Android Open Source - assignment1_todolist Main Activity

• Back to App/assignment  ↑

From Project

Back to project page assignment1_todolist.

License

The source code is released under:

GNU General Public License

Java Source Code

package com.example.mswillia_notes002;
//from  w w  w. java  2s.c o  m

import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
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.util.SparseBooleanArray;
import android.view.ActionMode;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.nio.charset.CoderMalfunctionError;
import java.util.ArrayList;
import java.util.List;

import android.widget.AbsListView.MultiChoiceModeListener;
 
public class MainActivity extends Activity {
 
  /*
   * MainActivity is the primary view
   * Active todos and archived todos are stored in two TodoList objects.
   * Todo list mode - the application starts in this mode.
   * List mode has a menu, with summary, and view archive/todo list options.
   * Selection mode - a long press/click on any of the todo items activates context action bar selection mode, and allows
   *   for edit, delete, archive/unarchive, and email functions on the selected items
   * 
   *   
   * Primary functions:
   * setOnItemClickListener():
   *   Monitors clicks on individual todos in list
   *        
   *setMultiChoiceModeListener():
   *  Long press on a ListView item activates multiple selection listener, with context action bar menu.
   *   Implements all edit, delete, archive/unarchive, and email functions.
   * 
   * addTodo():
   *   Implements addition of Todo item to todo list, as well as saving edited todo items.
   * 
   * summary():
   *   Activates the summary activity via an intent
   * 
   * Design rationale: to prevent redundant code and an additional activity class, both lists are implemented
   *   within the same view, via swapping of todo list objects into the ListView adapter
   * 
   * Source code attribution:
   *   setMultiChoiceModeListener() section (and associated ListViewAdapter class) partially based on tutorial code:
   *     http://www.androidbegin.com/tutorial/android-delete-multiple-selected-items-listview-tutorial/
   *   setOnItemClickListener() section based on tutorial code:
   *    http://www.mysamplecode.com/2012/07/android-listview-checkbox-example.html
   *   email intent code based upon instructor recommended link:
   *     http://stackoverflow.com/questions/2197741/how-can-i-send-emails-from-my-android-application
   */
  

    private ListView list;          //UI view containing the todo list to be displayed
    private ListViewAdapter listviewadapter;//binds the UI list view to the currently selected list (todo or archive)
    private TodoList todoList;        //active todo list: TodoList object consisting of multiple Todo objects
    private TodoList todoArchive;      //archived todo list: TodoList object consisting of multiple Todo objects
    private CombinedList cl;        //CombinedList object consisting of both todo and archive lists, used 
                        //  primarily for file load and save operations    
    boolean toggleViewMode;         //toggle alternates visible todo list based on user menu selection
                        //  false = Active todo list view, true = Archived todo list view

  private InterfaceFileManager todoFileManager;   //interface for file manager object, instantiated via 
                          //TodoListFileManager class
    
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);        
       
        setContentView(R.layout.listview_main); // main layout view from listview_main.xml
        
        //Variable initialization
        cl = new CombinedList();
        todoFileManager = new TodoListFileManager(this);
        todoList = new TodoList();
        todoArchive = new TodoList();
        toggleViewMode = false;        

        list = (ListView) findViewById(R.id.listViewArchive); //ListView that displays current todo list
 
        // Bind active todo list to list view
        listviewadapter = new ListViewAdapter(this, R.layout.listview_item, todoList.getTodoList());
        list.setAdapter(listviewadapter);
        list.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL); //enable multiple selections within list

        
        list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
          
          // Listener observing clicks on list items
          public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            // determine whether clicked list item has checkbox checked, and toggle state
              boolean flag = listviewadapter.getTodoList().get(position).getTodoChecked();
              listviewadapter.getTodoList().get(position).setTodoChecked(!flag);
              
              //persist changed state to storage via TodoListFileManager class object
                cl = new CombinedList();            
              cl.setTodolist(todoList);
              cl.setTodoarchive(todoArchive);
                todoFileManager.saveTodoList(cl);           
                //update UI list view and bound data set to reflect checked item changed state
            //list.invalidateViews();
            listviewadapter.notifyDataSetChanged();
          }
                
        });

        
        // Long press on a ListView item activates multiple selection listener, with context action bar menu
        list.setMultiChoiceModeListener(new MultiChoiceModeListener() {     
          
            @Override
            public void onItemCheckedStateChanged(ActionMode mode, int position, long id, boolean checked) {
                // Total number of selected list items
                final int checkedCount = list.getCheckedItemCount();
                // context action bar indicates number of items selected
                mode.setTitle(checkedCount + " Selected");
                
                listviewadapter.toggleSelection(position);
                listviewadapter.getTodoList().get(position).setTodoChecked(true); //retrieve checked state from list view
                
