I have a SQLite database in my app for which I made a ContentProvider class.
I also have a RecyclerView into which I load an ArrayList of objects into its adapter to populate the RecyclerView.
Currently, when the activity starts I get a Cursor via my ContentProvider, loop through the Cursor to create an ArrayList of objects that I then set as part of my RecyclerView.Adapter.
All that works, but what I really want is for my RecyclerView to dynamically update as new data is loaded into the SQLite database via the content provider.
I have seen posts listing this library CursorRecyclerAdapter but I do not want to use it because you do not get the nice RecyclerView animations on insert/delete.
I was trying to somehow use the LoaderManager.LoaderCallbacks<Cursor> call back methods to get a cursor, convert to arraylist, then swap that in my RecyclerView adapter but couldn't figure it out.
Could someone please show me some example code on how to set it up in my Activity so that the RecyclerView will refresh when new data is written into the local database via a local content provider?
Here is what my RecyclerView.Adapter looks like:
public class MyAdapter extends RecyclerView.Adapter<AdapterTodoList.Holder> {
private List<TodoItem> itemList;
private Context mContext;
//data
String message;
Long datetime;
//this class takes a context and a list of the items you want to populate into the recycler view
public AdapterTodoList(Context context, List<TodoItem> itemList) {
this.itemList = itemList;
this.mContext = context;
}
#Override
public Holder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
//our xml showing how one row looks
View row = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.recycler_view_todo_item, viewGroup, false);
Holder holder = new Holder(row);
return holder;
}
#Override
public void onBindViewHolder(Holder holder, final int position) {
holder.recyclerLinearLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Toast.makeText(mContext, "Recycle Click" + position, Toast.LENGTH_SHORT).show();
}
});
//get one item
TodoItem data = itemList.get(position);
Log.d("Test", "onBindViewHolder position " + position);
message = data.getMessage();
datetime = data.getDatetime();
//convert long to date
String dateString = new SimpleDateFormat("MM/dd/yyyy").format(new Date(datetime));
//set the holder
holder.messageTextView.setText(message);
}
#Override
public int getItemCount() {
return itemList.size();
}
public class Holder extends RecyclerView.ViewHolder {
protected ImageView checkBoxImageView;
protected TextView messageTextView;
protected LinearLayout recyclerLinearLayout;
public Holder(View view) {
super(view);
//checkBoxImageView = (ImageView) view.findViewById(R.id.checkBoxImageView);
messageTextView = (TextView) view.findViewById(R.id.messageTextView);
//the whole view
recyclerLinearLayout = (LinearLayout) view.findViewById(R.id.recyclerItemLinearLayout);
}
}
}
Here is what my Activity looks like so far:
public class HomeRec extends AppCompatActivity implements LoaderManager.LoaderCallbacks<Cursor>{
private Toolbar mToolbar;
//recyclerview and adapter
private RecyclerView mRecyclerView;
private MyAdapter adapter;
//the swipe refresh layout that wraps the recyclerview
private SwipeRefreshLayout mSwipeRefreshLayout;
//this will hold all of our results from our query.
List<TodoItem> itemList = new ArrayList<TodoItem>();
private Cursor mCursor;
//resources from layout
EditText toDoEditText;
Button cancelButton;
Button addButton;
//variables
private String message;
private long datetime;
//loader
private SimpleCursorAdapter mTodoAdapter;
private static final int TODO_LOADER = 0;
// These indices are tied to Projection. If Projection changes, these
// must change.
public static final int COL_ID = 0;
public static final int COL_MESSAGE = 1;
public static final int COL_DATETIME = 2;
public static final int COL_CHECKED = 3;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home_rec);
mToolbar = (Toolbar) findViewById(R.id.app_bar);
//set the Toolbar as ActionBar
setSupportActionBar(mToolbar);
// Initialize recycler view //
mRecyclerView = (RecyclerView) findViewById(R.id.todoRecyclerView);
mRecyclerView.hasFixedSize();
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
//set a grey line divider for each item in recycler view
mRecyclerView.addItemDecoration(
new DividerItemDecoration(this, null, false, true));
// END Initialize recycler view //
//initiate the swipe to refresh layout
mSwipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.swipeRefreshLayout);
mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
// Refresh items
refreshItems();
}
void refreshItems() {
// Load items
// ...
// Load complete
onItemsLoadComplete();
}
void onItemsLoadComplete() {
// Update the adapter and notify data set changed
// ...
// Stop refresh animation
mSwipeRefreshLayout.setRefreshing(false);
}
});
//set colors for swipe to refresh
mSwipeRefreshLayout.setColorSchemeResources(
R.color.refresh_progress_2,
R.color.refresh_progress_3);
//fire my asynctask to get data for the first time
new MessagesAsyncTask().execute();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_home_rec, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
//Not sure what to do here or how to make this work.
}
#Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
//Not sure what to do here or how to make this work.
}
#Override
public void onLoaderReset(Loader<Cursor> loader) {
//Not sure what to do here or how to make this work.
}
public class MessagesAsyncTask extends AsyncTask<Void, Void, List<TodoItem>> {
//the cursor for the query to content provider
private Cursor mCursor;
#Override
protected void onPreExecute() {
}
#Override
protected List<TodoItem> doInBackground(Void... params) {
// A "projection" defines the columns that will be returned for each row
String[] projection =
{
DataProvider.COL_ID, // Contract class constant for the COL_ID column name
DataProvider.COL_MESSAGE, // Contract class constant for the COL_MESSAGE column name
DataProvider.COL_DATETIME, // Contract class constant for the COL_DATETIME column name
DataProvider.COL_CHECKED // Contract class constant for the COL_CHECKED column name
};
// Defines a string to contain the selection clause
String selectionClause = null;
// An array to contain selection arguments
String[] selectionArgs = null;
// An ORDER BY clause, or null to get results in the default sort order
String sortOrder = DataProvider.COL_DATETIME + " DESC";
// Does a query against the table and returns a Cursor object
mCursor = getContentResolver().query(
DataProvider.CONTENT_URI_TODO, // The content URI of the Todo table
projection, // The columns to return for each row
selectionClause, // Either null, or the word the user entered
selectionArgs, // Either empty, or the string the user entered
sortOrder); // The sort order for the returned rows
// Some providers return null if an error occurs, others throw an exception
if (null == mCursor) {
// Insert code here to handle the error.
