How to Iterate Through a View's Elements

How to iterate through a view's elements

I've done something similar in some code I don't have with me at the moment, but from memory it should be something like this (assuming a parent view LinearLayout with an id of "layout"):

LinearLayout layout = (LinearLayout)findViewById(R.id.layout);
boolean success = formIsValid(layout);

public boolean formIsValid(LinearLayout layout) {
    for (int i = 0; i < layout.getChildCount(); i++) {
        View v = layout.getChildAt(i);
        if (v instanceof EditText) {
            //validate your EditText here
        } else if (v instanceof RadioButton) {
            //validate RadioButton
        } //etc. If it fails anywhere, just return false.
    }
    return true;
}

How to iterate through a view's elements

I've done something similar in some code I don't have with me at the moment, but from memory it should be something like this (assuming a parent view LinearLayout with an id of "layout"):

LinearLayout layout = (LinearLayout)findViewById(R.id.layout);
boolean success = formIsValid(layout);

public boolean formIsValid(LinearLayout layout) {
    for (int i = 0; i < layout.getChildCount(); i++) {
        View v = layout.getChildAt(i);
        if (v instanceof EditText) {
            //validate your EditText here
        } else if (v instanceof RadioButton) {
            //validate RadioButton
        } //etc. If it fails anywhere, just return false.
    }
    return true;
}

How to iterate through all activity components(views) in Android

this may help you...

public ArrayList<Button> getButtons() {
    ArrayList<Button> buttons = new ArrayList<Button>();
    ViewGroup viewGroup = (ViewGroup) getWindow().getDecorView();
    findButtons(viewGroup, buttons);
    return buttons;
}

private static void findButtons(ViewGroup viewGroup,ArrayList<Button> buttons) {
    for (int i = 0, N = viewGroup.getChildCount(); i < N; i++) {
        View child = viewGroup.getChildAt(i);
        if (child instanceof ViewGroup) {
            findButtons((ViewGroup) child, buttons);
        } else if (child instanceof Button) {
            buttons.add((Button) child);
        }
    }
}

How do iterate through all the views/items in a RecyclerView?

RecyclerView views are created/destroyed as needed when you scroll. You cannot rely on them being available.

I assume you are trying to retrieve the selection state. It is better to store this within your object in the adapter and update its value upon clicking a radio button.

Then you can implement a getItem method in your adapter that returns the object and it's current selection state.

Loop through all subviews of an Android view?

@jqpubliq Is right but if you really want to go through all Views you can simply use the getChildCount() and getChildAt() methods from ViewGroup. A simple recursive method will do the rest.

Android : How iterate through views of a expandableList

Add new Class CustomChilds

package stack.buy.com.stackdemos;

 /**
* Created by Desktop - Ganesh on 10/14/2016.
*/
public class CustomChilds {
 String Quntity;
String Unit;
String Note;
String GroupName;

public String getQuntity() {
    return Quntity;
}

public void setQuntity(String quntity) {
    Quntity = quntity;
}

public String getUnit() {
    return Unit;
}

public void setUnit(String unit) {
    Unit = unit;
}

public String getNote() {
    return Note;
}

public void setNote(String note) {
    Note = note;
}

public String getGroupName() {
    return GroupName;
}

public void setGroupName(String groupName) {
    GroupName = groupName;
}

public CustomChilds(String quntity, String unit, String note, String groupName) {
    Quntity = quntity;
    Unit = unit;
    Note = note;
    GroupName = groupName;
}

public CustomChilds() {
}
 }

Adapter:

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<CustomChilds>> _listDataChild;
// private final HashMap<String, String, String> mCheckedItems;
String cat, item, quty, units, notes;

