Lists, Views, Cursors, Exceptions, Dialogs, SQL in android
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WHY
Because now I have 2 smart phones which know java pretty good and I could do stuff with them .. this is just the beginning ! Run the program and look at the logcat to see what calls what in which order and with what params
HOW
src/helloworld.java
package tk.d3xt3r01;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.database.Cursor;
import android.os.Bundle;
import android.util.Log;
import android.view.ContextMenu;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.AdapterView.AdapterContextMenuInfo;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.View.OnCreateContextMenuListener;
public class helloworld extends Activity {
private static final String TAG = "d3x";
public long selected_id;
private static final int menu_add_a_number = Menu.FIRST;
private static final int menu_quit = Menu.FIRST + 2;
private static final int edit_this_number = Menu.FIRST + 3;
private static final int delete_this_number = Menu.FIRST + 4;
private DataBaseWork dh;
public void refresh(){
Cursor info = dh.selectAll();
startManagingCursor(info);
ListView list = (ListView) findViewById(R.id.lista);
ListAdapter lista = new SimpleCursorAdapter(this, R.layout.lista, info, new String[]{ "name", "number" }, new int[] {R.id.name, R.id.number} );
try {
list.setAdapter(lista);
}catch(Exception NullPointerExceptionError){
Log.e(TAG, "list.setAdapter(lista) made a boooboo. List: "+list+"; Lista: "+lista);
}
list.setOnCreateContextMenuListener(new OnCreateContextMenuListener() {
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
Log.i(TAG, "onCreateContextMenu();");
menu.setHeaderTitle("Action");
menu.add(0, delete_this_number, 0, R.string.delete_this_number);
menu.add(0, edit_this_number, 0, R.string.edit_this_number);
}
});
}
@Override
public void onCreate(Bundle savedInstanceState) {
Log.i(TAG, "onCreate();");
this.dh = new DataBaseWork(this);
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
refresh();
}
@Override
public void onDestroy(){
Log.i(TAG, "onDestroy();");
dh.close();
super.onDestroy();
}
@Override
public boolean onCreateOptionsMenu(Menu menu){
Log.i(TAG, "onCreateOptionsMenu();");
menu.add(0, menu_add_a_number, 0, R.string.menu_add_a_number);
menu.add(0, menu_quit, 0, R.string.menu_quit);
return(super.onCreateOptionsMenu(menu));
}
@Override
public boolean onOptionsItemSelected(MenuItem item){
Log.i(TAG, "onOptionsItemSelected("+item.getItemId()+");");
switch(item.getItemId()){
case menu_add_a_number:
showDialog(item.getItemId());
break;
case menu_quit:
super.finish();
break;
}
return super.onOptionsItemSelected(item);
}
@Override
public Dialog onCreateDialog(int id){
Dialog return_dialog = null;
switch(id){
case menu_add_a_number:
Log.i(TAG, "onCreateDialog(add_a_number " + id + ");");
LayoutInflater factory = LayoutInflater.from(this);
final View textEntryView = factory.inflate(R.layout.input_user, null);
final EditText name = (EditText) textEntryView.findViewById(R.id.name_edit);
final EditText number = (EditText) textEntryView.findViewById(R.id.telefon_edit);
final AlertDialog alertdialog = new AlertDialog.Builder(this)
.setTitle(R.string.menu_add_a_number)
.setView(textEntryView)
.setPositiveButton(R.string.ok_button, new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog, int i){
Log.i(TAG, "onCreateDialog(add_a_number " + i + "): Clicked on OK");
name.requestFocus();
dh.insert(name.getText().toString(), number.getText().toString());
Log.i(TAG, "Name: "+ name.getText().toString());
Log.i(TAG, "Number: "+ number.getText().toString());
name.setText("");
number.setText("");
refresh();
dialog.dismiss();
}
})
.setNegativeButton(R.string.cancel_button, new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog, int i){
Log.i(TAG, "onCreateDialog("+ i +"): Clicked on Cancel");
