I'm trying to modify the SurfaceView I use for doing a camera preview in order to display an overlaying square. However, the onDraw method of the extended SurfaceView is never called.
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Basically I'm calling the onDraw method like so...
code:...................
You see I'm drawing it on top of a Camera view and the information being drawn is subject to change. I have a listener setup which will update the variables being drawn at the appropriate time but I now want to "refresh" this draw in that listener.
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 getting this error ( in the end of this post) which I guess I understand it's because I'm calling something after releasing it.. but I can't find a wy to work it around.I've tried all combinations.. I've tried: mCamera.setPreviewCallback(null); This class, where the surfaceview is implemented can be accessed by 2 different classes one that doesnt implement surfaceview and other that does the error just shows me when I go from the activity that uses the camera to the activity that also uses camera.I don't know what else to do.
View 4 Replies View RelatedIs the onUpgrade method of SQLiteOpenHelper ever called? If so, when is it called and by what? Or if it is not called by developers, then why is it there? What should be done in the method I have seen examples where it drops all the tables, but then a comment says that dropping all the tables is NOT what you should do.
View 1 Replies View RelatedI am new to Android development and have been following the tutorials available on the Android website. I am currently on the section of tutorials for Views, specifically the one for Grid Views: Hello, Grid View Tutorial.I am having trouble understanding how views are made through an adapter. I understand that you must override the getView() method in your adapter class and in this method is where you define how your Views are set up. What I don't understand is where does getView() actually get called? Perhaps I've got the wrong kind of mentality here, but in the code below (the Grid View tutorial) I don't see any calls to getView() (or any other things used in the adapter class such as getCount()).
View 1 Replies View RelatedI'm writing a Tetris application on Android for my bachelor thesis at the University of Hasselt. Currently I have a working Tetris base game, but it just keeps on ticking when the activity gets in the background. I'm trying to fix this by overwriting the onStop()and onRestart()methods.when I press my home button on my device I will go to my home screen and onStop() is called. Because the gamemode is now "PAUSE", the game wil not tick anymore. But now, when I longpress my home button and select my tetris activity again, the activity pops up, but it isn't ticking! This is because the onRestart() is never called when I return to play my application.What is the reason that this method is never called? Am I understanding the activity lifecycle wrong?
View 3 Replies View Relateda service started by a broadcast receiver starts an activity. I want to make it possible for this activity to communicate back to the service. I have chosen to use AIDL to make it possible. Everything seems works good except for bindService() method called in onCreate() of the activity. bindService(), in fact, throws a null pointer exception because onServiceConnected() is never called while onBind() method of the service is. Anyway bindService() returns true.The service is obviously active because it starts the activity.I know that calling an activity from a service could sound strange, but unfortunately this is the only way to have speech recognition in a service.
View 4 Replies View RelatedI'm trying to prevent my application to call the same method twice in the event of a double-click, or if the user presses different buttons quickly, almost at the same time.I have clickable Views, acting as buttons, that call the same method but passing different parameters.Inside this method I'm creating a new Thread, because it queries a web server for the result.The problem is that upon two quick clicks, the method is fired twice, two threads are created, and consequently two new activities are created. That makes my app crash.But this only seems to work on slower phones like the G1, I tried on Nexus and before it set blocked = true, the second request has was granted. So is there any way I can block the method being called if it's already running, or if the thread has started so it wont create a new one.
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View 1 Replies View RelatedIn my android app I call the voice recognition in my onCreate method of my startup activity. I have made it a preference to start up with the voice control or not. However, the app takes about 5-7 seconds to load when voice recognition is on. When it is off, the app starts almost instantly. Below is sample code, I have added Free_Form, max_results 1, and a custom prompt to mine.Why would calling the normal android speech recognition take sooo long to load in my OnCreate method?
View 1 Replies View RelatedOne using a Surfaceview, and the other using a custom view. According to the android SDK development guide, using a surface view is better because you can spawn a separate thread to handle graphics. Th SDK development guide claims that using a custom view with invalidate calls is only good for slower animations, less intense graphics.However, in my simple app, I can clearly see that using a custom view with calls to invalidate seems to render faster.What do you guys know/think about this?My touchEvent code is exactly the same, and my drawing code is exactly the same. The only difference is that one is all in the UI thread, and the other is using a tread to handle the drawing.
View 1 Replies View RelatedI'm using a class extends with view. I'm using timer in that class. I'm using onTouchEvent() also. I onTouchEvent() I'm using invalidate(). So it is calling onDraw(). When i use invalidate() in Timer. It is not calling onDraw().
View 8 Replies View RelatedI hope this question belongs in the Android Developers and not Android Beginners group but I have a question about ScrollViews. I am currently working with a customized GraphView class and am trying to put it into a ScrollView but it doesn't seem to work. Whenever I run the code, it comes up with a blank screen. I've written the code in XML and also tried to create the ScrollView encapsulating the GraphView programmatically but whenever the code runs, it comes up with just a blank screen and GraphView's onDraw() is never called.Code...
