Android ListView headers

Question

I have ListView that has some kind of events on it  Events are sorted by day  and I would like to have header with date on it for every day  and then events listen below   Here is how I populate that list   ArrayList lt TwoText gt  crs   new ArrayList lt TwoText gt      crs add new TwoText  This will be header   event getDate       for  Event event   events        crs add new TwoText event getStartString      -    event getEndString    event getSubject         arrayAdapter   new TwoTextArrayAdapter this  R layout my list item  crs   lv1 setAdapter arrayAdapter     and this is how my class TwoText looks   public class TwoText       public String classID      public String state       public TwoText String classID  String state            this classID   classID          this state   state            and this is how my TwoTextArrayAdapter class looks   import java util ArrayList  import android app Activity  import android content Context  import android view LayoutInflater  import android view View  import android view ViewGroup  import android widget ArrayAdapter  import android widget TextView   public class TwoTextArrayAdapter extends ArrayAdapter lt TwoText gt         private ArrayList lt TwoText gt  classes      private Activity con      TextView seperator       public TwoTextArrayAdapter Activity context  int textViewResourceId  ArrayList lt TwoText gt  classes            super context  textViewResourceId  classes           this con   context          this classes   classes               Override      public View getView int position  View convertView  ViewGroup parent             View v   convertView           if  v    null                 LayoutInflater vi    LayoutInflater  con getSystemService Context LAYOUT INFLATER SERVICE                v   vi inflate R layout my list item  null                       TwoText user   classes get position            if  user    null                 TextView content1    TextView  v findViewById R id list content1                TextView content2    TextView  v findViewById R id list content2                if  content1    null                     content1 setText user classID                                if content2    null                     content2 setText user state                                   return v            and this is my list item xml   lt  xml version  1 0  encoding  utf-8   gt   lt LinearLayout xmlns android  http   schemas android com apk res android      android layout width  match parent      android layout height  match parent      android orientation  vertical   gt        lt TextView         style   android attr listSeparatorTextViewStyle          android id    id separator          android text  Header          android layout width  fill parent          android layout height  wrap content          android background   757678          android textColor   f5c227    gt        lt LinearLayout         xmlns android  http   schemas android com apk res android          android layout width  match parent          android layout height  match parent          android orientation  horizontal   gt            lt TextView             android id    id list content1              android layout width  wrap content              android layout height  match parent              android layout margin  5dip              android clickable  false              android gravity  center              android longClickable  false              android paddingBottom  1dip              android paddingTop  1dip              android text  sample              android textColor   ff7f1d              android textSize  17dip              android textStyle  bold    gt            lt TextView             android id    id list content2              android layout width  wrap content              android layout height  match parent              android layout margin  5dip              android clickable  false              android gravity  center              android linksClickable  false              android longClickable  false              android paddingBottom  1dip              android paddingTop  1dip              android text  sample              android textColor   6d6d6d              android textSize  17dip    gt       lt  LinearLayout gt    lt  LinearLayout gt    what I do at the moment is that I am adding header just as regular list object  but Id like it to be as header and in my case have a date on it   I have this code in my xml for header    lt TextView         style   android attr listSeparatorTextViewStyle          android id    id separator          android text  Header          android layout width  fill parent          android layout height  wrap content          android background   757678          android textColor   f5c227    gt    and I tried hiding it when it is unneccessary and showing it when neccessary but I just messed up rest of my code  I tried few more tutorials but they also had same effect   Could anyone guide me on how to do that easy way

User · Answer

You probably are looking for an ExpandableListView which has headers  groups  to separate items  childs    Nice tutorial on the subject  here

User · Answer

What I did to make the Date  e g December 01  2016  as header  I used the StickyHeaderListView library   https   github com emilsjolander StickyListHeaders  Convert the date to long in millis  do not include the time  and make it as the header Id    Override public long getHeaderId int position        return  lt date in millis gt

