I'm trying to build a simple notes and checklist app. I'm using ActionBar tabs with Fragment for three sections 'Notes', 'Checklists' and 'Reminders'.
Now I am trying to make three individual sections for these tabs.
To make the section for 'Notes', I followed this google tutorial for a simple notepad. However, the tutorial uses ListActivity and ListView, and does not use Fragment Tabs.
You can see the source codes from the tutorial's link. (Notepadv3Solution is the one)
So I want to make similar notepad as shown in the tutorial but by putting it into the 'Notes' tab of my app.
I know we can use ListView with fragments along with SimpleCursorAdapter. So then, I followed this tutorial. The tutorial here uses a simple String Array to populate the list. The use of SimpleCursorAdapter is also shown there but I couldn't understand it.
I somehow got my app to display a ViewList using String Array on the tab 'Notes' without using database. Here's the FragmentNotes.java that handles the fragment:
package com.swifeen.organizo;
import android.database.Cursor;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import java.util.ArrayList;
public class FragmentNotes extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_notes_layout, container, false);
//super.onActivityCreated(savedInstanceState);
ListView lstItems = (ListView)v.findViewById(android.R.id.list);
String[] values = new String[] { "Android", "iPhone", "WindowsMobile",
"Blackberry", "WebOS", "Ubuntu", "Windows7", "Max OS X",
"Linux", "OS/2" };
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(),
android.R.layout.simple_list_item_1, values);
lstItems.setAdapter(adapter);
return v;
}
}
Finally, here's to the main question. I want to make a basic notepad section in the 'Notes' tab. I tried to mix up things from google's tutorial and the ones from vogella's tutorial. The following are the source codes I tried with. There is something wrong I've done in the FragmentNotes.java. It is supposed to display a ListView generating lists from database if available. If there's no data in the database, it should be displaying "No Notes Yet" as per the layout file.
FragmentNotes.java
package com.swifeen.organizo;
import android.database.Cursor;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
public class FragmentNotes extends Fragment {
private static final int ACTIVITY_CREATE=0;
private static final int ACTIVITY_EDIT=1;
private static final int INSERT_ID = Menu.FIRST;
private static final int DELETE_ID = Menu.FIRST + 1;
private NotesDbAdapter mDbHelper;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_notes_layout, container, false);
mDbHelper = new NotesDbAdapter(getActivity());
mDbHelper.open();
// Get all of the rows from the database and create the item list
Cursor notesCursor = mDbHelper.fetchAllNotes();
getActivity().startManagingCursor(notesCursor);
// Create an array to specify the fields we want to display in the list (only TITLE)
String[] from = new String[]{NotesDbAdapter.KEY_TITLE};
// and an array of the fields we want to bind those fields to (in this case just text1)
int[] to = new int[]{R.id.text1};
//super.onActivityCreated(savedInstanceState);
ListView lstItems = (ListView)v.findViewById(android.R.id.list);
SimpleCursorAdapter notes =
new SimpleCursorAdapter(getActivity(), R.layout.notes_row, notesCursor, from, to);
lstItems.setAdapter(notes);
return v;
}
}
Here are the other source code files:
AppSectionsPagerAdater.java
package com.swifeen.organizo;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
/**
* A {@link FragmentPagerAdapter} that returns a fragment corresponding to one of the primary
* sections of the app.
*/
public class AppSectionsPagerAdapter extends FragmentPagerAdapter {
public AppSectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int i) {
switch (i) {
case 0:
return new FragmentNotes();
case 1:
return new FragmentChecklists();
case 2:
return new FragmentReminders();
default:
return null;
}
}
@Override
public int getCount() {
return 3;
}
@Override
public CharSequence getPageTitle(int position) {
//return "Section " + (position + 1);
if(position==0) {
return "Notes";
}
else if(position==1){
return "Checklists";
}
else if(position==2) {
return "Reminders";
}
else{
return "Invalid";
}
}
}
MainActivity.java
package com.swifeen.organizo;
import android.app.ActionBar;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
public class MainActivity extends FragmentActivity implements ActionBar.TabListener {
/**
* The {@link android.support.v4.view.PagerAdapter} that will provide fragments for each of the
* three primary sections of the app. We use a {@link android.support.v4.app.FragmentPagerAdapter}
* derivative, which will keep every loaded fragment in memory. If this becomes too memory
* intensive, it may be best to switch to a {@link android.support.v4.app.FragmentStatePagerAdapter}.
