I have a view with a button and a list view backed by a cursor adapter containing bindView() and newView() for customized views. Each row of a list contains a Text and a checkbox. The data for each view comes from the database. I'm passing my Database adapter in the cursor adapter constructor. This I use to update the database when a checkbox is check or unchecked (works well). Of course I run "re-query" on cursor and view.refreshDrawableState()). Is this a good idea? What would be a better solution?
Second problem more serious, when a Button is clicked it starts a new activity. After hitting the back button from the new activity I get back my list View. But when I try to click on the checkbox this time I get Database close exception. Why? How do I fix this error?
Following is the list view and code snippet.
Button --------> Starts a new activity
CheckBox | TextView
CheckBox | TextView
MyActivity.java
onCreate() {
...
Button add_item_btn = (Button) findViewById(R.id.add_item_btn_id);
add_item_btn.setOnclickListener(new OnClickListener() {
//Start a new activity
});
}
protected void onPause() {
adapter.close();
mCursor.close();
}
protected void onResume() {
mListView = getListView();
adapter = new DBAdapter(getApplication());
adapter.open();
mCursor = adapter.getAllItems();
mCustomAdapter = new MyCursorAdapter(MyActivity.this, mCursor, adapter);
mListView.setAdapter(mCustomAdapter);
}
MyCursorAdapter.java
public class MyCursorAdapter extends CursorAdapter {
Cursor mCursor;
DBAdapter adapter;
public MyCursorAdapter(Context context, Cursor c, DBAdapter _adapter) {
...
mCursor = c;
adapter = _adapter;
}
public void bindView(final View view, Context context, final Cursor cursor) {
final CheckBox itemStatusCB = (CheckBox)
view.findViewById(R.id.item_status_id);
idx = cursor.getColumnIndex(myItem.ITEM_STATUS);
final long itemStatus = cursor.getLong(idx);
if (itemStatus == 1) {
itemStatusCB.setChecked(true);
} else {
itemStatusCB.setChecked(false);
}
itemStatusCB.setOnClickListener(new OnClickListener() {
#Override public void onClick(View v) {
int newStatus = 0;
if (((CheckBox) v).isChecked()) {
newStatus = 1;
}
adapter.updateItemStatus(itemId, newStatus);
mCursor.requery();
view.refreshDrawableState();
});
}
}
}
I was able to solve this. The new activity which was called had a DB connection open on onStart() and DB close on onDestroy(). After returning from that activity I was getting Database Illegal state Exception error as described with stack trace. I think it was returning cached version of DB connection. Once I removed DB.close() from the guest activity, it stopped issuing database not open error. Normally you would think that every activity can open a DB connection in it's onResume() or onStart() and close it in it's onPause() or onStop() or onDestroy() and it won't affect the connection across activities. Does this Make sense?
Related
I have written a program to add mobile no into my sqlite database on a button click which is working properly , I am also using a listview to show the data added for which I am using a CustomCursorLoader class to query my results .
The problem which I am facing is , suppose I have nothing in my database so the cursor count is 0 but when I insert a data for the first time , the cursor count should become 1 but it shows 0 , and then again when I insert another data at that moment i am getting cursor count as 1 but the data which was previously inserted is being shown in the listview
Posting my code
public class Home_Page extends Activity implements
LoaderManager.LoaderCallbacks<Cursor> {
DriverStatusAdapter driverStatusAdapter;
ListView listDriverId;
private static final int URL_LOADER = 0;
CustomCursorLoader loader = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
try{
dbListHelper = new DriverSqliteHelper(getBaseContext());
dbListHelper.open(getBaseContext());
}catch (Exception e){
e.printStackTrace();
}
String[] columns = new String[]
{DriverSqliteHelper.DbListHelper.DRIVER_USER_ID};
int[] to = new int[]{R.id.DriverId};
driverStatusAdapter = new DriverStatusAdapter(getBaseContext(),
R.layout.view_userid_item,null,columns,to,0);
listDriverId = (ListView) findViewById(R.id.driverIDList);
listDriverId.setAdapter(driverStatusAdapter);
registerForContextMenu(listDriverId);
Log.i("LoaderManager", "Started on activity start");
getLoaderManager().initLoader(0, null, Home_Page.this);
txtAdd.setOnClickListener(new View.OnClickListener() {
String userId = edtUserId.getText().toString();
if (userId.equals(""))
{
Snackbar snackbar = Snackbar.make(coordinatorLayout, "Please
enter user id", Snackbar.LENGTH_LONG);
View sbView = snackbar.getView();
TextView textView = (TextView)
sbView.findViewById(android.support.design.R.id.