} else if (mCursor.getCount() < 1) {
// If the Cursor is empty, the provider found no matches
} else {
// Insert code here to do something with the results
}
//convert cursor to arraylist of objects
while (mCursor.moveToNext()) {
itemList.add(new TodoItem(mCursor.getInt(mCursor.getColumnIndex(DataProvider.COL_ID)),
mCursor.getString(mCursor.getColumnIndex(DataProvider.COL_MESSAGE)),
mCursor.getLong(mCursor.getColumnIndex(DataProvider.COL_DATETIME)),
mCursor.getInt(mCursor.getColumnIndex(DataProvider.COL_CHECKED))
));
}
mCursor.close();
return itemList;
}
#Override
protected void onPostExecute(List<TodoItem> itemList) {
if (!itemList.isEmpty()) {
adapter = new MyAdapter(HomeRec.this, itemList);
mRecyclerView.setAdapter(adapter);
} else {
Toast.makeText(getApplicationContext(), "No data to display", Toast.LENGTH_LONG).show();
}
}
}
}
I m not sure what you need but I think you should add this method To adapter and call once your data was pulled
public void swapItems(List< TodoItem > todolist){
this.mTodoList = todolist;
notifyDataSetChanged();
}
Hope this would help :D
from your question I assume that you are loading the data from the database and somewhere there is a code that is updating the database. And on every update you want to update your RecyclerView, If this is the case continue reading. I am not going to explain this completely but there are a lot of source that will explain you this.
Use BroadcastReciever : In the place where you are updating your database sendBroadcast(). And in the activity use the BroadcastReceiver
example and in the onReceive() function call load the data in your ArrayList and call the adapter.notifyDataSetChanged()
Instead of making new adapter each time in onPostExecute and set it to recyclerview again you can notify adapter after modifying list elements.
OR
If you want to make adapter using arraylist instead of cursoradapter using loader i have made sample for you with data provided by you. You can use this as a reference:
public class DataBaseActivity extends AppCompatActivity implements LoaderManager.LoaderCallbacks<Cursor> {
private List itemList;
private MyAdapter mAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_data_base);
RecyclerView recycle=(RecyclerView)findViewById(R.id.rv_data);
SwipeRefreshLayout swipeRefreshLayout= (SwipeRefreshLayout) findViewById(R.id.srl_data);
recycle.setLayoutManager(new LinearLayoutManager(this));
itemList=new ArrayList();
mAdapter= new MyAdapter(this, itemList);
recycle.setAdapter(mAdapter);
swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
getContentResolver().notifyChange(DataProvider.CONTENT_URI_TODO, null); //if you are using content provider
//getSupportLoaderManager().restartLoader(100, null, DataBaseActivity.this); // if you are using support lib
//getLoaderManager().restartLoader(100, null, DataBaseActivity.this); //if you are not using support lib
}
});
// getLoaderManager().initLoader(100, null, this); //if you are not using support lib
getSupportLoaderManager().initLoader(100, null, this);
}
#Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
String[] projection =
{
DataProvider.COL_ID, // Contract class constant for the COL_ID column name
DataProvider.COL_MESSAGE, // Contract class constant for the COL_MESSAGE column name
DataProvider.COL_DATETIME, // Contract class constant for the COL_DATETIME column name
DataProvider.COL_CHECKED // Contract class constant for the COL_CHECKED column name
};
// Defines a string to contain the selection clause
String selectionClause = null;
// An array to contain selection arguments
String[] selectionArgs = null;
// An ORDER BY clause, or null to get results in the default sort order
String sortOrder = DataProvider.COL_DATETIME + " DESC";
return new CursorLoader(this,DataProvider.CONTENT_URI_TODO, // The content URI of the Todo table
projection, // The columns to return for each row
selectionClause, // Either null, or the word the user entered
selectionArgs, // Either empty, or the string the user entered
sortOrder);
}
#Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
if(data!=null && data.getCount()>0)
{
itemList.clear();
while (data.moveToNext()) {
itemList.add(new TodoItem(data.getInt(data.getColumnIndex(DataProvider.COL_ID)),
data.getString(data.getColumnIndex(DataProvider.COL_MESSAGE)),
data.getLong(data.getColumnIndex(DataProvider.COL_DATETIME)),
data.getInt(data.getColumnIndex(DataProvider.COL_CHECKED))
));
}
}
else
Toast.makeText(getApplicationContext(), "No data to display", Toast.LENGTH_LONG).show();
if(data!=null)
data.close();
mAdapter.notifyDataSetChanged();
}
#Override
public void onLoaderReset(Loader<Cursor> loader) {
}
}
For "listening" to your ContentProvider changes, you'll could try to integrate ContentObserver into your ContentProvider, so it can trigger the necessary events when a transaction is done on your ContentProvider. After which, you'll declare an ContentObserver to your CONTENT_URI, then you can trigger an update to your RecyclerView.
More info on implementing ContentObserver here.