User · Answer

Here s how I do it  the keys are getItemViewType and getViewTypeCount in the Adapter class   getViewTypeCount returns how many types of items we have in the list  in this case we have a header item and an event item  so two   getItemViewType should return what type of View we have at the input position   Android will then take care of passing you the right type of View in convertView automatically   Here what the result of the code below looks like        First we have an interface that our two list item types will implement  public interface Item       public int getViewType        public View getView LayoutInflater inflater  View convertView       Then we have an adapter that takes a list of Item  public class TwoTextArrayAdapter extends ArrayAdapter lt Item gt        private LayoutInflater mInflater       public enum RowType           LIST ITEM  HEADER ITEM            public TwoTextArrayAdapter Context context  List lt Item gt  items            super context  0  items           mInflater   LayoutInflater from context               Override     public int getViewTypeCount             return RowType values   length               Override     public int getItemViewType int position            return getItem position  getViewType              Override public View getView int position  View convertView  ViewGroup parent       return getItem position  getView mInflater  convertView        EDIT Better For Performance   can be noticed when scrolling  private static final int TYPE ITEM   0   private static final int TYPE SEPARATOR   1    public View getView int position  View convertView  ViewGroup parent         ViewHolder holder   null      int rowType   getItemViewType position       View View      if  convertView    null            holder   new ViewHolder            switch  rowType                case TYPE ITEM                  convertView   mInflater inflate R layout task details row  null                   holder View getItem position  getView mInflater  convertView                   break              case TYPE SEPARATOR                  convertView   mInflater inflate R layout task detail header  null                   holder View getItem position  getView mInflater  convertView                   break                    convertView setTag holder             else               holder    ViewHolder  convertView getTag              return convertView       public static class ViewHolder       public  View View         Then we have classes the implement Item and inflate the correct layouts   In your case you ll have something like a Header class and a ListItem class      public class Header implements Item       private final String         name       public Header String name            this name   name              Override     public int getViewType             return RowType HEADER ITEM ordinal                Override     public View getView LayoutInflater inflater  View convertView            View view          if  convertView    null                view    View  inflater inflate R layout header  null                  Do some initialization           else               view   convertView                     TextView text    TextView  view findViewById R id separator           text setText name            return view             And then the ListItem class      public class ListItem implements Item       private final String         str1      private final String         str2       public ListItem String text1  String text2            this str1   text1          this str2   text2              Override     public int getViewType             return RowType LIST ITEM ordinal                Override     public View getView LayoutInflater inflater  View convertView            View view          if  convertView    null                view    View  inflater inflate R layout my list item  null                  Do some initialization           else               view   convertView                     TextView text1    TextView  view findViewById R id list content1           TextView text2    TextView  view findViewById R id list content2           text1 setText str1           text2 setText str2            return view             And a simple Activity to display it  public class MainActivity extends ListActivity         Override     protected void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setContentView R layout activity main            List lt Item gt  items   new ArrayList lt Item gt             items add new Header  Header 1             items add new ListItem  Text 1    Rabble rabble             items add new ListItem  Text 2    Rabble rabble             items add new ListItem  Text 3    Rabble rabble             items add new ListItem  Text 4    Rabble rabble             items add new Header  Header 2             items add new ListItem  Text 5    Rabble rabble             items add new ListItem  Text 6    Rabble rabble             items add new ListItem  Text 7    Rabble rabble             items add new ListItem  Text 8    Rabble rabble              TwoTextArrayAdapter adapter   new TwoTextArrayAdapter this  items           setListAdapter adapter              Layout for R layout header   lt  xml version  1 0  encoding  utf-8   gt   lt LinearLayout xmlns android  http   schemas android com apk res android      android layout width  match parent      android layout height  match parent      android orientation  horizontal   gt        lt TextView         style   android attr listSeparatorTextViewStyle          android id    id separator          android text  Header          android layout width  fill parent          android layout height  wrap content          android background   757678          android textColor   f5c227    gt    lt  LinearLayout gt    Layout for R layout my list item   lt  xml version  1 0  encoding  utf-8   gt   lt LinearLayout xmlns android  http   schemas android com apk res android      android layout width  match parent      android layout height  match parent      android orientation  horizontal   gt        lt TextView         android id    id list content1          android layout width  wrap content          android layout height  match parent          android layout margin  5dip          android clickable  false          android gravity  center          android longClickable  false          android paddingBottom  1dip          android paddingTop  1dip          android text  sample          android textColor   ff7f1d          android textSize  17dip          android textStyle  bold    gt        lt TextView         android id    id list content2          android layout width  wrap content          android layout height  match parent          android layout margin  5dip          android clickable  false          android gravity  center          android linksClickable  false          android longClickable  false          android paddingBottom  1dip          android paddingTop  1dip          android text  sample          android textColor   6d6d6d          android textSize  17dip    gt    lt  LinearLayout gt    Layout for R layout activity main xml   lt RelativeLayout xmlns android  http   schemas android com apk res android      xmlns tools  http   schemas android com tools      android layout width  match parent      android layout height  match parent      tools context   MainActivity   gt        lt ListView         android id   android id list          android layout width  fill parent          android layout height  fill parent    gt    lt  RelativeLayout gt    You can also get fancier and use ViewHolders  load stuff asynchronously  or whatever you like

