Public screen closing bug in OS4.1 (FIXED)

Easy workaround is close that Ringhio window before closing your app.

btw, I have downloaded and installed your litle patch)

No public screen will close if there is a window open on it.

The screen closing is automatic in the sense that the last visitor window on a public screen doesn't need to explicitly close a screen when the window closes.

ChrisH wrote:
Quote:

The screen closing is automatic in the sense that the last visitor window on a public screen doesn't need to explicitly close a screen when the window closes.

This is NOT happening, hence my bug report.

NAME
LockPubScreen -- Prevent a public screen from closing. (V36)

SYNOPSIS
struct Screen *screen = LockPubScreen(CONST_STRPTR name);

FUNCTION
Prevents a public screen (or the Workbench) from closing
while you examine it in preparation of opening a visitor window.

The sequence you use to open a visitor window that needs to
examine fields in the screen it is about to open on is:
LockPubScreen()
... examine fields ...
OpenWindow() on public screen
UnlockPubScreen()
... use your window ...
CloseWindow()

NOTE
You needn't hold the "pubscreen lock" for the duration that
your window is opened. LockPubScreen() basically has the
same effect as an open visitor window: it prevents the
screen from being closed.

If you pass the string "Workbench" or you pass NULL and there
is no default public screen, the Workbench screen will
be automatically opened if it is not already present.

INPUTS
name - name string for public screen or NULL for default public
screen. The string "Workbench" indicates the Workbench
screen.

RESULT
screen - Returns pointer to a screen if successful or NULL.
The call can fail for reasons including that the named
public screen doesn't exist or is in private state.

NAME
CloseWindow -- Close an Intuition window.

SYNOPSIS
CloseWindow( Window )

VOID CloseWindow( struct Window * );

FUNCTION
Closes an Intuition window. Unlinks it from the system, deallocates
its memory, and makes it disappear.

...

New for V36: If your window is a "Visitor Window" (see OpenWindow)
CloseWindow will decrement the "visitor count" in the public screen
on which the window was open. When the last visitor window is
closed, a signal will be sent to the public screen task, if this
was pre-arranged (see OpenScreen).

NAME
OpenWindow -- Open an Intuition window.

SYNOPSIS
Window = OpenWindow( NewWindow )

struct Window *OpenWindow( struct NewWindow * );

FUNCTION

...

WA_PubScreenName - This tag item declares that you want your window
to open as a visitor window on the public screen whose name
is pointed to by (STRPTR) ti_Data.

WA_PubScreen - Open as a visitor window on the public screen
whose address if provided as (struct Screen *) ti_Data.
To ensure that this screen remains open long enough, you
must either:
1) Be the screen's owner
2) have another window already open on the screen
3) use LockPubScreen()
Using exec.library/Forbid() is not sufficient.

You can provide ti_Data to be NULL (zero), without any
of the above precautions, to specify the default public screen.

WA_PubScreenFallBack - This Boolean attribute specifies that a
visitor window should "fall back" to opening on the default
public screen if the explicitly specify public screen is not
available.

...

NOTES
Regarding Public Screens, you can specify a window to be a
"visitor window" on a public screen in one of several ways.
In each case, you must be sure not to specify a NewWindow
type of CUSTOMSCREEN. You should use the value PUBLICSCREEN.

There are actually several ways you can specify which screen
you want a visitor window to be opened on:

1) Specify the name of the public screen WA_PubScreenName,
or a NULL pointer, in ti_Data. The name might have been
provided by the user. A NULL pointer means to use the
default public screen.

If the named screen cannot be found, the default public screen
will be used if the Boolean attribute WA_PubScreenFallBack
is TRUE.

2) Specify a pointer to a public screen using the
WA_PubScreen tag item. The WA_PubScreenFallBack
attribute has no effect. You can specify the default
public screen by providing a NULL pointer.

You can also specify the pointer by setting NewWindow.Type
to PUBLICSCREEN, and specifying the public screen pointer
in NewWindow.Screen. The WA_PubScreen tag item has precedent
over this technique.

Unless NULL, the screen pointer provided MUST be a valid
public screen. You may ensure this several ways:

- Be the owner of the screen.
- Have a window already open on the screen.
- Use LockPubScreen() to prevent the screen from closing.
- specifying the WFLG_VISITOR bit in NewWindow.Flags is not
supported.

It is anticipated that the last will be the most common method
of opening public screens because you often want to examine
properties of the screen your window will be using in order
to compensate for differences in dimension, depth, and font.

The standard sequence for this method is as follows:
LockPubScreen() - obtain a pointer and a promise
layout window - adapt your window to the screen you will use
OpenWindow() - using the pointer you specify
UnlockPubScreen() - once your window is open, you can let go
of the lock on the public screen
... normal window even processing ...
CloseWindow().

NAME
OpenScreen -- Open an Intuition screen.

SYNOPSIS
Screen = OpenScreen( NewScreen )

struct Screen *OpenScreen( struct NewScreen * );

or

struct Screen *OpenScreen( struct ExtNewScreen * );

FUNCTION

...

The following two tag items specify the task and signal to be issued
to notify when the last "visitor" window closes on a public screen.
This support is to assist envisioned public screen manager programs.

SA_PubTask: Task to be signalled. If absent (and SA_PubSig is
valid), use the task which called OpenScreen() or
OpenScreenTagList()).

SA_PubSig: Data is a UBYTE signal number (not flag) used to notify
a task when the last visitor window closes on a public screen.[b]

...

[b]A_ErrorCode: ti_Data points to a ULONG in which Intuition will
stick an extended error code if OpenScreen[TagList]() fails.
Values are of this include 0, for success, and:
OSERR_NOMONITOR - monitor for display mode not available.
OSERR_NOCHIPS - you need newer custom chips for display mode.
OSERR_NOMEM - couldn't get normal memory
OSERR_NOCHIPMEM - couldn't get chip memory
OSERR_PUBNOTUNIQUE - public screen name already used

A program which opened a screen and made it public must be aware that visitor windows can exist and that CloseScreen can fail. In this case it has to wait until all visitor windows are gone before it closes the screen. It must not quit before the screen is closed.

xenic wrote:
The problem is with Ringhio and not Intuition or Screens preferences and I think that patching CloseScreen() is a misguided attempt to compensate for a Ringhio problem. Without Ringhio, my public screens (whether program created or Screen prefs created) all work as they should. I think Ringhio should use system compliant requesters instead of the current method.

However, the OS4 Screens preferences program enables system created screens that are opened automatically whenever a program attempts to open on a screen with that name.

I agree with you patching CloseScreen() so that it never fails might not be a good idea because this means that some programs that rely on the fact that CloseScreen() returns immediately might get stuck for ever without being prepared of this...

I cannot replicate the problem using AOS4.1 beta (upd2 + daily updates) OWB (3.32) correctly close the screen when the last Ringhio notification fades away, so the bug seems to be fixed.

It would be nice if someone involved in OS4 development would comment on the wisdom of patching CloseScreen() in this way.

I have to wonder how MUI will react if it gets stuck in CloseScreen() of an MUI defined screen.

As thomas said, theres simply no need for a CloseScreen() patch. Just follow the development guidelines