I have a similar problem. The fact that the Activity is destroyed and re-created every time the orientation changes doesn't make sense to me.
Mark Murphy's second suggestion (overriding the default orientation- handling code, so your activity is not destroyed and recreated) actually makes the most sense, and part of me thinks that it should be the default behavior. In my personal opinion, the only thing that an activity should need to do when the orientation changes is to re-draw whatever UI components are already being shown. All this extra work of stopping and restarting dialogs, background tasks, etc. seems unnecessary and extremely bug-prone. Has anyone tried this strategy? If so, how easy was it to re-draw the UI? And what other challenges did you face with this solution? -- PJ On Nov 11, 4:16 am, Lee Jarvis <ljjar...@googlemail.com> wrote: > Ahh! That makes total sense, I was trying to do more or less the same > thing but it got tricky a there were a few flaws, this is great. I > have a much better understanding of things now. > > Thanks > > On 11 Nov, 01:22, Lance Nanek <lna...@gmail.com> wrote: > > > > > Here's a quick attempt at rewriting it without a static. Turned out > > more complex than I'd like. Pastebin version:http://pastebin.com/m7b8b184 > > > Inline version: > > public class MyActivity extends Activity { > > > private final static String LOG_TAG = MyActivity.class.getSimpleName > > (); > > > private final static int DIALOG_ID = 1; > > > private Task mTask; > > > private boolean mShownDialog; > > > @Override > > protected void onPrepareDialog(int id, Dialog dialog) { > > super.onPrepareDialog(id, dialog); > > > if ( id == DIALOG_ID ) { > > mShownDialog = true; > > } > > } > > > private void onTaskCompleted() { > > Log.i(LOG_TAG, "Activity " + this + " has been notified the > > task is > > complete."); > > > //Check added because dismissDialog throws an exception if > > the > > current > > //activity hasn't shown it. This Happens if task finishes > > early > > enough > > //before an orientation change that the dialog is already > > gone when > > //the previous activity bundles up the dialogs to reshow. > > if ( mShownDialog ) { > > dismissDialog(DIALOG_ID); > > Toast.makeText(this, "Finished..", > > Toast.LENGTH_LONG).show(); > > } > > } > > > @Override > > protected void onCreate(Bundle savedInstanceState) { > > super.onCreate(savedInstanceState); > > setContentView(R.layout.main); > > > Object retained = getLastNonConfigurationInstance(); > > if ( retained instanceof Task ) { > > Log.i(LOG_TAG, "Reclaiming previous background > > task."); > > mTask = (Task) retained; > > mTask.setActivity(this); > > } else { > > Log.i(LOG_TAG, "Creating new background task."); > > mTask = new Task(this); > > mTask.execute(); > > } > > } > > > @Override > > public Object onRetainNonConfigurationInstance() { > > mTask.setActivity(null); > > return mTask; > > } > > > @Override > > protected Dialog onCreateDialog(int id) { > > switch (id) { > > case DIALOG_ID: > > ProgressDialog dialog = new > > ProgressDialog(this); > > dialog.setMessage("Loading stuff.."); > > dialog.setCancelable(true); > > return dialog; > > } > > return super.onCreateDialog(id); > > } > > > private static class Task extends AsyncTask<Void, Void, Void> { > > > private MyActivity activity; > > > private boolean completed; > > > private Task(MyActivity activity) { > > this.activity = activity; > > } > > > @Override > > protected void onPreExecute() { > > activity.showDialog(DIALOG_ID); > > } > > > @Override > > protected Void doInBackground(Void... unused) { > > try { > > Log.i(LOG_TAG, "Background thread starting > > sleep."); > > Thread.sleep(15 * 1000); > > } catch (InterruptedException e) { > > Log.e(LOG_TAG, "Thread interrupted:", e); > > } > > Log.i(LOG_TAG, "Background thread finished sleep."); > > return null; > > } > > > @Override > > protected void onPostExecute(Void unused) { > > completed = true; > > notifyActivityTaskCompleted(); > > } > > > private void notifyActivityTaskCompleted() { > > if ( null != activity ) { > > activity.onTaskCompleted(); > > } > > } > > > private void setActivity(MyActivity activity) { > > this.activity = activity; > > if ( completed ) { > > notifyActivityTaskCompleted(); > > } > > } > > > } > > > } > > > On Nov 10, 5:41 pm,LeeJarvis<ljjar...