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| author | Marc Mutz <marc.mutz@kdab.com> | 2021-07-02 08:32:09 +0200 |
|---|---|---|
| committer | Marc Mutz <marc.mutz@kdab.com> | 2021-07-13 16:57:31 +0200 |
| commit | 2b50c8bec086ae975ac5152e08f6b3dcf76306a0 (patch) | |
| tree | 656fded2be7e3e7d8d7d7c9336da8e1bad0d7ac7 /examples/widgets/painting | |
| parent | 1edb51a315c4ab307878d6620d8d7484cc080d09 (diff) | |
QObject: optimize the common case of findChildren(QString())
Outside tests, all in-tree callers of QObject::findChildren() pass no
name to match, and in my experience that is also true for the vast
majority of out-of-tree users.
Avoid the temporary QString creation in the caller and the repeated
QString::isNull() checks in the implementation by overloading
findChildren() without a name argument and checking for name.isNull()
only once, forking off into separate helper functions.
Adjust in-tree callers that used an explicit `QString()` argument in
order to pass options, which goes to show that `name` should never
have been the first argument of findChilden() in the first place, even
though I appreciate the symmetry with findChild() (the use-cases of
which, however, are radically different).
Change a `findChildren().size() == 0` call found while scanning for
findChildren() calls to `!findChild()` as a drive-by.
Modernize loops in the various qt_qFindChild{,ren}_helper() overloads
to match how the new code looks.
[ChangeLog][QtCore][QObject] Added findChildren() overload taking no
name (thus optimizing this common case).
Change-Id: Ifc56e5438023d079b40c67f11ae274a3e128ad5e
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Diffstat (limited to 'examples/widgets/painting')
| -rw-r--r-- | examples/widgets/painting/shared/arthurstyle.cpp | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/examples/widgets/painting/shared/arthurstyle.cpp b/examples/widgets/painting/shared/arthurstyle.cpp index 31be899357..42afeb44c1 100644 --- a/examples/widgets/painting/shared/arthurstyle.cpp +++ b/examples/widgets/painting/shared/arthurstyle.cpp @@ -441,7 +441,7 @@ int ArthurStyle::pixelMetric(PixelMetric pm, const QStyleOption *opt, const QWid void ArthurStyle::polish(QWidget *widget) { if (widget->layout() && qobject_cast<QGroupBox *>(widget)) { - if (widget->findChildren<QGroupBox *>().size() == 0) { + if (!widget->findChild<QGroupBox *>()) { widget->layout()->setSpacing(0); widget->layout()->setContentsMargins(12, 12, 12, 12); } else { |