Re: [android-beginners] Re: Application still consumes battery even tough it is closed
On Sat, Jul 3, 2010 at 7:42 PM, Indicator Veritatis mej1...@yahoo.com wrote: That may be true, but if so, there is a serious problem with the online Android documentation. For as I have already shown, the documentation clearly states that there is a possible transition direct from the started state to the stopped state, one that does not call onPause() first. That would occur in fairly rare cases, when something occurs on the device after onStart() and before onResume(). Since those methods are invoked in rapid succession, something else taking over the screen (e.g., phone call comes in) during that window is rather unlikely. Developers should not be worrying about that particular scenario very much, if at all. So other than your own authority, on what grounds do you say that the docs are wrong? The docs are not wrong. However, my previous post was covering the 99.999% case, not every possible scenario. On Sat, Jul 3, 2010 at 7:50 PM, Indicator Veritatis mej1...@yahoo.com wrote: This is certainly wrong. No, it is certainly correct. Pressing the Back key does NOT cause onDestroy() to be called. Yes, it does. It causes onPause() to be called. And onStop(), and onDestroy(). I have run this in the emulator too many times myself to believe that it does. I even had to run my own test, just to confirm I hadn't slid into some parallel dimension, before writing my previous post. onDestroy() is called after the BACK button is pressed, just like it is supposed to. It has behaved this way for over two years. If you are unable to replicate this, there is a problem in your development environment. -- Mark Murphy (a Commons Guy) http://commonsware.com | http://github.com/commonsguy http://commonsware.com/blog | http://twitter.com/commonsguy Android Consulting: http://commonsware.com/consulting -- You received this message because you are subscribed to the Google Groups Android Beginners group. NEW! Try asking and tagging your question on Stack Overflow at http://stackoverflow.com/questions/tagged/android To unsubscribe from this group, send email to android-beginners+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en
[android-beginners] Re: Application still consumes battery even tough it is closed
Hi, Mark- As I should have expected for someone who did write a good book on Android, I see your knowledge of the Android life-cycle really is better than mine. But I am seeing something else that vitiates this superior knowledge, your habit of stating unconditionally, in a very general form, things that are only sometimes true. For that is what you have done in both issues: 1) the issue of whether or not there is a direct transition to the stopped state and 2) the issue of whether it is true that Back always caused onDestroy() to be called. In neither case is your sweeping generalization justifiable, in both cases you are misleading readers rather than helping them. Do you really want to encourage, for example, Android programmers to fail to handle correctly the case where onStop() is called without a preceding, corresponding call to onPause()? Such programming sounds very careless to me. Even if most of the time (even your 99.999% is an overstatement), the programmer can ignore this scenario, he should be aware that it exists, so then when he needs to take care of it, he knows that he needs to do so. Similarly with the second issue: even Google violates the rule [that onBackPressed() should cause onDestroy() to be called] often enough that your readers are going to be confused if they forget that some apps really do override onBackPressed(), they don't all call onDestroy(). Finally, yes the docs are wrong. I already showed how they contradict each other. And others have found other similar contradictions in the docs. Take a look at my previous posts on this and see for yourself: I provided the direct quotations. On Jul 4, 2:14 am, Mark Murphy mmur...@commonsware.com wrote: On Sat, Jul 3, 2010 at 7:42 PM, Indicator Veritatis mej1...@yahoo.com wrote: That may be true, but if so, there is a serious problem with the online Android documentation. For as I have already shown, the documentation clearly states that there is a possible transition direct from the started state to the stopped state, one that does not call onPause() first. That would occur in fairly rare cases, when something occurs on the device after onStart() and before onResume(). Since those methods are invoked in rapid succession, something else taking over the screen (e.g., phone call comes in) during that window is rather unlikely. Developers should not be worrying about that particular scenario very much, if at all. So other than your own authority, on what grounds do you say that the docs are wrong? The docs are not wrong. However, my previous post was covering the 99.999% case, not every possible scenario. On Sat, Jul 3, 2010 at 7:50 PM, Indicator Veritatis mej1...