Android : Why Do We Create Inner Classes / Subclasses In Droid?
Oct 26, 2010My Question is, why do we create inner classes or subclasses in android. Like the following example ...
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Android : Create Another Classes Object In A Class In Droid?
Jul 12, 2010Is it possible to create another classes object in a class in android. code...
View 4 Replies View RelatedAndroid : Create A Library For Different Classes?
Jul 17, 2010I'm new to JNI, i'm developing a native library for an Android project. I read some papers about JNI programming but i didn't understand if it is possible to create a library that can be loaded in different project classes with different packages. I read that to declare a new JNI method the syntax is:
the prefix "Java_"
an encoded fully qualified class name
an underscore ("_") separator
an encoded method name
Based on this definition it shouldn't be possible...
Suppose i had defined a class A in the package pkg1 with the native method foo contained in libfoo, and then i defined a class B in the package pkg2. Can i use libfoo and the foo method in B? How should i define the native method to achieve the result?
Android : When To Use Layouts / Create New Activity Classes?
Mar 3, 2010I'm writing a game for Android. My GUI has the following basic screens (i.e. the information and interactions required on each of these would take up the whole display):
Main menu (let you start a new game, enter settings, see high scores, see about screen)
Game screen i.e. where the actual game is played.
Settings screen.
High scores screen.
About screen (i.e. credits and a back button)
Game over screen (arrived at when the game ends)
Pause screen (pauses game and can access settings)
The following are some example transitions the user might make between these screens:
1->2->7->2->6 (starts new game, pauses game, returns to game, finishes game)
1->5->1->4->1 (views about screen, goes back to main, views score screen, goes back to main)
I'm really confused about when to have just one activity that switches layouts and when to create new activity classes. For example, when my game loads, I have a "main" activity that loads the main menu layout. When you click the settings button, I launch a "settings" activity (which uses android's standard settings GUI). For the moment, when you start a game, I switch the layout of "main" to the game screen layout (which just contains one big surface view). I'm not really sure what the best way to integrate the game over screen, high score screen, about screen etc.
Creating a new activity for each seems really heavy weight to me. There's quite a lot of boiler plate code involved for each activity. Plus, communication between activities seems like a pain as you have to use bundles. Using just one activity means I can just share object fields directly. It seems that using layouts for the above would be more compact. Can anyone give me some recommendations?
Android :: Static Fields In Activity Classes Guaranteed To Outlive Create / Destroy Cycle?
Oct 28, 2009I frequently run into the problem that I have to preserve state between several invocations of an activity (i.e. going through several onCreate()/onDelete() cycles). Unfortunately, Android's support for doing that is really poor. As an easy way to preserve state, I thought that since the class is only loaded once by the class loader, that it would be safe to store temporary data that's shared between several instances of an activity in a static Bundle field. However, occasionally, when instance A creates the static bundle and stores data in it, then gets destroyed, and instance B tries to read from it, the static field is suddenly NULL. Doesn't that mean that the class had been removed and reloaded by the classloader while the activity was going through a create/destroy cycle? How else could a static field suddenly become NULL when it was referencing an object before?
View 2 Replies View RelatedAndroid :: Known Indirect Subclasses?
Apr 27, 2010Looking at various pages in the Android docs, some of them list "Known Indirect Subclasses". What does this mean?
View 1 Replies View RelatedAndroid :: Subclasses Vs Constructors - Difference Between Them?
Jan 15, 2010Could someone explain the difference between a subclass and a constructor?
View 2 Replies View RelatedAndroid :: Loop Through All Subclasses In View?
Apr 8, 2010I'm working on a game for Android. To help implement it, my idea is to create a subclass of a view. I would then insert several instances of this class as children of the main view. Each instance would handle detecting when it was pressed (via OnTouchListener).
The problem I'm having now is how do I loop through all these sub-views so I can read their statuses and process them? (I.e. when they all reach a certain state something should happen). Or is there a better way to have several objects on the screen that respond to touch and whose status I can check?
