Does the CursorAdapter run on a background thread and posts updates via the UI looper thread? If not what is the best pattern to load data asynchronously from a ContentProvider?
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I have a listactivity as a startup screen in my application. Which is displaying database records using custom cursor adapter. On create I set the filterable flag - getListView().setTextFilterEnabled(true)
My cursoradapter overrides runQueryOnBackgroundThread which runs corresponding query. The problem is that after typing some text and hitting enter, runQueryOnBackgroundThread never gets called. However, when the item click in the same view launches another activity(detail view of the record) and I come back to the original list activity, hitting back button, then text filtering works just fine. I don't call setTextFilterEnabled anywhere except during the initialization process and I can't really find any other API affecting this behavior, so any guesses why text filtering doesn't work initially, but all of the sudden starts working when I come back to the list activity from child activity?
I need to run a background thread in my application. Could you please share the best practices where to initiate the thread so that keeps running irrespective of the Activity is being shown and things to consider. The purpose of this background thread is to fire transactions from the Simulator to the server and get the response back from the host.
View 2 Replies View RelatedAs is mentioned above,What i'm trying is to protect a sub- thread,and keep it going on as long as the App that starts it is still alive.In other words,If the system need more resources,Let it kill both the App main thread and the sub-thread started from it,Instead of just kill the sub-thread.Is there any way i can do this ?? And another question here,The android system seems to be "rude",As it killed my thread without telling me,even in the logs,Is this the case?
View 6 Replies View Relatedis there any way to leave a thread in background when i close the app in android? I read about a Service but implementing it is too much than i need.
View 2 Replies View RelatedI need to popup dialog to be showed when i get a message from differnt thread but the dialog should be not dependent on Activity i.e, it should display the dialog wherever the screen focus is .can it be done ..because the dialog is handled per Activity ,i thought of using service but again it would be one more thread added so want to avoid that.
View 2 Replies View RelatedIn my activity there's some stuff going on in a background thread, which gets started in Activity_1. The processing of the background thread takes a while and I want to notify the user when it's completed via an AlertDialog. However, the user might have changed to Activity_2 or Activity_3 in the meantime and I would like to pop up the AlertDialog always in the current Activity.
View 2 Replies View Relatedhow create thread in background for playing sound?
View 2 Replies View RelatedHow can I stop a background thread on keyboard flip in android?
View 1 Replies View RelatedI've read up quite a bit on the exception thrown while using BaseAdapter, but i can't seem to find an alternative solution: Make sure the content of your adapter is not modified from a background thread. What i want to achieve is to keep a copy of a message queue in memory, and use this message queue to populate the BaseAdapter for my ListView. The reason im doing this is that the message queue will keep getting messages from a socket even when the ListView is not currently present (for example a chat window).
The problem comes when i have the Activity with the ListView in foreground, BaseAdapter binded to the message queue's data, and a message comes in the socket. Adding the new message into the queue will throw the exception mentioned above. Unless i pre-populate my BaseAdapter with the message queue (as in the BaseAdapter having its own message queue) and updating both of them when a new message come in, i can't really find a way around this issue. I don't really want to double up the effort on keeping those 2 queues up-to-date like this, surely there is a better way of doing this? Send broadcasts around doesn't work either because of the potential delay in the adapter serving a scroll and the notifyDataSetChanged call is made.
My purpose is very simple : each 1second, I want to redraw an object on different place on background. I do not know where my error on this code below. Here is my code:
public class My_View extends View{ private Bitmap mBackground_img;
private Drawable mMoveObject; private int mObjectw,mObjecth; private int Dx,Dy;
private Handler myHandler = new Handler(); private long lasttime;
public My_View(Context context,AttributeSet ats,int ds) {
super(context,ats,ds); init(context);
} public My_View(Context context,AttributeSet ats) { super(context,ats);
init(context); } public My_View(Context context) { super(context);
init(context); } public void change() { invalidate();
} private void init(Context context) {
Resources res = context.getResources();
mMoveObject = res.getDrawable (R.drawable.lander_firing);
mBackground_img = BitmapFactory.decodeResource(res, R.drawable.my_pic);
mObjectw = mMoveObject.getIntrinsicWidth();
mObjecth = mMoveObject.getIntrinsicHeight();
Dx = Dy = 0; lasttime = System.currentTimeMillis() + 1000;
Thread mthread = new Thread(null,doBackground,"Background");
mthread.start(); } private Runnable doBackground = new Runnable() {
public void run() { long now = System.currentTimeMillis();
if(lasttime < now ) { Dx = Dx + 10; Dy = Dy + 10;
lasttime = now + 1000; myHandler.post(change_view);
} } }; private Runnable change_view = new Runnable() {
public void run() { change();
} };
@Override public void onDraw(Canvas canvas) {
canvas.drawBitmap(mBackground_img,0 ,0 , null);
mMoveObject.setBounds(Dx, Dy, Dx+mObjectw, Dy+mObjecth);
mMoveObject.draw(canvas);
} }
I have written a very simple game with some simple animations, but I've noticed that when the phone checks email, or several other apps are running, the animations that update in my thread start behaving slowly or choppy. This is a problem as the game mechanic requires some careful timing of your screen touches based on the animations. So if it starts behaving erratically, the game doesn't really work well - and isn't much fun.
