I am writing an activity, that loads data from a server and displays it as a list using ArrayAdapter. For that I'm showing a progress dialog i.e loading, while it loads all data from the server. Then i dismiss the dialog in a handler. My problem is that when ever i change the orientation, the progress dialog is again shown, which is not needed, because all the data is displayed already?
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I have a TabActivity, and each Tab corresponds to its own Activity. In one of them, in the onCreate method, I use startActivityForResult to show a dialog (specifically, Bump's BumpAPI activity).
code:...............
The problem is that when the screen orientation changes, it tries to create the tab's activity again which makes another BumpAPI dialog, resulting in multiple stacked on top of each other. Do I have a hook into the started activity to cancel the previous one when the orientation changes?
A workaround seems to be to add a button that when clicked, starts the second activity, but that adds an unnecessary step.
Also, I can't fix the screen orientation for the entire tabActivity because some of them require typing and users may want to use their physical keyboards.
I know that by default a screen orientation change destroys and recreates an activity, so the activity can load new layout, drawable, and string resources.
I also read about using onRetainNonConfigurationInstance() to save an Object before rotating and getLastNonConfigurationInstance() to restore it after.
But realistically, what are the special cases when an app would use android:configChanges="orientation|keyboard|keyboardHidden" to avoid activity recreation during orientation change? Are there any gotchas involved in using configChanges?http://developer.android.com/reference/android/app/Activity.html#Conf...
I have created an activity for my game which handles all orientation changes by itself and has a fixed "portrait" layout. Actually it uses the accelerometer and is rendered using 2D canvas methods. If the level has been completed I show up a highscore dialog in which the user can enter his name. The dialog is floating above the underlying level screen which gets blurred out nicely. This generally works.
Problem is that the dialog does not get rotated if the orientation of the phone changes. So even if the keyboard is exposed the dialog is shown in portrait mode instead of landscape. I have tried to use an activity with dialog theme instead but the behavior didn't change. After several tries it seems that I have found the reason for this: Once there's an activity with fixed orientation in the activity stack then all subsequent activities keep this orientation, too. They will not react on orientation changes anymore (e.g. if the keyboard gets exposed).
After upgrading to 1.5 SDK the described behavior changed a little bit. Now at subactivities indead react on orientation changes like expected. However, the need to have an opaque background! That means that neither dialogs nor activities with dialog theme will work. Those will stick with the orientation of the underlaying activity. So my workaround is to first start a sub-activity with an opaque black background. This activity then shows my highscore dialog on top. It looks quite okay but I wonder if there's a better solution? Is it possible to show a dialog above a fixed portrait or landscape activity which automatically adapts to orientation changes?
Maybe I'm missing something obvious, but how do you handle orientation changes for a Cupcake desktop widget?When it is initially created, the onUpdate method of my AppWidgetProvider calls views.setOnClickPendingIntent(buttonID, pendingIntent) to register for my button events, but when the orientation changes, new buttons are created and I don't have an opportunity to re-register the "onClick" listeners. What is the proper way to do this?
View 6 Replies View RelatedI have an app that communicates with a server.While it is communicating, it shows a progress dialog.The way this actually works is that I have a class that I call my Network Gateway.Each method takes a Handler as a callback so that the gateway can send back the response as a bundle when it has finished. Right now when someone changes orientation while a network operation is occuring, the activity doesn't know that a thread is running the network code and then the callback might be invalid.What's the right way to do this? I want to make it so that after the orientation switch, the activity can check something to see if a network operation is running and if so, display the progress dialog again and wait for the callback, or set itself as the callback handler now, invalidating the old one.My first guess is that this is exactly the kind of thing services were designed for, but I'd like specifics if anyone can supply them.
View 25 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 RelatedWhen views with different type have same id and screen orientation changes,
either java.lang.ClassCastException: android.view.AbsSavedState$1 or java.lang.IllegalArgumentException: Wrong state class -- expecting View State will occur. (depends on the view's order)
Because View.dispatchRestoreInstanceState() checks id only.
You may wonder why anyone would make views with different type to have same id.
But it can happen when you use tab activity.
Imagine you have tab activity with two children activity.
Tab1 is ListActivity and Tab2 is ExpandableListActivity.
Both activity have id of "@android:id/list" but the type of view is different.
This means we cannot use ListActivity & ExpandableListActivit at the same in one tab activity.