Android :: Combining Subclasses Which Have Different Fields For Efficiency?
Feb 7, 2010I'm working on a Java Android game. Games here generally need to use memory pools to avoid garbage collection.Making use of subclasses is a pain when using memory pools as you need to e.g. say how many Roamer and Chaser objects you want upfront and not just how many Enemy objects you might need.I would then have an update function that checked the "type" variable and updated accordingly. This is obviously a more C-like approach. It feels hacky though because e.g. a roamer enemy will have a "target" variable it never uses. I'm unlikely to have more than a 100 enemies in memory at a time though so it really isn't a big deal memory wise. I just want some compromise between nice code and speed.Does anyone have any comments on how best to structure this? Is merging classes like this going too far? Is this ever a good idea? Should I just use a regular class tree?
View 4 Replies View RelatedAndroid : How Many Droid Widget Classes Are There
Jan 9, 2010Any one know about In Android Widget Package how many Classes are there?
View 2 Replies View RelatedAndroid : Droid Jvm Unloads Classes?
Sep 29, 2009A static field which was initialized becomes null at some point. Can it be because that class was unloaded and loaded again?
View 3 Replies View RelatedAndroid :: Why I Can't Access Protected Member Variables In Droid Classes?
Jun 18, 2009When I extend a View, I cannot access the protected member variables from my code. Eclipse just says that there exists no variable with that name (for instance mScrollX). Why is that?
View 2 Replies View RelatedAndroid :: Include Utility Classes In Eclipse (droid Programming)?
Jul 19, 2010I am doing Android programing with Eclipse (Helios), and I have some utility classes created. How do I set up Eclipse, so that if I use one of my utility classes it gets included when the project compiles?
View 1 Replies View RelatedAndroid : Class Generator For Data Classes Used In Java / Droid From Existing Wsdl File?
Apr 3, 2010Is there any class generators to process web services in Android/Java? I may have to write my own to generate classes against WSDL but I'm trying not to. Also is there one for REST services as well?
If not providing me with discovery service suggestions like disco/wsdl are good enough.
Android :: Want To Use Accessibility Classes
Oct 29, 2010I want to use the accessibility classes, but I'm a begginer in android programming and i can't understando how to use them. I don't find any example using these classes. Somebody can give me some use examples? Another thing Can I set enable the Accessility mode in the emulator?
View 2 Replies View RelatedAndroid : Need Dynamic Classes App
May 18, 2009I am writing a app, which has sort of plugin framework. public abstract class AbstractService {public abstract AbstractService getInstance(String name)..
View 2 Replies View RelatedAndroid : Get Classes In An Apk Using DexClassLoader?
May 29, 2009I have an apk installed in /data/app. I want to use the class methods in there. Here is what I tried. code...
I got "ClassNotFoundException". By peeking into the apk, I don't see class files but classes.dex. I would assume SystemProperties class is in classes.dex. Why can I load it?
Android :: VideoEncoder Classes Can't Be Resolved
Apr 7, 2009I am developing sample Video Recorder for Android.Following is My code snippet.
CODE:............
But when i am trying to run in eclipse,am getting following errors. MediaRecorder.VideoSource can't be resolved. MediaRecorder.VideoEncoder can't be resolved.
I am using android-sdk-windows-1.1_r1 as my android SDK,and didn update this from 1.0 instead i installed it freshly.
I guess there might be some problem with the SDK.
Android :: Can't Find Certain Implementing Classes
Mar 19, 2010I am looking for the implementation of the IAlarmManager.I am interested in the scheduling done by the AlarmManager.setInexactRepeating method and so I started looking for the implementation but I haven't been able to find anything.Internally to AlarmManager, I can see that the actual work is being done by an android.app.IAlarmManager interface.After googling around for a bit there seems to reference to an implementing class called android.app.IAlarmManager.Stub but that is as far I get.I am working with Android 1.6.
View 1 Replies View RelatedAndroid :: Proper Way To Use Non Extended Classes?