@yahoo.com wrote: This is certainly wrong. No, it is certainly correct. Pressing the Back key does NOT cause onDestroy() to be called. Yes, it does. It causes onPause() to be called. And onStop(), and onDestroy(). I have run this in the emulator too many times myself to believe that it does. I even had to run my own test, just to confirm I hadn't slid into some parallel dimension, before writing my previous post. onDestroy() is called after the BACK button is pressed, just like it is supposed to. It has behaved this way for over two years. If you are unable to replicate this, there is a problem in your development environment. -- Mark Murphy (a Commons Guy)http://commonsware.com|http://github.com/commonsguyhttp://commonsware.com/blog|http://twitter.com/commonsguy Android Consulting:http://commonsware.com/consulting -- You received this message because you are subscribed to the Google Groups Android Beginners group. NEW! Try asking and tagging your question on Stack Overflow at http://stackoverflow.com/questions/tagged/android To unsubscribe from this group, send email to android-beginners+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en
Re: [android-beginners] Re: Application still consumes battery even tough it is closed
On Sun, Jul 4, 2010 at 7:21 PM, Indicator Veritatis mej1...@yahoo.com wrote: Do you really want to encourage, for example, Android programmers to fail to handle correctly the case where onStop() is called without a preceding, corresponding call to onPause()? Such programming sounds very careless to me. Generally, I'd recommend the implementations be independent. Wherever possible, onStop() should not care whether or not onPause() preceded it, even though most of the time, it will. That's pretty basic state machine design. Even if most of the time (even your 99.999% is an overstatement), the programmer can ignore this scenario, he should be aware that it exists, so then when he needs to take care of it, he knows that he needs to do so. I'm not arguing that it'd be nice if the docs explained the circumstances of all of these corner cases better. Similarly with the second issue: even Google violates the rule [that onBackPressed() should cause onDestroy() to be called] often enough that your readers are going to be confused if they forget that some apps really do override onBackPressed(), they don't all call onDestroy(). I am sincerely hoping that somebody who overrides onBackPressed() will notice that their fingers typed those keystrokes and will therefore consider that, gee, maybe onBackPressed() might have something to do with what happens when BACK is pressed. I am not aware of any supplied Activity implementation (e.g., ListActivity) that overrides onBackPressed(), so such behavior will not be hidden too often. -- Mark Murphy (a Commons Guy) http://commonsware.com | http://github.com/commonsguy http://commonsware.com/blog | http://twitter.com/commonsguy Android Consulting: http://commonsware.com/consulting -- You received this message because you are subscribed to the Google Groups Android Beginners group. NEW! Try asking and tagging your question on Stack Overflow at http://stackoverflow.com/questions/tagged/android To unsubscribe from this group, send email to android-beginners+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en
[android-beginners] Re: Application still consumes battery even tough it is closed
I can do it now! I finally solve my problem :) thx 4 the discussion ^^ -- You received this message because you are subscribed to the Google Groups Android Beginners group. NEW! Try asking and tagging your question on Stack Overflow at http://stackoverflow.com/questions/tagged/android To unsubscribe from this group, send email to android-beginners+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en
[android-beginners] Re: Application still consumes battery even tough it is closed
This is certainly wrong. Pressing the Back key does NOT cause onDestroy() to be called. It causes onPause() to be called. I have run this in the emulator too many times myself to believe that it does. The application goes into the background, but it remains in memory, on the activity stack. Only much later, if at all, is onDestroy() called. Since most applications do not provide an 'Exit' button/key, and many users do not use a Task Killer, onDestroy() might not be called until power-down (or the next configuration change). On Jul 2, 12:55 pm, Mark Murphy mmur...@commonsware.com wrote: On Fri, Jul 2, 2010 at 3:38 PM, david2 enki1...