diff options
| author | Paul Olav Tvete <paul.tvete@qt.io> | 2019-02-28 10:23:16 +0100 |
|---|---|---|
| committer | Paul Olav Tvete <paul.tvete@qt.io> | 2019-03-05 12:09:19 +0000 |
| commit | 6e9e15b7c3aa598b942477f1a5b8e9a8b8bee8ef (patch) | |
| tree | 8fa19a7c3ff3f573c2dcdf306e86bfb9d1608f0b /src/extensions | |
| parent | c9970025bc912c6d3b2fe6183762c6f254e84aef (diff) | |
Guarantee compatibility for Qt's extension protocols
Spell out and formalize the policy that we have been following
since Qt 5.4: We don't break compatibility for our internal
protocols. Otherwise, it would not be safe to use a Qt client
with a Qt-based compositor.
Change-Id: I632e9fbb56095ab07560413977c79777ae9fdcd2
Reviewed-by: Johan Helsing <johan.helsing@qt.io>
Reviewed-by: Pier Luigi Fiorini <pierluigi.fiorini@liri.io>
Diffstat (limited to 'src/extensions')
| -rw-r--r-- | src/extensions/README.md | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/src/extensions/README.md b/src/extensions/README.md index f75e0f236..8024ffa80 100644 --- a/src/extensions/README.md +++ b/src/extensions/README.md @@ -3,12 +3,10 @@ The protocol extensions in this folder are considered implementation details of Qt. I.e. they may removed, renamed or changed without warning. -## Suffixed protocols - -For protocols that have a version suffix, however, we will strive to not break -backwards compatibility without bumping the suffix (renaming the protocol). -E.g.: If your client sees a `zqt_key_v1` global, it can safely bind to it: -the key event will always take the same number of arguments, regardless of +However, starting with Qt 5.4, we promise not to break backwards compatibility +without renaming (or removing) the protocol. I.e., if your client sees a global +from one of these extensions, it can safely bind to it: the existing events +and requests will always take the same number of arguments, regardless of compositor version. This is important also within a Qt-only scope if there are multiple versions of @@ -16,3 +14,11 @@ Qt on the system. Consider for instance an application statically linked to Qt (such as Qt Creator) running against a Qt compositor installed by the distro). In such cases we don't want the compositor and client to disagree on the protocol definition. + +## Protocol versioning. + +Protocol extensions in this folder should be versioned (e.g. `zqt_key_v1`). +If it is necessary to break protocol compatibility, they will be renamed by +incrementing the version number. For legacy reasons, there are also unversioned +protocols in this folder. Those protocols should be renamed to be versioned +if compatibility is broken. |