Android focusability demo ListActivity.Reference for Qs "Can someone explain descendantFocusability = afterDescendants ?" with answer @ https://stackoverflow.com/a/45522137/3239250

FocusabilityDemo.java

package net.sosiouxme.listviews;
 
import android.app.AlertDialog; 
import android.app.Dialog; 
import android.app.ListActivity; 
import android.content.DialogInterface; 
import android.content.SharedPreferences; 
import android.content.DialogInterface.OnCancelListener; 
import android.content.DialogInterface.OnMultiChoiceClickListener; 
import android.os.Bundle; 
import android.preference.PreferenceManager; 
import android.util.Log; 
import android.view.ContextMenu; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.view.View; 
import android.view.ViewGroup; 
import android.view.ContextMenu.ContextMenuInfo; 
import android.view.View.OnCreateContextMenuListener; 
import android.view.View.OnLongClickListener; 
import android.widget.AdapterView; 
import android.widget.ArrayAdapter; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.ListView; 
import android.widget.Toast; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.AdapterView.OnItemLongClickListener; 
import android.widget.AdapterView.OnItemSelectedListener; 
 
public class FocusabilityDemo extends ListActivity { 
  
 private static final int DIALOG_LAYOUT = 0; 
 private static final int DIALOG_SIZE = 1; 
 private static final int DIALOG_SCROLLING_HEADER = 2; 
 private static final int DIALOG_SCROLLING_FOOTER = 3; 
 private static final int DIALOG_EVENTS = 4; 
 private static final int DIALOG_STRATEGIES = 5; 
 private static final String PREF_LAYOUTS = "layouts"; 
 private static final String PREF_SIZES = "sizes"; 
 private static final String PREF_SCROLLING_HEADER = "scrolling_header"; 
 private static final String PREF_SCROLLING_FOOTER = "scrolling_footer"; 
 public static final String TAG = "Listviews"; 
 private SharedPreferences mPrefs = null; 
 private View mHeaderView = null; 
 private View mFooterView = null; 
 public int mDialogShown; 
  
 private static int[] LAYOUTS = { 
  R.layout.l_01_plain, 
  R.layout.l_02_static_header_linear, 
  R.layout.l_03_static_footer_linear, 
  R.layout.l_04_naive_static_both_linear, 
  R.layout.l_04b_static_both_linear_fix, 
  R.layout.l_05_naive_static_both_relative, 
  R.layout.l_05b_static_both_relative 
 }; 
 private static int[] SIZES = { 
  R.array.size_0, 
  R.array.size_1, 
  R.array.size_3, 
  R.array.size_10 
 }; 
 private static int[] SCROLLING_HEADERS = { 
  0, 
  R.layout.w_scrolling_header, 
  R.layout.w_scrolling_header_wbutton, 
  R.layout.w_scrolling_header_wedit, 
  R.layout.w_scrolling_header_wboth 
 }; 
 private static int[] SCROLLING_FOOTERS = { 
  0, 
  R.layout.w_scrolling_footer, 
  R.layout.w_scrolling_footer_wbutton, 
  R.layout.w_scrolling_footer_wedit, 
  R.layout.w_scrolling_footer_wboth 
 }; 
 
  
 /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
     mPrefs = PreferenceManager.getDefaultSharedPreferences(this); 
        setupListView();         
    } 
 
    private void setupListView() { 
        ListView lv = getListView(); 
 
        // get rid of any previous header/footer settings 
     if(mHeaderView != null) lv.removeHeaderView(mHeaderView); 
     if(mFooterView != null) lv.removeFooterView(mFooterView); 
     mHeaderView = mFooterView = null; 
     setListAdapter(null); // can't set new headers/footers with adapter still there 
      
     // now set up the listview and adapter 
     setContentView(LAYOUTS[getIntPref(PREF_LAYOUTS)]); 
        ArrayAdapter<CharSequence> aa = ArrayAdapter.createFromResource(this, SIZES[getIntPref(PREF_SIZES)], android.R.layout.simple_list_item_1); 
        lv = getListView(); 
 
        // add a header if one is specified 
        int sHeaderLayout = SCROLLING_HEADERS[getIntPref(PREF_SCROLLING_HEADER)]; 
        if(sHeaderLayout > 0) { 
         EventListener el = new EventListener("header", R.menu.header_item); 
         mHeaderView = getLayoutInflater().inflate(sHeaderLayout, null); 
         lv.addHeaderView(mHeaderView); 
         addHFEventListeners(mHeaderView, el); 
        } 
 