Oct 7, 2010I have an app I am working on and being new to Android Dev I am running into a situation. I have a Scores class not extended from anything (Activity,Service, etc) but in the same package that needs to access SharedPreferences
public class Scores {
Context ctcx;
public Scores(Context context) { ctcx = context;
}
Android :: Classes To Use For UI Game Development
Aug 30, 2010I am trying to determine how to structure the code of a simple android game I am writing. I am focused on the UI portion. The behind the scenes portion (like a pause/restart/switching/etc) does not concern me. The Android demo games source code already do a great job with this. Essentially my game will need a UI with a series of objects on the screen (roughly 100 or 10x10) that the user can interact with. I need to supply an image for each object as well as implement the touch events and animation events for each object. What I am wondering is what type of class do I use for each object so that I can successfully implement these methods and how do I implement that particular class. Note that this game only executes on a user interaction with one of these objects, meaning I don't need a "real-time" implementation.....
View 2 Replies View RelatedAndroid :: Compatibility With Nonexistant Classes
Apr 19, 2010I have read the Backward Compatibility Article, and I don't full understand how (or if I can) make a program backwards compatible if I want to use a class introduced in later versions. For example, I want to use WallpaperManager for apis 5+, but make the app as a whole compatible with api 3+. Is this possible?
View 14 Replies View RelatedAndroid :: Use Java Classes In Project?
Apr 28, 2010Since i'm still new on Android programming, I have some problems on some issues. I have a QuadTree data structure implementation in 3 seperated Java files and i would like to use this data structure in my application. But i don't know how to use this .java files in an Android project. I tried to put them in a new Android project, just for testing, but I get lots of errors. Could anyone help me about using this java classes in my Application?
View 3 Replies View RelatedAndroid :: Passing Paramters Between Classes
Apr 6, 2010I have a class2 which is involved by class1 when clicks are made. I have to pass some parameters/objects from class1 to class2. I only know the standard way which does not have an option of passing parameters.
CODE:.................
Android :: Java Classes Not Inclded ?
Sep 26, 2010How can I install java classes not included with android ?
Is it possible to add java.awt.image package into android?
Where can I find above package jar file?
Android :: When Do Classes Get Unloaded By System
Mar 15, 2010This is a very weird problem. My app that runs just fine but somehow if I leave my phone for an hour or two while my app is running, I get the following error when I come back to it later:
CODE:................
I know for a fact that my yoga.database.Manager class was loaded at the time when the app was launched, but somehow the class must have been unloaded by the system as I left the phone.
Does Android unload classes automatically after certain periods? What can I do when my class gets unloaded? The above error causes my app to crash, but I can easily re-launch it and it runs just fine. The problem occurs mostly on my HTC Magic phone running Android 1.6.
Android :: How To Include Third Party Classes Into The Apk
Mar 19, 2010I have a couple of third party classes which serve as a library I can build my application upon. They are contained in a folder which was added Java Build Path -> Libraries (in Eclipse) with "Add Class Folder". It works fine so far an my app compiles. But the produced .apk contains only my classes and therefore the application does not run. How can I tell Eclipse to package the third party classes into the .apk as well?
View 1 Replies View RelatedAndroid :: Putting Serializable Classes Into SQL?
May 4, 2010I have a bunch of objects that implement Serializable that I want to store in a SQL database.
I have two questions:
Is there a way to serialize the object directly into the database. Is that the best way to do it or should I Write the object out to a formatting String and put it in the database that way and then parse it back out
Write each member to the database with a field that is unique to each object.
Android :: Using Utility Classes In Programming
Oct 14, 2010I have a little idea of the Utility Classes with a slight doubt on demand.
If I use a Utility class in my Application than to use that class in my main Activity do I have to create the object of that class or I can directly Import that class in my main activity?
In the nutshell, all I want to be clear about is that basically how can I use the utility class in my Main Activity?
Android :: Java Not Able To Find Classes
Nov 24, 2010When calling javah on a .java file in my android project, javah was unable to find the android classes (specifically android.graphics.Bitmap).
Here's the terminal output:
CODE:..................