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Diffstat (limited to 'kwin/HACKING')
| -rw-r--r-- | kwin/HACKING | 174 |
1 files changed, 0 insertions, 174 deletions
diff --git a/kwin/HACKING b/kwin/HACKING deleted file mode 100644 index 3dcd579f3..000000000 --- a/kwin/HACKING +++ /dev/null @@ -1,174 +0,0 @@ -Mailing list and bugzilla: -========================== - -The KWin mailing list is twin@kde.org . It's rather low traffic. - -The bugs.kde.org product for KWin is 'twin'. Currently the components are 'general' (KWin core), -'decorations' (decoration plugins), 'compatibility' (problems with non-KDE WMs/apps) and -'eyecandy' (transparency and similar effects). -There are also two kcontrol components 'kcmtwindecoration' and 'kcmtwinoptions' related -to KWin's KControl modules. - - -KWin parts: -=========== - -There are four parts of KWin: -- The KWin core, located in kdebase/twin/*, which implements the actual functionality. -- The decoration plugins, located in kdebase/twin/clients and kdeartwork/twin-styles, which - are responsible for the visual representation of the windows. -- The libkdecoration library, located in kdebase/twin/lib/*, which is used for communication - between the core and the decoration, and also implements some shared functionality - for the decorations. -- KControl modules, located in kdebase/twin/kcmtwin. - - -KWin decorations: -================= - -If you want to develop a decoration plugin for KWin, a HOWTO is available at -http://www.usermode.org/docs/twintheme.html . It is currently not possible to create -a new decoration without knowledge of C++, but it should be possible to write a themeable -decoration (I'm not aware of any such decoration though). - - -Restarting KWin: -================ - -Since KWin takes care of focus handling, first killing KWin and then launching new instance -can cause focus trouble. Therefore it's possible to run 'twin --replace', which will start -new KWin instance and tell the old one to quit. - - -Handling the case when KWin crashes: -==================================== - -Again, without KWin running there may be focus problems. The simplest way to solve them -is to add the 'Run Command' applet to Kicker - it can receive focus even without KWin running. -If you can't add the applet or can reach it for some reason, switch to text console, and run -'DISPLAY=:0 twin --replace' (and then you can run 'twin --replace' again from X). - -If KWin is temporarily unusable because of some change and e.g. crashes during startup, it -is possible to run another window manager, for example Metacity, OpenBox or FVWM (the command -is similar to restarting KWin, i.e. 'metacity --replace', 'openbox --replace' or 'fvwm -replace'). - - -Debugging KWin: -=============== - -Focus problems once more. It is not possible to debug KWin in gdb in the X session that KWin is managing, -because that'd block focus and window operations. It is necessary to switch to a text console -and attach to the running KWin instance from there, or launch it as 'DISPLAY=:0 gdb twin'. - -Since KWin is such an important component of KDE, it is usually better to start another X for development. -Note that XNest is quite buggy and is therefore not recommended to use. - - -Window manager spec: -==================== - -The EWMH window manager specification, also known as NETWM, is located at the freedesktop.org site, -http://www.freedesktop.org/wiki/Standards_2fwm_2dspec . It defines how the window manager -communicates information with the applications and other desktop utilities such as the taskbar -or pager. - - -KWin structure: -=============== - -KWin has relatively few classes. The two main classes are Client, which represents windows -on the screen, and Workspace, which represents the whole screen and manages windows. Both these -classes are rather large, because they fulfil complicated tasks. In other to reduce size -of their source files these some functionality is in separate .cpp file grouped by the purpose: - -- workspace.* - core of class Workspace -- client.* - core of class Client -- activation.cpp - focus handling and window activation -- events.cpp - event handling is in events.cpp -- geometry.cpp - geometry-related code -- layers.cpp - stacking-related code -- manage.cpp - code dealing with new windows -- placement.cpp - window placements algorithms -- rules.cpp - code for window-specific settings -- sm.cpp - session management code -- useractions.cpp - handling of the Alt+F3 menu, shortcuts and other user actions - -The rest of the files contain additional helper classes: - -- atoms.* - so-called atoms (symbolic names for constants in X) -- bridge.* - communication with the decoration plugin -- geometrytip.* - window displaying window geometry while moving/resizing -- group.* - grouping related windows together (warning! This is currently really messy and scary code - that should be rewritten). -- killwindow.* - handling of the Ctrl+Esc feature -- twinbindings.cpp - KWin's keyboard shortcuts (used by kdebase/kcontrol/keys) -- notifications.* - for KNotify -- options.* - all configuration options for KWin are stored in this class -- plugins.* - loading of the right decoration plugin -- popupinfo.* - showing temporary information such as virtual desktop name when switching desktops -- tabbox.* - the Alt+Tab dialog -- utils.* - various small utility functions/classes - -KWin also uses code from kdelibs, specifically files netwm.cpp, netwm.h, netwm_def.h and netwm_p.h -from kdelibs/tdecore. These files implement support for the EWMH window manager specification, -originally called NETWM (hence the filenames). - - -Developing KWin: -================ - -So, you feel brave, huh? But KWin is not THAT difficult. Some parts, especially the X-related ones, -can be very complicated, but for many parts even knowledge of X and Xlib is not necessary. Most X -code is wrapped in helper functions, and I can handle problems there ;) . However, although many -features don't require touching X/Xlib directly, still X/Xlib may impose their semantics on the way -things are done. When in doubt, simply ask. - -All patches for KWin core should be sent to twin@kde.org for review first. Even seemingly harmless -changes may have extensive consequences. - -Various notes: - -- kdDebug has overloaded operator << for the Client class, so you can e.g. use 'kdDebug() << this << endl;' -in class Client and it will print information about the window. - -- KWin itself cannot create any normal windows, because it would have trouble managing its own windows. -For such cases (which should be rare) a small external helper application is needed (kdialog should often -do, and for special cases such a utility needs to be written like twin/killer). - - -X documentation: -================ - -As already said, many parts of KWin don't need knowledge of Xlib or even how X actually works. -Some parts do, and it may be also useful to have at least a basic understand for general -understanding. A reference manual for Xlib can be found e.g. -at ftp://ftp.x.org/pub/X11R7.0/doc/PDF/xlib.pdf , a tutorial explaining basic can be found -e.g. at ttp://users.actcom.co.il/~choo/lupg/tutorials/xlib-programming/xlib-programming.html -(note that you don't need to know that all - e.g. GC's are very rarely needed and the -section on fonts is today outdated). - - -Coding style: -============= - -There are only three rules for patches for KWin: - -- the code should be relatively nice and clean. Seriously. Any messy code can be hard to comprehend, -but if the code is in a window manager it will be twice as difficult. - -- unless the functionality of the code is obvious, there should be either at least a short comment explaining -what it does, or it should be obvious from the commit log. If there's a hack needed, if there's a potentional -problem, if something is just a temporary fix, say so. Comments like "this clever trick is necessary" -don't count. See rule #1 above for reasons. I needed more than two years to understand all of KWin, -and there were parts I never got and had to rewrite in order to fix a problem with them. - -- put matching opening { and closing } in the same column. That's the only formatting rule I ask for. -I don't really care if they're aligned with the block one level higher or if they're aligned with the block -they surround like I do (which is the only thing about the "weird coding style in KWin") or if you align them -with something else, just put them in the same column. If I can handle about half a dozen different formatting -styles when working on various parts of KDE, this shouldn't be much work for you (and you can do that only -right before sending the patch). I don't care where you do and don't put spaces or what exactly you call local -variables, as long as I can read it (trying to make it look like the rest of the code is bonus points though ;) ). - - -twin@kde.org |