        // add a footer if one is specified 
        int sFooterLayout = SCROLLING_FOOTERS[getIntPref(PREF_SCROLLING_FOOTER)]; 
        if(sFooterLayout > 0) { 
         EventListener el = new EventListener("footer", R.menu.footer_item); 
         mFooterView = getLayoutInflater().inflate(sFooterLayout, null); 
         lv.addFooterView(mFooterView); 
         addHFEventListeners(mFooterView, el); 
        } 
         
        // must come after adding header/footer 
        setListAdapter(aa); 
 
        EventListener el = new EventListener("list"); 
         
        // set a listener to respond when something is clicked on 
        if(getBoolPref(Events.LI_CLICK)) lv.setOnItemClickListener(el); 
        // set a listener to respond when something is long-clicked 
        if(getBoolPref(Events.LI_LONGCLICK)) lv.setOnItemLongClickListener(el); 
        // set a listener to respond when a context menu is created 
        if(getBoolPref(Events.LI_CTXMENU)) lv.setOnCreateContextMenuListener(el); 
        // set a listener to set focus properly when sub-elements get focus 
        if(getBoolPref(Strategy.FOCUS_SELECT_LISTEN)) { 
         lv.setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS); 
         lv.setOnItemSelectedListener(new FocusSelectListener()); 
        } 
        if(getBoolPref(Strategy.SET_ITEMS_CAN_FOCUS)) { 
         lv.setItemsCanFocus(true); 
        } 
    } 
 
 private void addHFEventListeners(View v, EventListener el) { 
        // set a listener to respond when something is clicked on 
        if(getBoolPref(Events.HF_CLICK)) v.setOnClickListener(el); 
        // set a listener to respond when a button is clicked on 
  if(getBoolPref(Events.HF_BUTTON_CLICK)) { 
   Button b = (Button) v.findViewById(R.id.button); 
   if(b != null) 
    b.setOnClickListener(el); 
  } 
        // set a listener to respond when something is long-clicked 
  if(getBoolPref(Events.HF_LONGCLICK)) 
   v.setOnLongClickListener(el); 
        // set a listener to respond when a context menu is created 
  if(getBoolPref(Events.HF_CTXMENU)) 
   v.setOnCreateContextMenuListener(el); 
 } 
     
    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
  getMenuInflater().inflate(R.menu.menu, menu); 
     return super.onCreateOptionsMenu(menu); 
    } 
 
 @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
  switch(item.getItemId()) { 
  case R.id.layout: 
   showDialog(DIALOG_LAYOUT); 
   break; 
  case R.id.size: 
   showDialog(DIALOG_SIZE); 
   break; 
  case R.id.scrolling_header: 
   showDialog(DIALOG_SCROLLING_HEADER); 
   break; 
  case R.id.scrolling_footer: 
   showDialog(DIALOG_SCROLLING_FOOTER); 
   break; 
  case R.id.events: 
   showDialog(DIALOG_EVENTS); 
   break; 
  case R.id.strategies: 
   showDialog(DIALOG_STRATEGIES); 
   break; 
  } 
     return super.onOptionsItemSelected(item); 
    } 
  
 
  
 private void setIntPref(String pref, int i) { 
  Log.d(TAG, "set " + pref + " to " + i); 
  mPrefs.edit().putInt(pref, i).commit(); 
 } 
 private int getIntPref(String pref) { 
  return mPrefs.getInt(pref, 0); 
 } 
 protected void setBoolPref(String pref, boolean b) { 
  Log.d(TAG, "set " + pref + " to " + b); 
  mPrefs.edit().putBoolean(pref, b).commit(); 
 } 
 protected boolean getBoolPref(String pref) { 
  return mPrefs.getBoolean(pref, false); 
 } 
 protected boolean getBoolPref(Events ev) { 
  return getBoolPref(ev.toString()); 
 } 
 protected boolean getBoolPref(Strategy s) { 
  return getBoolPref(s.toString()); 
 } 
 
