Support multiple UIWindows in an app

siasl · 05-27-2009, 02:26 AM

Hi,

Short Version:
=========

What is the API to remove the additional UIWindows (I have more than one) from UIApplication?

Long Version:
=========

I am trying to add two UIWindows in an app. I am using the second UIWindow to implement a view similar to UIActionSheet.

I can achieve the same by adding the new view to the existing UIWindow, but UIActionSheet does it by adding a new UIWindow and setting the windowLevel and I thought I may also implement in the same fashion.

I was able to create a new UIWindow, add new views and I was able to display it on top of the existing UIWindow by making a call to makeKeyAndVisible. I verified that it is reflected in the "windows" property of UIApplication as well.

The problem I am facing is I can't find any API to remove the new UIWindow from the list of windows in UIApplication. I tried calling makeKeyAndVisible on the previous window and it makes the new window disappear. But all the key presses are still going to the new UIWindow views.

How can I remove the new UIWindow from the windows list of the app?

- siasl

macoholic · 05-27-2009, 02:33 AM

You should not use more than one Window in an application....an application can have multiple views but only one window....

AS per iPhoneAppProgrammingGuide from apple you should not create more than one UIWindow in an App.

Macoholic

siasl · 05-27-2009, 04:20 AM

Yeah I have looked at AppProgramming Guide and it does mention the same. I have working code using a single UIWindow.

I am trying to create a clone of UIActionSheet and UIActionSheet itself uses additional UIWindow for its functionality. It seems to be a little more elegant solution than adding these additional views on to the same UIWindow.

Let me know if you know how to remove the extra UIWindow from the list.

Quote:

Originally Posted by macoholic

You should not use more than one Window in an application....an application can have multiple views but only one window....

AS per iPhoneAppProgrammingGuide from apple you should not create more than one UIWindow in an App.

Macoholic

macoholic · 05-27-2009, 04:35 AM

Your extra UIWindow in this case will be a sub view to your parent view or Window.

You could get the array of sub views and then remove what you want.

A suggestion...if apple suggests use a single UIWindow it's better to stick to it!
No harm experimenting but I am sure what you are truing to do can be done using Views too...coz primarily a UIWindow is derived from UIView.

Additional I have seen that not following apple's suggestion can lead to necessary performance issues...leaks and all.....

Any ways that's my point of view...see if the above suggestion helps you get rid of the extra UIWindow.....

If it doesn't and there is an alternate solution do let me know

Macoholic

siasl · 05-27-2009, 05:17 AM

The new UIWindow is not present in the same view heirarchy. It is present in an array of UIWindows (property "windows", readonly) in UIApplication. I can't find any API to remove it from this list.

I captured the view heirarchy for both the UIWindows and they sit at the same level (This view heirarchy is from a UIActionSheet and not from my code). I have truncated the main UIWindow view heirarchy, but it gives the idea.

Code:

