override
public int getChildrenCount(int groupPosition) {
    // no idea why this code is working
    return 1;
}

@Override
public Object getGroup(int groupPosition) {
    return parentHeaders[groupPosition];
}

@Override
public Object getChild(int group, int child) {
    return child;
}

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

@Override
public long getChildId(int groupPosition, int childPosition) {
    return childPosition;
}

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

@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
    LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    convertView = inflater.inflate(R.layout.row_first, null);
    TextView text = (TextView) convertView.findViewById(R.id.rowParentText);
    text.setText(this.parentHeaders[groupPosition]);
    return convertView;
}

@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
    final SecondLevelExpandableListView secondLevelELV = new SecondLevelExpandableListView(context);
    String[] headers = secondLevel.get(groupPosition);
    List<String[]> childData = new ArrayList<>();
    HashMap<String, String[]> secondLevelData = data.get(groupPosition);
    for (String key : secondLevelData.keySet()) {
        childData.add(secondLevelData.get(key));
    }
    secondLevelELV.setAdapter(new SecondLevelAdapter(context, headers, childData));
    secondLevelELV.setGroupIndicator(null);
    secondLevelELV.setOnGroupExpandListener(new ExpandableListView.OnGroupExpandListener() {
        int previousGroup = -1;
        @Override
        public void onGroupExpand(int groupPosition) {
            if (groupPosition != previousGroup)
                secondLevelELV.collapseGroup(previousGroup);
            previousGroup = groupPosition;
        }
    });

    secondLevelELV.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
        @Override
        public boolean onChildClick(ExpandableListView expandableListView, View view, int i, int i1, long l) {
            int ppos = (int)expandableListView.getTag();
            mThreeLevelListViewListener.onFinalChildClick(ppos, i, i1);
            String plItem = (String)getGroup(ppos);
            SecondLevelAdapter adapter = (SecondLevelAdapter)expandableListView.getExpandableListAdapter();
            String slItem = (String)adapter.getGroup(i);
            String tlItem = (String)adapter.getChild(i, i1);
            mThreeLevelListViewListener.onFinalItemClick(plItem, slItem, tlItem);
            return true;
        }
    });
    secondLevelELV.setTag(groupPosition);

    return secondLevelELV;
}

@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
    return true;
}

public interface ThreeLevelListViewListener{
    void onFinalChildClick(int plpos, int slpos, int tlpos);
    void onFinalItemClick(String plItem, String slItem, String tlItem);
}
}

Hope that helps!

Answered By - i_A_mok