[android-developers] Re: Activity Issue on G1 phone
Ah.. Thank you. That clears up a lot !!! I was thinking that a static variable created in an activity would be global only to that activity, and any spawned processes of that activity. But now. knowing it is at the application level open up many possibilities. When I was designing my current process I remember thinking that it would be very handy to have an application level global variable, but never got around to asking the question. And because I am coding on a Windows machine with Eclipse, I'd rather go to the dentist than try to trace through the Android source code :-) Actually, I was thinking of moving some of my threads to a service just for efficiency reasons (to save on multiple requests for the same information), but now.. I think if I implement this the way you laid it out, the service seems to be overkill. My threads only download small thumbnail bitmaps, or send fairly fast REST queries to my server, so I don't think I'd need the service at all. I think you just saved me several days coding ;) Hmm.What happens in this sequence : Activity A sets the static variable, and then creates the thread to get some information. The user then clicks on the first piece of information returned, and goes to Activity B. But activity B then takes the user to another instance of activity A. Then the two instances of activity A would be sharing the static variable that points to the second instance of activity A ... correct? I don't think this is a huge problem because my activity A can only be called in two ways, and I can declare two static variables in activity A and then assign the one that corresponds to how activity A was called, and use it to pass to the threads, so that each instance of Activity A would have their own static variable to use with the threads that they create.. Does that sound correct? Sincerely, Brad Gies - Brad Gies 27415 Greenfield Rd, # 2, Southfield, MI, USA 48076 www.bgies.com www.truckerphone.com www.EDI-Easy.com www.pricebunny.com - Moderation in everything, including abstinence _ From: android-developers@googlegroups.com [mailto:android-develop...@googlegroups.com] On Behalf Of Dianne Hackborn Sent: Sunday, January 25, 2009 8:23 PM To: android-developers@googlegroups.com Subject: [android-developers] Re: Activity Issue on G1 phone I meant that the static variable would -hold- the current activity. Everything in your .apk runs in one process. When you declare a static variable, that is creating a global to all code in that process. You can make a static variable pointing to an Activity: static Activity mCurActivity = null; In your activity's onCreate() set it to 'this'. In onDestroy() set it to null. Now someone else -- a thread or whatever -- can come in, and retrieve the value of mCurActivity to find out the current activity that has been set. On Sun, Jan 25, 2009 at 4:47 PM, Brad Gies rbg...@gmail.com wrote: --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
[android-developers] Re: Activity Issue on G1 phone
Dianne, I can't quite figure out what you mean by setting a static variable in the current activity, and how it would work. If I set a static variable in my activity and then pass that static variable to my thread, then the activity is destroyed, and a new one is created.. Then what happens? The new activity will create another static variable, but the thread won't know about it, so how would it help? And the new activity doesn't know about the thread, so I don't think it would have the information it needed to alert the thread that it can now accept the information. What am I missing? What I currently do is set a static variable in my thread which is the handler to my activity, and then if the activity is destroyed before the thread completes, it sets the handler variable in the thread to null before it completes. The thread then checks the Handler variable before it tries to send the information, and just cleans up after itself if it cannot send the information. Then, when the new activity is created it checks to see if it still needs the information and creates a new thread if needed. BUT.. if there is a way for the new activity to get the Handle of the Thread created by the old activity, then I could easily change the thread to wait for a few seconds waiting for a new Handler to be assigned, and that would be much more efficient. Do you have an example you can point me to? Sincerely, Brad Gies - Brad Gies 27415 Greenfield Rd, # 2, Southfield, MI, USA 48076 www.bgies.com www.truckerphone.com www.EDI-Easy.com www.pricebunny.com - Moderation in everything, including abstinence _ From: android-developers@googlegroups.com [mailto:android-develop...