*/
AppSectionsPagerAdapter mAppSectionsPagerAdapter;
/**
* The {@link ViewPager} that will display the three primary sections of the app, one at a
* time.
*/
ViewPager mViewPager;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Create the adapter that will return a fragment for each of the three primary sections
// of the app.
mAppSectionsPagerAdapter = new AppSectionsPagerAdapter(getSupportFragmentManager());
// Set up the action bar.
final ActionBar actionBar = getActionBar();
// Specify that the Home/Up button should not be enabled, since there is no hierarchical
// parent.
actionBar.setHomeButtonEnabled(false);
// Specify that we will be displaying tabs in the action bar.
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Set up the ViewPager, attaching the adapter and setting up a listener for when the
// user swipes between sections.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mAppSectionsPagerAdapter);
mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
// When swiping between different app sections, select the corresponding tab.
// We can also use ActionBar.Tab#select() to do this if we have a reference to the
// Tab.
actionBar.setSelectedNavigationItem(position);
}
});
// For each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mAppSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by the adapter.
// Also specify this Activity object, which implements the TabListener interface, as the
// listener for when this tab is selected.
actionBar.addTab(
actionBar.newTab()
.setText(mAppSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
@Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
@Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
// When the given tab is selected, switch to the corresponding page in the ViewPager.
mViewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
}
NotesDbAdapter.java
package com.swifeen.organizo;
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.util.Log;
public class NotesDbAdapter {
public static final String KEY_TITLE = "title";
public static final String KEY_BODY = "body";
public static final String KEY_ROWID = "_id";
private static final String TAG = "NotesDbAdapter";
private DatabaseHelper mDbHelper;
private SQLiteDatabase mDb;
/**
* Database creation sql statement
*/
private static final String DATABASE_CREATE =
"create table notes (_id integer primary key autoincrement, "
+ "title text not null, body text not null);";
private static final String DATABASE_NAME = "data";
private static final String DATABASE_TABLE = "notes";
private static final int DATABASE_VERSION = 2;
private final Context mCtx;
private static class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(DATABASE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS notes");
onCreate(db);
}
}
/**
* Constructor - takes the context to allow the database to be
* opened/created
*
* @param ctx the Context within which to work
*/
public NotesDbAdapter(Context ctx) {
this.mCtx = ctx;
}
/**
* Open the notes database. If it cannot be opened, try to create a new
* instance of the database. If it cannot be created, throw an exception to
* signal the failure
*
* @return this (self reference, allowing this to be chained in an
* initialization call)
* @throws SQLException if the database could be neither opened or created
*/
public NotesDbAdapter open() throws SQLException {
mDbHelper = new DatabaseHelper(mCtx);
mDb = mDbHelper.getWritableDatabase();
return this;
}
public void close() {
mDbHelper.close();
}
/**
* Create a new note using the title and body provided. If the note is
* successfully created return the new rowId for that note, otherwise return
* a -1 to indicate failure.
