android开发的todo_list源代码

package com.paad.todolist; import java.sql.Date; import java.util.ArrayList; import android.app.Activity; import android.content.SharedPreferences; import android.database.Cursor; import android.os.Bundle; import android.view.ContextMenu; import android.view.KeyEvent; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.View.OnKeyListener; import android.widget.AdapterView; import android.widget.EditText; import android.widget.ListView; public class Todo_ListActivity extends Activity { private ArrayList<ToDoItem> todoItems; private ListView myListView; private EditText myEditText; private ToDoItemAdapter aa; private ToDoDBAdapter toDoDBAdapter; private Cursor toDoListCursor; private static final String TEXT_ENTRY_KEY="TEXT_ENTRY_KEY"; private static final String ADDING_ITEM_KEY="ADDING_ITEM_KEY"; private static final String SELECTED_INDEX_KEY="SELECTED_INDEX_KEY"; private boolean addingNew = false; // Define the new menu item identifiers static final private int ADD_NEW_TODO = Menu.FIRST; static final private int REMOVE_TODO = Menu.FIRST + 1; /** Called when the activity is first created. */ @Override public void onCreate(Bundle icicle) { super.onCreate(icicle); // Inflate your view setContentView(R.layout.main); // Get references to UI widgets myListView = (ListView)findViewById(R.id.myListView); myEditText = (EditText)findViewById(R.id.myEditText); // Create the Todo List ArrayList and Adapter and assign is to the ListView todoItems = new ArrayList<ToDoItem>(); aa = new ToDoItemAdapter(getApplicationContext(), R.layout.todolist_item, todoItems); myListView.setAdapter(aa); // Assign the KeyListener to the DPad button to add new items myEditText.setOnKeyListener(new OnKeyListener() { public boolean onKey(View v, int keyCode, KeyEvent event) { if (event.getAction() == KeyEvent.ACTION_DOWN) if (keyCode == KeyEvent.KEYCODE_ENTER) { // Add a new todo item and clear the input box. ToDoItem newItem=new ToDoItem(myEditText.getText().toString()); toDoDBAdapter.insertTask(newItem); updateArray(); //todoItems.add(0, newItem); myEditText.setText(""); aa.notifyDataSetChanged(); cancelAdd(); return true; } return false; } }); registerForContextMenu(myListView); restoreUIState(); toDoDBAdapter = new ToDoDBAdapter(this); // Open or create the database toDoDBAdapter.open(); populateTodoList(); } private void populateTodoList() { // TODO Auto-generated method stub toDoListCursor=toDoDBAdapter.getAllToDoItemsCursor(); startManagingCursor(toDoListCursor); updateArray(); } private void updateArray() { // TODO Auto-generated method stub toDoListCursor.requery(); todoItems.clear(); if (toDoListCursor.moveToFirst()) do { String task = toDoListCursor.getString(ToDoDBAdapter.TASK_COLUMN); long created = toDoListCursor.getLong(ToDoDBAdapter.CREATION_DATE_COLUMN); ToDoItem newItem = new ToDoItem(task, new Date(created)); todoItems.add(0, newItem); } while(toDoListCursor.moveToNext()); aa.notifyDataSetChanged(); } @Override protected void onPause(){ super.onPause(); SharedPreferences uiState=getPreferences(0); SharedPreferences.Editor editor=uiState.edit(); //添加ui状态首选项的值 editor.putString(TEXT_ENTRY_KEY, myEditText.getText().toString()); editor.putBoolean(ADDING_ITEM_KEY, addingNew); editor.commit(); } @Override public boolean onCreateOptionsMenu(Menu menu) { super.onCreateOptionsMenu(menu); // Create and add new menu items. MenuItem itemAdd = menu.add(0, ADD_NEW_TODO, Menu.NONE, R.string.add_new); MenuItem itemRem = menu.add(0, REMOVE_TODO, Menu.NONE, R.string.remove); // Assign icons itemAdd.setIcon(R.drawable.add_new_item); itemRem.setIcon(R.drawable.remove_item); // Allocate shortcuts to each of them. itemAdd.setShortcut('0', 'a'); itemRem.setShortcut('1', 'r'); return true; } @Override public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) { super.onCreateContextMenu(menu, v, menuInfo); menu.setHeaderTitle("Selected To Do Item"); menu.add(0, REMOVE_TODO, Menu.NONE, R.string.remove); } @Override public boolean onPrepareOptionsMenu(Menu menu) { super.onPrepareOptionsMenu(menu); int idx = myListView.getSelectedItemPosition(); String removeTitle = getString(addingNew ? R.string.cancel : R.string.remove); MenuItem removeItem = menu.findItem(REMOVE_TODO); removeItem.setTitle(removeTitle); removeItem.setVisible(addingNew || idx > -1); return true; } /** Process the options menu item selection */ @Override public boolean onOptionsItemSelected(MenuItem item) { super.onOptionsItemSelected(item); int index = myListView.getSelectedItemPosition(); switch (item.getItemId()) { case (REMOVE_TODO): { if (addingNew) { // If adding a new item, cancel this action cancelAdd(); } else { // If not adding a new item, remove the currently selected one. removeItem(index); } return true; } case (ADD_NEW_TODO): { // Add a new item addNewItem(); return true; } } return false; } /** Process the context menu item selection */ @Override public boolean onContextItemSelected(MenuItem item) { super.onContextItemSelected(item); switch (item.getItemId()) { case (REMOVE_TODO): { AdapterView.AdapterContextMenuInfo menuInfo = (AdapterView.AdapterContextMenuInfo)item.getMenuInfo(); int index = menuInfo.position; removeItem(index); return true; } } return false; } /** Cancel the action of adding a new todo list item */ private void cancelAdd() { addingNew = false; myEditText.setVisibility(View.GONE); } /** Present the text entry box for adding a new todo item */ private void addNewItem() { addingNew = true; myEditText.setVisibility(View.VISIBLE); myEditText.requestFocus(); } /** Remove the specified item from the todo list */ private void removeItem(int _index) { //todoItems.remove(_index); //aa.notifyDataSetChanged(); toDoDBAdapter.removeTask(todoItems.size()-_index); updateArray(); } private void restoreUIState(){ SharedPreferences settings=getPreferences(Activity.MODE_PRIVATE); String text=settings.getString(TEXT_ENTRY_KEY, ""); Boolean adding=settings.getBoolean(ADDING_ITEM_KEY, false); if(adding) { addNewItem(); myEditText.setText(text); } } @Override public void onSaveInstanceState(Bundle savedInstanceState) { savedInstanceState.putInt(SELECTED_INDEX_KEY, myListView.getSelectedItemPosition()); super.onSaveInstanceState(savedInstanceState); } @Override public void onRestoreInstanceState(Bundle savedInstanceState) { int pos = -1; if (savedInstanceState != null) if (savedInstanceState.containsKey(SELECTED_INDEX_KEY)) pos = savedInstanceState.getInt(SELECTED_INDEX_KEY, -1); myListView.setSelection(pos); } @Override public void onDestroy() { // Close the database toDoDBAdapter.close(); super.onDestroy(); } }