Expandable lists in Android, I want only one parent list to expand at a time

Question

I want only one item in the parent list to expand at a time, my code for onCreate is currently as follows. (It works the way I want, but the method of opening only one parent at a time does not work)

public void onCreate(Bundle savedInstanceState) { try{ super.onCreate(savedInstanceState); setContentView(R.layout.main); final SimpleExpandableListAdapter expListAdapter = new SimpleExpandableListAdapter( //FOR LEVEL 1 SCREEN this, createGroupList(), // METHOD TO CREATE PARENTLIST Creating group List. R.layout.group_row, // REF TO XML FILENAME. new String[] { "Group Item" }, // STRING ARRAY HOLDING ONE KEY THAT REF ALL PARENT LIST ITEMS. new int[] { R.id.row_name }, // REF TO ID OF PARENT XML. ID of each group item.-Data under the key goes into this TextView. createChildList(), // METHOD TO CREATE CHILD LST. childData describes second-level entries. R.layout.child_row, // XMLFILE NAME FOR CHILD LIST.Layout for sub-level entries(second level). new String[] {"Sub Item"}, // KEY FOR CHILD ITEMS IN HASHMAP. Keys in childData maps to display. new int[] { R.id.grp_child} // XML ID FOR TEXTVIEW. Data under the keys above go into these TextViews. ); setListAdapter( expListAdapter ); // setting the adapter in the list. //**THIS IS WHAT I DONT KNOW HOW TO CODE:** list = (ExpandableListView) findViewById(R.id.row_name); list.setAdapter( expListAdapter); list.setGroupIndicator(null); list.setOnGroupExpandListener(new OnGroupExpandListener() { public void onGroupExpand(int groupPosition) { int len = expListAdapter.getGroupCount(); for (int i = 0; i < len; i++) { if (i != groupPosition) { list.collapseGroup(i); } } } }); }catch(Exception e){ System.out.println("Errrr +++ " + e.getMessage()); } } 

I understand the code above. However, I do not use expandableListViews, Im refferncing my program into my .xml files with extensible list layouts. And so I don’t know how to apply the above to my program ...

main.xml

 <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <ExpandableListView android:id="@+id/list" android:layout_width="fill_parent" android:layout_height="fill_parent" android:background="@drawable/bkg"/> <TextView android:id="@+id/android:empty" android:layout_width="fill_parent" android:layout_height="fill_parent" android:text="No items"/> </LinearLayout> 

The method that I do not know how to apply is as follows:

  list = (ExpandableListView) findViewById(R.id.row_name); list.setAdapter( expListAdapter); list.setGroupIndicator(null); list.setOnGroupExpandListener(new OnGroupExpandListener() { public void onGroupExpand(int groupPosition) { int len = expListAdapter.getGroupCount(); for (int i = 0; i < len; i++) { if (i != groupPosition) { list.collapseGroup(i); } } } }); 

1) how can I cancel the “list” for my expandable list activity?

List

defined in the class as private ExpandableListView list;

I have no errors right now, but the method does not work.

Any help is much appreciated!

Answer 1

The problem was solved by creating a public explist variable called a list and then referring to it with the adapter in question by the next call.

 list = getExpandableListView(); 

Because of this, because of this, because of this, I unpacked the acceleration method. After reorganizing list.collapsegroup into, it worked fine.

 public void onGroupExpand(int groupPosition) { System.out.println("GROUP LISTENER WORKS?"); if(adptr=="expListAdapter"){ int len = expListAdapter.getGroupCount(); //System.out.println(len); for (int i = 0; i < len; i++) { if (i != groupPosition) { list.collapseGroup(i); } } } else if(adptr=="expListAdapter2"){ int len = expListAdapter2.getGroupCount(); for (int i = 0; i < len; i++) { if (i != groupPosition) { list.collapseGroup(i); } } //System.out.println(len); } else if(adptr=="expListAdapter3"){ int len = expListAdapter3.getGroupCount(); for (int i = 0; i < len; i++) { if (i != groupPosition) { list.collapseGroup(i); } } } } 

Answer 2

 // Declare variable private static int prev = -1; // and OnGroupExpandListener implement mExpandableList.setOnGroupExpandListener(new OnGroupExpandListener() { @Override public void onGroupExpand(int groupPosition) { if(prev!=-1) { mExpandableList.collapseGroup(prev); } prev=groupPosition; } }); 

---

Update with updated solution

 mExpandableList.setOnGroupExpandListener(new OnGroupExpandListener() { // Keep track of previous expanded parent int previousGroup = -1; @Override public void onGroupExpand(int groupPosition) { // Collapse previous parent if expanded. if ((previousGroup != -1) && (groupPosition != previousGroup)) { mExpandableList.collapseGroup(previousGroup); } previousGroup = groupPosition; } }); 

Answer 3

Easiest approach

You can implement ExpandableListView.OnGroupExpandListener where you run collapseGroup() for all list groups except the ones that were clicked. This will do what you want.

  expandableList.setOnGroupExpandListener(new OnGroupExpandListener() { int previousGroup = -1; @Override public void onGroupExpand(int groupPosition) { if(groupPosition != previousGroup) expandableList.collapseGroup(previousGroup); previousGroup = groupPosition; } }); 

