I often run into the following dilemma: I need some singleton-like object in my app (typically some central manager-like thing) and this object needs a context for various things. This means that I either have to pass a context to all methods needing one or have some sort of init-pattern to the object. Neither is pretty I think. What is the correct way of doing this? Or is this simply (even the definition of) a Service?
View 15 Replies
I'm considering creating a singleton wrapper for a Context so my model objects, if necessary, can open and read from a database connection. My model objects do not have access to a Context, and I'd like to avoid needing to pass a reference to a Context from object to object.I was planning to place into this singleton a reference to the Context returned by Application.getApplicationContext(). This singleton object would be initialized in my custom Application instance before anything else would need to or have a chance to use it.Can anyone think of a reason to not do this?
View 3 Replies View RelatedIn order to communicate with the server I need a huge global object (class with some hashmaps). all my activities (about 10) need that huge global object. which options do I have? I am thinking about passing the object using intends and about the possibility to make the object a singleton. using the db will be much too slow.
View 3 Replies View RelatedCan I pass a singleton class's object from one activity to another activity using intent? I am using singleton class as image class img = image class.get Instance();, so i need the img instance for another activity, how can i pass an object instance in Android.
View 2 Replies View RelatedI'm confused about the concept of the Context class. I see that it's a base class of Activity, but the Android docs also mentions the Context storing global information about the app environment. So in my app which has 3 activities, does that mean I have 3 distinct Context objects, or do they actually refer to 1 entity? Also, what is the lifetime of a Context object- does it live until the last component of this activity's process is garbage collected?
View 1 Replies View RelatedWhat is the lifetime of an app's global android.content.Context object? Does it last until the last component of the app is terminated by the Android runtime?
View 2 Replies View RelatedThis is a followup to this post: http://stackoverflow.com/questions/3897176/findviewbyid-in-a-subclassed-surfaceview-throwing-runtimeexception Based on Romain Guy's feedback (which I'll accept shortly as it is a solution), I'd like to obtain the calling Activity from within the View, so that I can use it to obtain the desired Text View resource. I don't see any methods in View that return Activity. What is the proper way to do this? Or is there a better alternative for working with TextViews from within another View context. Basically, I am calling setContentView(R.layout.xxx) in onCreate() (as usual), so I don't really have a way to pass in references to additional TextViews unless I awkwardly retrieve the View after setContentView and then make calls on it.
View 1 Replies View RelatedI have this code fragment: Code...
View 3 Replies View RelatedIn my Android application, I have to call the getSharedPreferences in non-activity classes. In order to avoid passing a Context object to each constructor of these classes (and because many of them are classes with only static methods which don't have a constructor), I have implemented these steps : The main activity of my application (which is launched at startup) is called Dispatcher. In the onCreate method of this class, I keep a reference to the created Dispatcher object in a static public variable of the Dispatcher class which can be accessed from any class in the project.
View 2 Replies View RelatedI 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 RelatedAndroid has such concept as a Service. It makes sense for interprocess communication. But if I need this service from Activities running in the same process regular singleton seems to be more convenient. No need to register, to bind. Are there any benefits to use service in the same process?
View 17 Replies View RelatedI'm quite new to Android development. When is it a good idea to create an Android Service instead of just using a simple Singleton class?
Take, for example, the data layer downloading information feeds from the internet. Using a Service seems too much for some cases but sometimes I might need access to a Context so I'm a little unsure about how to design the app.
I'd like to know if it's possible to create a Singleton Service throughout an application ? Let's say I'd like to cerate a Service to play some mp3... I'd like it to be a Singleton, we don't want two mp3 tracks playing through each other (well maybe some would want that, but in my case I'm not making a DJ app) :P Also this Service should be somewhat dynamic as in there should be some interface so that I can stop, pauze and play the mp3 file/ stream. Now I have a couple of questions : - is this feasible ? - should I be using a Service or something else ? - how can an interface be set up in between an application and a service so that I can start, stop, pauze stuff ? - can there be something like a Singleton Service?
View 9 Replies View RelatedI have a singleton class and I am using it to access databases. I would like to know how it would behave if I use the same from my remote service class which runs as a separate process. Will it create a new instance in that process or will it use the instance from the other process?
View 3 Replies View RelatedI'm adapting Image Downloader from Google Android blog. I want ImageDownloader to be singleton since I'll be using it in multiple places in my application. I want also to be able to manipulate Bitmaps using different Strategies (eg. produce transparent bitmaps).I want to be able to use ImageDownloader in one activity and set transparent bitmaps, and in another use the same ImageDownloader but get black&white bitmaps using different strategy object.
View 5 Replies View RelatedI have a singleton in an activity. When I end my application (like pressing back button), and start it again after some time, the singleton is not recreated, but is holding previous state. Singleton is not destroyed if the application is destroyed? Do I have to null its static members in onDestroy() to avoid memory leak.