@gmail.com wrote: onPause() is called whenever the activity loses the foreground from an input standpoint. onStop() is also called, if the activity is no longer visible on the screen. onDestroy() is also called, if the activity instance is going away for good. Hence, BACK calls onPause(), onStop(), and onDestroy(). HOME calls onPause() and onStop(). Not true. Back does not call onDestroy. Yes, it does. On destroy is called when the system decides the application is going away. Such as when the user presses the BACK button. This does not normally occur on a back button or home button. Yes, it does normally occur on a BACK button. Processes stay around until memory is needed elsewhere. Which has little to do with onDestroy() of individual components within that process. And even then, documentation states that onDestroy may never get called even when the application is killed. Correct. In general BACK doesn't do anything additional vs. HOME. Yes, it does. It causes the activity to be destroyed. -- Mark Murphy (a Commons Guy)http://commonsware.com|http://github.com/commonsguyhttp://commonsware.com/blog|http://twitter.com/commonsguy Android Training...At Your Office:http://commonsware.com/training -- You received this message because you are subscribed to the Google Groups Android Beginners group. NEW! Try asking and tagging your question on Stack Overflow at http://stackoverflow.com/questions/tagged/android To unsubscribe from this group, send email to android-beginners+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en
[android-beginners] Re: Application still consumes battery even tough it is closed
But what about when the user presses the home key? According to the docs, onPause() is called WHENEVER the application goes invisible, not just on the Back key, not just when another application is launched. So no, it is not just on the Back key. On Jun 26, 9:13 am, mahesh askmah...@gmail.com wrote: And you have to unregister it in your OnPause() and onStop(). Just as ref if you do not know this already - OnPause() is called when you quit the application via the back button or start another app. OnStop() is called when it is actually killed (via task manager) - maheshhttp://android.maheshdixit.com On Jun 25, 2:25 pm, Mark Murphy mmur...@commonsware.com wrote: On Fri, Jun 25, 2010 at 5:21 PM, Flamechamp flamechamp1...@yahoo.com wrote: This may sound stupid, but I have a problem with my application. I made an application to check the accelerometer and orientation sensor. I tested it on my Nexus One and it works. The problem starts when I close it. (I pressed the - button in the phone) When I checked the Battery usage. That program I made is still there. You also need to be sure to unregister your sensor listeners. If you do not, your program will not truly end, and you will continue receiving sensor data. -- Mark Murphy (a Commons Guy)http://commonsware.com|http://github.com/commonsguyhttp://commonsware.com/blog|http://twitter.com/commonsguy _The Busy Coder's Guide to *Advanced* Android Development_ Version 1.6 Available! -- You received this message because you are subscribed to the Google Groups Android Beginners group. NEW! Try asking and tagging your question on Stack Overflow at http://stackoverflow.com/questions/tagged/android To unsubscribe from this group, send email to android-beginners+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en
Re: [android-beginners] Re: Application still consumes battery even tough it is closed
On Fri, Jul 2, 2010 at 2:32 PM, Indicator Veritatis mej1...@yahoo.com wrote: But what about when the user presses the home key? According to the docs, onPause() is called WHENEVER the application goes invisible, not just on the Back key, not just when another application is launched. So no, it is not just on the Back key. onPause() is called whenever the activity loses the foreground from an input standpoint. onStop() is also called, if the activity is no longer visible on the screen. onDestroy() is also called, if the activity instance is going away for good. Hence, BACK calls onPause(), onStop(), and onDestroy(). HOME calls onPause() and onStop(). -- Mark Murphy (a Commons Guy) http://commonsware.com | http://github.com/commonsguy http://commonsware.com/blog | http://twitter.com/commonsguy Android Training...At Your Office: http://commonsware.com/training -- You received this message because you are subscribed to the Google Groups Android Beginners group. NEW! Try asking and tagging your question on Stack Overflow at http://stackoverflow.com/questions/tagged/android To unsubscribe from this group, send email to android-beginners+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en
[android-beginners] Re: Application still consumes battery even tough it is closed