@googlegroups.com] On Behalf Of Dianne Hackborn Sent: Friday, January 23, 2009 3:07 PM To: android-developers@googlegroups.com Subject: [android-developers] Re: Activity Issue on G1 phone There are two reasons for this: 1. Both screen rotation and keyboard shown/hidden are configuration changes, which means that after the state changes the application's resources can have any arbitrary new values -- anything from specific strings (for ex in a particular language you may need a abbreviation when in portrait mode) to layout resources and anything else. Trying to keep track of, and update, any of these values that could have changed would require a lot of work in the system, and a fair amount of effort from the developer to help the system, so it is far easier to just restart the entire activity with the new configuration. 2. To be a correct application, you already need to deal with saving and restoring state so you will always be returned to the user in your previous state after being in the background. By relying on this same mechanism for configuration changes, we get to take advantage of the work the developer has already done, and also further encourage them to actually do that work which otherwise often only causes problems in the application in obscure cases, so can often be missed. For the case of a thread running in the background that wants to communicate back with the current activity, an easy way to deal with this is to have a static variable that is the current activity, which you set in your onCreate() and clear in onDestroy(). Then instead of pointing to the activity that originally started it, the thread can just retrieve the current value in that variable when it needs it. (And of course it will need to deal with the race where it can temporarily be null between the old activity being destroyed and the new one created... but if you are doing multithreaded programming, this should be familiar territory!) On Fri, Jan 23, 2009 at 9:52 AM, Stanley.lei xiaofeng.lei...@gmail.com wrote: I rather agree with you! In fact, I could not understand why Google designs like this. The keyboard action could impact the rotation, but why changing rotation impacts the activity? In my case, the thread is destroyed, which will destroy all tasks in the thread. In worst case, the user will have to re-create their data from scratch. stanley On Jan 24, 1:47 am, cindy ypu01...@yahoo.com wrote: Then android's implementation has problem. For example, if my application needs to create account, of cause, the key board will open first. After user typed in user name and password, then he clickes the create button.Request sends to server in a thread. After that, he closes the keyboard, the activity will be destroyed. So the callback function in thread to update UI will crashed. It happens exactly in my application. On Jan 23, 7:20 am, James Patillo ja...@patillo.org wrote: I think what happens is that the activity's state is saved, the activity is destroyed, and then it is recreated with its saved state. This is the same thing that happens when
[android-developers] Re: Activity Issue on G1 phone
I meant that the static variable would -hold- the current activity. Everything in your .apk runs in one process. When you declare a static variable, that is creating a global to all code in that process. You can make a static variable pointing to an Activity: static Activity mCurActivity = null; In your activity's onCreate() set it to 'this'. In onDestroy() set it to null. Now someone else -- a thread or whatever -- can come in, and retrieve the value of mCurActivity to find out the current activity that has been set. On Sun, Jan 25, 2009 at 4:47 PM, Brad Gies rbg...@gmail.com wrote: Dianne, I can't quite figure out what you mean by setting a static variable in the current activity, and how it would work. If I set a static variable in my activity and then pass that static variable to my thread, then the activity is destroyed, and a new one is created…. Then what happens? The new activity will create another static variable, but the thread won't know about it, so how would it help? And the new activity doesn't know about the thread, so I don't think it would have the information it needed to alert the thread that it can now accept the information. What am I missing? What I currently do is set a static variable in my thread which is the handler to my activity, and then if the activity is destroyed before the thread completes, it sets the handler variable in the thread to null before it completes. The thread then checks the Handler variable before it tries to send the information, and just cleans up after itself if it cannot send the information. Then, when the new activity is created it checks to see if it still needs the information and creates a new thread if needed. BUT…. if there is a way for the new activity to get the Handle of the Thread created by the old activity, then I could easily change the thread to wait for a few seconds waiting for a new Handler to be assigned, and that would be much more efficient. Do you have an example you can point me to? Sincerely, Brad Gies - Brad Gies 27415 Greenfield Rd, # 2, Southfield, MI, USA 48076 www.bgies.com www.truckerphone.com www.EDI-Easy.com www.pricebunny.com - Moderation in everything, including abstinence -- *From:* android-developers@googlegroups.com [mailto: android-develop...