User · Answer

As an alternative  there s a nice 3rd party library designed just for this use case  Whereby you need to generate headers based on the data being stored in the adapter  They are called Rolodex adapters and are used with ExpandableListViews  They can easily be customized to behave like a normal list with headers   Using the OP s Event objects and knowing the headers are based on the Date associated with it   the code would look something like this   The Activity        There s no need to pre-compute what the headers are  Just pass in your List of objects       EventDateAdapter adapter   new EventDateAdapter this  mEvents       mExpandableListView setAdapter adapter     The Adapter  private class EventDateAdapter extends NFRolodexArrayAdapter lt Date  Event gt         public EventDateAdapter Context activity  Collection lt Event gt  items            super activity  items               Override     public Date createGroupFor Event childItem              This is how the adapter determines what the headers are and what child items belong to it         return  Date  childItem getDate   clone                Override     public View getChildView LayoutInflater inflater  int groupPosition  int childPosition                               boolean isLastChild  View convertView  ViewGroup parent              Inflate your view            Gets the Event data for this view         Event event   getChild groupPosition  childPosition              Fill view with event data             Override     public View getGroupView LayoutInflater inflater  int groupPosition  boolean isExpanded                               View convertView  ViewGroup parent              Inflate your header view            Gets the Date for this view         Date date   getGroup groupPosition              Fill view with date data             Override     public boolean hasAutoExpandingGroups               This forces our group views  headers  to always render expanded            Even attempting to programmatically collapse a group will not work          return true              Override     public boolean isGroupSelectable int groupPosition              This prevents a user from seeing any touch feedback when a group  header  is clicked          return false

