I'm subclassing Android's view class, but whenever I make an instance of the view from another class, the constructor never gets called (or so it seems). I've implemented both public myclass (Context context) and public myclass (Context context, AttributeSet, attrs) I can't figure out what I'm doing wrong. Do I need to override onDraw and onMeasure?
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I get a NullPointerException calling a Superclass Method in Subclass Inner Class Constructor... What's the Deal?
In my application's main class (subclass of Application), I have a public inner class that simply contains 3 public string objects. In the parent class I declare an object of that inner class.
CODE:...................
After I instantiate the object in the constructor, I get a runtime error when I try to assign a value in the inner class with a superclass method.
Can you not call superclass methods in the subclass constructor?
I don't think this problem is caused from my ListActivity subclass. I think it has something to do with with my BaseAdapter subclass:
package com.mohit.gtodo;
import com.mohit.gtodo.database.TasksDBAdapter;
import android.content.Context;
import android.database.Cursor;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CheckBox;
import android.widget.CursorAdapter;
import android.widget.TextView;............................
From the documentation for android.app.Application:
"Base class for those who need to maintain global application state"
I am using my own subclass to maintain an object that I'm using to query a server. Also from the documentation:
"onTerminate() Called when the application is stopping."
However, onTerminate() in my class is never called. I press the back button while viewing my main activity, and everything seems to shut down. My main Activity's onDestroy() method is called and isFinishing() returns true, but my android.app.Application's onTerminate() method is never called.
The "View" instance currently provides a way to retrieve the saved state using the methods below, but there doesn't seem a way to retrieve the view's saved state in the constructor, or onFinishInflate. The custom view is constructed via XML, so I cannot pass the saved bundle from the Activity to the View's constructor.
Relevant methods: - protected Parcelable onSaveInstanceState() and - protected void onRestoreInstanceState(Parcelable state)
I need this because I make an asynchronous network request in a custom view constructor, and if there is a configuration (orientation) change, the custom view is getting reconstructed, and the request is getting performed again. I want to intercept the second request in the constructor. I can do this in the onRestoreInstanceState, but I need to handle this in the constructor.
It would be nice if there was a method such as getSavedState so that the decision can be made in a constructor or onFinishInflate instead of waiting for the onRestoreInstanceState trigger.
I'm implementing custom widget exdending a View class. But I've found that View's protected field (e.g. mLeft) is not accessible from subClass
View 2 Replies View RelatedI've run into an early problem with developing for android. I've made my own custom View (which works well). In the beginning i just added it to the layout programmatically, but i figured i could try putting it into the XML layout instead (for consistency).
So what i got is this:
main.xml:
CODE:..........
(Theres obviously more, but you get the point)
Now, this is the stacktrace:
CODE:...........
Why cant i cast my custom view? I need it to be that type since it has a few extra methods in it that i want to access. Should i restructure it and have another class handle the logic, and then just having the view being a view? I'd really like this to work though.
I'm using Eclipse and have an emulator running Android 2.1 and my IntentService. I'd like to step through my onHandleIntent() overridden function. I've put in a breakpoint on the first statement of the function, which is Context context = getBaseContext();. When the intent is called the program just fails and does not go to debug view in Eclipse.
View 1 Replies View RelatedI have a ListView and to create context menu I need to know what view created the menu. The View parameter of onCreateContextMenu is always the same and equals the first view in ListView. Is there any way to get position or id of view that called onCreateContextMenu?
View 2 Replies View RelatedI have a View that I've placed into a ScrollView.The View paginates text.If the text changes, then the height of this view will also change (expand or contract, depending on whether the new text takes more vertical space or less).For debugging, I draw a rectangle around the view to show its current size. After I repaginate, I cannot get Android to cause the View to change its size -- I have tried calling measure() myself, calling requestLayout(), and calling forceLayout() -- even though my overloaded onMeasure gets called, and calls setMeasuredDimension() with the correct values, the view remains the same size as it was before repagination. What am I missing?