*
* @param title the title of the note
* @param body the body of the note
* @return rowId or -1 if failed
*/
public long createNote(String title, String body) {
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_TITLE, title);
initialValues.put(KEY_BODY, body);
return mDb.insert(DATABASE_TABLE, null, initialValues);
}
/**
* Delete the note with the given rowId
*
* @param rowId id of note to delete
* @return true if deleted, false otherwise
*/
public boolean deleteNote(long rowId) {
return mDb.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
}
/**
* Return a Cursor over the list of all notes in the database
*
* @return Cursor over all notes
*/
public Cursor fetchAllNotes() {
return mDb.query(DATABASE_TABLE, new String[] {KEY_ROWID, KEY_TITLE,
KEY_BODY}, null, null, null, null, null);
}
/**
* Return a Cursor positioned at the note that matches the given rowId
*
* @param rowId id of note to retrieve
* @return Cursor positioned to matching note, if found
* @throws SQLException if note could not be found/retrieved
*/
public Cursor fetchNote(long rowId) throws SQLException {
Cursor mCursor =
mDb.query(true, DATABASE_TABLE, new String[] {KEY_ROWID,
KEY_TITLE, KEY_BODY}, KEY_ROWID + "=" + rowId, null,
null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
/**
* Update the note using the details provided. The note to be updated is
* specified using the rowId, and it is altered to use the title and body
* values passed in
*
* @param rowId id of note to update
* @param title value to set note title to
* @param body value to set note body to
* @return true if the note was successfully updated, false otherwise
*/
public boolean updateNote(long rowId, String title, String body) {
ContentValues args = new ContentValues();
args.put(KEY_TITLE, title);
args.put(KEY_BODY, body);
return mDb.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0;
}
}
NoteEdit.java
package com.swifeen.organizo;
import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class NoteEdit extends Activity {
private EditText mTitleText;
private EditText mBodyText;
private NotesDbAdapter mDbHelper;
private Long mRowId;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mDbHelper = new NotesDbAdapter(this);
mDbHelper.open();
setContentView(R.layout.note_edit);
mTitleText = (EditText) findViewById(R.id.title);
mBodyText = (EditText) findViewById(R.id.body);
Button confirmButton = (Button) findViewById(R.id.confirm);
mRowId = (savedInstanceState == null) ? null :
(Long) savedInstanceState.getSerializable(NotesDbAdapter.KEY_ROWID);
if (mRowId == null) {
Bundle extras = getIntent().getExtras();
mRowId = extras != null ? extras.getLong(NotesDbAdapter.KEY_ROWID)
: null;
}
populateFields();
confirmButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
setResult(RESULT_OK);
finish();
}
});
}
private void populateFields() {
if (mRowId != null) {
Cursor note = mDbHelper.fetchNote(mRowId);
startManagingCursor(note);
mTitleText.setText(note.getString(
note.getColumnIndexOrThrow(NotesDbAdapter.KEY_TITLE)));
mBodyText.setText(note.getString(
note.getColumnIndexOrThrow(NotesDbAdapter.KEY_BODY)));
}
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
saveState();
outState.putSerializable(NotesDbAdapter.KEY_ROWID, mRowId);
}
@Override
protected void onPause() {
super.onPause();
saveState();
}
@Override
protected void onResume() {
super.onResume();
populateFields();
}
private void saveState() {
String title = mTitleText.getText().toString();
String body = mBodyText.getText().toString();
if (mRowId == null) {
long id = mDbHelper.createNote(title, body);
if (id > 0) {
mRowId = id;
}
} else {
mDbHelper.updateNote(mRowId, title, body);
}
}
}
And here are the XML codes:
activity_main.xml
<android.support.v4.view.ViewPager xmlns:android="http://ift.tt/nIICcg"
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
fragment_notes_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://ift.tt/nIICcg"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ListView android:id="@android:id/list"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<TextView android:id="@android:id/empty"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/no_notes"/>
</LinearLayout>
note_edit.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://ift.tt/nIICcg"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/title" />
<EditText android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"/>
</LinearLayout>
<TextView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/body" />
<EditText android:id="@+id/body" android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:scrollbars="vertical" />
<Button android:id="@+id/confirm"
android:text="@string/confirm"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
notes_row.xml
<?xml version="1.0" encoding="utf-8"?>
<TextView android:id="@+id/text1" xmlns:android="http://ift.tt/nIICcg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
Also, the other two sections 'checklists' and 'reminders' are just empty for now with some basic layout.
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