 @Override 
 protected Dialog onCreateDialog(int id) { 
  switch(id) { 
  case DIALOG_LAYOUT: 
  return new AlertDialog.Builder(this) 
   .setTitle(R.string.choose_layout) 
   .setSingleChoiceItems(R.array.layout, getIntPref(PREF_LAYOUTS), new DialogListener(PREF_LAYOUTS)) 
   .create(); 
  case DIALOG_SIZE: 
   return new AlertDialog.Builder(this) 
   .setTitle(R.string.choose_size) 
   .setSingleChoiceItems(R.array.size, getIntPref(PREF_SIZES), new DialogListener(PREF_SIZES)) 
   .create(); 
  case DIALOG_SCROLLING_HEADER: 
   return new AlertDialog.Builder(this) 
   .setTitle(R.string.choose_scrolling_header) 
   .setSingleChoiceItems(R.array.scrolling_header, getIntPref(PREF_SCROLLING_HEADER), new DialogListener(PREF_SCROLLING_HEADER)) 
   .create(); 
  case DIALOG_SCROLLING_FOOTER: 
   return new AlertDialog.Builder(this) 
   .setTitle(R.string.choose_scrolling_footer) 
   .setSingleChoiceItems(R.array.scrolling_footer, getIntPref(PREF_SCROLLING_FOOTER), new DialogListener(PREF_SCROLLING_FOOTER)) 
   .create(); 
  case DIALOG_EVENTS: 
   DialogListener listener = new DialogListener("events"); 
   return new AlertDialog.Builder(this) 
   .setTitle(R.string.choose_events) 
   .setMultiChoiceItems(R.array.events, Events.getPrefs(this), listener) 
   .setPositiveButton(R.string.ok_button, listener) 
   .setOnCancelListener(listener) 
   .create(); 
  case DIALOG_STRATEGIES: 
   listener = new DialogListener("strategies"); 
   return new AlertDialog.Builder(this) 
   .setTitle(R.string.choose_strategy) 
   .setMultiChoiceItems(R.array.strategy, Strategy.getPrefs(this), listener) 
   .setPositiveButton(R.string.ok_button, listener) 
   .setOnCancelListener(listener) 
   .create(); 
  } 
  return super.onCreateDialog(id); 
 } 
  
 @Override 
 protected void onPrepareDialog(int id, Dialog dialog) { 
  mDialogShown = id; 
  super.onPrepareDialog(id, dialog); 
 } 
  
 class EventListener implements View.OnClickListener, OnCreateContextMenuListener, OnItemClickListener, OnItemLongClickListener, OnLongClickListener { 
  private final String context; 
  private final int menuId; 
 
  public EventListener(String what) { 
    context = what; 
    menuId = R.menu.list_item; 
  } 
  public EventListener(String what, int menuId) { 
   context = what; 
   this.menuId = menuId; 
  } 
   
  // View.OnClickListener 
  public void onClick(View v) { 
   String msg = "clicked on " + context + " " + v.getClass().getSimpleName(); 
   Toast.makeText(FocusabilityDemo.this, msg, Toast.LENGTH_SHORT).show(); 
   Log.d(TAG, msg); 
  } 
 
  // OnCreateContextMenuListener   
  public void onCreateContextMenu(ContextMenu menu, View v, 
    ContextMenuInfo menuInfo) { 
   String msg = "Creating ctxt menu for View " 
       + v.getClass().getSimpleName() 
       + (menuInfo == null ? "" : menuInfo.toString()); 
   Toast.makeText(FocusabilityDemo.this, msg, Toast.LENGTH_LONG).show(); 
   Log.d(TAG, msg); 
   if(menu.size() > 0) { 
    Log.d(TAG, "Menu already created, skipping.");     
   } else { 
    getMenuInflater().inflate(menuId, menu); 
   } 
  } 
 
  // OnItemClickListener  
  public void onItemClick(AdapterView<?> parent, View view, int position, 
    long id) { 
   // When clicked, show a toast with the position 
   String msg = "Clicked on item at position " + position; 
   Toast.makeText(FocusabilityDemo.this, msg, Toast.LENGTH_SHORT).show(); 
   Log.d(TAG, msg); 
  } 
 
  // OnItemLongClickListener 
  public boolean onItemLongClick(AdapterView<?> parent, View view, 
    int position, long id) { 
   String msg = "Long-clicked on item at position " + position; 
   Toast.makeText(FocusabilityDemo.this, msg, Toast.LENGTH_SHORT).show(); 
   Log.d(TAG, msg); 
   return false; 
  } 
   