A sample code for updating an item in your RecyclerView would be,
public void update(T data){
synchronized (mLock){
if(data != null && mData.contains(data)){
int index = mData.indexOf(data);
mData.set(index, data);
notifyItemChanged(index);
}
}
}
Wherein T is the type of object if your row returns, mLock is just an instance object to acquire a lock, mData the list of items you've provided to your RecyclerView. You get the gist. :D
Hope it helps.
Refresh cursor every second
final Handler handler = new Handler();
final int delay = 1000; //milliseconds
handler.postDelayed(new Runnable(){
public void run(){
//Call cursor loader to refresh cursor
getSupportLoaderManager().restartLoader(LOADER_ID, null, MainActivity.this);
handler.postDelayed(this, delay);
}
}, delay);
Related
My app was very laggy, so I decided to use an AsyncTask to do the heaviest operations inside it and so, the app wouldn't be so slow at changing tabs.
But now, it is behaving in a very weird way. Let me explain: I have a ViewPager2, and inside that ViewPager, I have a recyclerview.
I put an AsyncTask inside the ViewPager, because it is the heaviest operation done in the fragment, and in the adapter of that ViewPager, I retrieve some values from a Database via a class called DatabaseHelper which one that extends SQLiteOpenHelper and has this method.
public Cursor getAllTasksByList(int ListID)
{
SQLiteDatabase db = this.getWritableDatabase();
Cursor c = db.rawQuery("SELECT * FROM " + Db.Tables.Tasktable.TASKS_TABLE + " WHERE " + Db.Tables.Tasktable.COL_LIST_ID + " = " + ListID, null);
return c;
}
Because the DatabaseHelper only returns one Cursor, I use another class to keep the code organized, this class takes the Cursor as argument and returns a list of "ListItem". This class is called "FolderUtils" and contains the following method (which one that I use to populate my RecyclerView inside that is inside my ViewPager):
public ArrayList<TaskItem> getTasksByList(int ListID, Context context) {
ArrayList<TaskItem> tasks = new ArrayList<>();
DatabaseHelper d = new DatabaseHelper(context);
Cursor c = d.getAllTasksByList(ListID);
while (c.moveToNext()) {
int id = c.getInt(0);
int listid = c.getInt(1);
boolean checked = c.getInt(2) > 0;
String title = c.getString(3);
tasks.add(new TaskItem(id, listid, checked, title));
}
return tasks;
}
But here it is the problem, sometimes this List is empty, but another times, it just retrieves the first value of the that Table I look for, strangely, sometimes it returns wrong values and it only works sometimes if I move my ViewPager to another position or if I just put some breakpoints. Here is my Adapter code.
#Override
public void onBindViewHolder(#NonNull ListHolder holder, int position) {
new LoadData(mList.get(position), holder).execute();
}
#Override
public int getItemCount() {
return mList.size();
}
private class LoadData extends AsyncTask<Void, Void, Void> {
private ListItem item;
private ListHolder holder;
public LoadData(ListItem item, ListHolder holder) {
this.item = item;
this.holder = holder;
}
#Override
protected void onPreExecute(){
super.onPreExecute();
//I set the visibility to GONE so that the user can just see the final layout and not the layout "Building" itself.
holder.itemView.setVisibility(View.GONE);
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
setItems(item, holder); //setItems is for setting the UI Content.
AttachRecycler(holder, item); //AttachRecycler creates an adapter for the recyclerview with the TaskList values, and attaches it to the recyclerview inside the ViewPager item.
holder.itemView.setVisibility(View.VISIBLE); //Shows the finished item
}
#Override
protected Void doInBackground(Void... voids) {
SetList(item); //SetList is where it takes the values from database and adds it to the list.
return null;
}
}
private void SetList(ListItem item) {
TaskList = new ArrayList<>();
else if (Mode == 1)
{
//Mode by default is 1. The line below does gets executed, however, it returns the wrong values.
TaskList.addAll(FolderUtils.getInstance().getTasksByList(item.getID(), context));
}
private void AttachRecycler(ListHolder holder, ListItem item)
{
LinearLayoutManager manager = new LinearLayoutManager(context);
holder.recycler.setLayoutManager(manager);
adapter = new TaskAdapter(TaskList, item.getColor(), context, item.getID());
holder.recycler.setAdapter(adapter);
}
How could I fix this? Thank You.
Solved this by myself.
Solution was to make TaskList a private variable inside the LoadData class, not a private variable of the entire Adapter, this acts like a local variable for every item instance, removing the duplicates in some items.
I have a RecyclerView list of CardView items. I save CardView data to a SQLite database. The user can drag CardViews up and down in the list to change the order of the items. When the user exits the app, I'd like to save the current order of the RecyclerView items. Then when the user re-opens the app, I'd like to restore that exact order of the RecyclerView items.
I have tried multiple approaches based on other SO posts with no luck:
--How to save RecyclerView's scroll position using RecyclerView.State?
--RecyclerView store / restore state between activities
--How to save scroll position of RecyclerView in Android?
What I get each time I re-open the app is my default order based on the CardView's original timestamp. It shows the newest CardView item at the top of the list, descending to the last item which is the oldest CardView.