snackbar_text);
snackbar.show();
}
else{
sendUserStatus(); ///// method to send mobile no to server
//// if status received from server is ok then i am inserting
////the data into the database
Log.i("LoaderManager", "Restarted on button click");
getLoaderManager().restartLoader(0, null, Home_Page.this);
}
#Override
public Loader<Cursor> onCreateLoader(int i, Bundle bundle) {
switch (i){
case URL_LOADER:
Log.i("Case URL Loader", "Custom Cursor Loader called");
loader = new CustomCursorLoader(getBaseContext());
return loader;
default:
Log.i("Case default", "Default Case called");
return null;
}
}
#Override
public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) {
Log.i("LoaderManager", "Finished load entry... - Cursor: " +
cursor.getCount());
this.loader = (CustomCursorLoader)loader;
driverStatusAdapter.changeCursor(cursor);
}
#Override
public void onLoaderReset(Loader<Cursor> loader) {
Log.i("LoaderManager", "Resetting loader...");
driverStatusAdapter.changeCursor(null);
}
}
CustomCursorLoader.java
public class CustomCursorLoader extends CursorLoader{
Context context;
DriverSqliteHelper driverSqliteHelper;
Cursor cursor;
public CustomCursorLoader(Context context) {
super(context);
try {
driverSqliteHelper = new DriverSqliteHelper(context);
driverSqliteHelper.open(context);
}catch (Exception e){
e.printStackTrace();
}
}
public Cursor loadInBackground(){
cursor = driverSqliteHelper.getDriverStatus();
return cursor;
}
}
My Logcat
I/LoaderManager﹕ Started on activity start
I/Case URL Loader﹕ Custom Cursor Loader called
I/LoaderManager﹕ Finished load entry... - Cursor: 2
********on my first button click ********
I/LoaderManager﹕ Restarted on button click
I/Case URL Loader﹕ Custom Cursor Loader called
I/LoaderManager﹕ Finished load entry... - Cursor: 2
********* on my second button click ********
I/LoaderManager﹕ Restarted on button click
I/Case URL Loader﹕ Custom Cursor Loader called
I/LoaderManager﹕ Finished load entry... - Cursor: 3
I want my cursor count to change on first button click itself , can anyone suggest me what changes do i need to make ?
Ok i have found the solution myself , i put the getLoaderManager().restartLoader(0, null, Home_Page.this); inside sendUserStatus() method where i am also inserting the data.
Now the cursor count is incrementing and the listview is also getting updated automcatically
I have one small problem, after i click on list item, checkbox on item dont change state. Update works perfectly, setChecked maybe, but change will appear after exiting and re-running activity. I read lot of about notifyDataSetChange(), it may work, but not. How can i fix it, like after click on item chechbox value will change.
public class SviatokPridajActivity extends Activity
{
private DatabaseOp mDbHelper;
ListView listview;
String username;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.sviatok_pridaj);
this.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
listview = (ListView) findViewById(R.id.listSviatok);
showUserSettings();
mDbHelper = new DatabaseOp(this);
mDbHelper.open();
Cursor sviatokCursor = mDbHelper.fetchAllSviatokNastav(username, 3);
if (sviatokCursor.getCount()==0)
{
mDbHelper.naplnSviatky(username);
sviatokCursor = mDbHelper.fetchAllSviatokNastav(username, 3);
}
final SviatokCursorAdapter adapter = new SviatokCursorAdapter(this, sviatokCursor);
listview.setAdapter(adapter);
listview.setOnItemClickListener(new OnItemClickListener()
{
#Override
public void onItemClick(AdapterView<?> arg0, View arg1, int stlpec, long arg3)
{
// TODO Auto-generated method stub
Cursor cur = (Cursor) adapter.getItem(stlpec);
String odosli = cur.getString(cur.getColumnIndex("_id"));
String zobraz = cur.getString(cur.getColumnIndex("dlzka"));
CheckBox check = (CheckBox)findViewById(R.id.checkBox);
if (Integer.parseInt(zobraz)==0)
{
mDbHelper.updateSviatok(odosli, username, 1);
} else {
mDbHelper.updateSviatok(odosli, username, 0);
}
check.setChecked(!check.isChecked());
adapter.notifyDataSetChanged();
}
});
}
#Override
public void onPause()
{
super.onPause();
mDbHelper.close();
}
private void showUserSettings()
{
SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(this);
username = sharedPrefs.getString("prefUsername", "NULL");
}
}
you have checked your CheckBox in itemclick but it's not reflected to your itemList so before calling adapter.notifyDataSetChanged(); you should have to refresh listItems with new changes.
I ve answered this question in this : https://stackoverflow.com/a/22954806/1332870
can you check it? if it does not solve your problem please let me know
Reload your Cursor and instead of adapter.notifyDataSetChanged(); use adapter.changeCursor(reloadedCursor);
Not sure if this is a strain on the main thread but you could just set the adapter again in the on click method.
i have a Main activity which has a list view.
the listview items are loaded with LoaderManager.
when i click an item in the listview i open another activity that shows more information
(with "startActivityForResult")
the problem is :
when i go back(using the return key on) from the activity that shows information to the main activity and then click again i get an exception - Attempt to re-open an already closed object.
but if i go back from that activity(that shows more information) with a Button that i made there(which is actually "finish()") to the main activity and then cllick again then i get no exception
anyone knows what is the problem?