  // OnLongClickListener  
  public boolean onLongClick(View v) { 
   String msg = "Long-clicked on view " + v.getClass().getSimpleName(); 
   Toast.makeText(FocusabilityDemo.this, msg, Toast.LENGTH_SHORT).show(); 
   Log.d(TAG, msg); 
   return false; 
  } 
 } 
  
 class FocusSelectListener implements OnItemSelectedListener { 
  // OnItemSelectedListener, part of the FOCUS_SELECT_LISTEN strategy 
  public void onItemSelected(AdapterView<?> parent, View view, 
    int position, long id) { 
   ListView listView = getListView(); 
   Log.d(TAG, "onItemSelected gave us " + view.toString()); 
   Button b = (Button) view.findViewById(R.id.button); 
   EditText et = (EditText) view.findViewById(R.id.editor); 
      if (b != null || et != null) { 
          // Use afterDescendants to keep ListView from getting focus 
          listView.setDescendantFocusability(ViewGroup.FOCUS_AFTER_DESCENDANTS); 
          if(et!=null) et.requestFocus(); 
          else if(b!=null) b.requestFocus(); 
      } else { 
          if (!listView.isFocused()) { 
              // Use beforeDescendants so that previous selections don't re-take focus 
              listView.setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS); 
              listView.requestFocus(); 
          } 
      } 
 
  } 
  public void onNothingSelected(AdapterView<?> parent) { 
   // happens on scrolling - make sure listview gets focus by default 
   getListView().setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS); 
  } 
 } 
  
 class DialogListener implements Dialog.OnClickListener, OnMultiChoiceClickListener, OnCancelListener { 
  private final String pref; 
  public DialogListener(String pref) { 
   this.pref = pref; 
  } 
   
  public void onClick(DialogInterface dialog, int which) { 
   dialog.dismiss(); 
   setIntPref(this.pref, which); 
   setupListView(); 
  } 
 
  public void onClick(DialogInterface dialog, int which, boolean isChecked) { 
   if(mDialogShown == DIALOG_EVENTS) 
    setBoolPref(Events.values()[which].toString(), isChecked); 
   else    
    setBoolPref(Strategy.values()[which].toString(), isChecked); 
  } 
 
  // in the case of the multi-item select, make sure to re-create 
  // the screen on cancel as options may have changed 
  public void onCancel(DialogInterface dialog) { 
   setupListView(); 
  } 
   
 } 
  
 enum Events { 
  // need to be the same order as the array describing event enablement  
  LI_CLICK("event_li_click"), 
  LI_BUTTON_CLICK("event_li_button_click"), 
  LI_LONGCLICK("event_li_lclick"), 
  LI_CTXMENU("event_li_ctx"), 
  HF_CLICK("event_hf_click"), 
  HF_BUTTON_CLICK("event_hf_button_click"), 
  HF_LONGCLICK("event_hf_lclick"), 
  HF_CTXMENU("event_hf_ctx"), 
  ; 
   
  private final String pref; 
  private Events(String pref) { 
   this.pref = pref; 
  } 
  @Override 
  public String toString() { 
   return pref; 
  } 
   
  public static boolean[] getPrefs(FocusabilityDemo m) { 
   Events[] values = values(); 
   boolean[] arr = new boolean[values.length]; 
   for(int i = 0; i < values.length; i++) { 
    arr[i] = m.getBoolPref(values[i].pref); 
   } 
    return arr;  
  } 
  public static void setPrefs(FocusabilityDemo m, boolean[] values) { 
   Events[] events = values(); 
   for(int i = 0; i < values.length; i++) { 
    m.setBoolPref(events[i].pref, values[i]); 
   }    
  } 
 } 
  
 enum Strategy { 
  // need to be the same order as the array describing strategy setting 
   
  SET_ITEMS_CAN_FOCUS("strategy_items_can_focus"), 
  // Select whether the item gets focus or the subelements; use a listener 
  // when the item is selected and check children and assign focus; see 
  // http://stackoverflow.com/questions/2679948/focusable-edittext-inside-listview 
  FOCUS_SELECT_LISTEN("strategy_enable_subelement_focus") 
  ; 
   
  private final String pref; 
  private Strategy(String pref) { 
   this.pref = pref; 
  } 
  @Override 
  public String toString() { 
   return pref; 
  } 
   
  public static boolean[] getPrefs(FocusabilityDemo m) { 
   Strategy[] values = values(); 
   boolean[] arr = new boolean[values.length]; 
   for(int i = 0; i < values.length; i++) { 
    arr[i] = m.getBoolPref(values[i].pref); 
   } 
    return arr;  
  } 
  public static void setPrefs(FocusabilityDemo m, boolean[] values) { 
   Strategy[] events = values(); 
   for(int i = 0; i < values.length; i++) { 
    m.setBoolPref(events[i].pref, values[i]); 
   }    
  } 
 } 
 
}