You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
283 lines
14 KiB
283 lines
14 KiB
$Id$
|
|
|
|
|
|
Application startup notification
|
|
Lubos Lunak <l.lunak@kde.org>
|
|
--------------------------------
|
|
--------------------------------
|
|
|
|
|
|
When a new application is started in KDE, together with it a startup
|
|
notification is sent, which is used to show a startup entry in taskbar,
|
|
the busy icon next to the cursor and put the window of the started app
|
|
on correct desktop.
|
|
This application startup notification ( ASN for short in the following
|
|
text ) usually works fine without problems, but some applications and
|
|
some special cases may need special handling.
|
|
Right now, this is only an internal KDE standard, but since a toolkit
|
|
support would improve the results a bit, I'll try to discuss this
|
|
on http://www.freedesktop.org .
|
|
|
|
|
|
Starting apps with ASN :
|
|
-------------------------
|
|
|
|
When an application is started from the TDE Menu or the minicli, and from other
|
|
places, ASN is sent automatically for it, assuming a matching .desktop file
|
|
is found for the starting application. Application without a .desktop file
|
|
don't get ASN ( this may change, but it's unlikely as it creates too many
|
|
ASNs which will stay too long until a timeout ). For improving the quality
|
|
of ASN and reducing the number of ASNs that don't detect when the application
|
|
has started, some .desktop file entries may be helpful ( see below ).
|
|
If you want to start an application in your code, prefer using KRun or
|
|
TDEApplication::startServiceByXXX() calls. Classes like TDEProcess don't create
|
|
ASN, so if you need to use it, you have to send it manually ( only in case
|
|
ASN is useful in this case, it shouldn't be sent e.g. for system processes ).
|
|
|
|
|
|
.desktop files :
|
|
-----------------
|
|
|
|
These following .desktop file entries affect ASN :
|
|
|
|
X-TDE-StartupNotify=<bool>
|
|
- if true, this app/service will get app startup notify
|
|
- if false, this app/service will _not_ get app startup notify
|
|
- if not set
|
|
- if it's service, it will _not_ get app startup notify
|
|
- if it's app, it will get app startup notify, but
|
|
X-TDE-WMClass will be assumed to be "0" ( non-compliant )
|
|
X-TDE-WMClass=<string>
|
|
- if set, and it's different from "0" ( without quotes ), this
|
|
is the WMClass value for startup notification
|
|
- if it's "0" ( without quotes ), such app is considered non-compliant,
|
|
and the startup notification will stop
|
|
- either if its windows is correctly detected using the default
|
|
WMClass value ( the name of the binary )
|
|
- or if a window is mapped that is not recognized ( doesn't have
|
|
neither _KDE_STARTUP_ID nor _NET_WM_PID property /*CHECKME*/),
|
|
it's assumed this window belongs to the started app;
|
|
the start-on-desktop feature won't work then too
|
|
- if not set, it defaults to the binary name of the app ( ok for most apps,
|
|
including KDE ones )
|
|
- to get the WMCLASS value for any app, run 'xprop' and click on the app's
|
|
window, WMCLASS value for this app should be any of the strings listed
|
|
in the WM_CLASS property ( it's usually the same as the name of the
|
|
app's binary file, in such case it doesn't need to be explicitly set )
|
|
MapNotify=<bool>
|
|
- this key is obsolete
|
|
- true is equivalent to X-TDE-StartupNotify=true and no X-TDE-WMClass set
|
|
- false is equivalent to X-TDE-StartupNotify=true and X-TDE-WMClass=0
|
|
- many .desktop files in KDE ( especially in tdebase/kappfinder )
|
|
seem to have MapNotify=false even though it's not needed, this
|
|
needs to be checked and replaced by the needed X-TDE-* values,
|
|
often just X-TDE-StartupNotify=true should be enough
|
|
|
|
The best way to check if the entries are set correctly is to start
|
|
the application and switch to other desktop. If the startup notification
|
|
disappears and the application appears on the desktop on which it was
|
|
started, it's correct ( with X-TDE-WMClass=0, the start-on-desktop
|
|
feature may not work ).
|
|
|
|
Ideally, every .desktop file should have X-TDE-StartupNotify set to the correct
|
|
value, and for apps which need it also X-TDE-WMClass should be set. This
|
|
sometimes gives slightly better behavior than when these entries are not set.
|
|
|
|
|
|
The TDEStartupInfo classes :
|
|
--------------------------
|
|
|
|
In some cases, or if you are interested in getting the ASN information, you
|
|
have to use the TDEStartupInfo classes in tdelibs/tdecore.
|
|
|
|
Receiving the application startup notification information :
|
|
------------------------------------------------------------
|
|
|
|
Create an instance of class TDEStartupInfo and connect to its slots, they
|
|
will be emitted whenever a ASN info is received.