View 2 Replies View RelatedI am trying to draw an animation. To do so I have extended View and overridden the onDraw() method. What I would expect is that each time onDraw() is called the canvas would be in the state that I left it in and I could choose to clear it or just draw over parts of it (This is how it worked when I used a SurfaceView) but each time the canvas comes back already cleared. Is there a way that I can not have it cleared? Or maybe save the previous state into a Bitmap so I can just draw that Bitmap and then draw over top of it?
View 4 Replies View RelatedI can add children just fine, but I'm never getting my custom onDraw() being called. dispatchDraw() gets called, but that seems to have a different canvas (the one that's within the padding. I need to draw on the whole layout area). Is there some flag that needs to get set to get onDraw() called for the layout?
View 1 Replies View RelatedI have a ListView with an adapter attached. In the individual list items are placed views with widgets that continually update themselves within the list. Everything works well except for this case: Touch the list and start scrolling it just before the longTouch event would be thrown. Then lift your finger from the ListView. At this point the widget views in the ListView no longer receive onDraw events in response to the invalidate calls that continue to be made on the ListView. It is like the ListView starting blocking the invalidate calls during the scroll and forgot to re-allow them when the scrolling stopped. If I touch and scroll with out holding or scroll with a fling this does not happen. The ListView will start allowing the onDraw events back through if you touch anywhere in the list. Any ideas on how to help the ListView not block those onDraw calls?
View 3 Replies View RelatedWe came across a strange behavior. The clip rect of our custom view is getting reset to its entire visible region, if we change the value of another view.
View 4 Replies View RelatedThe green plane is shown on the golden-brown surface but when I press a key nothing happens. I want eventually be able to move the plane pressing 4 different keys + another one for shooting but that's easy if I can just get the thing moving in the first place. When I press a key in the emulator, nothing happens at all.
CODE:............................
I have create a subclass of View and overwritten onDraw() - see some test code below. It draws a line consisting of some points. Before the line is drawn the canvas is rotated and restore after the drawing. The angle by which the canvas is rotated increases by 5 degrees every time onDraw() is called. The view is invalidated about once a second causing the view to be redrawn. Due to the rotated canvas the line drawn looks like a clock hand rotating counter-clockwise. This works - but not always. Sometimes the line is not drawn for one or more seconds, although I know from the log statement that onDraw() was called. Sometimes means: The line may be not shown after 8 seconds, then again after 35 seconds and so on. If the canvas is not rotated the problem does not occur. This also happens when I use a SurfaceView instead of a View. It does not only occur in the simulator but also on my G1 - both using Android 1.6.
CODE:.............
I'm trying to override the onBackPressed() method of the ActivityGroup class:
public class MyClass extends ActivityGroup {
@Override
public void onBackPressed() {
// do something
return;
}
but I'm getting the error The method onBackPressed() of type MyClass must override a superclass method. I'm relatively new to Java, I've seen here that people do it and it works for them Why I'm getting this error? I'm writing an app for android 1.5, could the problem be here?
In Eclipse, when I mouse hover over a built-in method, it displays a method definition including stuff like what the method does, input objects, return objects etc. If I have a yellow line (warning) under the method I'm trying to use, I can't get the mouse-over to show the definition. If I try hitting F3, I get a "The Jar of this class file belongs to container "Android 1.6" How do I show the definition of the method I am using when there is a warning?
View 1 Replies View RelatedI have a simple draw application on Canvas. User should be able to draw with a chosen color. On MotionEvent.ACTION_UP, invalidate() is called. Now it redraws previously drawn lines with the current color ( Redrawing the entire drawing with the current color). I do not want to change the color of previously drawn lines. I am not sure what is missing. Can I make it redraw only newly drawn lines?
View 4 Replies View RelatedI am trying to use annotation - method.getAnnotation( ) or method.isAnnotationPresent( ) and it is not working. I am using eclipse emulator for 2.1 OS version with JDK 1.6. Following is information about what I did..................
View 4 Replies View RelatedSpecifically I want to know if one can give me better performance. I want to draw the whole surface myself as I am scrolling a large bitmap. Basically I am trying to figure out how things like ListView / GridView do smooth scrolling (see thumbnails in picture viewer app) and writing custom views (even using surface views) seem to be flicker a lot.
View 2 Replies View RelatedIm creating a simple game using a SurfaceView for drawing the Graphics. It works fine, but now I tried to add a title screen, which is (for now) only a LinearLayout and a Start-button, specified in XML. However, when I click this button and try to switch to my SurfaceView (By doing setContentView(R.layout.game), the screen turns black. But if I do setContentView(R.layout.game) immediatly in my Activity.onCreate it works. But not if I start with my Title-screen and then try to switch
View 3 Replies View RelatedI am finally testing my application on a G1 and even though it works fine on the emulator, it crashes on the G1
It crashes when it does:
CODE:.........
And the view is defined like this:
CODE:..............