Android :: How To Tell A Thread From A Previous Instance Of Your Activity Has Finished
Oct 31, 2010
I'm writing a bitmap editor and I'm trying to write an autosave feature. When onPause is called, I write the application state to an autosave file. As this takes between 0.1s and 1.5s, I've been advised this IO operation be performed in a background thread.
In the onCreate method of my activity, I check to see if the autosave file exists and, if it does, I open it.
Are there any scenarios I have to consider where the user can somehow leave the activity, the autosave thread starts and the user can return to the activity before the thread has finished? If so, how can I detect this and wait for the thread to finish before I check the state of the autosave file?
I was going to make it that, when the user backs out of my activity, they're asked to wait a second while the data is saved. This seems OK, but I can't do this when my activity is interrupted by something like a phone call.
Also, I'm a bit confused about how multiple versions of the same activity can be started as this makes dealing with autosaving more complex. Is there a way to make sure only one instance of my activity is allowed to run at a time?
View 2 Replies
Apr 20, 2010
I am using an Application object to store app-wide instance data--data that I need to remain in existence for the entire lifetime of the app, so the Application class seems like the proper place to put it. I have just finished reading this thread http://groups.google.com/group/android-developers/browse_thread/threa... that goes into pretty good detail and receives confirmation from Googler hackbod as to how the Application class performs--and from that info it seems this strange behavior I am receiving should not be happening...
Basically, every once in a while when I resume my app in any of its Activities (it is still running in memory so onCreate is not called) I get NullPointerExceptions because instance variables in my Application class are returning null when I request them from my Activity (via a getter method in my custom Application class). It seems as if sometimes Android saves the states of my Activities but deletes all my instance variable data... This can't be an Android problem--there must be something wrong with my code.
Has anyone else ever ran into an issue of this kind? Any ideas as to what may be causing this? I'm not going to post my code here as that won't help anyone, but hopefully someone can point me in some helpful directions.
View 11 Replies
View Related
Jul 1, 2010
Im trying to show a ProgressDialog while the activity is loading. my problem is that although i completed all the work in the activity. it takes a long time for the activity to load, i suspect this is because i use
multiple views with multiple listviews with custom array adapters inside a viewflipper. it takes a long time for the UI to show.how would i go about checking that all the UI inside the activity finished loading? or is there a way to preload all the activity and the UI?
View 2 Replies
View Related
Apr 27, 2010
How to finish any previous activity in application stack (at any level , I mean not immediate parent) , from current activity like on some particular event I want to invalidate this previous activity?
View 1 Replies
View Related
Nov 5, 2010
The default behavior from my observation is if current activity force closes Android tries to go to previous activity on stack How can I control this behavior? I want force close to close all activities
View 2 Replies
View Related
Jul 9, 2010
I have a Contact Activity which is derived from ListActivity, which displays list of contacts, and on click of item, a new Activity Message Activity derived from ListActivity is initialized.Now I know, I can pack some information in Bundle and pass it before creating activity, but is there a way I can get instance of "ContactActivity" in onCreate method of "MessageActivity"?
View 1 Replies
View Related
Dec 30, 2009
I am developing an application in which the user require to register first and than got the user page. For that i have made layout and the layout consist many fields, so, i have made part of layout and also made the separate activity for the each layout. The layout like address, phone, etc... After that i have wrote the code for calling an activity and it works fine. It means when i press the "Next" button the another page will come and it will also consist some textview ,edittext and previous and next button. Actually, i want something different like -- When the user fill the first form and he will proceed to next, the content written by the user should not gone when the user press "Next" button. The content should be there which was written by user. And same way i have have 6 pages like that way to complete the registration process. So, have you any idea to solve above problem? I really need your help because right now i stuck at this point. So, please any body help me out of this problem. I would appreciate your help. I am waiting for your reply.
View 15 Replies
View Related
Apr 3, 2010
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 Related
Jul 9, 2010
Is there a way to get an instance of the activity that has called the currently running activity from the intent object that has been passed to it? eg. if A has called B, I would like to retrieve A's instance from the intent in B's onCreate method. As Activity is not Serializable i am not able to pass the instance in the extras bundle.
View 1 Replies
View Related
May 9, 2010
I have a bunch of tab activities (which I implemented myself, didn't want to use the tabviews with activities inside them), so It's basically 5 activities calling each other every time the user clicks on the tabs displayed as a row of LinearLayouts at the bottom of the screen.
The thing is that the way I do it now, everytime the user jumps from one activity to another, a new activity is created and launched. Of course, I can see I'm wasting resources this way. So what I would like to do is to create every activity only once; and then if the user wants to go back to the previous (or any one that was already created and is probably paused) just check on some kind of list or array to see if the activity can be recovered and only in the case it can't; to lauch a new one.
My question is, how can I check this? should I save the intents? and how to recover the activities afterwards? I'm kind of new with java.
View 2 Replies
View Related
Jul 19, 2010
Is there any way to get the instance of a launched activity(or any view in that activity )of a application in another application.