Here is my code:
public class MainActivity extends AppCompatActivity {
private ArrayList<ListItem> allList;
private RecyclerView mRecyclerView;
private SQLiteDB sqLiteDB;
private MyRecylerAdapter adapter;
private static final String KEY_RECYCLER_STATE = "recycler_state";
private Parcelable recyclerViewState;
protected void onCreate(Bundle savedInstanceState) {
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
allList = new ArrayList<>();
allList.clear();
allList = sqLiteDB.getAllDBItems();
adapter = new MyRecylerAdapter(this, allList);
mRecyclerView.setAdapter(adapter);
}
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putParcelable(KEY_RECYCLER_STATE, mRecyclerView.getLayoutManager().onSaveInstanceState());
}
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
recyclerViewState = savedInstanceState.getParcelable(KEY_RECYCLER_STATE);
}
#Override
protected void onResume() {
super.onResume();
if (mRecyclerView !=null) {
mRecyclerView.getLayoutManager().onRestoreInstanceState(recyclerViewState);
}
}
}
public class SQLiteDB extends SQLiteOpenHelper {
...
public ArrayList<ListItem> getAllDBItems() {
ArrayList<ListItem> modelList = new ArrayList<>();
SQLiteDatabase db = getReadableDatabase();
String[] columns = {
ItemContract.ItemEntry.A,
ItemContract.ItemEntry.B,
ItemContract.ItemEntry.C,
ItemContract.ItemEntry.D,
ItemContract.ItemEntry.E,
ItemContract.ItemEntry.F,
ItemContract.ItemEntry.G,
ItemContract.ItemEntry.H,
ItemContract.ItemEntry.I,
ItemContract.ItemEntry.J
};
Cursor getCursor = db.query(
TABLE_NAME,
columns,
null,
null,
null,
null,
null
);
try {
if (getCursor.getCount() > 0) {
getCursor.moveToFirst();
while (!getCursor.isAfterLast()) {
do {
ListItem listItem = new ListItem();
listItem.setId(Integer.parseInt(getCursor.getString(getCursor.getColumnIndex(A))));
listItem.setType(getCursor.getString(getCursor.getColumnIndex(B)));
listItem.setTypeColor(Integer.parseInt(getCursor.getString(getCursor.getColumnIndex(C))));
listItem.setTodo(getCursor.getString(getCursor.getColumnIndex(D)));
listItem.setNote1(getCursor.getString(getCursor.getColumnIndex(E)));
listItem.setNote2(getCursor.getString(getCursor.getColumnIndex(F)));
listItem.setDuedate(getCursor.getString(getCursor.getColumnIndex(G)));
listItem.setDuetime(getCursor.getString(getCursor.getColumnIndex(H))); listItem.setTimestamp(Long.parseLong(getCursor.getString(getCursor.getColumnIndex(I))));
listItem.setRandint(Integer.parseInt(getCursor.getString(getCursor.getColumnIndex(J))));
modelList.add(0,listItem);
} while (getCursor.moveToNext());
}
}
} finally {
if (getCursor != null && !getCursor.isClosed()) {
getCursor.close();
}
} if(db.isOpen()) {
db.close();
}
return modelList;
}
public class ListItem {
private int _id;
private int _sortorder;
public void setSortorder(int sortorder) {
_sortorder = sortorder;
}
}
Add a field called "SortOrder" to your database table and increment the value in this column every time you add a new row. (You could use the MAX function to ensure the value is always the next one up from the current highest)
Sort by this column when retrieving the items.
When you drop a card after dragging it to a new position, update the field with the new sort order/position.
I am building a budget database and I can get all the transactions into the listview and displayed on the screen. I have created a textview to hold the sum of all the transaction values but can't figure out how to get it to display in the textview. I get the following error:
Attempt to invoke virtual method
'android.database.sqlite.SQLiteDatabase
android.content.Context.openOrCreateDatabase(java.lang.String, int,
android.database.sqlite.SQLiteDatabase$CursorFactory)' on a null
object reference.
Here is the code I am trying to get to work:
SQLiteDatabase database = mDbHelper.getReadableDatabase();
public int cmIncomeSum() {
int total = 0;
Cursor sumQuery = database.rawQuery("SELECT SUM(income) FROM transactions WHERE income >=0 AND expense ISNULL AND strftime('%m',date)=strftime('%m',date('now')) AND strftime('%Y',date)=strftime('%Y',date('now'))", null);
if (sumQuery.moveToFirst()) {
total = sumQuery.getInt(0);
}
return total;
}
and the textview:
TextView cmIncomeSumTextView = (TextView) findViewById(R.id.cm_income_sum_text_view);
cmIncomeSumTextView.setText(sum);
and here is the entire activity:
public class CMIncomeTransactionsActivity extends AppCompatActivity implements
LoaderManager.LoaderCallbacks<Cursor> {
/** Identifier for the transaction data loader */
private static final int TRANSACTION_LOADER = 0;
/** Adapter for the ListView */
IncomeCursorAdapter mCursorAdapter;
// Database helper object //
private BudgetDbHelper mDbHelper;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_cm_income_transactions);
// Setup FAB to open EditorActivity
Button fab = (Button) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(CMIncomeTransactionsActivity.this, IncomeEditorActivity.class);
startActivity(intent);
}
});
// Find the ListView which will be populated with the transaction data
ListView incomeListView = (ListView) findViewById(R.id.list);
// Find and set empty view on the ListView, so that it only shows when the list has 0 items.
View emptyView = findViewById(R.id.empty_view);
incomeListView.setEmptyView(emptyView);
// Setup an Adapter to create a list item for each row of transaction data in the Cursor.
mCursorAdapter = new IncomeCursorAdapter(this, null);
incomeListView.setAdapter(mCursorAdapter);
// Setup the item click listener
incomeListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
// Create new intent to go to {#link EditorActivity}
Intent intent = new Intent(CMIncomeTransactionsActivity.this, IncomeEditorActivity.class);
// Form the content URI that represents the specific transaction that was clicked on,
// by appending the "id" (passed as input to this method) onto the
// {#link BudgetEntry#CONTENT_URI}.