|
|
The clean_on_cantdetect argument to the constructor means whether all
|
|
ASN info for non-compliant apps should be removed when a window is mapped
|
|
which cannot be identified ( it's not possible to say if it belong to one
|
|
of the starting applications or not ). If the argument is true, it is
|
|
assumed that the window does belong to one of the starting applications,
|
|
and all ASN info for non-compliant apps must be removed, otherwise the ASN
|
|
info would timeout ( e.g. kdesktop sets it to true, otherwise the busy
|
|
icon would sometimes stay for too long, which is oftern annoying ).
|
|
On the other hand, KWin, which maps the first window of the starting apps
|
|
to the given virtual desktop, sets it to false, because there's no visual
|
|
representation and if a window for a starting non-compliant application is
|
|
detected later, it still will be successfully places on the correct virtual
|
|
desktop.
|
|
Note that the ASN info is often send in several messages, and the slots
|
|
will be therefore emitted several times, with the updated info ( e.g. the
|
|
binary name or PID is not know from the beginning ).
|
|
|
|
Sending the application startup notification information :
|
|
----------------------------------------------------------
|
|
|
|
Before an application is started, ASN info for it must be sent ( unless
|
|
it's done by classes like KRun ). See e.g. KRun sources for details.
|
|
During the starting of the application, the info may need some updating
|
|
( e.g. right after starting the app, the PID with hostname may be sent,
|
|
or a PID change when KUniqueApplication forks into background ).
|
|
When it's detected that the started process exited, it an ASN info
|
|
about the finished process should be sent. Since the application may
|
|
have forked into background, the finish info should include the PID
|
|
and hostname, and the notification will be stopped only if there's
|
|
no other PID for it. On the other hand, if you simply really need
|
|
to stop ASN, send only the identification ( TDEStartupInfo::sendFinish()
|
|
with only TDEStartupInfoId argument ).
|
|
|
|
|
|
|
|
Implementation details :
|
|
------------------------
|
|
|
|
The ASN info data is sent using X ClientMessages as text ( see below ),
|
|
this is mainly in hope also non-TDE people will start using it, and
|
|
they wouldn't be very happy with DCOP.
|
|
Before starting an application, and environment variable called
|
|
KDE_STARTUP_ENV is added to it's environment, and it's set to unique
|
|
identifier of its startup notification, or "0" for disabled ASN.
|
|
Ideally, the application should read it, and set a window property
|
|
called _KDE_STARTUP_ID ( type XA_STRING ) at least on its first mapped
|
|
toplevel window to this value. It should also unset it, so it doesn't get
|
|
propagated to other applications started from it. It should also
|
|
update the ASN info when necessary, e.g. when KUniqueApplication
|
|
forks into background, it sends the PID change. That's how compliant
|
|
applications should work, and this support for ASN should be provided
|
|
by toolkits. All KDE application should be compliant by now, since
|
|
tdelibs do all the necessary things. The KDE_STARTUP_ENV variable
|
|
is read and unset in TDEApplication constructor, and _KDE_STARTUP_ID
|
|
is set on every toplevel window in TDEApplication::setTopWidget().
|
|
However, majority of applications aren't compliant now, and even
|
|
if I succeed making this thing a standard ( part of NETWM_SPEC
|
|
or whatever ), there still will be old applications that won't behave
|
|
this way. Not unsetting KDE_STARTUP_ENV is not a big problem, since
|
|
the ASN for its value will usually timeout, and when the app starts
|
|
a new application, this ASN identification value will get reused without
|
|
problems. The other problem is detecting, which newly mapped windows
|
|
belong to which starting application. If a newly mapped window doesn't
|
|
have _KDE_STARTUP_ID property, the code tries to read its _NET_WM_PID
|
|
property, and if it's set, it tries to match it ( together with
|
|
WM_CLIENT_MACHINE ) with PIDs of all ASN infos. And if the window
|
|
doesn't have even the _NET_WM_PID property, WM_CLASS property is used
|
|
then. It's usually set to two strings, and at least one of them is
|
|
usually the binary name of the application, so it's converted
|
|
to lowercase and compared. For applications, where such comparison
|
|
would fail, the X-TDE-WMClass .desktop file entry should be set
|
|
to the correct WMClass value ( e.g. for XEmacs, the binary name
|
|
is 'xemacs', but WM_CLASS is 'emacs', 'Emacs', so its X-TDE-WMClass
|
|
in its .desktop file should be set to 'emacs' - the case doesn't
|
|
matter ).
|
|
The ASN identification string must be a unique string for every ASN.
