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| author | Alejandro Exojo <suy@badopi.org> | 2014-12-09 18:21:07 +0100 |
|---|---|---|
| committer | Alejandro Exojo Piqueras <suy@badopi.org> | 2014-12-10 11:09:25 +0100 |
| commit | dd670a2f3dfaff00016c24468f1f6e66efbcd2c3 (patch) | |
| tree | a2b78f65be402167e56a7571fa9c5cbe0cd28bc5 /src/corelib/doc | |
| parent | f17d7a124f0fa817a7e1a2dda6f48098432c0dc0 (diff) | |
doc: Clarify NOTIFY emission with MEMBER variables
Document that NOTIFY signals should be emitted only when really needed,
and that such is the case with MEMBER variables.
Change-Id: Icc38a0790aa43ffe8f24d124da966b4240a41a6f
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Diffstat (limited to 'src/corelib/doc')
| -rw-r--r-- | src/corelib/doc/src/objectmodel/properties.qdoc | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/corelib/doc/src/objectmodel/properties.qdoc b/src/corelib/doc/src/objectmodel/properties.qdoc index 8a6c7f53d9..dbdc080dff 100644 --- a/src/corelib/doc/src/objectmodel/properties.qdoc +++ b/src/corelib/doc/src/objectmodel/properties.qdoc @@ -97,7 +97,10 @@ of the property changes. \c NOTIFY signals for \c MEMBER variables must take zero or one parameter, which must be of the same type as the property. The parameter will take the - new value of the property. + new value of the property. The \c NOTIFY signal should only be emitted when + the property has really been changed, to avoid bindings being unnecessarily + re-evaluated in QML, for example. Qt emits automatically that signal when + needed for MEMBER properties that do not have an explicit setter. \li A \c REVISION number is optional. If included, it defines the property and its notifier signal to be used in a particular |