user interface - Multi-level ExpandableListView with CheckBoxes in Android -

i'm trying implement 3-level expandablelistview in android.

it looks this:

• level 1
  • level 2
  • level 2
    • level 3
  • level 2
• level 1
  • level 2
  • level 2

level 2 , level 3 supposed have checkbox-es. , when checkbox in level 2 selected, children in level 3 selected well.

i've done 2 adapters - both extends baseexpandablelistadapter. in end 2 inserted expandablelistview-s - 1 level 1 - level 2, , other level 2 - level 3.

also have 2 separate layouts - 1 level 1 , 1 levels 2-3 (since same). its atextviewwith id insiderelativeview`.

the questions:

• when i'm changing textview checkboxes , setting text them, cannot expand list third level. don't understand why it's happening , it, can me?

• how can hide indicators (those arrow showing expanded/collapsed state) level 2 items, have no children?

• i don't why expandablelistview doesn't want fit screen vertically, consumes 1/4 of it. i've tried change params in customexpandablelistview, not worked.

here screenshots:

screenshot 1:

screenshot 2:

as can see, when expand asia list, europe list hides itself.

here`s code level 1:

public class regionsadapter extends baseexpandablelistadapter {  private list<object> objects; private activity activity; private layoutinflater inflater;  public regionsadapter(activity activity, list<object> objects) {     this.objects = objects;     this.activity = activity;     this.inflater = (layoutinflater) activity.getsystemservice(context.layout_inflater_service); }  @override public object getchild(int groupposition, int childposition) {     return objects.get(groupposition).getobjects().get(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) {      object object = (object) getchild(groupposition, childposition);     customexpandablelistview subobjects = (customexpandablelistview) convertview;      if (convertview == null) {         subobjects = new customexpandablelistview(activity);     }     countriesadapter adapter = new countriesadapter(activity, object);     subobjects.setadapter(adapter);      return subobjects; }  @override public int getchildrencount(int groupposition) {     return objects.get(groupposition).getobjects().size(); }  @override public object getgroup(int groupposition) {     return objects.get(groupposition); }  @override public int getgroupcount() {     return objects.size(); }  @override public long getgroupid(int groupposition) {     return groupposition; }  @override public view getgroupview(int groupposition, boolean isexpanded,                          view convertview, viewgroup parent) {      object object = (object) getgroup(groupposition);     if (convertview == null) {         convertview = inflater.inflate(r.layout.layout_region_item, null);     }      textview name = (textview) convertview.findviewbyid(r.id.name);     name.settext(object.getname());      return convertview; }  @override public boolean hasstableids() {     return true; }  @override public boolean ischildselectable(int groupposition, int childposition) {     return true; } } 

and code level 2-3:

public class countriesadapter extends baseexpandablelistadapter {  private object object; private layoutinflater inflater; private activity activity;  public countriesadapter(activity activity, object object) {     this.activity = activity;     this.object = object;     this.inflater = (layoutinflater) activity.getsystemservice(context.layout_inflater_service); }  @override public object getchild(int groupposition, int childposition) {     return object.getobjects().get(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) {      object object = (object) getchild(0, childposition);     if (convertview == null) {         convertview = inflater.inflate(r.layout.layout_country_item, null);          resources r = activity.getresources();         float px40 = typedvalue.applydimension(typedvalue.complex_unit_dip, 40, r.getdisplaymetrics());         convertview.setpadding(                 convertview.getpaddingleft() + (int) px40,                 convertview.getpaddingtop(),                 convertview.getpaddingright(),                 convertview.getpaddingbottom());     }      textview name = (textview) convertview.findviewbyid(r.id.name);     name.settext(object.getname());      return convertview; }  @override public int getchildrencount(int groupposition) {      if (object.getobjects() == null) {         return 0;     }     return object.getobjects().size(); }  @override public object getgroup(int groupposition) {     return object; }  @override public int getgroupcount() {     return 1; }  @override public long getgroupid(int groupposition) {     return groupposition; }  @override public view getgroupview(int groupposition, boolean isexpanded,                          view convertview, viewgroup parent) {      if (convertview == null) {         convertview = inflater.inflate(r.layout.layout_country_item, null);         resources r = activity.getresources();         float px20 = typedvalue.applydimension(typedvalue.complex_unit_dip, 20, r.getdisplaymetrics());         convertview.setpadding(                 convertview.getpaddingleft() + (int) px20,                 convertview.getpaddingtop(),                 convertview.getpaddingright(),                 convertview.getpaddingbottom());     }      textview name = (textview) convertview.findviewbyid(r.id.name);     name.settext(object.getname());      return convertview; }  @override public boolean hasstableids() {     return true; }  @override public boolean ischildselectable(int groupposition, int childposition) {     return true; } } 

also have custom expandablelistview:

public class customexpandablelistview extends expandablelistview {  public customexpandablelistview(context context) {     super(context); }  protected void onmeasure(int widthmeasurespec, int heightmeasurespec) {     widthmeasurespec = measurespec.makemeasurespec(960, measurespec.at_most);     heightmeasurespec = measurespec.makemeasurespec(600, measurespec.at_most);     super.onmeasure(widthmeasurespec, heightmeasurespec); } } 

and mainactivity code:

public class mainactivity extends appcompatactivity {  public static customexpandablelistview list;  @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_main);      list<item> objectslvl1 = new arraylist<item>();      list<item> objectsasia = new arraylist<item>();     list<item> objectseurope = new arraylist<item>();      list<item> objectschina = new arraylist<item>();      list<item> objectsgermany = new arraylist<item>();      objectslvl1.add(new item("asia", objectsasia));     objectslvl1.add(new item("europe", objectseurope));      objectsasia.add(new item("china", objectschina));     objectsasia.add(new item("japan"));      objectschina.add(new item("central", null));     objectschina.add(new item("north", null));     objectschina.add(new item("south", null));       relativelayout parent = (relativelayout) findviewbyid(r.id.parent);      list = new customexpandablelistview(this);     regionsadapter regionsadapter = new regionsadapter(this, objectslvl1);     list.setadapter(regionsadapter);      if (parent != null) {         parent.addview(list);     } } } 

yet again, in end i've figured out. answer.

• expanding list checkboxes:

this 1 pretty simple. i've added onclicklistener textview inside getgroupview method:

    view.onclicklistener clicklistener = new view.onclicklistener() {     @override     public void onclick(view v) {             if (!isexpanded) {                 expandablelistview.expandgroup(groupposition);             } else {                 expandablelistview.collapsegroup(groupposition);             }         }     };      holder.childname.setonclicklistener(clicklistener);     holder.childindicator.setonclicklistener(clicklistener); 

• hiding indicators:

it easier replace standart indicators , add own. , then, inside getgroupview work it.

at first, setting default groupindicator null:

expandablelistview.setgroupindicator(null); 

than, working custom images:

holder.childindicator = (imageview) convertview.findviewbyid(r.id.imgchildindicator);      if (getchildrencount(groupposition) == 0) {         holder.childindicator.setalpha(0);     } else {         holder.childindicator.setimageresource(isexpanded ? r.drawable.expanded : r.drawable.collapsed);     } 

and finally, hiding groupindicator level 3 items:

holder.childindicator.setalpha(0); 

the same changes made level 1 items.

• fitting expandablelistview on screen:

i've put expandablelistview inside relativelayout in activity_main.

and changed realization inside mainactivity:

expandablelistview list = (expandablelistview) findviewbyid(r.id.expandablelistview_parent);      if (list != null) {         parentadapter adapter = new parentadapter(this, objectslvl1);         list.setadapter(adapter);     } 

this solved issue, have full screen expandablelist.