Main UIWindow
==========

2009-05-27 15:42:23.710 HG[39753:20b] UILayoutContainerView:[{{0, 20}, {320, 460}}]
2009-05-27 15:42:23.711 HG[39753:20b] .  UITransitionView:[{{0, 0}, {320, 411}}]
2009-05-27 15:42:23.715 HG[39753:20b] .  .  UILayoutContainerView:[{{0, 0}, {320, 411}}]
2009-05-27 15:42:23.716 HG[39753:20b] .  .  .  UITransitionView:[{{0, 44}, {320, 367}}]
2009-05-27 15:42:23.718 HG[39753:20b] .  .  .  .  UIView:[{{0, 0}, {320, 367}}]
2009-05-27 15:42:23.718 HG[39753:20b] .  .  .  .  .  UIView:[{{0, 0}, {320, 367}}]
2009-05-27 15:42:23.726 HG[39753:20b] .  .  .  .  .  .  HGTableView:[{{0, 0}, {320, 367}}]
2009-05-27 15:42:23.726 HG[39753:20b] .  .  .  .  .  .  .  HGBaseNewDetailedTableViewCell:[{{0, 5}, {320, 45}}]
2009-05-27 15:42:23.726 HG[39753:20b] .  .  .  .  .  .  .  .  UIGroupTableViewCellBackground:[{{41, 0}, {270, 45}}]
2009-05-27 15:42:23.732 HG[39753:20b] .  .  .  .  .  .  .  .  .  UIImageView:[{{0, 0}, {270, 45}}]
2009-05-27 15:42:23.733 HG[39753:20b] .  .  .  .  .  .  .  .  UIView:[{{42, 1}, {245, 43}}]
2009-05-27 15:42:23.733 HG[39753:20b] .  .  .  .  .  .  .  .  .  UILabel:[{{10, 10}, {80, 23}}]
2009-05-27 15:42:23.735 HG[39753:20b] .  .  .  .  .  .  .  .  .  UILabel:[{{90, 10}, {145, 23}}]
2009-05-27 15:42:23.736 HG[39753:20b] .  .  .  .  .  .  .  .  .  UILabel:[{{10, 10}, {180, 23}}]
2009-05-27 15:42:23.739 HG[39753:20b] .  .  .  .  .  .  .  .  _UITableViewCellRemoveControl:[{{0, 0}, {41, 45}}]
2009-05-27 15:42:23.740 HG[39753:20b] .  .  .  .  .  .  .  .  .  UIRemoveControlMinusButton:[{{0, 0}, {41, 45}}]
2009-05-27 15:42:23.740 HG[39753:20b] .  .  .  .  .  .  .  .  .  .  UIImageView:[{{14, 22}, {13, 3}}]
.
.
.
.
truncated
.
.
.
.

UIActionSheet UIWindow:
================

2009-05-27 15:42:23.852 HG[39753:20b] UIView:[{{0, 0}, {320, 480}}]
2009-05-27 15:42:23.853 HG[39753:20b] UIView:[{{0, 0}, {320, 480}}]
2009-05-27 15:42:23.853 HG[39753:20b] .  UIView:[{{0, 20}, {320, 460}}]
2009-05-27 15:42:23.854 HG[39753:20b] .  .  UIView:[{{0, 0}, {320, 411}}]
2009-05-27 15:42:23.854 HG[39753:20b] .  .  .  UIView:[{{0, 0}, {320, 411}}]
2009-05-27 15:42:23.856 HG[39753:20b] .  .  .  .  UIView:[{{0, 44}, {320, 367}}]
2009-05-27 15:42:23.856 HG[39753:20b] .  .  .  .  .  UIView:[{{0, 0}, {320, 367}}]
2009-05-27 15:42:23.857 HG[39753:20b] .  .  .  .  .  .  UIActionSheet:[{{0, 262}, {320, 154}}]
2009-05-27 15:42:23.859 HG[39753:20b] .  .  .  .  .  .  .  UIThreePartButton:[{{21, 21}, {278, 46}}]
2009-05-27 15:42:23.860 HG[39753:20b] .  .  .  .  .  .  .  UIThreePartButton:[{{21, 88}, {278, 46}}]

Quote:

Originally Posted by macoholic

Your extra UIWindow in this case will be a sub view to your parent view or Window.

You could get the array of sub views and then remove what you want.

A suggestion...if apple suggests use a single UIWindow it's better to stick to it!
No harm experimenting but I am sure what you are truing to do can be done using Views too...coz primarily a UIWindow is derived from UIView.

Additional I have seen that not following apple's suggestion can lead to necessary performance issues...leaks and all.....

Any ways that's my point of view...see if the above suggestion helps you get rid of the extra UIWindow.....

If it doesn't and there is an alternate solution do let me know

Macoholic

Shinohara · 12-02-2011, 03:50 PM

After you've added a window to your hierarchy via -makeKeyAndVisible, you can remove it from the screen by calling it's -resignKeyWindow method.

Quote:

Originally Posted by siasl

The new UIWindow is not present in the same view heirarchy. It is present in an array of UIWindows (property "windows", readonly) in UIApplication. I can't find any API to remove it from this list.

I captured the view heirarchy for both the UIWindows and they sit at the same level (This view heirarchy is from a UIActionSheet and not from my code). I have truncated the main UIWindow view heirarchy, but it gives the idea.