User · Answer

Here is a sample project  based on antew s detailed and helpful answer  that implements a ListView with multiple headers that incorporates view holders to improve scrolling performance   In this project  the objects represented in the ListView are instances of either the class HeaderItem or the class RowItem  both of which are subclasses of the abstract class Item  Each subclass of Item corresponds to a different view type in the custom adapter  ItemAdapter  The method getView   on ItemAdapter delegates the creation of the view for each list item to an individualized getView   method on either HeaderItem or RowItem  depending on the Item subclass used at the position passed to the getView   method on the adapter  Each Item subclass provides its own view holder   The view holders are implemented as follows  The getView   methods on the Item subclasses check whether the View object that was passed to the getView   method on ItemAdapter is null  If so  the appropriate layout is inflated  and a view holder object is instantiated and associated with the inflated view via View setTag    If the View object is not null  then a view holder object was already associated with the view  and the view holder is retrieved via View getTag    The way in which the view holders are used can be seen in the following code snippet from HeaderItem    Override View getView LayoutInflater i  View v        ViewHolder h      if  v    null            v   i inflate R layout header  null           h   new ViewHolder v           v setTag h         else           h    ViewHolder  v getTag              h category setText text         return v     private class ViewHolder       final TextView category       ViewHolder View v            category   v findViewById R id category             The complete implementation of the ListView follows  Here is the Java code   import android app ListActivity  import android os Bundle  import android view LayoutInflater  import android view View  import android view ViewGroup  import android widget ArrayAdapter  import android widget TextView   import java util ArrayList  import java util Collections  import java util HashSet  import java util List  import java util Set   public class MainActivity extends ListActivity        Override     protected void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setListAdapter new ItemAdapter getItems                 class ItemAdapter extends ArrayAdapter lt Item gt            final private List lt Class lt   gt  gt  viewTypes           ItemAdapter List lt Item gt  items                super MainActivity this  0  items               if  items contains null                   throw new IllegalArgumentException  null item                viewTypes   getViewTypes items                      private List lt Class lt   gt  gt  getViewTypes List lt Item gt  items                Set lt Class lt   gt  gt  set   new HashSet lt  gt                 for  Item i   items                   set add i getClass                 List lt Class lt   gt  gt  list   new ArrayList lt  gt  set               return Collections unmodifiableList list                       Override         public int getViewTypeCount                 return viewTypes size                        Override         public int getItemViewType int position                Item t   getItem position               return viewTypes indexOf t getClass                         Override         public View getView int position  View v  ViewGroup unused                return getItem position  getView getLayoutInflater    v                        abstract private class Item           final private String text           Item String text                this text   text                     String text     return text             abstract View getView LayoutInflater i  View v              private class HeaderItem extends Item           HeaderItem String text                super text                       Override         View getView LayoutInflater i  View v                ViewHolder h              if  v    null                    v   i inflate R layout header  null                   h   new ViewHolder v                   v setTag h                 else                   h    ViewHolder  v getTag                              h category setText text                 return v                     private class ViewHolder               final TextView category               ViewHolder View v                    category   v findViewById R id category                                      private class RowItem extends Item           RowItem String text                super text                       Override         View getView LayoutInflater i  View v                ViewHolder h              if  v    null                    v   i inflate R layout row  null                   h   new ViewHolder v                   v setTag h                 else                   h    ViewHolder  v getTag                              h option setText text                 return v                     private class ViewHolder               final TextView option               ViewHolder View v                    option   v findViewById R id option                                      private List lt Item gt  getItems             List lt Item gt  t   new ArrayList lt  gt             t add new HeaderItem  Header 1             t add new RowItem  Row 2             t add new HeaderItem  Header 3             t add new RowItem  Row 4              t add new HeaderItem  Header 5             t add new RowItem  Row 6             t add new HeaderItem  Header 7             t add new RowItem  Row 8              t add new HeaderItem  Header 9             t add new RowItem  Row 10             t add new HeaderItem  Header 11             t add new RowItem  Row 12              t add new HeaderItem  Header 13             t add new RowItem  Row 14             t add new HeaderItem  Header 15             t add new RowItem  Row 16              t add new HeaderItem  Header 17             t add new RowItem  Row 18             t add new HeaderItem  Header 19             t add new RowItem  Row 20              t add new HeaderItem  Header 21             t add new RowItem  Row 22             t add new HeaderItem  Header 23             t add new RowItem  Row 24              t add new HeaderItem  Header 25             t add new RowItem  Row 26             t add new HeaderItem  Header 27             t add new RowItem  Row 28             t add new RowItem  Row 29             t add new RowItem  Row 30              t add new HeaderItem  Header 31             t add new RowItem  Row 32             t add new HeaderItem  Header 33             t add new RowItem  Row 34             t add new RowItem  Row 35             t add new RowItem  Row 36              return t             There are also two list item layouts  one for each Item subclass  Here is the layout header  used by HeaderItem    lt  xml version  1 0  encoding  utf-8   gt   lt LinearLayout xmlns android  http   schemas android com apk res android      android layout width  match parent      android layout height  wrap content      android background   FFAAAAAA       gt       lt TextView         android id    id category          android layout width  wrap content          android layout height  wrap content          android layout margin  4dp          android textColor   FF000000          android textSize  20sp          android textStyle  bold            gt    lt  LinearLayout gt    And here is the layout row  used by RowItem    lt LinearLayout xmlns android  http   schemas android com apk res android      android layout width  match parent      android layout height  wrap content      android minHeight   android attr listPreferredItemHeight       gt       lt TextView         android id    id option          android layout width  wrap content          android layout height  wrap content          android textSize  15sp            gt   lt  LinearLayout gt    Here is an image of a portion of the resulting ListView

[java] Android ListView headers

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