@googlegroups.com] *On Behalf Of *Dianne Hackborn *Sent:* Friday, January 23, 2009 3:07 PM *To:* android-developers@googlegroups.com *Subject:* [android-developers] Re: Activity Issue on G1 phone There are two reasons for this: 1. Both screen rotation and keyboard shown/hidden are configuration changes, which means that after the state changes the application's resources can have any arbitrary new values -- anything from specific strings (for ex in a particular language you may need a abbreviation when in portrait mode) to layout resources and anything else. Trying to keep track of, and update, any of these values that could have changed would require a lot of work in the system, and a fair amount of effort from the developer to help the system, so it is far easier to just restart the entire activity with the new configuration. 2. To be a correct application, you already need to deal with saving and restoring state so you will always be returned to the user in your previous state after being in the background. By relying on this same mechanism for configuration changes, we get to take advantage of the work the developer has already done, and also further encourage them to actually do that work which otherwise often only causes problems in the application in obscure cases, so can often be missed. For the case of a thread running in the background that wants to communicate back with the current activity, an easy way to deal with this is to have a static variable that is the current activity, which you set in your onCreate() and clear in onDestroy(). Then instead of pointing to the activity that originally started it, the thread can just retrieve the current value in that variable when it needs it. (And of course it will need to deal with the race where it can temporarily be null between the old activity being destroyed and the new one created... but if you are doing multithreaded programming, this should be familiar territory!) On Fri, Jan 23, 2009 at 9:52 AM, Stanley.lei xiaofeng.lei...@gmail.com wrote: I rather agree with you! In fact, I could not understand why Google designs like this. The keyboard action could impact the rotation, but why changing rotation impacts the activity? In my case, the thread is destroyed, which will destroy all tasks in the thread. In worst case, the user will have to re-create their data from scratch. stanley On Jan 24, 1:47 am, cindy ypu01
[android-developers] Re: Activity Issue on G1 phone
Stanley.lei wrote: Hi all, I met a very strange issue when I tested my application on G1 phone. As usual method, I started a thread in an activity, and stopped the thread in the onDestroy method. But to my surprise, when I tried to slide down the keypad, the onDestroy method was called and the thread was stopped, and more surprising thing was that the activity was still alive and visible. From the activity's life cycle diagram, http://code.google.com/android/reference/android/app/Activity.html, we can see that onDestroy is called only before the activity is shut down. Correct. But my activity is still active and visible!!! A new instance of your activity was created. Who could tell me what the hidden story is? By default, when you slide the G1 keyboard open/closed, your activity is destroyed and recreated. I have a series of blog posts that cover this topic: http://androidguys.com/?s=rotational+forces -- Mark Murphy (a Commons Guy) http://commonsware.com _The Busy Coder's Guide to Android Development_ Version 2.0 Published! --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
[android-developers] Re: Activity Issue on G1 phone
It's so interesting! Thanks On Jan 23, 11:21 pm, Mark Murphy mmur...@commonsware.com wrote: Stanley.lei wrote: Hi all, I met a very strange issue when I tested my application on G1 phone. As usual method, I started a thread in an activity, and stopped the thread in the onDestroy method. But to my surprise, when I tried to slide down the keypad, the onDestroy method was called and the thread was stopped, and more surprising thing was that the activity was still alive and visible. From the activity's life cycle diagram, http://code.google.com/android/reference/android/app/Activity.html, we can see that onDestroy is called only before the activity is shut down. Correct. But my activity is still active and visible!!! A new instance of your activity was created. Who could tell me what the hidden story is? By default, when you slide the G1 keyboard open/closed, your activity is destroyed and recreated. I have a series of blog posts that cover this topic: http://androidguys.com/?s=rotational+forces -- Mark Murphy (a Commons Guy)http://commonsware.com _The Busy Coder's Guide to Android Development_ Version 2.0 Published! --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
[android-developers] Re: Activity Issue on G1 phone