Answer 4

I believe that a direct solution would be to implement one adapter to handle any events that interest you.

 public class MyExpandableListAdapter extends SimpleExpandableListAdapter { public Activity mActivity; public MyExpandableListAdapter([ARGS USED IN QUESTION], Activity activity) {super([ARGS USED IN QUESTIONS]); mActivity = activity; } // then just override the method public void onGroupExpanded(int groupPosition) { int len = super.getGroupCount(); ExpandableListView list = (ExpandableListView) mActivity.findViewById(R.id.list); for (int i = 0; i < len; i++) { if (i != groupPosition) { list.collapseGroup(i); } } } } 

By separating the list adapter in another class, you will not clutter up the action code with one-time listener implementations. Instead, in each operation, just create an adapter instance and set it in the list

 @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // No try catch needed MyExpandableListAdapter mAdapter = new MyExpandableListAdapter([ARGS SHOWN IN QUESTION], MainActivity.this); ExpandableListView epView = (ExpandableListView) findViewById(R.id.list); epView.setAdapter(mAdapter); return true; } 

Answer 5

  @Override public void onGroupExpanded(int groupPosition) { super.onGroupExpanded(groupPosition); int len = getGroupCount(); for (int i = 0; i < len; i++) { if (i != groupPosition) { expListView.collapseGroup(i); } } } 

Answer 6

Changed answer from Iram: So you can open the same group again

 // Listview Group expanded listener expListView.setOnGroupExpandListener(new OnGroupExpandListener() { @Override public void onGroupExpand(int groupPosition) { if (prevouriousExpandedGroupNumber != -1 && prevouriousExpandedGroupNumber != groupPosition) { expListView.collapseGroup(prevouriousExpandedGroupNumber); } prevouriousExpandedGroupNumber = groupPosition; } }); 

Answer 7

Iram Bukhari's answer is working fine. but I once changed:

 private static int prev = -1; // and OnGroupExpandListener implement mExpandableList.setOnGroupExpandListener(new OnGroupExpandListener() { @Override public void onGroupExpand(int groupPosition) { if(prev!=-1 && prev!=groupPosition ) { mExpandableList.collapseGroup(prev); } prev=groupPosition; } }); 

I added prev! = GroupPosition as an additional condition. Because if

 item 1 has clicked(opened) item 1 has clicked(closed) item 1 has clicked(Not opening. because prev has same position so the item is opened and collapsed immediatly ) 

After adding the condition

 item 1 has clicked(opened) item 1 has clicked(closed) item 1 has clicked(opened) 