This is a great discussion. This is probably the most important aspect of Android. It is critical for all developers to properly understand activity lifecycle. From the apps I've seen, most do not. Google should also do a better job of clarifying and documenting this lifecycle with additional examples and discussion. On Jul 2, 2:35 pm, Mark Murphy mmur...@commonsware.com wrote: On Fri, Jul 2, 2010 at 2:32 PM, Indicator Veritatis mej1...@yahoo.com wrote: But what about when the user presses the home key? According to the docs, onPause() is called WHENEVER the application goes invisible, not just on the Back key, not just when another application is launched. So no, it is not just on the Back key. onPause() is called whenever the activity loses the foreground from an input standpoint. onStop() is also called, if the activity is no longer visible on the screen. onDestroy() is also called, if the activity instance is going away for good. Hence, BACK calls onPause(), onStop(), and onDestroy(). HOME calls onPause() and onStop(). Not true. Back does not call onDestroy. On destroy is called when the system decides the application is going away. This does not normally occur on a back button or home button. Processes stay around until memory is needed elsewhere. And even then, documentation states that onDestroy may never get called even when the application is killed. In general BACK doesn't do anything additional vs. HOME. In general, I'd rely primarily on onPause since you're likely to get this call. onStop may not even be called in extreme situations, but is normally called. -- Mark Murphy (a Commons Guy)http://commonsware.com|http://github.com/commonsguyhttp://commonsware.com/blog|http://twitter.com/commonsguy Android Training...At Your Office:http://commonsware.com/training -- You received this message because you are subscribed to the Google Groups Android Beginners group. NEW! Try asking and tagging your question on Stack Overflow at http://stackoverflow.com/questions/tagged/android To unsubscribe from this group, send email to android-beginners+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en
[android-beginners] Re: Application still consumes battery even tough it is closed
That is what the diagram says, yes. But the text of the table says something different: it says onPause() is called when the system is about to resume another activity. But it also says that onStop() may be called when the activity is no longer visible to the user. More importantly, it says that this may happen EITHER because another activity is being resumed (in which case onPause() will be called) OR because it (the current activity) is being destroyed. The implication is that no, we cannot count on onPause() being called before onStop() is called, even if this is by far the more common case. Similarly, the same table says elsewhere that the next state for onStart() can be EITHER onResume() OR onStop(). Again, no stop at onPause(). Finally, I should point out that in http://developer.android.com/guide/topics/fundamentals.html#actlife, the doc we are all following to discuss this issue, it says explicitly that this table offers MORE detail than the diagram (following table describes each of these methods in more detail). That implies that the diagram is incomplete, but the table is if not complete, at least more complete. In a formal spec, the distinction would probably have been 'normative' versus 'reference'. But the Android online docs do not use this terminology. On Jun 26, 4:51 pm, RichardC richard.crit...@googlemail.com wrote: Why both onPause() and onStop()? Looking at the application lifecycle diagram http://developer.android.com/images/activity_lifecycle.png it's not possible to get to onStop() without going through onPause(). If however, you have found this not to be the case, I will have to change my programs and also deal with possible exceptions from resources being released twice. Do you have a simple test as I have never seen this (onPause being skipped) happen? /Richard On 26 June, 17:13, mahesh askmah...@gmail.com wrote: And you have to unregister it in your OnPause() and onStop(). Just as ref if you do not know this already - OnPause() is called when you quit the application via the back button or start another app. OnStop() is called when it is actually killed (via task manager) - maheshhttp://android.maheshdixit.com On Jun 25, 2:25 pm, Mark Murphy mmur...@commonsware.com wrote: On Fri, Jun 25, 2010 at 5:21 PM, Flamechamp flamechamp1...@yahoo.com wrote: This may sound stupid, but I have a problem with my application. I made an application to check the accelerometer and orientation sensor. I tested it on my Nexus One and it works. The problem starts when I close it. (I pressed the - button in the phone) When I checked the Battery usage. That program I made is still there. You also need to be sure to unregister your sensor listeners. If you do not, your program will not truly end, and you will continue receiving sensor data. -- Mark Murphy (a Commons Guy)http://commonsware.com|http://github.com/commonsguyhttp://commonsware.com/blog|http://twitter.com/commonsguy _The Busy Coder's Guide to *Advanced* Android Development_ Version 1.6 Available! -- You received this message because you are subscribed to the Google Groups Android Beginners group. NEW! Try asking and tagging your question on Stack Overflow at http://stackoverflow.com/questions/tagged/android To unsubscribe from this group, send email to android-beginners+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en