I think what happens is that the activity's state is saved, the activity is destroyed, and then it is recreated with its saved state. This is the same thing that happens when the home button is pressed and the app is reopened. This just what I have come to understand, and may be wrong. -Original Message- From: Stanley.lei [mailto:xiaofeng.lei...@gmail.com] Sent: Friday, January 23, 2009 9:04 AM To: Android Developers Cc: jinnan@gmail.com Subject: [android-developers] Activity Issue on G1 phone Hi all, I met a very strange issue when I tested my application on G1 phone. As usual method, I started a thread in an activity, and stopped the thread in the onDestroy method. But to my surprise, when I tried to slide down the keypad, the onDestroy method was called and the thread was stopped, and more surprising thing was that the activity was still alive and visible. From the activity's life cycle diagram, http://code.google.com/android/reference/android/app/Activity.html, we can see that onDestroy is called only before the activity is shut down. But my activity is still active and visible!!! Who could tell me what the hidden story is? Any reply will be appreciated. Thanks, Stanley --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
[android-developers] Re: Activity Issue on G1 phone
Then android's implementation has problem. For example, if my application needs to create account, of cause, the key board will open first. After user typed in user name and password, then he clickes the create button.Request sends to server in a thread. After that, he closes the keyboard, the activity will be destroyed. So the callback function in thread to update UI will crashed. It happens exactly in my application. On Jan 23, 7:20 am, James Patillo ja...@patillo.org wrote: I think what happens is that the activity's state is saved, the activity is destroyed, and then it is recreated with its saved state. This is the same thing that happens when the home button is pressed and the app is reopened. This just what I have come to understand, and may be wrong. -Original Message- From: Stanley.lei [mailto:xiaofeng.lei...@gmail.com] Sent: Friday, January 23, 2009 9:04 AM To: Android Developers Cc: jinnan@gmail.com Subject: [android-developers] Activity Issue on G1 phone Hi all, I met a very strange issue when I tested my application on G1 phone. As usual method, I started a thread in an activity, and stopped the thread in the onDestroy method. But to my surprise, when I tried to slide down the keypad, the onDestroy method was called and the thread was stopped, and more surprising thing was that the activity was still alive and visible. From the activity's life cycle diagram,http://code.google.com/android/reference/android/app/Activity.html, we can see that onDestroy is called only before the activity is shut down. But my activity is still active and visible!!! Who could tell me what the hidden story is? Any reply will be appreciated. Thanks, Stanley --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
[android-developers] Re: Activity Issue on G1 phone
I rather agree with you! In fact, I could not understand why Google designs like this. The keyboard action could impact the rotation, but why changing rotation impacts the activity? In my case, the thread is destroyed, which will destroy all tasks in the thread. In worst case, the user will have to re-create their data from scratch. stanley On Jan 24, 1:47 am, cindy ypu01...@yahoo.com wrote: Then android's implementation has problem. For example, if my application needs to create account, of cause, the key board will open first. After user typed in user name and password, then he clickes the create button.Request sends to server in a thread. After that, he closes the keyboard, the activity will be destroyed. So the callback function in thread to update UI will crashed. It happens exactly in my application. On Jan 23, 7:20 am, James Patillo ja...@patillo.org wrote: I think what happens is that the activity's state is saved, the activity is destroyed, and then it is recreated with its saved state. This is the same thing that happens when the home button is pressed and the app is reopened. This just what I have come to understand, and may be wrong. -Original Message- From: Stanley.lei [mailto:xiaofeng.lei...@gmail.com] Sent: Friday, January 23, 2009 9:04 AM To: Android Developers Cc: jinnan@gmail.com Subject: [android-developers] Activity Issue on G1 phone Hi all, I met a very strange issue when I tested my application on G1 phone. As usual method, I started a thread in an activity, and stopped the thread in the onDestroy method. But to my surprise, when I tried to slide down the keypad, the onDestroy method was called and the thread was stopped, and more surprising thing was that the activity was still alive and visible. From the activity's life cycle diagram,http://code.google.com/android/reference/android/app/Activity.html, we can see that onDestroy is called only before the activity is shut down. But my activity is still active and visible!!! Who could tell me what the hidden story is? Any reply will be appreciated. Thanks, Stanley --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