View 1 Replies View RelatedIs the AudioTrack fundamentally designed to be a singleton? Methods on the OnPlaybackPositionUpdateListener receive just one argument, which is the AudioTrack itself. And since the AudioTrack does not have getTag/setTag methods I don't see any way to distinguish among multiple AudioTracks in the OnPlaybackPositionUpdateListener methods short of keeping track of references. So, if it's so why it's not implemented as a singleton? Any thoughts. I am trying to implement concurrent use of the AudioTrack. Anybody has any experience with this approach? Am I wasting time?
View 3 Replies View RelatedOn Wed, Sep 1, 2010 at 1:19 PM, siva <sivaraj.r...@gmail.com> wrote: > I have a singleton in an activity. When I end my application (like > pressing back button), and start it again after some time, the > singleton is not recreated, but is holding previous state. Singleton > is not destroyed if the application is destroyed?
View 4 Replies View RelatedI have a singleton which stores some prudent information about the user of my application. At the moment, it stores the user's login and the user's location.The location is found via a Service. At the moment, the Service references my singleton directly to stuff the longitude and latitude into it. I would like to use a Broadcast Receiver to send a broadcast that the singleton hears and uses to update the values, instead. However, to register the Broadcast Receiver, I need a Context in my singleton. What is the slickest way to achieve what I'm wanting. Is Broadcast Receiver possibly not the appropriate object? Also, what problems am I looking at with using a singleton? I assume that Android will possibly reclaim this memory at any given time (which would obviously be bad); so how can I prevent that? Would passing in the application's Context and storing it in a member variable thwart this? The Android documentation states: "But, the life cycle of a static is not well under your control; so to abide by the life-cycle model, the application class should initiate and tear down these static objects in the onCreate() and on Terminate() methods of the Application Class," but I'm not entirely sure how to accomplish this.
View 1 Replies View RelatedI have two services, both of them lies in separate apk, which run in same process. The two service share same jar file by <uses-library> method. The jar file implement a class, say "test", is a singleton. But I found that two instance of test is created under this case, could anybody give me some tips? I want to ensure it's singleton. Code...
View 8 Replies View RelatedLet me give you the scenario.
Say that my first Activity that loads up, also creates a thread, which will run indefinitely in the background.
Now, if I move to another Activity, I assume that the thread that I initially created in the main activity will continue to run.
So, now to my main question - in order to manage this background thread from other Activities, is it safe to store a reference to that thread in a singleton object?
It would be nice if StackOverflow had a section where we could post tutorials like mine so that I can answer literally hundreds of questions that have been asked here with a single blow. See... every day I read questions about how to pass complex objects between activities, how to save state so that your app can resume after orientation change, how to update listviews when the data changes, etc, etc. Here is the second part of a tutorial series I posted on my blog... I hope that you actually read it... because I haven't seen any examples like it anywhere... and it has changed how I think about developing for Android across the board. The question is... is there a downside or negative affect of developing like this?
Beyond Smart Lists - How Observable Singletons change the game. Please read through both of these tutorials carefully... I will answer any questions about it here that I can... I really want to know what you think about this and if it might solve issues for you. NOTE TO MODERATORS: there are no advertisements of any kind on my blog.. so don't just close this because you think I am spamming somehow... I am not going to duplicate my post here.
I 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:...................
How can I launch a contextmenu from a contextmenu? I'm trying to replicate the MediaPlayer action that happens when you long click a song, then click "Add to playlist" in the resulting contextmenu. When you click that menu item, another contextmenu pops up with "Add to playlist" as the title, and "Current playlist", "New", and however-many-playlists-you-have defined after that.
View 4 Replies View RelatedIf an Activity is a singleton in practice, I think I can gain some efficiency by declaring appropriate members "static", with zero risk. Yes?
View 4 Replies View Relatedi have got a stupid question to ask. I created a custom ContextMenu. But when i call the menu, the menu displayed will also have the default menu added in. Is there anyway for the default ContextMenu not to appear as well?Code requested: @Override public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo)
super.onCreateContextMenu(menu, v, menuInfo);
MenuInflater inflater = getMenuInflater();
menu.setHeaderTitle("Recipients");
inflater.inflate(R.menu.menu_contacts, menu);
Is there a way to get the current Context instance by using a static method? I'm looking for that way because i hate saving the context instance each time it changes.
View 1 Replies View RelatedWhen you are developing on an application level(Services, Activities) you always get this Context reference automatically. But what if I am on a lower level and developing a program started with app_process, how can I get hold of a Context then? Its a huge part of the API that need this context. What the proper way to create a Context instance?
View 7 Replies View Related