View 2 Replies View RelatedI have a weird problem on progress dialog: I have 2 views: Login View and say, Display View. In Login View, when I click the 'Login' button, a progress dialog is created (new ProgressDialog(...)), shown and stored in a variable 'mProgressDialog'. After login, the dialog is dismissed and some information are displayed in Display View (Login View hides). Now I want to display another progress dialog when 'Update' button is clicked and when the update is done, dismiss the dialog and display new information. So I use: the Display View for a blink and then shows the Login View. I tried to change the view etc. but same problem happens over and over again. So I am thinking it might because one activity can only be assigned to ONE progress dialog and no matter how you re-create it you still get the same progress dialog. And the dialog is linked to a certain view which will be shown automatically when the dialog dismisses.
View 8 Replies View RelatedI understand that Android Activities have specific lifecycles and that onCreate should be overridden and used for initialization, but what exactly happens in the constructor? Are there any cases when you could/should override the Activity constructor as well, or should you never touch it?
I'm assuming that the constructor should never be used because references to Activities aren't cleaned up entirely (thus hampering the garbage collector) and that onDestroy is there for that purpose. Is this correct?
I am trying to create a NinePatchDrawable programmatically, but there is no documentation on the constructor's argruments (Bitmap bitmap, byte[] chunk, Rect padding, String srcName). Does anyone know what chunk and padding are... and how to specify them?
View 7 Replies View RelatedI have a Activity and I have a class which extends this Activity. In this subclass I call:
startActivity(new Intent(this, CameraView.class))
Which should start the "CameraView" Activity. However, I always get this error:
CODE:...........
If it makes any difference the subclass creates a ListView and when a row of the ListView is clicked it calls startActivity();
I have an activity that when started needs access to two different ArrayLists. Both Lists are different Objects I have created myself.
Basically I need a way to pass these objects to the activity from an Intent. I can use addExtras() but this requires a Parceable compatible class. I could make my classes to be passed serializable but as I understand this slows down the program.
What are my options?
Can I pass an Enum?
As an an aside: is there a way to pass parameters to an Activity Constructor from an Intent?
I have one subclass which extends Dialog class, it seems I can not use startActivity() function to start a new Activity in this subclass which extends Dialog class, how to resolve it?
How to start a new Activity in a Dialog subclass? (In my customized dialog subclass, I have one button, when pressed, I would like to have a new Activity start).
I have subclassed ArrayAdapter to set the color of text to RED if the string does not contain 100%, this has been added to a ListView. The problem is that some of the rows show as red when they contain 100%.
CODE:.....................
I'm posting this to share the lessons I learned while working with IntentService. IntentService has a single constructor that takes a string argument "name". The documentation has no description of what name is used for. In looking at the sources, I found that its only use is in naming the worker thread for the IntentService. This thread is named IntentService [name].
I initially implemented the constructor of the derived class to also take a String argument and passed it along to the derived class. This is wrong. This will cause the startService() call to generated a java.lang.InstantiationException in the application containing the service i.e. you don't get the exception in the application calling startService(). A clue to the actual problem is a little further up in the logs:"newInstance failed: no <init>()"
The derived class must have a Default constructor and that constructor must call super() passing a string for the name component of the worker thread name.
public class MyIntentService extends IntentService {
public MyIntentService() { super("MyIntentService");
} @Override
protected void onHandleIntent(Intent intent) {
// Handle events on worker thread here }
I'm trying to create class with generics that will have ability to serialize its state using Parcelable interface.
The problem is that class has to contain constructor with single parameter - Parcel, but in my case I need to create class with additional parameters.
Besides, Parcelable.Creator doesn't allow to use generics.
Here is an example:
public class Sample<T> { ...
public Sample(Context ctx, SomeInterface iface, Parcel parcel) {...}
...}
What is the best practice to do it?
When I used BufferedInputStream and I specify a buffer size, Dalvik gives me this warning - Default buffer size used in BufferedInputStream constructor. It would be better to be explicit if an 8k buffer is required.
But right now, my buffer size is already at 8k. What am I doing wrong?
I had come across a code snippet which calls for an activity without referring to any context. Before, i was considering that context is used to tell about the calling component. But as i came see that another component can be called without any reference to context, it makes me wonder what purpose it might be serving. please put some light on it.