[android-developers] Re: Activity Issue on G1 phone
Yeah, threads are particularly fun to deal with in Android. -Original Message- From: Stanley.lei [mailto:xiaofeng.lei...@gmail.com] Sent: Friday, January 23, 2009 11:52 AM To: Android Developers Subject: [android-developers] Re: Activity Issue on G1 phone I rather agree with you! In fact, I could not understand why Google designs like this. The keyboard action could impact the rotation, but why changing rotation impacts the activity? In my case, the thread is destroyed, which will destroy all tasks in the thread. In worst case, the user will have to re-create their data from scratch. stanley On Jan 24, 1:47 am, cindy ypu01...@yahoo.com wrote: Then android's implementation has problem. For example, if my application needs to create account, of cause, the key board will open first. After user typed in user name and password, then he clickes the create button.Request sends to server in a thread. After that, he closes the keyboard, the activity will be destroyed. So the callback function in thread to update UI will crashed. It happens exactly in my application. On Jan 23, 7:20 am, James Patillo ja...@patillo.org wrote: I think what happens is that the activity's state is saved, the activity is destroyed, and then it is recreated with its saved state. This is the same thing that happens when the home button is pressed and the app is reopened. This just what I have come to understand, and may be wrong. -Original Message- From: Stanley.lei [mailto:xiaofeng.lei...@gmail.com] Sent: Friday, January 23, 2009 9:04 AM To: Android Developers Cc: jinnan@gmail.com Subject: [android-developers] Activity Issue on G1 phone Hi all, I met a very strange issue when I tested my application on G1 phone. As usual method, I started a thread in an activity, and stopped the thread in the onDestroy method. But to my surprise, when I tried to slide down the keypad, the onDestroy method was called and the thread was stopped, and more surprising thing was that the activity was still alive and visible. From the activity's life cycle diagram,http://code.google.com/android/reference/android/app/Activity.html, we can see that onDestroy is called only before the activity is shut down. But my activity is still active and visible!!! Who could tell me what the hidden story is? Any reply will be appreciated. Thanks, Stanley --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
[android-developers] Re: Activity Issue on G1 phone
should this be considered as a bug for android application. Usally, when people use keyboard, they are sending some information to server. After that UI will be updated in call back. On Jan 23, 10:20 am, James Patillo ja...@patillo.org wrote: Yeah, threads are particularly fun to deal with in Android. -Original Message- From: Stanley.lei [mailto:xiaofeng.lei...@gmail.com] Sent: Friday, January 23, 2009 11:52 AM To: Android Developers Subject: [android-developers] Re: Activity Issue on G1 phone I rather agree with you! In fact, I could not understand why Google designs like this. The keyboard action could impact the rotation, but why changing rotation impacts the activity? In my case, the thread is destroyed, which will destroy all tasks in the thread. In worst case, the user will have to re-create their data from scratch. stanley On Jan 24, 1:47 am, cindy ypu01...@yahoo.com wrote: Then android's implementation has problem. For example, if my application needs to create account, of cause, the key board will open first. After user typed in user name and password, then he clickes the create button.Request sends to server in a thread. After that, he closes the keyboard, the activity will be destroyed. So the callback function in thread to update UI will crashed. It happens exactly in my application. On Jan 23, 7:20 am, James Patillo ja...@patillo.org wrote: I think what happens is that the activity's state is saved, the activity is destroyed, and then it is recreated with its saved state. This is the same thing that happens when the home button is pressed and the app is reopened. This just what I have come to understand, and may be wrong. -Original Message- From: Stanley.lei [mailto:xiaofeng.lei...@gmail.com] Sent: Friday, January 23, 2009 9:04 AM To: Android Developers Cc: jinnan@gmail.com Subject: [android-developers] Activity Issue on G1 phone Hi all, I met a very strange issue when I tested my application on G1 phone. As usual method, I started a thread in an activity, and stopped the thread in the onDestroy method. But to my surprise, when I tried to slide down the keypad, the onDestroy method was called and the thread was stopped, and more surprising thing was that the activity was still alive and visible. From the activity's life cycle diagram,http://code.google.com/android/reference/android/app/Activity.html, we can see that onDestroy is called only before the activity is shut down. But my activity is still active and visible!!! Who could tell me what the hidden story is? Any reply will be appreciated. Thanks, Stanley --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
