I need to download an image from the internet,in a different thread,and then send that image object in the handler message, to the UI thread.And by the way, is this the most efficient way to pass an object to the UI Thread?
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I have recently hit a snag using the Android plugin to Eclipse. For some reason, ALL of my errors being thrown don't initialize and show me the error. Has anyone ever seen this issue before and if so, what did you do to correct it? In particular, I am seeing it when I try to invoke the HTTPGet in a HTTPClient object. If I have no connectivity, then I should get an error. The Catch block does fire when this occurs...however, when I check my general Exception object, the object is NULL (NULL Pointer). Why would this happen if the catch is grabbing the exception?
My exceptions used to be working and I was able to see the stack trace. However, I can no longer see any stack trace regardless of the Exception class I am using. Can someone please help me understand what the heck is wrong with Eclipse, Android, or both? Is there something I am missing on the configuration side?...is this a bug? Mind you, I have already used Stack Overflow for this question. It has been viewed 40 times but no answer yet.
I have an "open" animation and am using Handler.postDelayed(Runnable, delay) to trigger a "close" animation after a short delay. However, during the time between open and close, there is possibly another animation triggered by a click...my question is, how would I cancel the "close" animation in the handler?
View 1 Replies View RelatedI have an app with a two threads - main and data loader. When data loader finishes it posts a Runnable object to the main thread (as described in the DevGuide), but it never gets delivered and run. Here's the basic code:
class MyApp extends Application{
public void onCreate()
{LoaderThread t = new LoaderThread();
t.start(); }
private class LoaderThread extends Thread {
public void run()
{ SystemClock.sleep(2000);
boolean res = m_handler.post(m_runnable);
if(res)
Log.d(TAG, "Posted Runnable"); } ............
connect / login are executed in the same thread of the caller, then are blocking - The packetlistener callbacks are called from smack receiver thread - The sendpacket enqueues the message to a queue. when I receive a message, I need to propagate it. I can use an handler, but it only gets the runnable object. How can I pass the data to the runnable called by the handler? I can't use a local variabile, because if I receive a lot of messages it will be overridden and I will loose some of them. Is it ok to use a queue to feed the runnable? Are there other techniques?
View 3 Replies View RelatedI was curious about the nature of the handleMessage() and sendMessage() behavior of the Handler class. I want to be able to send message to another thread in such a way that the destination thread can process the message queue when it wants to. It seems, however, that the message is processed by handleMessage() practically as soon as it's sent.
I'm trying to design a game loop thread that does something like this:
CODE:.....
However, I as soon as sendMessage() is called (from the parent/calling thread), the Handler.handleMessage() is processed (in the child/receiving thread), even if the child/receiving thread is blocking in a while loop.
I've seen this problem solved in other games by using a thread-safe list (ConcurrentLinkedQueue). The UI thread just posts events to this queue, and the game loop can remove the events as it seems fit. I just assumed the Handler class was designed for this purpose. It seems it's more intended for asynchronous callbacks to the parent thread.
I am using an Executor [fixed thread pool] with my own ThreadFactory that adds a Looper:
CODE:...............
I am running a thread that makes network requests but if the network fails I would like a dialog message to be displayed to the user. This process is rather involving since it requires making AND displaying the request in the UI thread. I can wait for the user's response to the dialog by simply adding a Loop to the network thread and wait for a message to be send from the UI thread. This allows me to encapsulate the network requests in a while(tryAgain) thread. All works well except when the Looper.loop() method is called the second time (after a second network error dialog is displayed) and a message is sent by the dialog (in the UI thread) to the network thread's handler:
CODE:.............
In the AlertDialog instance is an OnClickListener:
CODE:...............
I've checked that the thread is still active with handler.getLooper().getThread().isAlive() which always returns true but it still gives me "sending message to a Handler on a dead thread". How is it that the Message/Handler has decided that the thread is dead? Shouldn't it rely on the .isAlive() method? In the end I am trying to avoid replicating the thread management build into the Android OS .
For example, say the main Activity has an custom object foo with a method called bar. When foo.bar() is called via the activity, it does a bunch of things on a thread and when it is finished it would somehow alert the main ui thread, the activity, it's parent that it is finished.