                // addButton performs dual function:
                //  1. when editing existing todo text, button text displays "Save" and saves edited text back to list item
                //  2. all other occasions button text displays "Add" and adds a new todo item to the list
                // editing of todo text is only available when a single list item is selected
                Button addButton = (Button) findViewById(R.id.addButtonArchive);
              EditText editText = (EditText) findViewById(R.id.editTodoText);              
                if (checkedCount != 1) {                                    
                    addButton.setText("Add");
                    editText.setText("");                                                        
                }

               mode.invalidate(); // force call to onPrepareActionMode(), which updates list view in UI
            }
 
            // select action based on user selection from context action bar menu
            @Override
            public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
              
              SparseBooleanArray selected = listviewadapter.getSelectedIds(); // get list of all currently selected list view items                     
              boolean email_all = false;  
              
              // context action bar menu selection
                switch (item.getItemId()) {
                

                case R.id.edit:                  
                    // menu selection: edit existing todo item text
                    // option only available when a single list item is selected
                  Button editButton = (Button) findViewById(R.id.addButtonArchive);
                  EditText editText = (EditText) findViewById(R.id.editTodoText);
                  
                  if (selected.size() == 1 ){ // single list item must be selected to have edit option
                    editButton.setText("Save"); // change button text to "Save", to save edited text
                    Todo selection = listviewadapter.getItem(selected.keyAt(0));
                    editText.setText(selection.getTodoText().toString()); //copy todo text to TextEdit field for editing
                    return true;
                  }
                  return false;
                  
                  case R.id.delete:
                    // menu selection: remove selected items from list view and associated TodoList object
                      // loop through selected items and remove
                      for (int i = (selected.size() - 1); i >= 0; i--) {
                          if (selected.valueAt(i)) {
                              Todo selecteditem = listviewadapter.getItem(selected.keyAt(i));
                              listviewadapter.remove(selecteditem);
                          }
                      }
                      
                      //persist changed state to storage via TodoListFileManager class object
                      cl = new CombinedList();
                    cl.setTodolist(todoList);
                    cl.setTodoarchive(todoArchive);
                      todoFileManager.saveTodoList(cl);
                      mode.finish(); // exit context action bar mode
                      return true;
                      
                case R.id.archive:
                  // menu selection: Archive/Unarchive: Move all selected items from currently visible
                  //  todo list to inactive list (menu item text changes from "Archive" to "Unarchive"
                  //  based upon currently active list
                  //  loop through selected items and move from one list to the other
                  for (int i = (selected.size() - 1); i >= 0; i--) {
                        if (selected.valueAt(i)) {
                            Todo selecteditem = listviewadapter.getItem(selected.keyAt(i));
                            listviewadapter.remove(selecteditem);                           
                            if (toggleViewMode){
                              todoList.addTodo(selecteditem);
                            } else {
                              todoArchive.addTodo(selecteditem);
                            }
                        }                        
                    } 
                  //persist changed state to storage via TodoListFileManager class object
                    cl = new CombinedList();
                  cl.setTodolist(todoList);
                  cl.setTodoarchive(todoArchive);
                    todoFileManager.saveTodoList(cl);
                    mode.finish(); // exit context action bar mode
                    return true;
                    
                case R.id.emailall:
                  // menu selection: email all todo and archive list items
              email_all = true; //flag set, case falls through to case:email for email intent handling
                case R.id.email:
                  // menu selection: email selected items
                if (selected.size() <= 0) { 
                  Toast.makeText(MainActivity.this, "No items selected", Toast.LENGTH_SHORT).show();
                  return false;
              }

                // initialize email intent and string to store todo items
                Intent intent = new Intent(Intent.ACTION_SEND);                             
                String fullstring = "Todo list (items: + checked, - unchecked)\n\n";
                // append todo items as strings
                if (email_all) { // email all option - all items on both lists
                  Toast.makeText(MainActivity.this, "Emailing All", Toast.LENGTH_SHORT).show();
                  for (Todo todo: todoList.getTodoList()){
                    if (todo.getTodoChecked()) { fullstring += "+ ";
                      } else { fullstring += "- ";}
                    fullstring += todo.getTodoText() + "\n";                    
                  }
                  fullstring += "\nArchived todos:\n";
                  for (Todo todo: todoArchive.getTodoList()){
                    if (todo.getTodoChecked()){ fullstring += "+ ";
                      } else { fullstring += "- ";
                      }
                    fullstring += todo.getTodoText() + "\n";                    
                  }
                } else { // email selected option - only selected items in currently visible list
                  for(int i = 0; i < selected.size(); i++) 
                  {                        
                    Todo todo = listviewadapter.getItem(selected.keyAt(i));
                    if (todo.getTodoChecked()){
                      fullstring += "+ ";
                    } else { 
                      fullstring += "- ";
                    }
                    fullstring += todo.getTodoText() + "\n";
                  }
                }
                
