From 733de76221223c2ad3ce94a588015e88c4c9dcc7 Mon Sep 17 00:00:00 2001 From: Simon Ser Date: Thu, 21 Nov 2019 12:25:00 +0100 Subject: Convert plaintext documents to Markdown This converts GOVERNANCE, MEMBERS and README to Markdown documents. These are only cosmetic changes, the actual contents and wording have been retained. GitLab pretty-prints Markdown and adds anchors. We can now add links from one document to another. Unfortunately GOVERNANCE lettered lists have been converted to numbered lists, because Markdown doesn't support the former. Signed-off-by: Simon Ser Closes: https://gitlab.freedesktop.org/wayland/wayland-protocols/issues/3 --- README.md | 150 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 150 insertions(+) create mode 100644 README.md (limited to 'README.md') diff --git a/README.md b/README.md new file mode 100644 index 0000000..16df4dc --- /dev/null +++ b/README.md @@ -0,0 +1,150 @@ +# Wayland protocols + +wayland-protocols contains Wayland protocols that add functionality not +available in the Wayland core protocol. Such protocols either add +completely new functionality, or extend the functionality of some other +protocol either in Wayland core, or some other protocol in +wayland-protocols. + +A protocol in wayland-protocols consists of a directory containing a set +of XML files containing the protocol specification, and a README file +containing detailed state and a list of maintainers. + +## Protocol directory tree structure + +Protocols may be "stable", "unstable" or "deprecated", and the interface +and protocol names as well as place in the directory tree will reflect +this. + +A stable protocol is a protocol which has been declared stable by +the maintainers. Changes to such protocols will always be backward +compatible. + +An unstable protocol is a protocol currently under development and this +will be reflected in the protocol and interface names. See [Unstable +naming convention](#unstable-naming-convention). + +A deprecated protocol is a protocol that has either been replaced by some +other protocol, or declared undesirable for some other reason. No more +changes will be made to a deprecated protocol. + +Depending on which of the above states the protocol is in, the protocol +is placed within the toplevel directory containing the protocols with the +same state. Stable protocols are placed in the `stable/` directory, +unstable protocols are placed in the `unstable/` directory, and +deprecated protocols are placed in the `deprecated/` directory. + +## Protocol development procedure + +To propose a new protocol, create a GitLab merge request adding the +relevant files and Makefile.am entry to the repository with the +explanation and motivation in the commit message. Protocols are +organized in namespaces describing their scope ("wp", "xdg" and "ext"). +There are different requirements for each namespace, see [GOVERNANCE +section 2](GOVERNANCE.md#2-protocols) for more information. + +If the new protocol is just an idea, open an issue on the GitLab issue +tracker. If the protocol isn't ready for complete review yet and is an +RFC, create a merge request and add the "WIP:" prefix in the title. + +To propose changes to existing protocols, create a GitLab merge request. + +If the changes are backward incompatible changes to an unstable protocol, +see [Unstable protocol changes](#unstable-protocol-changes). + +## Interface naming convention + +All protocols should avoid using generic namespaces or no namespaces in +the protocol interface names in order to minimize risk that the generated +C API collides with other C API. Interface names that may collide with +interface names from other protocols should also be avoided. + +For generic protocols not limited to certain configurations (such as +specific desktop environment or operating system) the `wp_` prefix +should be used on all interfaces in the protocol. + +For protocols allowing clients to configure how their windows are +managed, the `xdg_` prefix should be used. + +For operating system specific protocols, the interfaces should be +prefixed with both `wp_` and the operating system, for example +`wp_linux_`, or `wp_freebsd_`, etc. + +For more information about namespaces, see [GOVERNANCE section 2.1 +](GOVERNANCE.md#21-protocol-namespaces). + +## Unstable naming convention + +Unstable protocols have a special naming convention in order to make it +possible to make discoverable backward incompatible changes. + +An unstable protocol has at least two versions: the major version, which +represents backward incompatible changes, and the minor version, which +represents backward compatible changes to the interfaces in the protocol. + +The major version is part of the XML file name, the protocol name in the +XML, and interface names in the protocol. + +Minor versions are the version attributes of the interfaces in the XML. +There may be more than one minor version per protocol, if there are more +than one global. + +The XML file and protocol name also has the word 'unstable' in them, and +all of the interfaces in the protocol are prefixed with `z` and +suffixed with the major version number. + +For example, an unstable protocol called `foo-bar` with major version 2 +containing the two interfaces `wp_foo` and `wp_bar` both minor version 1 +will be placed in the directory `unstable/foo-bar/` consisting of one file +called `README` and one called `foo-bar-unstable-v2.xml`. The XML file +will consist of two interfaces called `zwp_foo_v2` and `zwp_bar_v2` with +the `version` attribute set to 1. + +## Unstable protocol changes + +During the development of a new protocol it is possible that backward +incompatible changes are needed. Such a change needs to be represented +in the major and minor versions of the protocol. + +Assuming a backward incompatible change is needed, the procedure for how to +do so is the following: + +- Make a copy of the XML file with the major version increased by 1. +- Increase the major version number in the protocol XML by 1. +- Increase the major version number in all of the interfaces in the + XML by 1. +- Reset the minor version number (interface version attribute) of all + the interfaces to 1. + +Backward compatible changes within a major unstable version can be done +in the regular way as done in core Wayland or in stable protocols. + +## Declaring a protocol stable + +Once it is decided that a protocol should be declared stable, meaning no +more backward incompatible changes will ever be allowed, one last +breakage is needed. + +The procedure of doing this is the following: + +- Create a new directory in the `stable/` toplevel directory with the + same name as the protocol directory in the `unstable/` directory. +- Copy the final version of the XML that is the version that was + decided to be declared stable into the new directory. The target name + should be the same name as the protocol directory but with the `.xml` + suffix. +- Rename the name of the protocol in the XML by removing the + `unstable` part and the major version number. +- Remove the `z` prefix and the major version number suffix from all + of the interfaces in the protocol. +- Reset all of the interface version attributes to 1. +- Update the `README` file in the unstable directory and create a new + `README` file in the new directory. + +There are other requirements for declaring a protocol stable, see +[GOVERNANCE section 2.3](GOVERNANCE.md#23-introducing-new-protocols). + +## Releases + +Each release of wayland-protocols finalizes the version of the protocols +to their state they had at that time. -- cgit v1.2.3