View 1 Replies
View Related
Aug 16, 2010
We all know that hitting the back button on the device doesn't kill the application, it merely finishes (destroys) the activity running on the foreground.
Well I have come across some code which helps me capture the back button signal so that I cannot exit the application. The only way to exit it in such cases is to press the home key.
Now this situation presents me with a unique disadvantage! The inability to kill finish the application on a time of my own choosing allows the application to keep running in the background like nothing has changed.
So in such cases is the task manager my only friend or is there a way for me to otherwise kill this application?
View 2 Replies
View Related
Sep 2, 2010
Is it possible to create/push-onto-stack a new Activity of the same main Activity in an Android application with an argument passed to the Activities constructor? Specifically from a Dialog object...
View 1 Replies
View Related
May 21, 2010
My app consists of an Activity and a service that runs in the background. The service periodically checks a website for an alarm condition. When the service detects the alarm, it should put a user notification into the status bar. If the user clicks the notification, it should display the app's activity. If the activity is already running, that activity should become visible. If the activity is not currently running, it should be created.
However the notification created by my service *always* creates a new instance of the activity, whether the activity is currently running or not. How do I get the desirable behavior?
Here is my service pseudo-code:
CODE:...............
View 3 Replies
View Related
Jul 24, 2009
This is an intermittent bug in one of my apps. I don't expect anyone to solve it immediately, but I'd appreciate any thoughts on how to start debugging!So, my app lets users edit an item (in the EditPage activity). When they press the Back key, the desired behaviour is that it saves their edits and returns them to the home page (the HomeList activity). The code for this is below. It works fine. Except.The bug is this. Some users report that sometimes when they reopen the application after a pause, they are seeing *not* the home page, where they left the application - but the previous edit activity. Crucially, they are also seeing the edit activity without their saved edits - effectively losing their most recent edits.I've been able to reproduce this myself. It only happens after the application hasn't been opened for a while. If I save something, minimize the application and reopen it straight away, it shows the HomeList activity just fine, and the edits have all been saved. But if I save something, leave it for a couple of hours and then reopen it, it shows the previous EditPage activity, without the saved edits (i.e. in the state that the EditPage activity was previously launched).
Any ideas, anyone? I had wondered whether it was due to the Back button being used to return the user to the HomeList activity - maybe Android thinks that the Back button means that the HomeList is not the most "recent" activity, instead the EditPage is. I'd like to carry on using the Back button if possible, though. And in particular, I'm puzzled why it only happens after the app has been idle for an hour or so, and not immediately? Is it something to do with Android's memory management?
View 4 Replies
View Related
Jun 2, 2010
I need a way to detect if this is the first time the user is ever opening the application, if so, start an activity. Then all previous application launches wouldn't start that activity. I've read in a few places about using preferences to accomplish this. Anyone got any ideas?
View 2 Replies
View Related
Feb 16, 2010
Can anyone tell me how to stop media player that was started in a previous activity?For ex. In activity-1 button pressed that did - mp.start(); then activity-2 starts for different layout with new buttons, then when button pressed, mp.stop is called, but does not stop the media from the first activity.
View 4 Replies
View Related
Dec 16, 2009
How to store previous activity value in android
View 2 Replies
View Related
Jul 14, 2009
Can any one tell me how to pass the value from one screen to its previous screen. Consider the case.i m having two screen first screen with one Textview and button and the second activity have one edittext and button. If i click the first button then it has to move to second activity and here user has to type something in the textbox. If he press the button from the second screen then the values from the textbox should move to the first activity and that should be displayed in the first activity textview.
View 4 Replies
View Related
May 28, 2009
I'm working to finish a small application, but I'm having problems seeing what combination of activity attributes and intent flags I need to achieve my intended application design. Trying my best not to describe the app in minute detail, here's the basic operation (I've supplied screenshots in the hope it makes sense easily): Users have a garden which contains flowers (GardenActivity).
http://www.tomgibara.com/images/daisy/garden/hut_screen.jpg
They can tap on a garden to see details of flowers (FlowerActivity)
http://www.tomgibara.com/images/daisy/garden/flower_screen.jpg
When flowers are fully grown a notification provided, tapping on the notification displays the garden containing the flower.
http://www.tomgibara.com/images/daisy/garden/notify_screen.jpg
Users can also use the GardenActivity as a picker to choose flowers to "exhibit" (ConfigureActivity)
http://www.tomgibara.com/images/daisy/garden/planting_screen.jpg
I want the app to operate so that if the user already has a GardenActivity somewhere in the stack (whether it's at the top, or underneath a FlowerActivity) the notification will alert the user by bringing that activity to the front (clearing any FlowerActivity that may be above it). I've tried using the FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_CLEAR_TOP combination (without changing any activity launch modes) on the notification's pending intent, but it still launches a new GardenActivity, even if one is already available.
I've also tried using android:launchMode="singleTask" on GardenActivity. The notifications then seem to work correctly, but it prevents GardenActivity from returning any result back to ConfigureActivity.