[android-beginners] Re: Application still consumes battery even tough it is closed
That link is a good start, and required reading, but I see they have still left in the vague and contradictory language concerning which callback must come next. I am referring to the wording in the state diagram and the table concerning whether onStart() or onRestart() are next, and which callback must follow these. The position in the table makes it look like onRestart() can follow onCreate() preceding onRestart(). But in fact, onRestart() can never follow onCreate() directly: it can only follow onStop(), when the user starts it again (as explained elsewhere at the same link). The above could be dismissed as reading too much into proximity of two items in the table. The same cannot be said for the following: the flowchart-style diagram shows only one possible transition from onStart(): the transition to onResume(). But the text in the table says it can transition to onStop() also. Both cannot be right. So which is correct? How is the Android beginner supposed to know? On Jun 28, 5:18 pm, RichardC richard.crit...@googlemail.com wrote: http://developer.android.com/intl/fr/guide/topics/fundamentals.html#l... On Jun 28, 7:49 pm, Flamechamp flamechamp1...@yahoo.com wrote: ermm... can someone show me or give me an URL that shows how to use the onDestroy, onPause or onStop?? I am really beginner and didn't understand how systems in Android are running. I really appreciate the help -- You received this message because you are subscribed to the Google Groups Android Beginners group. NEW! Try asking and tagging your question on Stack Overflow at http://stackoverflow.com/questions/tagged/android To unsubscribe from this group, send email to android-beginners+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en
[android-beginners] Re: Application still consumes battery even tough it is closed
ermm... can someone show me or give me an URL that shows how to use the onDestroy, onPause or onStop?? I am really beginner and didn't understand how systems in Android are running. I really appreciate the help -- You received this message because you are subscribed to the Google Groups Android Beginners group. NEW! Try asking and tagging your question on Stack Overflow at http://stackoverflow.com/questions/tagged/android To unsubscribe from this group, send email to android-beginners+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en
[android-beginners] Re: Application still consumes battery even tough it is closed
You are right. It should just be on onPause() and not needed on OnStop(). My bad... - mahesh On Jun 26, 4:51 pm, RichardC richard.crit...@googlemail.com wrote: Why both onPause() and onStop()? Looking at theapplicationlifecycle diagram http://developer.android.com/images/activity_lifecycle.png it's not possible to get to onStop() without going through onPause(). If however, you have found this not to be the case, I will have to change my programs and also deal with possible exceptions from resources being released twice. Do you have a simple test as I have never seen this (onPause being skipped) happen? /Richard On 26 June, 17:13, mahesh askmah...@gmail.com wrote: And you have to unregister it in your OnPause() and onStop(). Just as ref if you do not know this already - OnPause() is called when you quit theapplicationvia the back button or start another app. OnStop() is called when it is actually killed (via task manager) - maheshhttp://android.maheshdixit.com On Jun 25, 2:25 pm, Mark Murphy mmur...@commonsware.com wrote: On Fri, Jun 25, 2010 at 5:21 PM, Flamechamp flamechamp1...@yahoo.com wrote: This may sound stupid, but I have a problem with myapplication. I made anapplicationto check the accelerometer and orientation sensor. I tested it on my Nexus One and it works. The problem starts when I close it. (I pressed the - button in the phone) When I checked theBatteryusage. That program I made isstill there. You also need to be sure to unregister your sensor listeners. If you do not, your program will not truly end, and you will continue receiving sensor data. -- Mark Murphy (a Commons Guy)http://commonsware.com|http://github.com/commonsguyhttp://commonsware.com/blog|http://twitter.com/commonsguy _The Busy Coder's Guide to *Advanced* Android Development_ Version 1.6 Available! -- You received this message because you are subscribed to the Google Groups Android Beginners group. NEW! Try asking and tagging your question on Stack Overflow at http://stackoverflow.com/questions/tagged/android To unsubscribe from this group, send email to android-beginners+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en