Uri currentTransactionUri = ContentUris.withAppendedId(BudgetEntry.CONTENT_URI, id);
// Set the URI on the data field of the intent
intent.setData(currentTransactionUri);
// Launch the {#link EditorActivity} to display the data for the current transaction.
startActivity(intent);
}
});
// Kick off the loader
getLoaderManager().initLoader(TRANSACTION_LOADER, null, this);
// Define query for the SUM of the current month income and display it on the screen//
TextView cmIncomeSumTextView = (TextView) findViewById(R.id.cm_income_sum_text_view);
cmIncomeSumTextView.setText(cmIncomeSum());
}
SQLiteDatabase database = mDbHelper.getReadableDatabase();
public int cmIncomeSum() {
int total = 0;
Cursor sumQuery = database.rawQuery("SELECT SUM(income) FROM transactions WHERE income >=0 AND expense ISNULL AND strftime('%m',date)=strftime('%m',date('now')) AND strftime('%Y',date)=strftime('%Y',date('now'))", null);
if (sumQuery.moveToFirst()) {
total = sumQuery.getInt(0);
}
return total;
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu options from the res/menu/menu_catalog.xml file.
// This adds menu items to the app bar.
getMenuInflater().inflate(R.menu.menu_catalog, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
return super.onOptionsItemSelected(item);
}
#Override
public Loader<Cursor> onCreateLoader(int i, Bundle bundle) {
// Define a projection that specifies the columns from the table we care about.
String[] projection = {
BudgetEntry._ID,
BudgetEntry.COLUMN_DATE,
BudgetEntry.COLUMN_DESCRIPTION,
BudgetEntry.COLUMN_INCOME,
BudgetEntry.COLUMN_INCOME_CATEGORY,
BudgetEntry.COLUMN_EXPENSE,
BudgetEntry.COLUMN_STATUS};
// Where clause to only display income transactions //
String selection = "income >=0 AND expense ISNULL AND strftime('%m',date)=strftime('%m',date('now')) AND strftime('%Y',date)=strftime('%Y',date('now'))";
// This loader will execute the ContentProvider's query method on a background thread
return new CursorLoader(this, // Parent activity context
BudgetEntry.CONTENT_URI, // Provider content URI to query
projection, // Columns to include in the resulting Cursor //
selection, // Where selection clause /
null, // selection arguments //
BudgetEntry.COLUMN_DATE); // Default sort order //
}
#Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
// Update {#link IncomeCursorAdapter} with this new cursor containing updated transaction data
mCursorAdapter.swapCursor(data);
}
#Override
public void onLoaderReset(Loader<Cursor> loader) {
// Callback called when the data needs to be deleted
mCursorAdapter.swapCursor(null);
}
}
I have looked at many different posts here and none have been helpful.
Please help!
for example, I want show name of the characters that family is "Heard" or "Carry" or everybody you want who to be saved in a database and saved that in an array list:
in one of a method of the MyDataBaseClass:
public Cursor showName(String family){
SQLiteDatabase db = this.getWritableDatabase();
Cursor data = db.rawQuery(" SELECT Name FROM "+TBL_NAME+ " WHERE Family==?" , new String[]{family});
return data;
}
and in main scope:
MyDataBaseClass db = new MyDataBaseClass();
Cursor res = db.showName("Heard");
if (res.getCount() == 0) {
//do nothing
} else {
ArrayList<String> list = new ArrayList<>();
while (res.moveToNext()) {
list.add(res.getString(0));
}
}
this answer may not exactly what you want to do but I hope to help you
You have not initialized mDbHelper in CMIncomeTransactionsActivity class, so initialize mDbHelper in onCreate and try.
How can I make the phone number 3456781276 which is in my phone contacts appear at the very top of my listview, and then all other contacts below that as normal? I believe I pass that value into my custom adapter and into my getView() but not at all sure how to proceed. Can you help?
In my ListView I show all my phone contacts with the following code:
class LoadContact extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected Void doInBackground(Void... voids) {
// we want to delete the old selectContacts from the listview when the Activity loads
// because it may need to be updated and we want the user to see the updated listview,
// like if the user adds new names and numbers to their phone contacts.
selectPhoneContacts.clear();
// we have this here to avoid cursor errors
if (cursor != null) {
cursor.moveToFirst();
}
try {
// get a handle on the Content Resolver, so we can query the provider,
cursor = getApplicationContext().getContentResolver()
// the table to query
.query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
null,
null,
null,
// display in ascending order
ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME + " COLLATE LOCALIZED ASC");
// get the column number of the Contact_ID column, make it an integer.
// I think having it stored as a number makes for faster operations later on.
// get the column number of the DISPLAY_NAME column
int nameIdx = cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME);
// get the column number of the NUMBER column
int phoneNumberofContactIdx = cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER);
cursor.moveToFirst();
// We make a new Hashset to hold all our contact_ids, including duplicates, if they come up
Set<String> ids = new HashSet<>();
do {
System.out.println("=====>in while");
// get a handle on the display name, which is a string
name = cursor.getString(nameIdx);
// get a handle on the phone number, which is a string
phoneNumberofContact = cursor.getString(phoneNumberofContactIdx);
//----------------------------------------------------------
// get a handle on the phone number of contact, which is a string. Loop through all the phone numbers
// if our Hashset doesn't already contain the phone number string,
// then add it to the hashset
if (!ids.contains(phoneNumberofContact)) {
ids.add(phoneNumberofContact);
System.out.println(" Name--->" + name);
System.out.println(" Phone number of contact--->" + phoneNumberofContact);
SelectPhoneContact selectContact = new SelectPhoneContact();
selectContact.setName(name);
selectContact.setPhone(phoneNumberofContact);
selectPhoneContacts.add(selectContact);
}
} while (cursor.moveToNext());
} catch (Exception e) {
Toast.makeText(NewContact.this, "what the...", Toast.LENGTH_LONG).show();
e.printStackTrace();
// cursor.close();
} finally {
}
if (cursor != null) {
cursor.close();
}
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
adapter = new SelectPhoneContactAdapter(selectPhoneContacts, NewContact.this);
// we need to notify the listview that changes may have been made on
// the background thread, doInBackground, like adding or deleting contacts,
// and these changes need to be reflected visibly in the listview. It works
// in conjunction with selectContacts.clear()
adapter.notifyDataSetChanged();
listView.setAdapter(adapter);
//this function measures the height of the listview, with all the contacts, and loads it to be that
//size. We need to do this because there's a problem with a listview in a scrollview.