View 3 Replies
View Related
Jun 24, 2010
Application (non-wanted) behavior - application is started, some text is put into text-box and notification is created through button action. user "clicks" the home button, application is "minimized", notification is available in bar user selects the notification and the application is "maximized"
BUT - instead of the original instance, new instance is started (e.g. in the newest instance is missing the original text; when the latest instance is closed there is still the original instance with original text ) .
The code of the notification method
CODE:.....
I have also in the manifest xml file following tag android:launchMode="singleTask"
But it is still the same...The main problem is double/triple initialization of the application, i know that there are other means to preserve the values in resumed applications. Also it is needed that the applications stays running in background as the main functionality is the streaming of internet radio.
What is missing in the code ? What kind of information from my side is missing for to troubleshoot the issue ?
View 3 Replies
View Related
Apr 27, 2010
I've got an android app that pulls a random 20 questions (rows) as a cursor from a SQLite DB and loops through all the questions to ask the user all 20 questions.
Is there some way to save the cursor's state/location when the activity is paused or stopped so that when the activity resumes the cursor is restored and in the same position as it was when the activity was paused/stopped?
View 1 Replies
View Related
Oct 4, 2009
Before asking my doubt, let me clarify my understanding of allowTaskReparenting...
Suppose there exists a Task (say Task 1) and this task has an activity (say Activity 1) which wants to call my Activity (say Activity 2). Let my activity (activity 2) set the attribute allowTaskReparenting to true and let my activity have a specific taskAffinity(affinity1). When Activity1 calls my activity (activity2), my activity becomes part of the task1. But suppose another task (task2) is already present/created with the same taskAffinity as mine (affinity1) and an activity in that task (say activity3) tries to start my activity, my activity gets re- parented to task2.
Not sure if i was clear enough. If i were to rephrase my words...
If my activity has allowTaskReparenting set to true and an instance of my activity is already present in task1. If task2 with the same task affinity as my activity tries to start my activity, the EXISTING activity gets re-parented from task1 to task2.
My quesions:
(1) Is my understanding correct ?
(2) If I am correct then a single instance of my activity gets shifted from task1 to task2. So 2 activity objects of my activity are NOT created.
View 5 Replies
View Related
Feb 6, 2010
I'm using an intent-filter on URLs for my activity:
CODE:...............
the launchMode attribute is set to "singleTop", but it looks like a new activity is created every time I click a matching url. I thought that if the activity is already alive somewhere, it would simply be brought to the front of my activity stack?
I tried this on the emulator/device, same behavior, a new activity instance is always created.
View 2 Replies
View Related
Sep 7, 2010
I have two activities. A and B. A starts B. Both are running in the screen and both are visible. Say now B is visible.
On a special key press, I want to bring the A to the front and make it active. The problem I am facing is when the special key is pressed, another instance of A is launched and the new instance is brought to the front.
But I want the original A to come to the front. I want to make this change in the framework layer rather than application specific by using the singleInstance theme in the launchMode in AndroidManifest file.
Please help me in this regard as this is really urgent for me. Any inputs will be really valuable for me.
View 1 Replies
View Related
Apr 23, 2010
I have attached a menu to my TabActivity, and when a menu item is selected, I would like to do something different based on which view is being currently displayed in the TabHost.
int getCurrentTab() returns me the id of the current tab... but from that int how can I get the instance of the activity running?
I also tried getCurrentView(), getCurrentTabView(), but these return things I can't seem to cast to the class of the current activity.
View 3 Replies
View Related
Jul 4, 2010
I have two activities. The first is a list where the user selects one of the items which takes them to a second activity showing the details of the item they selected. When the user clicks the back button I want the app to return to the first activity.
Is there anything special i need to do to make this happen?
Right now when I click the back button from the second activity it exits the app just like the home button would.
Here is how I am starting the Second Activity. startActivity(new Intent(getApplication(), SecondActivity.class)); finish();
View 3 Replies
View Related
Aug 26, 2010
how to get font from the previous activity on current activity on canvas
View 1 Replies
View Related
Apr 21, 2010
I'm writing an application consisting of several activities and, on restarts, I'd like the application to initially display the application's activity that was the last to display in the application's previous session.
I save information about the last activity in SharedPreferences and I'm trying to start that last activity with a call to startActivity(intent) from my Application's onCreate handler.
The problem is that if I don't set the intent's FLAG_ACTIVITY_NEW_TASK, the result is a run-time exception message in logcat suggesting that I should set the flag. And if I set that intent flag, the correct activity gets started but doesn't fully initialize resulting in null pointer exceptions (which don't occur when I don't attempt to start the activity from my Application class).
CODE:...........
Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?
How to correctly start a particular activity from the Application class's onCreate handler?
View 3 Replies
View Related
Oct 4, 2011
1) I dont want to re-create activity once it is created in order to show. How can I do this ? like showing activity from back stack whenver thers a call for it. (It might appear at any index in back stack.)
View 1 Replies
View Related