                intent.setType("message/rfc822");
                intent.putExtra(Intent.EXTRA_EMAIL  , new String[]{"recipient@example.com"});
                intent.putExtra(Intent.EXTRA_SUBJECT, "subject of email");
                intent.putExtra(Intent.EXTRA_TEXT   , fullstring);
                try {
                    startActivity(Intent.createChooser(intent, "Send mail..."));
                } catch (android.content.ActivityNotFoundException ex) {
                    Toast.makeText(MainActivity.this, "No email clients installed.", Toast.LENGTH_SHORT).show();
                }            
                  return true;

                default:
                    return false;
                }
            }
 
            @Override
            public boolean onCreateActionMode(ActionMode mode, Menu menu) {
              //intialize context action mode menu
                mode.getMenuInflater().inflate(R.menu.activity_main, menu);                              
                return true;
            }
 
            @Override
            public void onDestroyActionMode(ActionMode mode) {
                listviewadapter.removeSelection();
            }
 
            @Override
            public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
              // called to refresh context action mode menu
            final int checkedCount = list.getCheckedItemCount(); // list of selectes list view items
            menu.clear();
            mode.getMenuInflater().inflate(R.menu.activity_main, menu);
            
            // hide edit option if more than single list item selected
            MenuItem item = menu.findItem(R.id.edit);              
              if (checkedCount == 1) { 
                item.setVisible(true);
              } else {
                item.setVisible(false);
              }
              // toggle archive/unarchive menu option based on visible todo list
              item = menu.findItem(R.id.archive);              
              if (toggleViewMode){
                item.setTitle("Unarchive");
              } else{
                item.setTitle("Archive");
              }           
              return true;
            }
        }); // end of setMultiChoiceListener()
         
    } // end of onCreate()
    
   
  @Override
  protected void onStart() {
    super.onStart();
    
    // load persistent CombinedList (contains todo list and archive list)
    CombinedList cl = new CombinedList();
    cl = todoFileManager.loadTodoList(); 
    todoList = cl.getTodolist();
    todoArchive = cl.getTodoarchive();

    // set ListViewAdapter to display active todo list on startup
    listviewadapter = new ListViewAdapter(this, R.layout.listview_item, todoList.getTodoList());
    list.setAdapter(listviewadapter);
    
  }
    
    
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
  }
  
  public void toggleListView(MenuItem menu) {

    // when called, swap the active todo list and the archive todo list into the ListViewAdaper
    // for display in UI

    toggleViewMode =  !toggleViewMode;
    if (toggleViewMode) {
      listviewadapter = new ListViewAdapter(this, R.layout.listview_item, todoArchive.getTodoList());
      setTitle("Archived Todo");
      menu.setTitle("View Todo");
    } else {
      listviewadapter = new ListViewAdapter(this, R.layout.listview_item, todoList.getTodoList());
      setTitle("Todo List");
      menu.setTitle("View Archive");
    }    
    list.setAdapter(listviewadapter);  
  }
  
  public void summary(MenuItem menu) {
    //set intent to SummaryActivity and start summary activity, passing todo and archive lists
    Intent intent = new Intent(MainActivity.this, SummaryActivity.class);
    intent.putExtra("todolist", todoList);
    intent.putExtra("todoarchive", todoArchive);
    startActivity(intent);
    
  }
  
  
    public void addTodo(View v) {
      
      // if edit mode is active (button indicates "Save") save EditText text to currently displayed
      // todo list, otherwise add a new todo to the list
    EditText newtext = (EditText) findViewById(R.id.editTodoText);
    Button editButton = (Button) findViewById(R.id.addButtonArchive);
    
    if (editButton.getText().toString() == "Save" && list.getCheckedItemCount() == 1) {
      // save edit text field text to selected list item
      SparseBooleanArray selected = listviewadapter.getSelectedIds();
      listviewadapter.getItem(selected.keyAt(0)).setTodoText(newtext.getText().toString());
      listviewadapter.notifyDataSetChanged();

    } else {
      //otherwise add a new todo item  to the current list
      if (newtext.length() > 0 ) {
        Todo newtodo = new Todo(false, newtext.getText().toString());
        listviewadapter.add(newtodo);
        newtext.setText("");
        listviewadapter.notifyDataSetChanged();
      }
    }
    //persist changed state to storage via TodoListFileManager class object
    cl = new CombinedList();
      cl.setTodolist(todoList);
      cl.setTodoarchive(todoArchive);
        todoFileManager.saveTodoList(cl);
    }
    
}

Java Source Code List

• Back to App/assignment  ↑