Here is the code which calls for an activity without referring to 'context'
CODE:............................
I've found a example on this site on how to make a subclass of the application for android.
I've created this code
package mensand.test;
class TestApp extends android.app.Application { }
Added this line to the manifest
android:name="mensand.test.TestApp"
And when i run the app it's starts with a force close message.
When i remove the line from the manifest all runs ok
I have a ListActivity which is being filled via an internal class "OrderAdapter" - while the list is being populated I set various OnClickListeners on the TextView elements which should open the same view with different parameter values per line. My problem I have is that no matter which entry in the list I click I will always get to a view with the same parameter ID (it's always the ID of the last line in the list) - even though the output of the ID varies if I output it to the TextView.
Here is the code of the internal class which populates the list in the ListActivity:
CODE:.............
Any ideas why it always opens the view with the same ID even though the TextView "tvCheatTitle" displays a different value in every line?
I have put some instructions in onLowMemory() callback and want to test the same. Is there a "direct" way to test onLowMemory function of the application subclass?
Or will I have to just overload the phone by starting many apps and doing memory intensive tasks?
I am having a problem with an application I am in the middle of writing which is causing me some serious headaches.
The situation is this:
The application allows the user to configure several different kinds of information in several activities.
One of the activities, which is a subclass of Activity, takes data from the user and stores it in a shared preferences instance that I create manually and edit in code. This activity requires a complex screen layout that I do not believe would work well with a PreferenceActivity, hence me rolling my own in this case.
Another one of the activities, which is a subclass of PreferenceActivity, is a straight forward list of preferences, each with a list options - standard stuff.
I am finding that any data that I store from the first activity, my bespoke preference screen which manually adds the data using a StoredPreferences.Editor instance is overwritten once the user selects an option in my activity that extends PreferenceActivity.
I am running into an issue with the way my asynctasks are executed. Here's the problem code:
firstTask = new background().new FirstTask(context);
if(firstTask.execute().get().toString().equals("1"))
secondTask = new background().new SecondTask(context);
What I'm doing here is creating a new asynctask object, assigning it to firstTask and then executing it. I then want to fire off a separate asynctask when the first one is done and making sure it returns a success value (1 in this case). This works perfectly on Android 2.0 and up. However, I am testing with Android 1.5 and problems start popping up. The code above will run the first asynctask but doInBackground() is never called despite onPreExecute() being called. If I am to execute the first task without the get() method, doInBackground() is called and everything works as expected. Except now I do not have a way to determine if the first task completed successfully so that I can tell the second task to execute. Is it safe to assume that this is a bug with asynctask on Android 1.5? Especially since the API says that the get method has been implemented since API 3. Is there any way to fix this? Or another way to determine that the first task has finished?
I'm developing an app that uses google maps, but for some reason it crashed every time I try to call the constructor code from the map class.
main
[HIGH]import android.app.Activity;
import android.os.Bundle;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
[Code] ......
Do static variables of an ApplicationContext subclass left untouched when the process is killed?
View 4 Replies View RelatedI am trying to set up a ViewFlipper that changes a SlidingDrawers content each time a button is pressed. So far every view I set up worked fine, but now I am trying to create a ListView (including single_choice_mode) within a child view of the ViewFlipper, but my attempt only let to a NullPointerException. As I only discovered ViewFlipper today, I am not yet familiar with it and may not have understood it completely. if someone could give me a hand and help me find out what I have done wrong, that would be great. Here is what I have done:
The code for the onClick event of the ImageButtons:
public void onClick(View v){
if (v == btnExposure){
mFlipper.setDisplayedChild(0); }
else if (v == btnProperties){
mFlipper.setDisplayedChild(1);}
else if (v == btnSpecialEffects){
mFlipper.setDisplayedChild(2);.............
I was reading through app suggestions and someone mentioned an app called mp3 Download that basically functions like limewire, letting you search and download mp3's to your phone. Does anyone know anything about this app and whether it is good or not? Or have suggestions for a similiar app? It had mixed reviews at appbrain and when I searched here it came up with a bunch of other threads.
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