Answer 8

His work See screenshots

 package com.keshav.myexpandablelistviewexampleworkinginactivity; import android.app.Activity; import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.ExpandableListView; import android.widget.ExpandableListView.OnChildClickListener; import android.widget.ExpandableListView.OnGroupClickListener; import android.widget.ExpandableListView.OnGroupCollapseListener; import android.widget.ExpandableListView.OnGroupExpandListener; import android.widget.Toast; import java.util.ArrayList; import java.util.HashMap; import java.util.List; public class MainActivity extends Activity { ExpandableListAdapter listAdapter; ExpandableListView expListView; List<String> listDataHeader; HashMap<String, List<String>> listDataChild; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // tODO get the listview expListView = (ExpandableListView) findViewById(R.id.lvExp); // TODO preparing list data prepareListData(); listAdapter = new ExpandableListAdapter(this, listDataHeader, listDataChild); // setting list adapter expListView.setAdapter(listAdapter); // Listview Group click listener expListView.setOnGroupClickListener(new OnGroupClickListener() { @Override public boolean onGroupClick(ExpandableListView parent, View v, int groupPosition, long id) { Toast.makeText(getApplicationContext(), "Group Clicked " + listDataHeader.get(groupPosition), Toast.LENGTH_SHORT).show(); return false; } }); // Listview Group expanded listener expListView.setOnGroupExpandListener(new OnGroupExpandListener() { // TODO Colapse Here Using this... in android int previousGroup = -1; boolean flag = false; @Override public void onGroupExpand(int groupPosition) { Log.e("keshav", "onGroupClick is -> " + groupPosition); Toast.makeText(getApplicationContext(), listDataHeader.get(groupPosition) + " Expanded", Toast.LENGTH_SHORT).show(); if (groupPosition != previousGroup && flag) { expListView.collapseGroup(previousGroup); } previousGroup = groupPosition; flag = true; } }); // Listview Group collasped listener expListView.setOnGroupCollapseListener(new OnGroupCollapseListener() { @Override public void onGroupCollapse(int groupPosition) { Toast.makeText(getApplicationContext(), listDataHeader.get(groupPosition) + " Collapsed", Toast.LENGTH_SHORT).show(); } }); // Todo Listview on child click listener expListView.setOnChildClickListener(new OnChildClickListener() { @Override public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) { // TODO Auto-generated method stub Toast.makeText( getApplicationContext(), listDataHeader.get(groupPosition) + " : " + listDataChild.get( listDataHeader.get(groupPosition)).get( childPosition), Toast.LENGTH_SHORT) .show(); return false; } }); } /* * Preparing the list data */ private void prepareListData() { listDataHeader = new ArrayList<String>(); listDataChild = new HashMap<String, List<String>>(); // Adding child data listDataHeader.add("Months"); listDataHeader.add("Top 250"); listDataHeader.add("Now Showing"); listDataHeader.add("Coming Soon.."); // Adding child data List<String> weeks = new ArrayList<String>(); weeks.add("Sunday"); weeks.add("Monday"); weeks.add("Tuesday"); weeks.add("Wednesday"); weeks.add("Thursday"); weeks.add("Friday"); weeks.add("Saturday"); // Adding child data List<String> top250 = new ArrayList<String>(); top250.add("Om Shanti Om"); top250.add("Badshah"); top250.add("Bahubali Part 1"); top250.add("Carry on Jatta"); top250.add("Sholey"); top250.add("Mard"); top250.add("Dewwar"); List<String> nowShowing = new ArrayList<String>(); nowShowing.add("Bahubali"); nowShowing.add("Kabali"); nowShowing.add("Luckky Di Unlukky Story"); nowShowing.add("Sachin Billions Dream"); nowShowing.add("Red 2"); List<String> comingSoon = new ArrayList<String>(); comingSoon.add("Tubelight "); comingSoon.add("Bahubali 3 2018"); comingSoon.add("Dhoom 4"); comingSoon.add("Hindi Medium"); listDataChild.put(listDataHeader.get(0), weeks); listDataChild.put(listDataHeader.get(1), top250); // Header, Child data listDataChild.put(listDataHeader.get(2), nowShowing); listDataChild.put(listDataHeader.get(3), comingSoon); } } ExpandableListAdapter package com.keshav.myexpandablelistviewexampleworkinginactivity; import java.util.HashMap; import java.util.List; import android.content.Context; import android.graphics.Typeface; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseExpandableListAdapter; import android.widget.TextView; public class ExpandableListAdapter extends BaseExpandableListAdapter { private Context _context; private List<String> _listDataHeader; // header titles // child data in format of header title, child title private HashMap<String, List<String>> _listDataChild; public ExpandableListAdapter(Context context, List<String> listDataHeader, HashMap<String, List<String>> listChildData) { this._context = context; this._listDataHeader = listDataHeader; this._listDataChild = listChildData; } @Override public Object getChild(int groupPosition, int childPosititon) { return this._listDataChild.get(this._listDataHeader.get(groupPosition)) .get(childPosititon); } @Override public long getChildId(int groupPosition, int childPosition) { return childPosition; } @Override public View getChildView(int groupPosition, final int childPosition, boolean isLastChild, View convertView, ViewGroup parent) { final String childText = (String) getChild(groupPosition, childPosition); if (convertView == null) { LayoutInflater infalInflater = (LayoutInflater) this._context .getSystemService(Context.LAYOUT_INFLATER_SERVICE); convertView = infalInflater.inflate(R.layout.list_item, null); } TextView txtListChild = (TextView) convertView .findViewById(R.id.lblListItem); txtListChild.setText(childText); return convertView; } @Override public int getChildrenCount(int groupPosition) { return this._listDataChild.get(this._listDataHeader.get(groupPosition)) .size(); } @Override public Object getGroup(int groupPosition) { return this._listDataHeader.get(groupPosition); } @Override public int getGroupCount() { return this._listDataHeader.size(); } @Override public long getGroupId(int groupPosition) { return groupPosition; } @Override public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) { String headerTitle = (String) getGroup(groupPosition); if (convertView == null) { LayoutInflater infalInflater = (LayoutInflater) this._context .getSystemService(Context.LAYOUT_INFLATER_SERVICE); convertView = infalInflater.inflate(R.layout.list_group, null); } TextView lblListHeader = (TextView) convertView .findViewById(R.id.lblListHeader); lblListHeader.setTypeface(null, Typeface.BOLD); lblListHeader.setText(headerTitle); return convertView; } @Override public boolean hasStableIds() { return false; } @Override public boolean isChildSelectable(int groupPosition, int childPosition) { return true; } } activity_mail.xml <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" android:background="#f4f4f4" > <ExpandableListView android:id="@+id/lvExp" android:layout_height="match_parent" android:layout_width="match_parent" android:cacheColorHint="#00000000"/> </LinearLayout> list_grou.xml <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="vertical" android:padding="8dp" android:background="#000000"> <TextView android:id="@+id/lblListHeader" android:layout_width="fill_parent" android:layout_height="wrap_content" android:paddingLeft="?android:attr/expandableListPreferredItemPaddingLeft" android:textSize="17dp" android:textColor="#f9f93d" /> </LinearLayout> list_item.xml <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="55dip" android:orientation="vertical" > <TextView android:id="@+id/lblListItem" android:layout_width="fill_parent" android:layout_height="wrap_content" android:textSize="17dip" android:paddingTop="5dp" android:paddingBottom="5dp" android:textColor="#000000" android:paddingLeft="?android:attr/expandableListPreferredChildPaddingLeft" /> </LinearLayout>