((EditText) textEntryView.findViewById(R.id.telefon_edit)).setText("");
((EditText) textEntryView.findViewById(R.id.name_edit)).setText("");
dialog.cancel();
}
}).create();
return_dialog = alertdialog;
break;
case edit_this_number:
Log.i(TAG, "onCreateDialog(edit_this_number " + id + ");");
LayoutInflater factory_edit = LayoutInflater.from(this);
final View textEntryView_edit = factory_edit.inflate(R.layout.input_user, null);
final EditText name_edit = (EditText) textEntryView_edit.findViewById(R.id.name_edit);
final EditText number_edit = (EditText) textEntryView_edit.findViewById(R.id.telefon_edit);
final AlertDialog alertdialog_edit = new AlertDialog.Builder(this)
.setTitle(R.string.edit_this_number)
.setView(textEntryView_edit)
.setPositiveButton(R.string.ok_button, new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog, int i){
Log.i(TAG, "onCreateDialog(edit_this_number " + i + "): Clicked on OK");
name_edit.requestFocus();
dh.update(selected_id, name_edit.getText().toString(), number_edit.getText().toString());
refresh();
dialog.dismiss();
}
})
.setNegativeButton(R.string.cancel_button, new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog, int i){
Log.i(TAG, "onCreateDialog("+ i +"): Clicked on Cancel");
((EditText) textEntryView_edit.findViewById(R.id.telefon_edit)).setText("");
((EditText) textEntryView_edit.findViewById(R.id.name_edit)).setText("");
dialog.cancel();
}
}).create();
return_dialog = alertdialog_edit;
break;
}
return return_dialog;
}
@Override
public void onPrepareDialog(final int id, Dialog dialog){
Log.i(TAG, "onPrepareDialog("+id+");");
switch(id){
case edit_this_number:
Log.i(TAG, "onPrepareDialog(edit_this_number + "+id+" + SQL: "+selected_id+");");
Cursor selected = dh.select(selected_id);
try{
((EditText) dialog.findViewById(R.id.name_edit)).setText(selected.getString(1));;
((EditText) dialog.findViewById(R.id.telefon_edit)).setText(selected.getString(2));;
}catch(NullPointerException e){
Log.e(TAG, "Error setting stuff in the dialog: "+selected.getString(1)+", "+selected.getString(2));
}
selected.close();
break;
}
}
@Override
public boolean onContextItemSelected(MenuItem aItem) {
Log.i(TAG, "onContextItemSelected();");
AdapterContextMenuInfo menuInfo = (AdapterContextMenuInfo) aItem.getMenuInfo();
long id = menuInfo.id;
switch (aItem.getItemId()){
case edit_this_number:
Log.i(TAG, "onContextItemSelected(edit_this_number + SQL:" + id + ");");
selected_id = id;
showDialog(edit_this_number);
break;
case delete_this_number:
Log.i(TAG, "onContextItemSelected(delete_this_number + SQL:" + id + ");");
dh.delete(menuInfo.id);
refresh();
break;
}
return false;
}
}
src/DataBaseWork.java
package tk.d3xt3r01;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteStatement;
import android.util.Log;
public class DataBaseWork {
private static final String DATABASE_NAME = "d3x";
private static final String TABLE_NAME = "users";
private static final int DATABASE_VERSION = 1;
private Context context;
private SQLiteDatabase db;
private SQLiteStatement insertStatemet;
private SQLiteStatement deleteStatemet;
private static final String INSERT = "insert into " + TABLE_NAME + "(name,number) values (?,?)";
private static final String DELETE = "delete from " + TABLE_NAME + " WHERE _id = ?";
private static final String TAG = "d3x";
public DataBaseWork(Context context) {
this.context = context;
OpenHelper openHelper = new OpenHelper(this.context);
this.db = openHelper.getWritableDatabase();
Log.i(TAG, "DataBaseWork("+INSERT+");");
this.insertStatemet = this.db.compileStatement(INSERT);
Log.i(TAG, "DataBaseWork("+DELETE+");");
this.deleteStatemet = this.db.compileStatement(DELETE);
}
public long insert(String name, String number){
Log.i(TAG, "insert("+name+", "+number+");");
this.insertStatemet.bindString(1, name);