I imagine this working the same way an event like a OnClickListener works. The bar() method would trigger an event saying "Hey I'm finished" and that would trigger the listener on the main activity.
I want to do some automated testcase with Instrumentation . Suggest that my AUT has 2 Activity. After clicking the button in ther first Activity, the second one will be shown with new content base on what we enter in the first Activity.) Instrumentation provides us the function called startActivitySync() and return the Activity object for processing. My question is how we can get the pointer of the second Activity after the it is shown by clicking the button on the first activity.?
View 2 Replies View RelatedI would like to convert a Picture object to Bitmap object in memory, without writing data to disk.
View 2 Replies View RelatedI have an Activity that running on system. I can get the Intent that is used to start the activity. But i don't know how to get the Activity object from the Intent object or something else. Can anyone tell me how to do this??? Note that, I don't use Instrumentation object.
View 11 Replies View RelatedI am trying to get a FileInputStream object on an image that the user selects from the picture gallery.
This is the android URI returned by android.provider.MediaStore.Images.Media.INTERNAL_CONTENT_URI content://media/external/images/media/3
When I try to construct a java URI object from this object, I get an IllegalArgumentException with the exception description Expected file scheme in URI: content://media/external/images/media/3 whereas the android URI shows the scheme as content
Never found a solution for the original question. But if you want the byte stream of an image in the pictures gallery, this piece of code will do that.
CODE:...................
I am working on an application wich has its own URI prefix. (dchub:// in this case) is there a way when someone open his browser, clicks on a link starting with dchub:// my app starts using this address? so far found a lot of examples the otherway around opening the browser from your app but thats not what i'm looking for.
View 1 Replies View RelatedI've got 2 classes GLLayer and GLCamTest. I'm attempting to run a method located in GLCamTest...
CODE:..........
I'm looking to run in on a thread from GLLayer but from what I understand I need a Handler..
CODE:.........
I'm starting the Thread from within public void onDrawFrame(GL10 gl) { my question is how would I implement said handler? I've read http://developer.android.com/reference/android/os/Handler.html but I still don't really understand how I'd implement it.
I am very confused about handlers and looper can anyone plz explain it in simple terms to me any good links would be great.
View 3 Replies View RelatedI'm confused as to when one would choose AsyncTask over a Handler. Say I have some code I want to run every n seconds which will update the UI. Why would I choose one over the other?
View 3 Replies View RelatedI'd like to know if Looper can enable handler to handle one message at a time, instead of handling all the messages in the queue together in one blocking call when Looper.loop() is called.
Because the looper sends all the messages in the queue to the handler one after the other in one blocking call, my application displays the ANR message. Instead, I want to be able to handle one single message, one blocking call at a time - the instant it falls into the queue.
The following code illustrates my problem: (pls note the lines referred: 1,2,3,4&5) Question 1: After calling looper.loop in line3, line4 and 5 don't run. Why is this? I tried quit(), but it doesn't help. Question 2: Instead of displaying 0,1,2,3,4 in one blocking call (at line3), I'd like to have 5 different blocking calls for each. Essentially (sorry, if i sound repetitive), I want to be able to use looper in such a way that each time, it ensures only one message gets handled.
Is there a way to do this?
CODE:..................
I've read the android AIDL documentation and have a general idea of how RPC works between an Activity and a Service. However, for my application it seems overboard to implement such features: basically, I want to pass a Service a nice handler so its thread can pass data to my Activity. Currently I'm getting around this by using a static public member (a hack) but I would prefer just passing a Handler object in the Service's starting Intent. However since a Handler isn't serialize-able , I haven't found a way to pass it to the service without a simple static member hack. Any insight? Or, am I just going to have to suck it up and do a formal RPC to the service?
View 1 Replies View RelatedI am using a handler inside my service to display notifications at a certain time using the Handler.postDelayed method. My application runs fine on the emulator just as expected satisfying all cases. But when I installed the same on my HTC Wildfire, it simply doesn't happen as anticipated. Notifications are displayed at a random manner after the scheduled time and some notifications even fail. I'm monitoring my service from the Applications > Running Services and still my service is active.