I'm having difficulties handling multiple instances of my root (main) activity for my application. My app in question has an intent filter in place to launch my application when opening an email attatchment from the "Email" app. My problem is if I launch my application first through the the android applications screen and then launch my application via opening the Email attachment it creates two instances of my root activity. steps: Launch root activity A, press home Open email attachment, intent filter triggers launches root activity A Is it possible when opening the Email attachment that when the OS tries to launch my application it detects there is already an instance of it running and use that or remove/clear that instance?
View 1 Replies View RelatedHow to handle Home key....Plzz Help me out.We can handle Home button.if you have seen the Nexus One device...when u reset the phone ..and switch it on again some tutorials kind of thng comes..at that time wen u press the home button its not taking u to the Launche Activity...if its not possible then how they are handling over there.I want the Answer..No one in this Blog has any idea how to handle it....or no one has tried on this..sum are sayng that we can handle it by PhoneWindowManager.java class,some r sayng we can handle it by Using onNewINtent() method.But the Question is how we can handle it by these two ways...Just provide me the sample code..where we are handling the HomeKey.
View 9 Replies View RelatedI have an Activity that will query a RESTful API every x seconds (polls using a handler). The results of the GET are used to update a ListView. This is done using an AsyncTask.
I want to put a Notification in the Notification bar when certain criteria are met in the new data. Everything I have read up to this point has suggested that notifications should be created and updated using a service so that the notifications can be made even when the application isn't in focus. I see the positive aspects of this.
However, I'm unsure if I should just create a service from within my activity or if I need to do something more complex than that. I'm undecided on if I should scrap my AsyncTask model in favor of using the Service to update my list view.
So, my questions are:
1) Is there a good tutorial showing how to make a local service from an activity?
The tutorial doesn't need to show how to make them communicate, the service could be isolated from the main activity.
2) Will #1 provide me with the notification benefits I'm looking for? (Notifications are generated even when the main app isn't visible)
3) Should I use this same service to update my listview?
The service would basically be making the same query that the AsyncTasks are, just doing different things with the results. The app would seem to make more sense to have the Service query, do notification processing, then give the results to the activity, but I haven't found a good resource that clearly demonstrates how to do something like this.
I am tring to invote internal media player of android from my activity. Seems there is some problem in menifest file .
Please look into this issue .
CODE:...........................
I have a problem regarding my intent. It seems that my app crashes when i select the intent. I found the line of error code due to the stack trace. But i couldn't find anything wrong with it. Hope anyone can help me with this.
This is the java code in line 121:
CODE:..............
This is the stack trace:
CODE:....................................
I'm having a couple of problems with an alarm app I am developing.
The first thing that I think is a bit weird is that when an alarm goes of and wakes the phone up. These things happend.
oncreate
onresume
onpause
onresume
Why are they run in that order? The last two should not be called? And this is what's causes me big trouble, because when i press home or back on the phone, onPause is run, which I want to call finish() from. And that part works as it should, but that does not work when the phone wakes upp from sleep bacause of the onPause call...
test.class type is right? How to? What should I do?
CODE:...............
I need my Android app to save it's state to disk when its activity is put in the background or killed. It's been suggested that I start a thread when onPause() is called and perform any expensive I/O procedures there (see http://stackoverflow.com/questions/3894668/saving-loading-document-state-quickly-and-robustly-for-image-editor).
In what situations will the OS kill the thread and how commonly do these situations occur?
I assume it will be like how Activities are dealt with where the OS can arbitrary decide to kill the thread but will mostly only do this when resources are extremely limited. It would be nice to find some specific documentation of this though.
From playing around, with some test code, a background thread started in onPause() will run indefinitely in the background on my device (I tried loading lots of apps and couldn't get it to be killed).
For my specific app, I'm writing a bitmap editor where I'm using the Command pattern and the Memento pattern to allow undo and redo of edits. I'd like the user to be able to undo/redo their edits even e.g. the user gets a phone call and the activity is killed when it is put in the background. The best solution I can think of is to use a background thread to constantly save my command and memento objects to disk during application use and to finish up saving any objects that are left in a background thread if onPause is called. In the worse case, if the thread is killed I'll only lose some edits.
I have an Android activity which in turn starts a thread. In the thread I open a persistent TCP socket connection. When the socket connects to the server dynamic data is downloaded. The thread sends messages using Handler-class to the activity when data has been received. Now if the user happens to switch from portrait to landscape mode the activity gets an onDestroy call. At this moment I close the socket and stop the thread. When Android has switched landscape mode it calls onCreate yet again and I have to do a socket re-connect. Also, all of the data the activity received needs to be downloaded once more because the server does not have the ability to know what has been sent before, i.e. there is no "resume" feature.