ArrayList<String> ss = new ArrayList<>();

public ExpandableListAdapter(Context context, List<String> listDataHeader,
                             HashMap<String, List<CustomChilds>> listChildData) {
    this._context = context;
    this._listDataHeader = listDataHeader;
    this._listDataChild = listChildData;
}
    @Override
    public CustomChilds 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 ( final int groupPosition, final int childPosition,
    boolean isLastChild, View convertView, ViewGroup parent){

        final CustomChilds childText =getChild(groupPosition, childPosition);
        final ViewHolder holder;

        View row = convertView;
        if (row == null) {
            LayoutInflater inflater = (LayoutInflater) this._context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            row = inflater.inflate(R.layout.list_item, parent, false);
            holder = new ViewHolder();
            holder.mm = (LinearLayout) row.findViewById(R.id.entries);
            holder.qty = (EditText) row.findViewById(R.id.qty1);
            holder.note = (EditText) row.findViewById(R.id.note);
            holder.unit = (Spinner) row.findViewById(R.id.unit);
            holder.cb = (CheckBox) row.findViewById(R.id.cb);
            holder.txtListChild = (TextView) row
                    .findViewById(R.id.lblListItem);
            row.setTag(holder);
        }

        else {
            // view already exists, get the holder instance from the view
            holder = (ViewHolder) row.getTag();
        }

        List<CustomChilds> temp = _listDataChild.get(this._listDataHeader.get(groupPosition));
        temp.set(childPosition,new  CustomChilds(holder.qty.getText().toString(),holder.unit.getSelectedItem().toString(),holder.note.getText().toString(),childText.GroupName));

        final int grp = groupPosition;

        holder.cb.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {

                final CheckBox cb = (CheckBox) v;

                if (cb.isChecked()) {
                    holder.mm.setVisibility(View.VISIBLE);
                } else {
                    holder.mm.setVisibility(View.GONE);

                }
                System.out.println(ss);
            }
        });

        holder.txtListChild.setText(childText.getGroupName());

        return row;
    }

@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;
}

// somewhere else in your class definition
static class ViewHolder {
    EditText qty;
    EditText note;
    Spinner unit;
    LinearLayout mm;
    CheckBox cb;
    TextView txtListChild;
}
 }

MainActivity

public class MainActivity extends AppCompatActivity {

ExpandableListAdapter listAdapter;
ExpandableListView expListView;
List<String> listDataHeader;
HashMap<String, List<CustomChilds>> listDataChild;

Button save;
Button cancel;

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

    save = (Button) findViewById(R.id.save);

    listAdapter = new ExpandableListAdapter(getApplicationContext(), listDataHeader, listDataChild);

    expListView.setDescendantFocusability(ViewGroup.FOCUS_AFTER_DESCENDANTS);

    save.setOnClickListener(new Button.OnClickListener() {
        public void onClick(View v) {
            System.out.println("Save clicked");
            for(int i = 0; i < listAdapter.getGroupCount();i++) {
                for (int k = 0; k < listAdapter.getChildrenCount(i); k++) {

                    CustomChilds child = listAdapter.getChild(i, k);
                    String unit=child.getUnit();
                    String note=child.getNote();
                    String qut=child.getQuntity();

                    System.out.println("For i="+i+" and k="+k+" string value is="+child.getNote());
                }
            }
        }
    });

}

private void prepareListData() {
    listDataHeader = new ArrayList<String>();
    listDataChild = new HashMap<String, List<CustomChilds>>();
    listDataHeader.add("Nokia");
    listDataHeader.add("Apple");
    listDataHeader.add("Samsung");

    List<CustomChilds> nokia = new ArrayList<CustomChilds>();
    nokia.add(new CustomChilds("","","","Nokia1"));
    nokia.add(new CustomChilds("","","","Nokia2"));

    List<CustomChilds> apple = new ArrayList<CustomChilds>();
    apple.add(new CustomChilds("","","","Apple1"));
    apple.add(new CustomChilds("","","","Apple2"));

