QSizeF: add qFuzzyCompare and qFuzzyIsNull overloads

[ChangeLog][QtCore][QSizeF] Added qFuzzyCompare and qFuzzyIsNull
overloads for QSizeF

Drop the custom qFuzzyCompare() implementation from
tst_qgraphicsgridlayout.cpp

Task-number: QTBUG-120308
Change-Id: I32d11c1c81d0503914a8168b5e960a8c6ce943d9
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qsize.cpp

@@ -808,7 +808,24 @@ QSizeF QSizeF::scaled(const QSizeF &s, Qt::AspectRatioMode mode) const noexcept
     \sa expandedTo(), scale()
 */
 
+/*!
+    \fn bool QSizeF::qFuzzyCompare(const QSizeF &lhs, const QSizeF &rhs)
+    \since 6.8
 
+    Returns \c true if the size \a lhs is approximately equal to the
+    size \a rhs; otherwise returns \c false.
+
+    The sizes are considered approximately equal if their width and
+    height are approximately equal.
+*/
+
+/*!
+    \fn bool QSizeF::qFuzzyIsNull(const QSizeF &size)
+    \since 6.8
+
+    Returns \c true if both width and height of the size \a size
+    are approximately equal to zero.
+*/
 
 /*****************************************************************************
   QSizeF stream functions

src/corelib/tools/qsize.h

@@ -246,12 +246,18 @@ public:
 private:
     QT_WARNING_PUSH
     QT_WARNING_DISABLE_FLOAT_COMPARE
-    friend constexpr bool comparesEqual(const QSizeF &s1, const QSizeF &s2) noexcept
+    friend constexpr bool qFuzzyCompare(const QSizeF &s1, const QSizeF &s2) noexcept
     {
+        // Cannot use qFuzzyCompare(), because it will give incorrect results
+        // if one of the arguments is 0.0.
         return ((!s1.wd || !s2.wd) ? qFuzzyIsNull(s1.wd - s2.wd) : qFuzzyCompare(s1.wd, s2.wd))
             && ((!s1.ht || !s2.ht) ? qFuzzyIsNull(s1.ht - s2.ht) : qFuzzyCompare(s1.ht, s2.ht));
     }
     QT_WARNING_POP
+    friend constexpr bool qFuzzyIsNull(const QSizeF &size) noexcept
+    { return qFuzzyIsNull(size.wd) && qFuzzyIsNull(size.ht); }
+    friend constexpr bool comparesEqual(const QSizeF &lhs, const QSizeF &rhs) noexcept
+    { return qFuzzyCompare(lhs, rhs); }
     Q_DECLARE_EQUALITY_COMPARABLE_LITERAL_TYPE(QSizeF)
     friend constexpr bool comparesEqual(const QSizeF &lhs, const QSize &rhs) noexcept
     { return comparesEqual(lhs, rhs.toSizeF()); }

tests/auto/corelib/tools/qsizef/tst_qsizef.cpp

@@ -39,9 +39,15 @@ private slots:
     void compare_data();
     void compare();
 
+    void fuzzyCompare_data();
+    void fuzzyCompare();
+
     void isNull_data();
     void isNull();
 
+    void fuzzyIsNull_data();
+    void fuzzyIsNull();
+
     void scale();
 
     void expandedTo();
@@ -100,6 +106,20 @@ void tst_QSizeF::compare()
     QT_TEST_EQUALITY_OPS(lhs, rhsFixed, mixedResult);
 }
 
+void tst_QSizeF::fuzzyCompare_data()
+{
+    compare_data();
+}
+
+void tst_QSizeF::fuzzyCompare()
+{
+    QFETCH(QSizeF, lhs);
+    QFETCH(QSizeF, rhs);
+    QFETCH(bool, result);
+
+    QCOMPARE_EQ(qFuzzyCompare(lhs, rhs), result);
+}
+
 void tst_QSizeF::isNull_data()
 {
     QTest::addColumn<qreal>("width");
@@ -114,6 +134,7 @@ void tst_QSizeF::isNull_data()
     QTest::newRow("0, -0.1") << qreal(0) << qreal(-0.1) << false;
     QTest::newRow("0.1, 0") << qreal(0.1) << qreal(0) << false;
     QTest::newRow("0, 0.1") << qreal(0) << qreal(0.1) << false;
+    QTest::newRow("qreal_min, -qreal_min") << qreal_min << -qreal_min << false;
 }
 
 void tst_QSizeF::isNull()
@@ -128,6 +149,33 @@ void tst_QSizeF::isNull()
     QCOMPARE(size.isNull(), isNull);
 }
 
+void tst_QSizeF::fuzzyIsNull_data()
+{
+    QTest::addColumn<qreal>("width");
+    QTest::addColumn<qreal>("height");
+    QTest::addColumn<bool>("fuzzyNull");
+
+    QTest::newRow("0, 0") << qreal(0.0) << qreal(0.0) << true;
+    QTest::newRow("-0, -0") << qreal(-0.0) << qreal(-0.0) << true;
+    QTest::newRow("0, -0") << qreal(0) << qreal(-0.0) << true;
+    QTest::newRow("-0, 0") << qreal(-0.0) << qreal(0) << true;
+    QTest::newRow("-0.1, 0") << qreal(-0.1) << qreal(0) << false;
+    QTest::newRow("0, -0.1") << qreal(0) << qreal(-0.1) << false;
+    QTest::newRow("0.1, 0") << qreal(0.1) << qreal(0) << false;
+    QTest::newRow("0, 0.1") << qreal(0) << qreal(0.1) << false;
+    QTest::newRow("qreal_min, -qreal_min") << qreal_min << -qreal_min << true;
+}
+
+void tst_QSizeF::fuzzyIsNull()
+{
+    QFETCH(qreal, width);
+    QFETCH(qreal, height);
+    QFETCH(bool, fuzzyNull);
+
+    QSizeF size(width, height);
+    QCOMPARE(qFuzzyIsNull(size), fuzzyNull);
+}
+
 void tst_QSizeF::scale() {
     QSizeF t1(10.4, 12.8);
     t1.scale(60.6, 60.6, Qt::IgnoreAspectRatio);

tests/auto/widgets/graphicsview/qgraphicsgridlayout/tst_qgraphicsgridlayout.cpp

@@ -2976,11 +2976,6 @@ static QSizeF wfh(Qt::SizeHint /*which*/, const QSizeF &constraint)
     return result;
 }
 
-bool qFuzzyCompare(const QSizeF &a, const QSizeF &b)
-{
-    return qFuzzyCompare(a.width(), b.width()) && qFuzzyCompare(a.height(), b.height());
-}
-
 void tst_QGraphicsGridLayout::heightForWidth()
 {
     QGraphicsWidget *widget = new QGraphicsWidget;