justifyListViewHeightBasedOnChildren(listView);
}
}
My model, getters and setters, is like:
public class SelectPhoneContact {
String phone;
public String getPhone() {return phone;}
public void setPhone(String phone) {
this.phone = phone;
}
String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
And my custom adapter:
public class SelectPhoneContactAdapter extends BaseAdapter {
//define a list made out of SelectContacts and call it theContactsList
public List<SelectPhoneContact> theContactsList;
//define an array list made out of SelectContacts and call it arraylist
private ArrayList<SelectPhoneContact> arraylist;
Context _c;
//define a ViewHolder to hold our name and number info, instead of constantly querying
// findviewbyid. Makes the ListView run smoother
ViewHolder v;
public SelectPhoneContactAdapter(List<SelectPhoneContact> selectPhoneContacts, Context context) {
theContactsList = selectPhoneContacts;
_c = context;
this.arraylist = new ArrayList<SelectPhoneContact>();
this.arraylist.addAll(theContactsList);
Collections.sort(this.arraylist, new Comparator<SelectPhoneContact>() {
#Override
public int compare(SelectPhoneContact t1, SelectPhoneContact t2) {
if(t2.getPhone().equals ("3456781276")) { // put the phone number you want on top here
return 1;
} else {
return t1.getName().compareTo(t2.getName());
}
}
});
}
#Override
public int getCount() {
return arraylist.size();
}
#Override
public Object getItem(int i) {
return arraylist.get(i);
}
#Override
public long getItemId(int i) {
return i;
}
#TargetApi(Build.VERSION_CODES.LOLLIPOP)
static class ViewHolder {
// In each cell in the listview show the items you want to have
// Having a ViewHolder caches our ids, instead of having to call and load each one again and again
CheckBox checkbox;
TextView title, phone, lookup;
// CheckBox check;
}
#Override
public View getView(int i, View convertView, ViewGroup viewGroup) {
//we're naming our convertView as view
View view = convertView;
if (view == null) {
//if there is nothing there (if it's null) inflate the layout for each row
LayoutInflater li = (LayoutInflater) _c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = li.inflate(R.layout.phone_inflate_listview, null);
//or else use the view (what we can see in each row) that is already there
} else {
view = convertView;
}
v = new ViewHolder();
// So, for example, title is cast to the name id, in phone_inflate_listview,
// phone is cast to the id called no etc
v.title = (TextView) view.findViewById(R.id.name);
// v.check = (CheckBox) view.findViewById(R.id.check);
v.phone = (TextView) view.findViewById(R.id.no);
// store the holder with the view
final SelectPhoneContact data = (SelectPhoneContact) arraylist.get(i);
v.title.setText(data.getName());
v.phone.setText(data.getPhone());
view.setTag(data);
return view;
}
}
What about using add(int index, E element)?
if (/* check your condition here: is it the number you are looking for? */) {
// insert the contact at the beginning
selectPhoneContacts.add(0, selectContact);
} else {
// insert it at the end (default)
selectPhoneContacts.add(selectContact);
}
Try to modify your adapter's constructor like this:
public SelectPhoneContactAdapter(List<SelectPhoneContact> selectPhoneContacts, Context context) {
theContactsList = selectPhoneContacts;
_c = context;
this.arraylist = new ArrayList<SelectPhoneContact>();
this.arraylist.addAll(theContactsList);
Collections.sort(this.arraylist, new Comparator<SelectPhoneContact>() {
#Override
public int compare(SelectPhoneContact t1, SelectPhoneContact t2) {
if(t2.getPhone().equals("3456781276")) { // put the phone number you want on top here
return 1;
} else {
return t1.getName().compareTo(t2.getName());
}
}
});
}
So we are basically sorting the ArrayList before the adapter starts using it.
So in this example, I am putting the phone number "3456781276" on top of everything else. If the phone number is NOT "3456781276", it will sort all the items by the name. (If you don't want to sort it by name, just remove the else statement.
Hope this helps.
EDIT:
in getView(), change:
final SelectPhoneContact data = (SelectPhoneContact) theContactsList.get(i);
to:
final SelectPhoneContact data = (SelectPhoneContact) arraylist.get(i);
Change getCount() method like this:
#Override
public int getCount() {
return arraylist.size();
}
Change getItem() method like this:
#Override
public Object getItem(int i) {
return arraylist.get(i);
}
You must use arraylist everywhere since that is the list we are sorting.
An easy way to achieve this, just use a view in XML which contains your phone number, and set it to invisible in default, if the list shows, set the view to be visible. I hope this post help you!!!
You can easily manipulate with items positions in ArrayList with Collections.swap(); by looping through your contacts and by simply checking is number matching your number if does put it on the top for example:
Collections.swap(myArrayList, i, 0);
Refering to: http://www.java2s.com/Code/Java/Collections-Data-Structure/SwapelementsofJavaArrayList.htm
How can I get the name of a specific cell in my listview to load into a new activity ? At present, when I click any of the arrows it loads the last person in my contacts (Yvonne) in the next activity that loads when the arrow is clicked. I want the name in the corresponding cell to load in the next activity. How can I do this?