Thanks !
private void display_listview()
{
// create an adapter from the SimpleCursorAdapter
dataAdapter = new SimpleCursorAdapter(
this,
R.layout.row_invite_layout,
null,
columns,
to,
0);
// Assign adapter to ListView
listView.setAdapter(dataAdapter);
//Ensures a loader is initialized and active.
getSupportLoaderManager().initLoader(0, null, this);
//add implementation to listview item click
listView.setOnItemClickListener(new OnItemClickListener()
{
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id)
{
Cursor cursor = (Cursor) listView.getItemAtPosition(position);
IInvite invite = LoadFromCursor(cursor);
cursor.close();
mUpdateFlag = true;
if(!mTrashFlag) // Trash Can is turned off
{
Intent intent = new Intent(getApplicationContext(), InviteViewActivity.class);
intent.putExtra("invite",(Invite)invite);
startActivityForResult(intent, INVITE_REQUEST_ID);
}
else // Trash Can is turned on
{
getContentResolver().delete(InviteContentProvider.CONTENT_URI, SQLdataHelper.KEY_ROWID+"="+invite.getID(), null);
ExtraDelete(invite);
getSupportLoaderManager().getLoader(0).forceLoad();
}
}
});
}
#Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data)
{
// Swap the new cursor in. (The framework will take care of closing the
// old cursor once we return.)
dataAdapter.swapCursor(data);
}
#Override
public void onLoaderReset(Loader<Cursor> loader)
{
dataAdapter.swapCursor(null);
}
#Override
public Loader<Cursor> onCreateLoader(int id, Bundle args)
{
String[] projection = {
SQLdataHelper.KEY_ROWID,
SQLdataHelper.INVITE_CLIENT_ID,
SQLdataHelper.INVITE_CREATION_DATE,
SQLdataHelper.INVITE_NAME,
SQLdataHelper.INVITE_NOTE,
SQLdataHelper.INVITE_REQUESTED_DATE,
SQLdataHelper.INVITE_TOTAL_PRICE,
SQLdataHelper.INVITE_STATUS
};
CursorLoader cursorLoader = new CursorLoader(this,
InviteContentProvider.CONTENT_URI, projection, null, null, null);
return cursorLoader;
}
UPDATE: FIXED IT. i added this method to my main activity..
#Override
public void onResume()
{
super.onResume();
getSupportLoaderManager().getLoader(0).forceLoad();
}
You can do it by creating public static fields, but I wouldn't recomend it. You can store data in shared preferences and then retrieve it whenever you want.
I'm currently facing a stupid issue. I've a listview with a custom adapter (extending CursorAdapter).
It displays a custom view with different buttons (share, like, delete). For the delete button, it has an alertdialog to confirm the removal of the item. When the user confirms, the item is deleted from the db. Everything works fine until here.
My question is, how can I update my listview efficiently with my new dataset?
Thanks a lot for your help.
Code:
public class CommentCursorAdapter extends CursorAdapter{
(...)
#Override
public void bindView(View view, Context arg1, Cursor cursor) {
(...)
holder.list_item_comment_discard_btn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
final String _id = v.getTag().toString();
AlertDialog.Builder builder = new AlertDialog.Builder(mActivity);
builder.setTitle("Delete");
builder.setMessage("Do you want to delete "+_id);
builder.setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// User clicked OK button
DBAdapter dba = new DBAdapter(mActivity);
dba.open();
dba.remove(_id);
Log.i("TAAG", "removed: "+_id);
dba.close();
// How to update the listview ??
}
});
builder.setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// User cancelled the dialog
}
});
AlertDialog d = builder.create();
d.show();
}
});
holder.list_item_comment_discard_btn.setTag(_id);
(...)
}
(...)
}
If you use LoaderManager to manage the lifecycle of your cursors (that is the right way to do this) you need only to call restartLoader and then (re)set the cursor of your adapter in onLoadFinished. Your listview will be reloaded with updated data.
The management of a cursor in your activity or fragment should be done in a very simple and straightforward way:
In order to initialize your cursor:
public void onCreate(Bundle savedInstanceState) { // or onStart
// ...
this.getLoaderManager().initLoader(MY_CURSOR_ID, null, this);
// ...
}
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
// TODO: create a cursor loader that will load your cursor here
}
public void onLoadFinished(Loader<Cursor> arg0, final Cursor arg1) {
// TODO: set your cursor as the cursor of your adapter here;
}
public void onLoaderReset(Loader<Cursor> arg0) {
// TODO: set null as the cursor of your adapter and 'free' all cursor
// references;
}
And then, when you need to reload your data:
this.getLoaderManager().restartLoader(MY_CURSOR_ID, null, this);
Call
cursor.requery();
notifyDataSetChanged();
.