Thus the problem is that there is alot of data which is resent all the time when landscape mode is changed. What are my options here? Should I create a service which handles the socket traffic towards the server thus I always got all the data which the server has sent in the service. Or should I disable landscape mode all together perhaps? Or would my best bet be to rewrite my server which is a VERY BIG job
Suppose I have something like an alarm activity which launches the alarm through the lock screen, accomplished via
getWindow().addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);
Now, from here I could press the back button to kill the activity, but I also want a press of the lock button to silence the alarm. How would I go about creating a handler for presses of the lock screen button?
I wrote CustomView Class, and load it in layout. so i trid to find CustomView using findViewById() in activiy to get handle. but findViewById() was return null.
Written Code is like below:
CODE:.........
MapCanvas.java:
CODE:...............
How does my android activity know (is there a callback) when there is a change in screen orientation?
View 1 Replies View RelatedI know on screen orientation changes activity restarted, but suppose i don't want to restart the activity then what should I do? I had tried it by adding in manifest.xml. android:configChanges="keyboardHidden|orientation"
and override public void onConfigurationChanged(Configuration newConfig) { super.onConfigurationChanged(newConfig); }
But still activity restarted each time when I change screen orientation.
I am having an interesting problem and would appreciate any advice. My app uses WebView as its primary view. Using a javascript hook, it can launch the camera so the user can take a picture. The camera is launched using: Intent i = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
When the camera starts, it makes sense to use landscape mode, so the user naturally turns the phone on its side. After the user takes a picture, control returns to my launching Activity (actually, my Acitivity gets restarted because it usually gets destroyed to free up memory for the camera on my Moto Droid). When my WebView gets recreated, I restore its state from the Bundle I saved in onSaveInstanceState().
Now everything looks ok, except the phone is still in landscape mode. However, when the user turns the phone upright bringing back into portrait mode, my WebView takes up only half of the screen. Somewhere along the way, the scale of my WebView got lost. This seems like such a minor issue, but it is driving me crazy.
Does anyone have an idea why this might be happening? What is the correct way to preserve the scale of my WebView? I am hesitant to hard code any scale factors because what looks good on my device may not be the same for another.
I finally got to the point where I was ready to deploy my app to my G1 and test it out and the first thing I noticed was that when I change my phone to landscape view my main activity restarts and resets all of my variables to their default settings. How can I avoid this?
View 7 Replies View RelatedMy main activity has some code that makes some database changes that should not be interrupted. I'm doing the heavy lifting in another thread, and using a progress dialog which I set as non-cancellable. However, I noticed that if I rotate my phone it restarts the activity which is REALLY bad for the process that was running, and I get a Force Close.
What I want to do is programatically disable screen orientation changes until my process completes, at which time orientation changes are enabled.
It is possible to set the orientation of an activity in the manifest file. but is it also possible to do it from code? if so, how?
View 2 Replies View RelatedI m currently working on landscape mode for android app in which i want to know how to maintain the state of the activity and views displayed on orientation change i.e from portrait mode to landscape mode ?
View 3 Replies View RelatedI am working on a MVC implementation for Android (to be subsequently hosted on SF and/or GC).
It works like this:
Activity (View) <=> Application (Controller) <=> Data (Model) <=> Persistence (DB/Network etc)
The scenario is:
1. Activity launch (main/launcher)
2. Notifies Application about performing a data transaction
3. Upon receipt of data response, controller devices which Activity to launch (or update existing)
4. Application has overridden the method onConfigurationChange
Problem: When the orientation is changed, the Application is notified about onConfigurationChange but:
a) The "current" activity is Destroyed and recreated -- which is fine to some extent b) The new instance which is created is automatically => onCreate, onPause, onStop, onDestroy.... now that's catastrophic.
My MainActivity (the one that is started by the android application) is a TabActivity which contains several tabs (which are implemented as activities as well). In a certain tab/activity I want to prevent the change of orientation/rotation when the phone is turned. What is the easiest way to achieve this?
View 2 Replies View Relatedi've developed an android app that's fetches an xml file and displays this data via several markers on the map. This works fine so far. The problem right now is that when i switch the orientation of the phone (portrait->landscape or vice versa) the markers disappear for a small moment, the xml processing is started again and then they reappear. Is there a way to prevent this re-loading of the file? It only takes about 2-3 seconds.
View 2 Replies View RelatedCan I temporarily disable automatic orientation changes in my Activity? I want to do this when my app does some background internet communication.
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