For example, in the image above, I want Alexi to load into the next Activity. But instead I keep getting Yvonne.
At present my code looks like this:
public class MainActivity extends Activity {
// ArrayList called selectContacts that will contain SelectContact info
ArrayList<SelectContact> selectContacts;
ListView listView;
SearchView search;
SelectContactAdapter adapter;
String name;
String phoneNumber;
String lookupkey;
CharSequence nameofcontact;
// *****18-04-2016***
Cursor cursor;
// ListView mainListView;
// ArrayList hashMapsArrayList;
public String cleartext;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//selectContacts is an empty array list that will hold our SelectContct info
selectContacts = new ArrayList<SelectContact>();
listView = (ListView) findViewById(R.id.contacts_list);
search = (SearchView) findViewById(R.id.searchView);
//*** setOnQueryTextListener ***
search.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
#Override
public boolean onQueryTextSubmit(String query) {
// TODO Auto-generated method stub
return false;
}
#Override
public boolean onQueryTextChange(String newText) {
// TODO Auto-generated method stub
adapter.filter(newText);
return false;
}
});
}
// Load data on background
class LoadContact extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected Void doInBackground(Void... voids) {
// Perhaps running this thread on the UI thread has solved the issue of the app
// crashing? ListView had not been updating properly, I think.
runOnUiThread(new Runnable() {
public void run() {
// we want to delete the old selectContacts from the listview when the Activity loads
// because it may need to be updated and we want the user to see the updated listview,
// like if the user adds new names and numbers to their phone contacts.
selectContacts.clear();
// we have this here to avoid cursor errors
if (cursor != null) {
cursor.moveToFirst();
}
try {
// get a handle on the Content Resolver, so we can query the provider,
cursor = getApplicationContext().getContentResolver()
// the table to query
.query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
// Null. This means that we are not making any conditional query into the contacts table.
// Hence, all data is returned into the cursor.
// Projection - the columns you want to query
null,
// Selection - with this you are extracting records with assigned (by you) conditions and rules
null,
// SelectionArgs - This replaces any question marks (?) in the selection string
// if you have something like String[] args = { "first string", "second#string.com" };
null,
// display in ascending order
ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME + " COLLATE LOCALIZED ASC");
// get the column number of the Contact_ID column, make it an integer.
// I think having it stored as a number makes for faster operations later on.
int Idx = cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.CONTACT_ID);
// get the column number of the DISPLAY_NAME column
int nameIdx = cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME);
// get the column number of the NUMBER column
int phoneNumberIdx = cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER);
// ****
int contactlookupkey = cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.LOOKUP_KEY);
// ****
cursor.moveToFirst();
// We make a new Hashset to hold all our contact_ids, including duplicates, if they come up
Set<String> ids = new HashSet<>();
do {
System.out.println("=====>in while");
// get a handle on the contactid, which is a string. Loop through all the contact_ids
String contactid = cursor.getString(Idx);
// if our Hashset doesn't already contain the contactid string,
// then add it to the hashset
if (!ids.contains(contactid)) {
ids.add(contactid);
HashMap<String, String> hashMap = new HashMap<String, String>();
// get a handle on the display name, which is a string
name = cursor.getString(nameIdx);
// get a handle on the phone number, which is a string
phoneNumber = cursor.getString(phoneNumberIdx);
// String image = cursor.getString(photoIdIdx);
lookupkey = cursor.getString(contactlookupkey);
System.out.println("Id--->" + contactid + " Name--->" + name);
System.out.println("Id--->" + contactid + " Number--->" + phoneNumber);
System.out.println("Id--->" + contactid + " lookupkey--->" + lookupkey);
SelectContact selectContact = new SelectContact();
selectContact.setName(name);
selectContact.setPhone(phoneNumber);
selectContacts.add(selectContact);
}
} while (cursor.moveToNext());
} catch (Exception e) {
e.printStackTrace();
} finally {
}
}});
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
//into each inflate_listview, put a name and phone number, which are the details making
// our SelectContact, above. And SelectContacts is all these inflate_listviews together
// This is the first property of our SelectContactAdapter, a list
// The next part, MainActivity.this, is our context, which is where we want the list to appear
adapter = new SelectContactAdapter(selectContacts, MainActivity.this);
// adapter.notifyDataSetChanged();
listView.setAdapter(adapter);
// Select item on listclick
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
listView.setFastScrollEnabled(true);
// we need to notify the listview that changes may have been made on
// the background thread, doInBackground, like adding or deleting contacts,
// and these changes need to be reflected visibly in the listview. It works
// in conjunction with selectContacts.clear()
// adapter.notifyDataSetChanged();
}
});
}}
//the is the arrow image, it opens the activity for show and edit
public void DisplayorEditContact(View v) {
System.out.println("works so far");
System.out.println(name);
Intent intent = new Intent(getApplicationContext(), EditorNewContact.class).putExtra("thecontactname",name);
startActivity(intent);
}
#Override
protected void onStop() {
super.onStop();
}
#Override
protected void onResume() {
//I want to clear the searchview text when my app resumes or closes, but I keep getting an error, my app shuts down
// cleartext = findViewById(R.id.searchView).toString();
// cleartext.isEmpty();
// search.setQuery("", false);
super.onResume();
// load the contacts again, refresh them, when the user resumes the activity
LoadContact loadContact = new LoadContact();
loadContact.execute();
// cursor.close();
}
}
The salient part of the code I believe is :