[android-beginners] Re: Application still consumes battery even tough it is closed
http://developer.android.com/intl/fr/guide/topics/fundamentals.html#lcycles On Jun 28, 7:49 pm, Flamechamp flamechamp1...@yahoo.com wrote: ermm... can someone show me or give me an URL that shows how to use the onDestroy, onPause or onStop?? I am really beginner and didn't understand how systems in Android are running. I really appreciate the help -- You received this message because you are subscribed to the Google Groups Android Beginners group. NEW! Try asking and tagging your question on Stack Overflow at http://stackoverflow.com/questions/tagged/android To unsubscribe from this group, send email to android-beginners+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en
[android-beginners] Re: Application still consumes battery even tough it is closed
And you have to unregister it in your OnPause() and onStop(). Just as ref if you do not know this already - OnPause() is called when you quit the application via the back button or start another app. OnStop() is called when it is actually killed (via task manager) - mahesh http://android.maheshdixit.com On Jun 25, 2:25 pm, Mark Murphy mmur...@commonsware.com wrote: On Fri, Jun 25, 2010 at 5:21 PM, Flamechamp flamechamp1...@yahoo.com wrote: This may sound stupid, but I have a problem with my application. I made an application to check the accelerometer and orientation sensor. I tested it on my Nexus One and it works. The problem starts when I close it. (I pressed the - button in the phone) When I checked the Battery usage. That program I made is still there. You also need to be sure to unregister your sensor listeners. If you do not, your program will not truly end, and you will continue receiving sensor data. -- Mark Murphy (a Commons Guy)http://commonsware.com|http://github.com/commonsguyhttp://commonsware.com/blog|http://twitter.com/commonsguy _The Busy Coder's Guide to *Advanced* Android Development_ Version 1.6 Available! -- You received this message because you are subscribed to the Google Groups Android Beginners group. NEW! Try asking and tagging your question on Stack Overflow at http://stackoverflow.com/questions/tagged/android To unsubscribe from this group, send email to android-beginners+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en
[android-beginners] Re: Application still consumes battery even tough it is closed
Why both onPause() and onStop()? Looking at the application lifecycle diagram http://developer.android.com/images/activity_lifecycle.png it's not possible to get to onStop() without going through onPause(). If however, you have found this not to be the case, I will have to change my programs and also deal with possible exceptions from resources being released twice. Do you have a simple test as I have never seen this (onPause being skipped) happen? /Richard On 26 June, 17:13, mahesh askmah...@gmail.com wrote: And you have to unregister it in your OnPause() and onStop(). Just as ref if you do not know this already - OnPause() is called when you quit the application via the back button or start another app. OnStop() is called when it is actually killed (via task manager) - maheshhttp://android.maheshdixit.com On Jun 25, 2:25 pm, Mark Murphy mmur...@commonsware.com wrote: On Fri, Jun 25, 2010 at 5:21 PM, Flamechamp flamechamp1...@yahoo.com wrote: This may sound stupid, but I have a problem with my application. I made an application to check the accelerometer and orientation sensor. I tested it on my Nexus One and it works. The problem starts when I close it. (I pressed the - button in the phone) When I checked the Battery usage. That program I made is still there. You also need to be sure to unregister your sensor listeners. If you do not, your program will not truly end, and you will continue receiving sensor data. -- Mark Murphy (a Commons Guy)http://commonsware.com|http://github.com/commonsguyhttp://commonsware.com/blog|http://twitter.com/commonsguy _The Busy Coder's Guide to *Advanced* Android Development_ Version 1.6 Available! -- You received this message because you are subscribed to the Google Groups Android Beginners group. NEW! Try asking and tagging your question on Stack Overflow at http://stackoverflow.com/questions/tagged/android To unsubscribe from this group, send email to android-beginners+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en