    List<CustomChilds> samsung = new ArrayList<CustomChilds>();
    samsung.add(new CustomChilds("","","","Samsung1"));
    samsung.add(new CustomChilds("","","","Samsung2"));

    listDataChild.put(listDataHeader.get(0), nokia); // Header, Child data
    listDataChild.put(listDataHeader.get(1), apple);
    listDataChild.put(listDataHeader.get(2), samsung);
}
 }

Get Unit, Quantity and Note onClick

save.setOnClickListener(new Button.OnClickListener() {
    public void onClick(View v) {
        System.out.println("Save clicked");
        for(int i = 0; i < listAdapter.getGroupCount();i++) {
            for (int k = 0; k < listAdapter.getChildrenCount(i); k++) {

                CustomChilds child = listAdapter.getChild(i, k);
                String unit=child.getUnit();
                String note=child.getNote();
                String qut=child.getQuntity();

                System.out.println("For i="+i+" and k="+k+" string value is="+child.getNote());
            }
        }
    }
});

How do I iterate through a list in my View?

I just posted this example in another question. Try something like this,

<table class="results" width="100%" border="0" cellpadding="5">
<thead class="tablehead">
  <tr> 
    <td width="55px"><b>Country</b></td>
    <td width="55px"><b>State</b></td>
    <td width="55px"><b>City</b></td>
    <td width="55px"><b>Town</b></td>
    <td width="55px"><b>Postal</b></td>
  </tr>
</thead>
<tbody>
<% 
    int count = 0;
    foreach (var item in (IEnumerable<MY_RESULTS>)ViewData["My_Results"])
    {
        if (count % 2 == 0) { Response.Write("<tr class='even'>"); } else { Response.Write("<tr class='odd'>"); }   
    %>
            <td><%= Html.Encode(item.Country)%></td>
            <td><%= Html.Encode(item.State)%></td>
            <td><%= Html.Encode(item.City)%></td>
            <td><%= Html.Encode(item.Town)%></td>
            <td><%= Html.Encode(item.Postal)%></td>
        </tr>

    <% count += 1; } %>
</tbody>
</table>

Iterate through a boost::multi_array view

Here is one way to do this:

#include <iostream>
#include <boost/multi_array.hpp>

// Functor to iterate over a Boost MultiArray concept instance.
template<typename T, typename F, size_t Dimensions = T::dimensionality>
struct IterateHelper {
   void operator()(T& array, const F& f) const {
      for (auto element : array)
         IterateHelper<decltype(element), F>()(element, f);
   }
};

// Functor specialization for the final dimension.
template<typename T, typename F>
struct IterateHelper<T, F, 1> {
   void operator()(T& array, const F& f) const {
      for (auto& element : array)
         f(element);
   }
};

// Utility function to apply a function to each element of a Boost
// MultiArray concept instance (which includes views).
template<typename T, typename F>
static void iterate(T& array, const F& f) {
   IterateHelper<T, F>()(array, f);
}

int main() {
   boost::multi_array<char, 2> a{boost::extents[2][6]};

   a[0][0] = 'B';
   a[0][1] = 'o';
   a[0][2] = 'o';
   a[0][3] = 's';
   a[0][4] = 't';
   a[0][5] = '\0';

   a[1][0] = 'L';
   a[1][1] = 'i';
   a[1][2] = 'o';
   a[1][3] = 'n';
   a[1][4] = 's';
   a[1][5] = '\0';

   typedef boost::multi_array<char, 2>::array_view<2>::type array_view;
   typedef boost::multi_array_types::index_range range;
   array_view b = a[boost::indices[range{0,2}][range{0,4}] ];

   // Use the utility to apply a function to each element.
   iterate(b, [](char& c) {
      std::cout << c << std::endl;
   });

   return 0;
};

The code above defines a utility function iterate(), to which you pass an object satisfying the Boost MultiArray concept (which includes views) and a function to apply to each element. The utility function works by using a Functor that iterates over each dimension recursively.

CoLiRu

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