//the is the arrow image, it opens the activity for show and edit
public void DisplayorEditContact(View v) {
System.out.println("works so far");
System.out.println(name);
Intent intent = new Intent(getApplicationContext(), EditorNewContact.class).putExtra("thecontactname",name);
startActivity(intent);
}
And the child activity, into which I want Alexi to load (at present I keep getting Yvonne) looks like this :
public class EditorNewContact extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.edit_contact);
String s= getIntent().getStringExtra("thecontactname");
System.out.println("the name is" + s);
EditText edittext = (EditText) findViewById(R.id.editText);
edittext.setText(s);
I was asked to share my SelectContactAdapter, so here it is :
public class SelectContactAdapter extends BaseAdapter {
//define a list made out of SelectContacts and call it _data
public List<SelectContact> _data;
//define an array list made out of SelectContacts and call it arraylist
private ArrayList<SelectContact> arraylist;
Context _c;
//define a ViewHolder to hold our name and number info, instead of constantly querying
// findviewbyid. Makes the ListView run smoother
ViewHolder v;
// RoundImage roundedImage;
public SelectContactAdapter(List<SelectContact> selectContacts, Context context) {
_data = selectContacts;
_c = context;
this.arraylist = new ArrayList<SelectContact>();
this.arraylist.addAll(_data);
}
#Override
public int getCount() {
return _data.size();
}
#Override
public Object getItem(int i) {
return _data.get(i);
}
#Override
public long getItemId(int i) {
return i;
}
#TargetApi(Build.VERSION_CODES.LOLLIPOP)
#Override
public View getView(int i, View convertView, ViewGroup viewGroup) {
//we're naming our convertView as view
View view = convertView;
//if there is nothing there (if it's null) inflate the layout for each row
if (view == null) {
LayoutInflater li = (LayoutInflater) _c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = li.inflate(R.layout.inflate_listview, null);
// Log.e("Inside", "here--------------------------- In view1");
//or else use the view (what we can see in each row) that is already there
} else {
view = convertView;
// Log.e("Inside", "here--------------------------- In view2");
}
v = new ViewHolder();
// So, for example, title is cast to the name id, in activity main,
// phone is cast to the id called no etc
v.title = (TextView) view.findViewById(R.id.name);
// v.check = (CheckBox) view.findViewById(R.id.check);
v.phone = (TextView) view.findViewById(R.id.no);
v.imageView = (ImageView) view.findViewById(R.id.arrowright);
// for each new cell with title, name, number etc...
//
final SelectContact data = (SelectContact) _data.get(i);
v.title.setText(data.getName());
// v.check.setChecked(data.getCheckedBox());
v.phone.setText(data.getPhone());
view.setTag(data);
return view;
}
// Filter Class
public void filter(String charText) {
charText = charText.toLowerCase(Locale.getDefault());
// _data is our list of contacts
_data.clear();
// If there is nothing in the searchview, if the charText length is 0,
// then show all the contacts
if (charText.length() == 0) {
_data.addAll(arraylist);
// or else....
} else {
for (SelectContact wp : arraylist) {
// If a contact's name matches the input thus far, which is charText,
// then include it in the listview.
if ((wp.getName().toLowerCase(Locale.getDefault())
.contains(charText)) || (wp.getPhone().toLowerCase(Locale.getDefault())
.contains(charText)))
{
_data.add(wp);
}
}
}
notifyDataSetChanged();
}
static class ViewHolder {
// In each cell in the listview show the items you want to have
ImageView imageView;
TextView title, phone;
// CheckBox check;
}
}
It is hard to predict how your code works without seeing the SelectContactAdapter source code. But I can suggest a probably easiest solution, which is using a tag
all you need to do is to set a tag to your arrow image somewhere in your adapter's getView method like this:
youArrowImage.setTag("here_is_a_name_of_a_row");
and then in your DisplayorEditContact(View v) you can access it like this:
String itemName = (String)v.getTag();
here I suppose that v is a reference to clicked arrow image
You could also just monitor the click in your ListView setOnItemClickListener.
// Click listener to bring to profile
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent viewProfileIntent = new Intent(getApplicationContext(), UserProfile.class);
viewProfileIntent.putExtra("name", selectContacts.get(position));
Log.i("User Tapped", selectContacts.get(position));
startActivity(viewProfileIntent);
}
});
Please add following line to your SelectContactsAdapter.java
final SelectContact data = (SelectContact) _data.get(i);
v.title.setText(data.getName());
v.phone.setText(data.getPhone());
// Please add this line to your existing code right after above lines
v.imageView.setTag(data.getName());
Modify your method as below
public void DisplayorEditContact(View v) {
System.out.println("works so far");
System.out.println(v.getTag().toString());
Intent intent = new Intent(getApplicationContext(), EditorNewContact.class).putExtra("thecontactname",v.getTag().toString());
startActivity(intent);
}
Hope this helps
Your this method will like this:
public void DisplayorEditContact(View v) {
TextView tvName = (TextView) v.findViewById(R.id.YOUR_TEXT_NAME);
System.out.println(tvName.getText().toString());
}
Hope this will solve your problem :)
You need to use onItemClickListener on your list view.
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
SelectContact contact = (SelectContact)parent.getItemAtPosition(position);
Intent secondActivity = new Intent(MainActivity.this, EditorNewContact.class);
secondActivity.putExtra("Key", contact);
startActivity(secondActivity);
}
});
Also, in your EditorNewContact activity, you will need to resolve this intent in the onCreate method, like:
Intent intent = getIntent();
SelectContact contact = (SelectContact) intent.get("Key");
Also, your SelectContact class can be Serializeable, If that is the can, the the intent will look like.
Intent secondActivity = new Intent(MainActivity.this, EditorNewContact.class);
secondActivity.putSerializeableExtra("Key", contact);
startActivity(secondActivity);
And, to resolve this:
Intent intent = getIntent();
SelectContact contact = (SelectContact) intent.getSerializableExtra("Key");
i hope this helps.