View 1 Replies View Relatedi want to do the following thing - when a user navigates to a web page, I want to have a link in there that looks like this: <p><a href="myprotocol://blah=42">Click here for fun.</a></p> Then when the user clicks on that from the phone browser, I want it to launch my intent with that full url. In my AndroidManifest.xml file, I have the following info: <activity android:name="com.test.MyActivity" style="@style/ MyStyle"> <!-- custom protocol association --><intent-filter><action android:name="android.intent.action.VIEW"></action> <category android:name="android.intent.category.DEFAULT"></category><category android:name="android.intent. category. BROWSABLE"> </category><data android:scheme="myprotocol"/></intent-filter></activity>When I try this, when I click on the link on the web page from the phone browser, it says -- Web page not available The Web page at myprotocol://blah=42 might be temporarily down or it may have moved permanently to a new web address.
View 20 Replies View RelatedI'm trying to call a web server that is using relative URL redirects for some of the calls. This of course isn't working with DefaultHttpClient as it isn't treating it as a relative URL. I've gotten as far as implementing a RedirectHandler in an attempt to catch the redirect and add in the base call but I can't work out how to get the location of the redirect.
With the following method how do I go about finding out where I am being redirected to? I can't find any fields on either response or context that have what I need and I don't know where else to look.
public URI getLocationURI(HttpResponse response, HttpContext context)
Assume that there activity A and B, A has a handler, now B is activate by A, how can i pass the handler to B? Currently i have a thread receive messages from socket, and dispatch messages to A and B, I think when B is activated, pass handler to B, then the handler can receive message from the thread. But I don't know how to do.
View 3 Replies View RelatedI need to update my ui for an android app and I'm trying to use the Handler class to do it, using http://developer.android.com/resources/articles/timed-ui-updates.html and the android developer resources "Common Task" for using Handlers as guides.
Basically, I need something between the two - a timed update of the user interface, but without a button. So here is the relevent code that I am working on.
CODE:...............
I will try to keep it simple:
In my main activity I make a handler:
CODE:.......
CODE:......
But if I call the handleMessage method from a callback function in a other Class, definitely from a other thread, I still get the exception message: CalledFromWrongThreadException (Only the original thread that created a view hierarchy can touch its views) :
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I created a full-screen application and set the default orientation to landscape. When I open the keyboard the application crashes therefore I would like to override the method which executes on keyboard slide. Does anyone know which method is that?
View 1 Replies View RelatedIn Handler, we can pass some data from a background thread to the UI thread like this:
private void someBackgroundThreadOperation() {
final String data = "hello";
handler.post(new Runnable() {
public void run() {
Log.d(TAG, "Message from bg thread: " + data);
}
}
}
If we use the above, we cannot then use Handler.removeCallbacks(Runnable r), because we won't have references to any of the anonymous runnables we created above. We could create a single Runnable instance, and post that to the handler, but it won't allow us to pass any data through:.............
I made a simple countdown timer and it works as expected when plugged in via usb for debugging but when I take it off debugging and the screen goes off either time out or power button the handler fails to fire at the end time. I have created a custom timer class that gets created from the main activity when needed, because its able to have multiple countdowns running at the same time. Am I right in thinking that the handler just gets paused when the screen goes off and if so what are my alternatives. The activity is still in the foreground and I assumed the handler would still fire if the screen goes off.
View 13 Replies View RelatedMy program threw a NullPointerException the other day when it tried to use a Handler created on another thread to send that thread a message. The Handler created by the other thread was not yet created, or not yet visible to the calling thread, despite the calling thread having already called start on the other thread. This only happens very rarely. Almost every test run does not get the exception. I was wondering what the best way is to avoid this problem for sure with minimal complication and performance penalty. The program is a game and very performance sensitive, especially once it is running. Therefore I try to avoid using synchronization after setup, for example, and would prefer to avoid spinning on a variable at any time.
View 2 Replies View RelatedThe first time issue it i give null as parameter to the function to the selection parameter is empty, meaning i don't filter any rows. The problem is i get only contacts i created myself using no syncAdapter. I used facebook app to synch my facebook contacts, but this query doesn't return them. I extracted the contacts.db from the emulator and the view_contacts view shows me all the contacts, so the DB is updated. What should i do to get all the contacts regardless of how they were created (with which synch adapter)
View 1 Replies View RelatedI wish to analyze the various data passing through the browser. I would need a handler of the browser to query the contents. Is there any way that my application can get this handler of the browser and query for these data.
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