Android :: What Exactly Is Handler And Loopers
Jun 29, 2010I 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 RepliesI 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 RepliesI 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...
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I'm looking to run in on a thread from GLLayer but from what I understand I need a Handler..
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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'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?
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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.
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I will try to keep it simple:
In my main activity I make a handler:
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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 RelatedI 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?
View 2 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.
View 5 Replies View RelatedI have to post messages from one process to another process by using handler .
I am using Handler.post/Handler.sendMessage but i am not getting those messages in another process. I am not getting any exceptions also.
Is it possible to sent messages across processes using Handler?
If it is the case how can i do it?
I have implement the following code in order to test playing a video from a remote web server through itīs URL.
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The code is working just fine, even in the Android emulator. I just would like to know if there's any listener (or handler) to detect the finish of the video that is being reproduced?
I would like to show a number of alertdialogs so the user has to handle off some questions (a little like a wizzard)
Is it possible to make the alertDialog wait until the user chooses something and then returning the choisen value?
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The execution of the program should wait until the user chooses 1 of the options in the alertDialog is this possible?
Like this:
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I have a class that uses a Handler for a timed, asynchronous activity.
Something like this:
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I seem to be having trouble with updating a TextView from a thread. I have a GameConnection class (which manages a socket connection) which I want to use across activities. It calls a local "onMessage", which then uses the target handler to call dispatch Message. The "Handler" in this case, is in my GameBrowser activity.
Here's code from the GameConnection class.
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As said above, a local method "onMessage" method handles dispatching of the message.
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However, when I get the response in the GameBrowser class, I get a CalledFromWrongThreadException . Initially, I was using a callback method, which of course wasn't working. So, after some research, I've found that I have to use a Handler, but I can't seem to get it right.
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My Problem is that I need to send messages with a delay of 1 second. The handler then initiates some action, you're getting the picture. There are nevertheless some conditions in which the already sent message should be deleted ( before the second elapsed ) to prevent the handler from doing anything. I couldn't figure out how to do this ( or if it's even possible ), so If anyone of you has a clue, please let me know.
View 2 Replies View RelatedIve set an in a running service a handler which does operation every X time. Now after certain time i wanna start an activity from that service, and in onCreate of the activity i wanna access that handler of the service(which started the acitivty) and stop it's schedualed operation
(mHandler.removeCallbacks(someTask));
any idea how will i access the handler which is in the service? the service and the called activity are in the same proccess.
I have a simple, classic, statement that every 200 milliseconds plays a sound (a metronome). I wrote it using Handlers, and then in another way, using Threads. The problem is the same in both ways: when I press hardware home button, or also simply when I press a button to open a ListView, the metronome terribly slowdown for a while. This problem (not so strong, but however present) presents also doing nothing and leaving the application in foreground. Any ideas?
View 2 Replies View RelatedI try to make several connection in a class and update the multiple progressbar in the main screen. But I've got the following error trying to use thread in android : Code: 05-06 13:13:11.092: ERROR/ConnectionManager(22854): ERROR:Can't create handler inside thread that has not called Looper.prepare() Here is a small part of my code in the main Activity.
public class Act_Main extends ListActivity
{ private ConnectionManager cm;
public void onCreate(Bundle savedInstanceState)
{ super.onCreate(savedInstanceState);
// Set up the window layout
requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
setContentView(R.layout.main);
getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.custom_title); }
public void startConnection() { ......
I am hoping to create my own protocol handler for urls in a webview. I have tried two approaches already. The first was to attempt something similar to the approach defined here to create a customer protocol handler. http://java.sun.com/developer /onlineTraining/ protocol handlers / This works in a command-line Java program if I correctly set the system property java.protocol.handler.pkgs, but it does not work in Android, probably because I cannot figure out where to define this system property. Defining the system property in the code does not work. I assume this is because it needs to be loaded when the application first starts. I have also attempted to use URL.setURLStreamHandlerFactory. This works for creating URL objects within the code, but it does not seem to be associated with the WebView. Any ideas on how to get this working?
View 6 Replies View RelatedI am using a class which extends Handler class to update my activity UI.
The code is as follows in side main activity...
But here i am facing one problem that is it is running after closing my application also .
please solve my problem to stop this handler when close this application.