@googlemail.com> wrote: > > > > I've tried that, too. But again to no avail, nothing I do seems to > > > work. I've tried using the callback features whilst also implementing > > > weak references which also doesn't work. Once I change orientation, > > > the progressDialog never disappears, it's bugging me to hell > > > > On 8 Nov, 17:41, Streets Of Boston <flyingdutc...@gmail.com> wrote: > > > > > If you do showDialog(dialogId) and dismissDialog(dailogId), Android > > > > actively manages the showing and hiding of the dialog on configuration > > > > changes. > > > > > E.g. if you called showDialog(id) and your rotate your screen, Android > > > > will make sure that the dialog is shown again when the activity is > > > > recreated for the new configuration. To dismiss it, you have to > > > > explicitly call dismissDialog(id). > > > > > However, you must call 'dismissDialog' on the currently active > > > > activity. That's where the trick with 'ACTIVE_INSTANCE' comes in: > > > > ACTIVE_INSTANCE.showDialog(ACTIVE_TASKING) and > > > > ACTIVE_INSTANCE.dismissDialog(DIALOG_TASKING). > > > > > On Nov 8, 4:28 am,LeeJarvis<ljjar...@googlemail.com> wrote: > > > > > > Well, that's the thing. It's not a progress 'bar' that I can just > > > > > show/ > > > > > hide which would seem a lot easier. I'm just using a ProgressDialog > > > > > that I dismiss in onPostExecute, The code you see above inside of my > > > > > AsyncTask is what I'm using to show/hide the dialog. I use showDialog > > > > > () in onPreExecute and dismissDialog() in onPostExecute, I realize one > > > > > a new activity is created and the old one is killed it'll lose > > > > > reference to that dialog so I'm guessing that's why dismissDialog() > > > > > doesn't work (on in fact the code in onPostExecute() doesn't get > > > > > executed because the phone has change orientation and it's trying to > > > > > dismiss a dialog which doesn't exist. > > > > > > On 8 Nov, 03:52, Streets Of Boston <flyingdutc...@gmail.com> wrote: > > > > > > > Show us your code that deals with showing/hiding the progress bar > > > > > > and > > > > > > show exactly what doesn't work. > > > > > > Maybe we can figure it out :) > > > > > > > On Nov 7, 5:32 pm,LeeJarvis<ljjar...@googlemail.com> wrote: > > > > > > > > Any other suggestions? I keep trying different things out but > > > > > > > nothing > > > > > > > seems to work, I keep seeing common applications with the same > > > > > > > functionality which is making it more frustrating because I know > > > > > > > it > > > > > > > should work fine > > > > > > > > On 7 Nov, 17:29,LeeJarvis<ljjar...@googlemail.com> wrote: > > > > > > > > > Thanks for your reply, it's made me understand things a little > > > > > > > > better. > > > > > > > > > Unfortunately that still doesn't seem to work.. > > > > > > > > > The Toast popup appears twice, then the ProgressDialog just > > > > > > > > continues > > > > > > > > to run regardless > > > > > > > > > On Nov 7, 5:14 pm, Streets Of Boston <flyingdutc...@gmail.com> > > > > > > > > wrote: > > > > > > > > > > Lance is absolutely right. I ran into this problem a few > > > > > > > > > months ago. > > > > > > > > > > Possible solution: > > > > > > > > > Hold a static handle to your currently active instance of your > > > > > > > > > activity (works only if you have at most one active instance > > > > > > > > > of your > > > > > > > > > activity at any given time in your process). > > > > > > > > > > public class MyActivity extends Activity { > > > > > > > > > public static final MyActivity ACTIVE_INSTANCE; > > > > > > > > > private final static int DIALOG_TASKING = 1; > > > > > > > > > > ProgressDialog mLoadingDialog; > > > > > > > > > > @Override > > > > > > > > > public void onCreate(Bundle savedInstanceState) { > > > > > > > > > > ACTIVE_INSTANCE = this; > > > > > > > > > > super.onCreate(savedInstanceState); > > > > > > > > > setContentView(R.layout.main); > > > > > > > > > > new Task().execute(); > > > > > > > > > } > > > > > > > > > > @Override > > > > > > > > > public void onDestroy() { > > > > > > > > > super.onDestroy(); > > > > > > > > > > ACTIVE_INSTANCE = null; > > > > > > > > > } > > > > > > > > > > @Override > > ... > > read more »- Hide quoted text - > > - Show quoted text - -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