|
|
In TDEStartupInfo class, it's created as 'hostname;tm.sec;tm.usec;pid',
|
|
tm being the current time. If the identification string is set to "0",
|
|
it means no ASN should be done ( e.g. for things like tdeio_uiserver,
|
|
which shouldn't get ASN ). Empty identification string means the same
|
|
like "0", except for the call to TDEStartupInfoId::initId(), where it means
|
|
to create a new one.
|
|
|
|
|
|
Format of the text messages :
|
|
-----------------------------
|
|
|
|
There are 3 types of messages :
|
|
- new: message
|
|
- this message announces that a new application is being started,
|
|
if there is not ASN info for this ASN identification, it should be
|
|
updated, otherwise it will be created
|
|
- the text of the message starts with 4 characters 'new:', followed
|
|
by the text entries ( see below )
|
|
- change: message
|
|
- this message is like new: message, but it's only for updating existing
|
|
ASN info, if there's no ASN info for the given identification, it won't
|
|
be created. This is used e.g. in KUniqueApplication when it forks
|
|
into background and sends info about the PID change - it should update
|
|
any existing ASN info, but mustn't create a new one, otherwise there
|
|
could appear ASN even for applications which shouldn't have ASN
|
|
- the text of the message starts with 4 characters 'change:', followed
|
|
by the text entries ( see below )
|
|
- remove: message
|
|
- this message is sent for stopping ASN with the given identification.
|
|
If the only item in the message is the identification string, the ASN
|
|
info should be removed. If there are also the PID and HOSTNAME entries
|
|
( see below ), the matching ASN info should be only removed if this
|
|
given PID is the only PID for it ( in this case, the identification
|
|
string may be omitted ).
|
|
- the text of the message starts with 4 characters 'remove:', followed
|
|
by
|
|
- only ID entry
|
|
- only ID, PID and HOSTNAME entries
|
|
- only PID and HOSTNAME entries
|
|
|
|
|
|
Text entries in the messages :
|
|
------------------------------
|
|
|
|
Every entry is of the form <name>=<value>. Value may be either a number
|
|
or a string. If the string contains spaces, it must be quoted ("), all
|
|
backslashes and quotes (") must be escaped by backslashes. If this ever
|
|
becomes more than an internal KDE standard, non-standard entry names should
|
|
start with an underscore.
|
|
|
|
Entries :
|
|
|
|
- ID - string
|
|
- the identification string of the startup notification
|
|
- it must be present in all messages except for the remove:
|
|
message with only PID and HOSTNAME
|
|
- BIN - string
|
|
- the binary name of the starting application
|
|
- usually used as a fallback value if WMCLASS is not present
|
|
- e.g. 'kcontrol'
|
|
- NAME - string
|
|
- the name of the starting application
|
|
- usually used only for displaying it when indicating that
|
|
the application is starting
|
|
- e.g. 'Control Center'
|
|
- ICON - string
|
|
- the icon for this startup notification
|
|
- it should be handled like the Icon= entry in .desktop files
|
|
- e.g. 'kcontrol'
|
|
- DESKTOP - number
|
|
- the virtual desktop on which the application should appear
|
|
- if the application's first window has _NET_WM_DESKTOP already
|
|
set when the window is mapped, it shouldn't be changed
|
|
- WMCLASS - string
|
|
- the WMCLASS value used for matching newly mapped windows
|
|
of non-compliant applications
|
|
- useful only if it's different from the binary
|
|
name of the application
|
|
- PID - number
|
|
- the PID of a process that belongs to this startup notification
|
|
- there may be several PIDs for one notification
|
|
- value 0 is also valid, meaning that there's a process
|
|
with unknown PID for this notification ( is used e.g.
|
|
by kfmclient when it sends a DCOP message to already running
|
|
konqueror instance to create a new window and exits immediately,
|
|
without adding the zero PID to the notification, process
|
|
that started kfmclient could detect it exited and would send
|
|
a remove: message for the notification with kfmclient's PID,
|
|
which would cause the notification to stop if there wasn't also
|
|
PID=0 for it
|
|
- HOSTNAME - string
|
|
- the hostname of the machine on which the application is being
|
|
started
|
|
- this is used together with the PID entry
|
|
|
|
--------------------
|
|
|
|
Well, I guess that's all. The KDE2.2 release will show if the users like it
|
|
or not ( it's quite good IMHO, even though there are probably some minor
|
|
details to fix or improve ). The only big thing remaining is to make also
|
|
non-TDE people agree on using something like this. My first attempt
|
|
https://listman.redhat.com/pipermail/xdg-list/2001-May/000083.html
|
|
didn't get much attention, but now that there's a working implementation,
|
|
I hope it will get better, when I try again sometime in the future.
|
|
|
|
|
|
|
|
Lubos Lunak <l.lunak@kde.org>
|
|
|