If you want real performance use the AsyncTaskLoader.
Just requery the Cursor like this:
public void onClick(DialogInterface dialog, int id) {
// User clicked OK button
DBAdapter dba = new DBAdapter(mActivity);
dba.open();
dba.remove(_id);
Log.i("TAAG", "removed: "+_id);
dba.close();
cursor.requery();
notifyDataSetChanged();
}
and then call notifyDataSetChanged() to tell the Adapter that the data has changed, and it has to build the adapter again.
This will be an intense operation if the requery takes long. Consider doing it in another thread.
After you delete the item in the DB, call notifyDataSetChanged on your CommentCursorAdapter, granted with this anonymous inner class you are using you will need a final reference to this since this in inside your CursorAdapter. This should trigger a refresh of your ListView.
http://developer.android.com/reference/android/widget/BaseAdapter.html#notifyDataSetChanged()
I am using a ListFragment for displaying a list from a database in my activity. I have included a search function. Unfortunately the "old" ListFragments seem to remain in the background and the ListFragments containing the result of the query are displayed on top of it. How can I avoid, that the old ListFragments are displayed?
My FragmentActivity:
private Button buttonSearch;
private TextView searchString;
public static String search = null;
static IShoppinglist shoppinglistManager;
static IAktionen aktionenManager;
private AktionenListListFragment listFragment;
#Override
public void onCreate(Bundle savedInstanceState) {
Log.d(TAG, "ListFragmentActivity created");
super.onCreate(savedInstanceState);
setContentView(R.layout.articlelist);
shoppinglistManager = new Shoppinglist(this);
aktionenManager = new Aktionen(this);
buttonSearch = (Button) findViewById(R.id.search_Button);
buttonSearch.setOnClickListener(searchListAktionen);
//show all entries on start
listFragment = new AktionenListListFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_articlelist, listFragment).commit();
}
OnClickListener searchListAktionen = new OnClickListener() {
public void onClick(View v) {
try{
searchString = (TextView) findViewById(R.id.input_search_bezeichnung);
search = searchString.getText().toString().trim();
Log.d(TAG, "search Button clicked "+search);
if(search.trim().length()==0){
search=null;
}
//show all entries on start
listFragment = new AktionenListListFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_articlelist, listFragment).commit();
}catch(Exception ex){
ex.printStackTrace();
}
}
};
Thanks in advance,
update:
thank you for your answers. I tried to implement them, but the main problem seems to be nowthat the onCreate and onActivityCreated method in the ListFragment are called twice (as I can see in my log messages).
my new code:
#Override
public void onCreate(Bundle savedInstanceState) {
Log.d(TAG, "ListFragmentActivity created");
super.onCreate(savedInstanceState);
//force commit
getSupportFragmentManager().executePendingTransactions();
if(getSupportFragmentManager().findFragmentByTag(tag) == null) {
setContentView(R.layout.articlelist);
shoppinglistManager = new Shoppinglist(this);
aktionenManager = new Aktionen(this);
buttonSearch = (Button) findViewById(R.id.search_Button);
buttonSearch.setOnClickListener(searchListAktionen);
listFragment = new AktionenListListFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_articlelist, listFragment,tag).commit();
}else{
Log.d(TAG, "ListFragment already exists");
}
}
I tried to set a unique tag for my ListFragment but this solution does not work.
I guess that one of the ListFragments is displayed in the background and the other is updated.
So first you need to stop making new ListFragments everytime your list is refreshed and just have a public method in your ListFragment that the Activity can call to restart the loader with the proper parameters. Then:
In your onLoadFinished(),
you should make a new adapter with the list you want to replace it with
myAdapter = new AktionenListCustomCursorAdapter(getActivity(), myCursor);
and call:
this.getListView().setAdapter(myAdapter);
So:
public void onLoadFinished(Loader<Cursor> mAdapter, Cursor myCursor) {
if(myCursor!=null){
//getting the data from the database
Log.d(TAG, "search String "+AktionenListFragmentActivity.search);
if(AktionenListFragmentActivity.search==null){
myCursor = AktionenListFragmentActivity.aktionenManager.fetchAllArticles();
}else{
myCursor = AktionenListFragmentActivity.aktionenManager.fetchItemsByBezeichnung(AktionenListFragmentActivity.search);
}
myAdapter = new AktionenListCustomCursorAdapter(getActivity(), myCursor);
this.getListView().setAdapter(myAdapter);
}
}
Hopefully this solved your question as I understood it. If you have any questions please leave it in the comment below and I will expand my answer. If it worked for you please accept answer. :D