Is there a way to prevent this? Can my threads have a higher priority when they need to run?
I am working on an application to sync contacts which are large in number. The syncing takes place in a background thread with user being able to browse through the rest of the application. I am displaying the sync status in the notification bar suing the progress bar. The problem I am facing is that there are instances when the activity is killed and hence the background thread used for syncing the contacts is purged.
View 1 Replies View RelatedI've got an Android activity which grabs an RSS feed from a URL, and uses the SAX parser to stick each item from the XML into an array. This all works fine but, as expected, takes a bit of time, so I want to use AsyncActivity to do it in the background. The line items = parser.getItems() works fine - items being the arraylist containing each item from the XML. The problem I'm facing is that on starting the activity, the ProgressDialog which i create in onPreExecute() isn't displayed until after the doInBackground() method has finished. i.e. I get a black screen, a long pause, then a completely populated list with the items in. Why is this happening? Why isn't the UI drawing, the ProgressDialog showing, the parser getting the items and incrementally adding them to the list, then the ProgressDialog dismissing?
View 3 Replies View RelatedMy program does some network activity in a background thread. Before starting, it pops up a progress dialog. The dialog is dismissed on the handler.This all works fine, except when screen orientation changes while the dialog is up (and the background thread is going). At this point the app either crashes, or deadlocks, or gets into a weird stage where the app does not work at all until all the threads have been killed.How can I handle the screen orientation change gracefully?
View 9 Replies View RelatedThe structure of some of my activities is a simple ListView with a custom CursorAdapter. The cursor is created in onCreate() on the activity from a SQLite database. The problem is that querying the SQLite database can be quite slow at times with lots of data (and let's assume I've already optimized the sql query as much as possible). Because it occurs in onCreate() on the UI thread, I get ugly black screens when opening the activity, which sometimes turn into ANRs, on a slow phone like the G1. I want to load the cursor in a background and show "Loading.." on screen while doing so. I saw AsyncQueryHandler used extensively in the framework, but this seems a solution geared more towards Content Providers and not application-local SQLite databases. I then thought of trying to load the cursor in a background thread, but realize that this might be problematic, as the CursorAdapter should be instantiated in onCreate() and should take a cursor as a parameter. The latest thought I had was to instantiate an empty MatrixCursor in onCreate() and pass that to the cursor adapter, while kicking off a thread/TimerTask to query the database. Then, on database cursor load, call cursorAdapter.change Cursor to the properly filled cursor. This doesn't seem very elegant and seems quite wasteful, however.
View 10 Replies View RelatedI am writing my own ContentProvider for my own application. And there is a ListView with a CursorAdapter pulling data from my Content Provider. My question is when there is a data change in my ContentProvider, how can I notify my CursorAdatper to requery the data and then have the ListView updated?
View 2 Replies View RelatedI'm watching this video http://www.youtube.com/watch?v=N6YdwzAvwOA and Romain Guy is showing how to make more efficient UI adapter code using the getView() method. Does this apply to CursorAdapters as well? I'm currently using bindView() and newView() for my custom cursor adapters. Should I be using getView instead?
View 1 Replies View RelatedI was using some of the code from DeskClock and found that when I tried to modify the CursorAdapter that newView was getting called for each item. (I actually wanted to add a divider and it seems like adding the dividers separately is better than adding them into a single listView)
If I have 3 items I get the following behavior:
CODE:.............
I would've expected newView/bindView to be called once per cursor item. But, that doesn't seem to be the case. This was kind of a problem for me because I wanted to select the appropriate view depending on the cursor data, but since bindView could be called before newView that doesn't work.
Is this some odd recycler behavior (or somehow normal/expected)? Or is there something broken with the code (I removed everything except the ListView and it's still doing this)? I'm not quite sure why you would try to bind views that haven't been created, and why newView gets called on the first item twice.
If someone has an easy way of adding dividers to ListViews I'd love to know. I was going to try to dig through the contacts example to see how they did it there if not.
In case anyone's wondering MergeAdapter was neat to mess around with and try (I'll use it in some other situations). But, I did just end up writing a single adapter that handles multiple views. It computes the type of each item (which is small), stores it in a map, initializes it at adapter creation, and updates it in notifyDataSetChanged.
