Is there any way to manually update cursor's item value from the setViewValue code? Currently I just fetch all records again and then changeCursor and notifyDataSetChanged, but it is very slow:
dbHelper = new DbAdapter(this);
dbHelper.open();
recordsCursor = dbHelper.fetchAllRecords();
startManagingCursor(recordsCursor);
String[] from = new String[]{DbAdapter.KEY_1, DbAdapter.KEY_2};
int[] to = new int[]{R.id.text1, R.id.background};
adapter = new SimpleCursorAdapter(this, R.layout.row, recordsCursor, from, to);
if (adapter != null) {
adapter.setViewBinder(new SimpleCursorAdapter.ViewBinder() {
#Override
public boolean setViewValue(View view, Cursor cursor, int columnIndex) {
int viewId = view.getId();
switch(viewId) {
case R.id.text1:
final Object item = adapter.getItem(cursor.getPosition());
...
// some logic is here, so the code below is run only when item is displayed for 5 seconds
dbHelper.open();
Boolean result = dbHelper.markRecordAsRead(text); // update the database
...
// the code below works, but since I read the whole database, it is SLOW
dbHelper.open();
recordsCursor = dbHelper.fetchAllRecords();
adapter.changeCursor(recordsCursor);
adapter.notifyDataSetChanged();
// is there any way just to update the cursor's item value?
Related
i have a list view filled with data coming from database, i want when i click on an item to
disappear, i used --list.remove(position)-- but i have an error add cast to list.
HERE the list view :
private void populateListViewFromDB() {
Cursor cursor = db.getAllRecords();
startManagingCursor(cursor);
String[] databaseColumnNames = new String[] { DBAdapter.col_Region };
int[] toViewIDs = new int[] { android.R.id.text1, android.R.id.text2 };
SimpleCursorAdapter myCursordapter = new SimpleCursorAdapter(this,
android.R.layout.simple_expandable_list_item_1, cursor,
databaseColumnNames, toViewIDs, FLAG_REGISTER_CONTENT_OBSERVER);
final ListView list = (ListView) findViewById(android.R.id.list);
list.setAdapter(myCursordapter);
HERE my code when i want to delete an item :
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(final AdapterView<?> arg0, View arg1,
final int position, long arg3) {
list.remove(position);
adapter.notifyDataSetChanged();}
There is no ListView.remove() method. You should remove correspondent item from the data model and then refresh your adapter.
In your OnItemClickListener listener get the bound data item:
Object itemObj = adapter.getItem(position);
Then, delete this item from your DB.
Then get new instance of your cursor and update your cursor adapter:
if (android.os.Build.VERSION.SDK_INT > android.os.Build.VERSION_CODES.GINGERBREAD){
adapter.swapCursor(newCurosr);
} else {
adapter.changeCursor(newCursor);
}
Then, notify your list view about data changes:
adapter.notifyDataSetChanged();
I have a ListView with android:choiceMode="multipleChoice". I fill this ListView from a Cursor through a SimpleCursorAdapter. Is there really no way to directly bind the "CheckBox" of the ListView's CheckedTextView layout to a boolean value from the cursor?
Currently I loop through the cursor calling ListView.setItemChecked() if the value is true:
private void showMyData(long myId) {
// fill the list
String[] fromColumns = { "myTextColumn" };
int[] toViews = { android.R.id.text1 };
Cursor myCursor = _myData.readData(myId);
CursorAdapter myAdapter = new SimpleCursorAdapter(this,
android.R.layout.simple_list_item_multiple_choice,
myCursor, fromColumns, toViews);
ListView myListView = (ListView) findViewById(R.id.myListView);
myListView.setAdapter(myAdapter);
// mark items that include the object specified by myId
int myBooleanColumnPosition = myCursor
.getColumnIndex("myBooleanColumn");
for (int i = 0; i < myCursor.getCount(); i++) {
myCursor.moveToPosition(i);
if (myCursor.getInt(myBooleanColumnPosition ) == 1) {
myListView.setItemChecked(i, true);
}
}
}
That does the job. But I would like to have code like this:
String[] fromColumns = { "myTextColumn", "myBooleanColumn" };
int[] toViews = { android.R.id.text1, android.R.id.Xyz };
and have no loop. Am I missing something here or is it Android?
