Will pressing the Home button really shut down app?

GO TO ADMIN PANEL > ADD-ONS AND INSTALL VERTIFORO SIDEBAR TO SEE FORUMS AND SIDEBAR

daihard

New member
Joined
Oct 25, 2006
Messages
795
Points
0
Location
Lynnwood, WA
I am asking because most of the people in this Japanese iPhone forum believe otherwise. They contend that the application "disappears" from the main screen but remains in the background when the Home button is pressed, and that you must hold down the Home button for a few seconds in order to shut the application down completely.

Knowing that folks here believe that pressing the Home button is (or should be) enough to shut down the application, I passed that opinion to them (i.e. those in the Japanese forum). One of them came back suggesting I do this.

1) Open Safari and display a Web site.
2) Press the Home button.
3) Open Safari again.

He says that Safari will open again without reloading the site. According to him, it must mean Safari was still running in the background. OTOH, he says, if you hold down the Home button for a few seconds in step (2), then Safari will reload the site when it reopens in step (3).

This seems to mean that pressing the Home button doesn't completely shut down the application but merely pushes it into the background, much like pressing the red button on the top left corner of the application window on Mac OS X. What do you guys think?
 
Joined
Nov 15, 2004
Messages
13,238
Points
36
Age
48
Location
Toronto, Canada
Website
www.ilounge.com
Some of the built-in Apple applications like Safari leave a "stub" of the app in memory to maintain state, but the app does not actually run in the background (ie, it doesn't use CPU cycles).

In fact, you can prove this with Safari by loading a complex web page and then exiting. Safari will not continue to load the page in the background, and if you return it will likely start reloading that page from scratch, although it may also just pick up where you left off.

Obviously programs like the iPod app do run in the background -- sort of -- so that your music keeps playing. Even in this case, however, it's a "stub" music playback app that runs in the background, and not the iPod app itself that stays resident in memory.

This behaviour is completely restricted to Apple's own built-in applications. Third-party apps built with the SDK are required to shut down completely when the Home button is pressed. They can still save state -- in fact the SDK recommends this to provide a seamless experience, but they do not "run" in the background.

Even with Safari, if you load up enough additional applications, you will find that Safari does reload the page when you return to it. The "stub" in this case is volatile, and will be pushed out of memory if another application requires that memory space.

On the other hand, holding down the HOME button for about 8 seconds will always "Force Quit" an app and all related processes.
 

cycler15

New member
Joined
Aug 4, 2004
Messages
82
Points
0
jhollington said:
Some of the built-in Apple applications like Safari leave a "stub" of the app in memory to maintain state, but the app does not actually run in the background (ie, it doesn't use CPU cycles).

In fact, you can prove this with Safari by loading a complex web page and then exiting. Safari will not continue to load the page in the background, and if you return it will likely start reloading that page from scratch, although it may also just pick up where you left off.

Obviously programs like the iPod app do run in the background -- sort of -- so that your music keeps playing. Even in this case, however, it's a "stub" music playback app that runs in the background, and not the iPod app itself that stays resident in memory.

This behaviour is completely restricted to Apple's own built-in applications. Third-party apps built with the SDK are required to shut down completely when the Home button is pressed. They can still save state -- in fact the SDK recommends this to provide a seamless experience, but they do not "run" in the background.

Even with Safari, if you load up enough additional applications, you will find that Safari does reload the page when you return to it. The "stub" in this case is volatile, and will be pushed out of memory if another application requires that memory space.

On the other hand, holding down the HOME button for about 8 seconds will always "Force Quit" an app and all related processes.
Good info. THanks.
 

daihard

New member
Joined
Oct 25, 2006
Messages
795
Points
0
Location
Lynnwood, WA
Thanks much for the useful information, Jesse! That makes a lot of sense. Keeping a stub piece instead of letting the whole application run in the background surely helps conserve CPU power and battery.

Now I have to translate it and post it in the Japanese forum. :)

[EDIT] I have translated your information and placed it on the Japanese forum. I'll see how people will respond to it. If something interesting comes up, I will share it with you here.
 
Last edited:
Top