[android-developers] Re: Activity Issue on G1 phone
Well, you can probably save the state of the thread when the activity is destroyed then open a new thread when the activity is resumed/recreated and restore the previous thread's state to the new one. -Original Message- From: cindy [mailto:ypu01...@yahoo.com] Sent: Friday, January 23, 2009 12:45 PM To: Android Developers Subject: [android-developers] Re: Activity Issue on G1 phone should this be considered as a bug for android application. Usally, when people use keyboard, they are sending some information to server. After that UI will be updated in call back. On Jan 23, 10:20 am, James Patillo ja...@patillo.org wrote: Yeah, threads are particularly fun to deal with in Android. -Original Message- From: Stanley.lei [mailto:xiaofeng.lei...@gmail.com] Sent: Friday, January 23, 2009 11:52 AM To: Android Developers Subject: [android-developers] Re: Activity Issue on G1 phone I rather agree with you! In fact, I could not understand why Google designs like this. The keyboard action could impact the rotation, but why changing rotation impacts the activity? In my case, the thread is destroyed, which will destroy all tasks in the thread. In worst case, the user will have to re-create their data from scratch. stanley On Jan 24, 1:47 am, cindy ypu01...@yahoo.com wrote: Then android's implementation has problem. For example, if my application needs to create account, of cause, the key board will open first. After user typed in user name and password, then he clickes the create button.Request sends to server in a thread. After that, he closes the keyboard, the activity will be destroyed. So the callback function in thread to update UI will crashed. It happens exactly in my application. On Jan 23, 7:20 am, James Patillo ja...@patillo.org wrote: I think what happens is that the activity's state is saved, the activity is destroyed, and then it is recreated with its saved state. This is the same thing that happens when the home button is pressed and the app is reopened. This just what I have come to understand, and may be wrong. -Original Message- From: Stanley.lei [mailto:xiaofeng.lei...@gmail.com] Sent: Friday, January 23, 2009 9:04 AM To: Android Developers Cc: jinnan@gmail.com Subject: [android-developers] Activity Issue on G1 phone Hi all, I met a very strange issue when I tested my application on G1 phone. As usual method, I started a thread in an activity, and stopped the thread in the onDestroy method. But to my surprise, when I tried to slide down the keypad, the onDestroy method was called and the thread was stopped, and more surprising thing was that the activity was still alive and visible. From the activity's life cycle diagram,http://code.google.com/android/reference/android/app/Activity.html, we can see that onDestroy is called only before the activity is shut down. But my activity is still active and visible!!! Who could tell me what the hidden story is? Any reply will be appreciated. Thanks, Stanley --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
[android-developers] Re: Activity Issue on G1 phone
Try that. If I send it again, in case case I will get error from server the user already exists. The request has sent to server. Problem is that it could not update UI since it is already destroyed. On Jan 23, 10:50 am, James Patillo ja...@patillo.org wrote: Well, you can probably save the state of the thread when the activity is destroyed then open a new thread when the activity is resumed/recreated and restore the previous thread's state to the new one. -Original Message- From: cindy [mailto:ypu01...@yahoo.com] Sent: Friday, January 23, 2009 12:45 PM To: Android Developers Subject: [android-developers] Re: Activity Issue on G1 phone should this be considered as a bug for android application. Usally, when people use keyboard, they are sending some information to server. After that UI will be updated in call back. On Jan 23, 10:20 am, James Patillo ja...@patillo.org wrote: Yeah, threads are particularly fun to deal with in Android. -Original Message- From: Stanley.lei [mailto:xiaofeng.lei...@gmail.com] Sent: Friday, January 23, 2009 11:52 AM To: Android Developers Subject: [android-developers] Re: Activity Issue on G1 phone I rather agree with you! In fact, I could not understand why Google designs like this. The keyboard action could impact the rotation, but why changing rotation impacts the activity? In my case, the thread is destroyed, which will destroy all tasks in the thread. In worst case, the user will have to re-create their data from scratch. stanley On Jan 24, 1:47 am, cindy ypu01...