EDIT:
I tried this as suggested by Luksprog:
public boolean setViewValue(View view, Cursor cursor,
int columnIndex) {
CheckedTextView ctv = (CheckedTextView) view;
ctv.setText(cursor.getString(cursor
.getColumnIndex("myTextColumn")));
if (cursor.getInt(cursor.getColumnIndex("myBooleanColumn")) == 1) {
ctv.setChecked(true);
Log.d("MY_TAG", "CheckBox checked");
}
return true;
}
That logged checking the CheckBox but didn't actually do it. Maybe that's a bug on my side. And while it's even more complicated than the initial loop at least it feels like one is using the framework, not working against it. So thank you Luksprog for the answer.
But to sum it up: Android is actually missing the straight forward approach.
Use a SimpleCursorAdapter.ViewBinder on your adapter. Make sure your Cursor has the boolean values column in it and then:
String[] fromColumns = { "myTextColumn" };
int[] toViews = { android.R.id.text1 };
Cursor myCursor = _myData.readData(myId);
CursorAdapter myAdapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_multiple_choice, myCursor, fromColumns, toViews);
myAdapter.setViewBinder(new ViewBinder() {
public boolean setViewValue (View view, Cursor cursor, int columnIndex) {
// set the text of the list row, the view parameter (simple use cursor.getString(columnIndex))
// set the CheckBox status(the layout used in the adapter is a CheckedTextView)
return true;
}
});
I am using database in my application,in that i have fetched data from database,but i dont know how to display it in the textview.
Here is my code:
super.onCreate(savedInstanceState);
setContentView(R.layout.report);
db.open();
Cursor c = db.getAllTitles();
startManagingCursor(c);
String[] from = new String[] { db.KEY_INCOME };
int[] to = new int[] { R.id.textView1 };
SimpleCursorAdapter notes =
new SimpleCursorAdapter(this, R.layout.report, c, from, to);
Here the notes have the database value.But don't know how to proceed how to display it in listview.
do like this
String[] titles= new String[] {c.TITLE };
int[] view = new int[] { R.id.textview };
SimpleCursorAdapter mAdapter = new SimpleCursorAdapter(this, R.layout.list_example_entry, c, titles, view );
listview.setAdapter(notes);
You need to find your listview and set your adapter. (Assuming you are not using a ListActivity)
ListView list = (ListView) this.findViewById(R.id.yourlistview);
list.setAdapter(notes);
If you are using a ListActivity (or ListFragment), it's even simpler as the framework assumes you are using a certain id and you can just set the adapter like so:
setListAdapter(notes);
if you want to set set Tesxt on list item click you can do iy like
#Override
protected void onListItemClick(ListView l, View v, int position, long id) {
Cursor c = (Cursor) arg0.getAdapter().getItem(arg2);
tv.setTextt(c.getString(1));
}
Ok, so this has been somewhat addressed alot on this site, however I do not believe the exact problem with what my code uses. I am filling a listView with CheckedTextViews which works completely. However when I click on an item it gets checked but when I scroll up and down random rows are also checked. I realize it must have something to do with how the ListView keeps track of the items. I am running into some errors at the moment. I attempted to fill a hashmap with the list of the rows so I can keep track which one is set to true and which are false. However I am not positive where to implement the map and try to fill it.
Here is my OnCreate
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.viewmenu);
//Get table name of menu clicked.
Bundle extras = getIntent().getExtras();
tableName = extras.getString("table");
// map each contact's name to a TextView in the ListView layout
String[] from = new String[] { "name" };
int[] to = new int[] { R.id.toppingCheckedTextView };
for(int i=0; i< from.length; i++){
map.put(i, false);
}
contactAdapter = new SimpleCursorAdapter(
ViewToppingListing.this, R.layout.toppings_list_item, null, from, to);
setListAdapter(contactAdapter); // set contactView's adapter
}
I attempt to place the map in the onCreate to fill it however it complains about a nullpointer.
Here is where I tried using the OnListItemClick method
#Override
protected void onListItemClick(ListView arg0, View arg1, int arg2, long arg3){
final int index = arg2 - arg0.getFirstVisiblePosition();
View v = arg0.getChildAt(index);
CheckedTextView ctv = (CheckedTextView) v.findViewById(R.id.toppingCheckedTextView);
if((Boolean)map.get(index) == true){
ctv.setChecked(true);
ctv.setVisibility(View.VISIBLE);
} else{
ctv.setVisibility(View.GONE);
}
}
I have read alot on this, and it seems that alot of solutions involves using getView(), however I don't know if that applies to my situation. Any help would be greatly appreciated!
First of all do you need a SimpleCursorAdapter? You set the adapter with a null cursor:
contactAdapter = new SimpleCursorAdapter(
ViewToppingListing.this, R.layout.toppings_list_item, null, from, to); // the third parameter is the cursor and you set it to null!