this.insertStatemet.bindString(2, number);
return this.insertStatemet.executeInsert();
}
public Cursor select(long id){
Log.i(TAG, "select("+id+");");
Cursor selected = null;
try {
selected = this.db.query(TABLE_NAME, new String[] { "_id", "name", "number" }, "_id = "+id, null, null, null, null);
selected.moveToFirst();
}catch(SQLException e){
Log.i(TAG, "Error on select query for "+e.toString());
}
return selected;
}
public void update(long id, String name, String number){
Log.i(TAG, "update("+id+", "+name+", "+number+");");
ContentValues update_entry = new ContentValues();
update_entry.put("name", name);
update_entry.put("number", number);
this.db.update(TABLE_NAME, update_entry, "_id = "+id, null);
}
public void delete(long id){
Log.i(TAG, "delete("+id+");");
this.deleteStatemet.bindString(1, Long.toString(id));
this.deleteStatemet.execute();
}
public void deleteAll() {
Log.i(TAG, "deleteAll();");
this.db.delete(TABLE_NAME, null, null);
}
public Cursor selectAll() {
Log.i(TAG, "selectAll();");
return(this.db.query(TABLE_NAME, new String[] { "name", "number", "_id" }, null, null, null, null, "name asc"));
}
public void close(){
db.close();
}
private static class OpenHelper extends SQLiteOpenHelper {
OpenHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
Log.i(TAG, "OpenHelper();");
}
@Override
public void onCreate(SQLiteDatabase db) {
String create_query = "CREATE TABLE " + TABLE_NAME + " (_id INTEGER PRIMARY KEY autoincrement, name TEXT, number TEXT)";
Log.i(TAG, "onCreate("+create_query+")");
db.execSQL(create_query);
db.setVersion(DATABASE_VERSION);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.i(TAG, "Upgrading database, this will drop tables and recreate.");
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
}
}res/values/strings.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">Hello World</string>
<!--
Menu options
-->
<string name="menu_add_a_number">Add a number</string>
<string name="menu_quit">Quit</string>
<!--
Input user layout texts
-->
<string name="name_edit">Name:</string>
<string name="telefon_edit">Phone:</string>
<!--
Context Menu texts
-->
<string name="edit_this_number">Edit this number</string>
<string name="delete_this_number">Delete this number</string>
<!--
Various Texts
-->
<string name="cancel_button">Cancel</string>
<string name="ok_button">Ok</string>
</resources>
res/layout/main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<ListView android:id="@+id/lista"
android:layout_width="fill_parent"
android:layout_height="0px"
android:layout_weight="1"
android:cacheColorHint="#00000000">
</ListView>
</LinearLayout>
res/layout/input_user.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:textSize="24px"
android:text="@string/name_edit"/>
<EditText android:id="@+id/name_edit"
android:textColor="#020905"
android:textSize="18sp"
android:layout_marginTop="6px"
android:layout_marginBottom="8px"
android:layout_marginLeft="12px"
android:layout_marginRight="12px"
android:layout_width="210px"
android:layout_height="wrap_content"
android:text=""
android:layout_weight="1"/>
</LinearLayout>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="24px"
android:text="@string/telefon_edit"/>
<EditText android:id="@+id/telefon_edit"
android:textColor="#020905"
android:textSize="18sp"
android:layout_marginTop="6px"
android:layout_marginBottom="8px"
android:layout_marginLeft="12px"
android:layout_marginRight="12px"
android:layout_width="210px"
android:layout_height="wrap_content"
android:text=""
android:phoneNumber="true"
android:layout_weight="1"/>
</LinearLayout>
</LinearLayout>
res/layout/lista.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView android:id="@+id/name"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="22px" />
<TextView android:id="@+id/number"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
</LinearLayout>