@yahoo.com wrote: Then android's implementation has problem. For example, if my application needs to create account, of cause, the key board will open first. After user typed in user name and password, then he clickes the create button.Request sends to server in a thread. After that, he closes the keyboard, the activity will be destroyed. So the callback function in thread to update UI will crashed. It happens exactly in my application. On Jan 23, 7:20 am, James Patillo ja...@patillo.org wrote: I think what happens is that the activity's state is saved, the activity is destroyed, and then it is recreated with its saved state. This is the same thing that happens when the home button is pressed and the app is reopened. This just what I have come to understand, and may be wrong. -Original Message- From: Stanley.lei [mailto:xiaofeng.lei...@gmail.com] Sent: Friday, January 23, 2009 9:04 AM To: Android Developers Cc: jinnan@gmail.com Subject: [android-developers] Activity Issue on G1 phone Hi all, I met a very strange issue when I tested my application on G1 phone. As usual method, I started a thread in an activity, and stopped the thread in the onDestroy method. But to my surprise, when I tried to slide down the keypad, the onDestroy method was called and the thread was stopped, and more surprising thing was that the activity was still alive and visible. From the activity's life cycle diagram,http://code.google.com/android/reference/android/app/Activity.html, we can see that onDestroy is called only before the activity is shut down. But my activity is still active and visible!!! Who could tell me what the hidden story is? Any reply will be appreciated. Thanks, Stanley --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
[android-developers] Re: Activity Issue on G1 phone
Pretty hard to write. Does anyone know a better and simple way to implememnt it? Thanks! Cindy On Jan 23, 11:22 am, cindy ypu01...@yahoo.com wrote: Try that. If I send it again, in case case I will get error from server the user already exists. The request has sent to server. Problem is that it could not update UI since it is already destroyed. On Jan 23, 10:50 am, James Patillo ja...@patillo.org wrote: Well, you can probably save the state of the thread when the activity is destroyed then open a new thread when the activity is resumed/recreated and restore the previous thread's state to the new one. -Original Message- From: cindy [mailto:ypu01...@yahoo.com] Sent: Friday, January 23, 2009 12:45 PM To: Android Developers Subject: [android-developers] Re: Activity Issue on G1 phone should this be considered as a bug for android application. Usally, when people use keyboard, they are sending some information to server. After that UI will be updated in call back. On Jan 23, 10:20 am, James Patillo ja...@patillo.org wrote: Yeah, threads are particularly fun to deal with in Android. -Original Message- From: Stanley.lei [mailto:xiaofeng.lei...@gmail.com] Sent: Friday, January 23, 2009 11:52 AM To: Android Developers Subject: [android-developers] Re: Activity Issue on G1 phone I rather agree with you! In fact, I could not understand why Google designs like this. The keyboard action could impact the rotation, but why changing rotation impacts the activity? In my case, the thread is destroyed, which will destroy all tasks in the thread. In worst case, the user will have to re-create their data from scratch. stanley On Jan 24, 1:47 am, cindy ypu01...@yahoo.com wrote: Then android's implementation has problem. For example, if my application needs to create account, of cause, the key board will open first. After user typed in user name and password, then he clickes the create button.Request sends to server in a thread. After that, he closes the keyboard, the activity will be destroyed. So the callback function in thread to update UI will crashed. It happens exactly in my application. On Jan 23, 7:20 am, James Patillo ja...@patillo.org wrote: I think what happens is that the activity's state is saved, the activity is destroyed, and then it is recreated with its saved state. This is the same thing that happens when the home button is pressed and the app is reopened. This just what I have come to understand, and may be wrong. -Original Message- From: Stanley.lei [mailto:xiaofeng.lei...@gmail.com] Sent: Friday, January 23, 2009 9:04 AM To: Android Developers Cc: jinnan@gmail.com Subject: [android-developers] Activity Issue on G1 phone Hi all, I met a very strange issue when I tested my application on G1 phone. As usual method, I started a thread in an activity, and stopped the thread in the onDestroy method. But to my surprise, when I tried to slide down the keypad, the onDestroy method was called and the thread was stopped, and more surprising thing was that the activity was still alive and visible. From the activity's life cycle diagram,http://code.google.com/android/reference/android/app/Activity.html, we can see that onDestroy is called only before the activity is shut down. But my activity is still active and visible!!! Who could tell me what the hidden story is? Any reply will be appreciated. Thanks, Stanley --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