The behavior you see it's because of the ListView is recycling views and yes you'll have to implement your own adapter and override bindView(). The code bellow is based on another answer to a similar question maybe you'll want to look at it( Getting the selected View from ListView ). Here is an example:
public class TestCursorAdapter extends ListActivity {
MySimpleAdapter adapter;
private HashMap<Long, Boolean> positionHide = new HashMap<Long, Boolean>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
String[] columns = new String[] { "_id", "name" };
MatrixCursor mc = new MatrixCursor(columns); // cursor for testing
for (int i = 1; i < 35; i++) {
long id = i;
mc.addRow(new Object[] { id, "Name" + i });
}
String[] from = new String[] { "name" };
int[] to = new int[] { R.id.checked_text };
adapter = new MySimpleAdapter(this,
R.layout.adapter_mysimpleadapter_row, mc, from, to);
setListAdapter(adapter);
}
private class MySimpleAdapter extends SimpleCursorAdapter {
public MySimpleAdapter(Context context, int layout, Cursor c,
String[] from, int[] to) {
super(context, layout, c, from, to);
}
#Override
public void bindView(View view, Context context, Cursor cursor) {
super.bindView(view, context, cursor);
CheckedTextView ctv = (CheckedTextView) view
.findViewById(R.id.checked_text);
long pos = cursor.getLong(0); // the id from the cursor
if (positionHide.get(pos) == null) {
ctv.setChecked(false);
// we don't have this id in the hashmap so the value is by
// default false, the TextView is GONE
} else {
// we have the value in the Hashmap so see what it is and set
// the textview visibility from this value
Boolean tmp = positionHide.get(pos);
if (tmp.booleanValue()) {
ctv.setChecked(true);
} else {
ctv.setChecked(false);
}
}
}
}
#Override
protected void onListItemClick(ListView l, View v, int position, long id) {
Boolean tmp = positionHide.get(id);
if (tmp == null) {
// if null we don't have this key in the hashmap so
// we add it with the value true
positionHide.put(id, true);
} else {
positionHide.put(id, !tmp.booleanValue());
// if the value exists in the map then inverse it's value
}
adapter.notifyDataSetChanged(); // notify the adapter that something has
// changed
}
}
I have an android.R.layout.simple_list_item_multiple_choice with checkboxes an want so initiate some of them.
How can I do that?
I have the following code:
private void fillList() {
Cursor NotesCursor = mDbHelper.fetchAllNotes();
startManagingCursor(NotesCursor);
String[] from = new String[] { NotesDbAdapter.KEY_TITLE, NotesDbAdapter.KEY_BODY, NotesDbAdapter.KEY_CHECKED };
int[] to = new int[] {
android.R.id.text1,
android.R.id.text2,
//How set checked or not checked?
};
SimpleCursorAdapter notes = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_multiple_choice, NotesCursor,
from, to);
setListAdapter(notes);
}
Put the resource id of your checkbox in your row layout into the to array, corresponding to the NotesDbAdapter.KEY_CHECKED cursor in from array.
Implement a SimpleCursorAdapter.ViewBinder.
Have the ViewBinder.setViewValue() method check for when its called for the NotesDbAdapter.KEY_CHECKED column.
When it is not the KEY_CHECKED column, have it return false the the adapter will do what it normally does.
When it is the KEY_CHECKED column, have it set the CheckBox view (cast required) to checked or not as you wish and then return trueso that adapter won't attempt to bind it itself. The cursor and corresponding column id is available to access query data to determine whether to check the checkbox or not.
Set your ViewBinder in your SimpleCursorAdapter via setViewBinder()
Here's one of my ViewBinder implementations. Its not for checboxes, rather its for doing some fancy formatting of a text view, but it should give you some idea for the approach:
private final SimpleCursorAdapter.ViewBinder mViewBinder =
new SimpleCursorAdapter.ViewBinder() {
#Override
public boolean setViewValue(
final View view,
final Cursor cursor,
final int columnIndex) {
final int latitudeColumnIndex =
cursor.getColumnIndexOrThrow(
LocationDbAdapter.KEY_LATITUDE);
final int addressStreet1ColumnIndex =
cursor.getColumnIndexOrThrow(
LocationDbAdapter.KEY_ADDRESS_STREET1);
if (columnIndex == latitudeColumnIndex) {
final String text = formatCoordinates(cursor);
((TextView) view).setText(text);
return true;
} else if (columnIndex == addressStreet1ColumnIndex) {
final String text = formatAddress(cursor);
((TextView) view).setText(text);
return true;
}
return false;
}
};