Then you just need to have getViewTypeCount() return the number of possible views. And getItemViewType to return the type from the map (which is 0 based, so 0-getViewTypeCount()). If you can compute your type from the position you don't need the map, but doing this on the fly wasn't possible so I just pre/recompute when needed.
I have a list view with 2 buttons on each row. I am using a cursoradpater to populate the list. I am also using the view holder pattern on newview() bindview().
My questions are: where do i put the clicklisteners for the buttons knowing that the action for the button is different from the action of the list item itself? Do i keep the onListItemClick ?
I am building a custom listview used to list contacts from the contact cursor into a list with two text view for the phone number and name of the contact as well as a place for the images. I am getting a nullpoint error when i try to setText for my TextView Even though i checked the variable to see if they contained a string I have no ideas whats wrong with it. Code...
View 1 Replies View RelatedDoes anyone tried to use CursorAdapter with old and new api?
Do you have some code examples of such solutions?
I have a cursor adapter and the logcat is filled with above errors, as soon as I click on a view. I am already releasing the CursorAdapter's cursor in onDestroy().Is there any way to get information about when the cursor was opened?
View 3 Replies View RelatedI have a CursorAdapter attached to a ListView, the ListView contains checkboxes for every row. When I check/uncheck a checkbox in a row it will update it to a 0 or 1 in the database (This is working fine) I also have another checkbox in the same Activity that when pressed will disable all the checkboxes in the ListView [ setEnabled(false) ].
The problem is that when I press this checkbox the ListView checkboxes return to their initial state when I started the activity. It does not matter the number of checkboxes I changed during the activity.
However, if I press the back button and then re-enter the activity all modifications are saved because the Cursor is refreshed. I am calling notifyDataSetChanged() at the end of the the methods that disables all the checkboxes.
I also tried this for every checkbox in the ListView but it did not work (was unable to check a checkbox) Any ideas?
I have a ListView backed by a custom adapter based on a CursorAdapter.The cursor I give it is based on a list of Notes in the database (each note is a DB row).Everything works just fine until I delete a note from the database. I'm not sure how to properly update the cursor/adapter/listview to display the new data.I've read conflicting posts on using adapter.notifyDataSetChanged() vs cursor.requery() to refresh the UI, but neither of them seems to work in this case.The only way I've been able to refresh it is by creating a new cursor from a new query and calling adapter.changeCursor(newCursor).Could someone demonstrate the proper way to update the backing data and then the UI (with psuedocode if possible).
View 2 Replies View RelatedI'm trying to clean up some code and now I'm determined to get this seemless ListView updating working...
I want my ListView to be updated when I call notifyDataSetChanged() but nothing happens... I'm also passing the autoRequery flag to true when creating my CursorAdapter.
Cursor c = FavoritesHandler.getCategoryFavorites(getSQLiteInstance(), category); m_favoriteAdapter.changeCursor(c); startManagingCursor(c);
How can I implement a run() method of thread if I create a Thread Global?
I mean If I create a Thread Globally then can I implement its run() method {" public void run()"} anywhere in my Application?
In the run() method I have to write the code to perform some action.
IF I can do it then please can anyone show me briefly how to do it particularly.
I am writing an application in which i need to handle messages between the main thread(the deafult UI related thread) and the user created Gamethread.
The requirement is like this.
An activity(say "Activity_X") is setting the view by "setContentView(some "View_Y")". In "Activity_X" i have implemeted "onCreateOptionsMenu()" and "onOptionsItemSelected()" fucntions for creating menus & a switch case for action to be taken on selecting those menus.Menu has items like "resume/pause/zoom/" .
All action to be take on selecting these menus are implemented in "View_Y" in a separate Gamethread by extending "Thread" class.
So whenever a menu is selected in "Activity_X" i need to send a message to "View_Y". And on receiving this ,a particular action/method should be called in View_Y(GameThread).
How can i achieve this using Handlers?Is there any other way of doing this? Please do share with me some code snippets for these.
I have a separate thread running to get data from the internet. After that, I would like to update the ListView in the main thread by calling adapter.notifyDataSetChanged(). But it does not work. Any workaround for that?
View 1 Replies View RelatedI want to do the drawing in another thread to speed up the game(it is way to slow right now). I was told to do this but don't quite understand why that would speed things up. Is it GameView that should implement Runnable? Should I make the thread sleep when not drawing? where should I start the thread? package com.android.WWS;
import android.app.Activity; import android.content.Context; import android.graphics.*; import android.os.Bundle; import android.view.SurfaceView; import android.view.KeyEvent; import android.view.View; import android.view.View.OnKeyListener; import java.lang.Runnable; import java.lang.Thread;...................