Utils: Introduce FileName::fileName()

* Replacement for QFileInfo::fileName()
* Supports additional path components

Change-Id: I2b3e3dfb02617c8f98f1d67e16396bed97f97526
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>

src/libs/utils/fileutils.cpp

@@ -560,6 +560,30 @@ QString FileName::toUserOutput() const
     return QDir::toNativeSeparators(toString());
 }
 
+QString FileName::fileName(int pathComponents) const
+{
+    if (pathComponents < 0)
+        return *this;
+    const QChar slash = QLatin1Char('/');
+    QTC_CHECK(!endsWith(slash));
+    int i = lastIndexOf(slash);
+    if (pathComponents == 0 || i == -1)
+        return mid(i + 1);
+    int component = i + 1;
+    // skip adjacent slashes
+    while (i > 0 && at(--i) == slash);
+    while (i >= 0 && --pathComponents >= 0) {
+        i = lastIndexOf(slash, i);
+        component = i + 1;
+        while (i > 0 && at(--i) == slash);
+    }
+
+    // If there are no more slashes before the found one, return the entire string
+    if (i > 0 && lastIndexOf(slash, i) != -1)
+        return mid(component);
+    return *this;
+}
+
 /// \returns a bool indicating whether a file with this
 /// FileName exists.
 bool FileName::exists() const

src/libs/utils/fileutils.h

@@ -73,6 +73,7 @@ public:
     static FileName fromUtf8(const char *filename, int filenameSize = -1);
     QString toString() const;
     QString toUserOutput() const;
+    QString fileName(int pathComponents = 0) const;
     bool exists() const;
 
     FileName parentDir() const;

tests/auto/utils/fileutils/tst_fileutils.cpp

@@ -47,6 +47,8 @@ private slots:
     void parentDir();
     void isChildOf_data();
     void isChildOf();
+    void fileName_data();
+    void fileName();
 };
 
 void tst_fileutils::parentDir_data()
@@ -132,5 +134,45 @@ void tst_fileutils::isChildOf()
     QCOMPARE(res, result);
 }
 
+void tst_fileutils::fileName_data()
+{
+    QTest::addColumn<QString>("path");
+    QTest::addColumn<int>("components");
+    QTest::addColumn<QString>("result");
+
+    QTest::newRow("empty 1") << "" << 0 << "";
+    QTest::newRow("empty 2") << "" << 1 << "";
+    QTest::newRow("basic") << "/foo/bar/baz" << 0 << "baz";
+    QTest::newRow("2 parts") << "/foo/bar/baz" << 1 << "bar/baz";
+    QTest::newRow("root no depth") << "/foo" << 0 << "foo";
+    QTest::newRow("root full") << "/foo" << 1 << "/foo";
+    QTest::newRow("root included") << "/foo/bar/baz" << 2 << "/foo/bar/baz";
+    QTest::newRow("too many parts") << "/foo/bar/baz" << 5 << "/foo/bar/baz";
+    QTest::newRow("windows root") << "C:/foo/bar/baz" << 2 << "C:/foo/bar/baz";
+    QTest::newRow("smb share") << "//server/share/file" << 2 << "//server/share/file";
+    QTest::newRow("no slashes") << "foobar" << 0 << "foobar";
+    QTest::newRow("no slashes with depth") << "foobar" << 1 << "foobar";
+    QTest::newRow("multiple slashes 1") << "/foo/bar////baz" << 0 << "baz";
+    QTest::newRow("multiple slashes 2") << "/foo/bar////baz" << 1 << "bar////baz";
+    QTest::newRow("multiple slashes 3") << "/foo////bar/baz" << 2 << "/foo////bar/baz";
+    QTest::newRow("single char 1") << "/a/b/c" << 0 << "c";
+    QTest::newRow("single char 2") << "/a/b/c" << 1 << "b/c";
+    QTest::newRow("single char 3") << "/a/b/c" << 2 << "/a/b/c";
+    QTest::newRow("slash at end 1") << "/a/b/" << 0 << "";
+    QTest::newRow("slash at end 2") << "/a/b/" << 1 << "b/";
+    QTest::newRow("slashes at end 1") << "/a/b//" << 0 << "";
+    QTest::newRow("slashes at end 2") << "/a/b//" << 1 << "b//";
+    QTest::newRow("root only 1") << "/" << 0 << "";
+    QTest::newRow("root only 2") << "/" << 1 << "/";
+}
+
+void tst_fileutils::fileName()
+{
+    QFETCH(QString, path);
+    QFETCH(int, components);
+    QFETCH(QString, result);
+    QCOMPARE(FileName::fromString(path).fileName(components), result);
+}
+
 QTEST_APPLESS_MAIN(tst_fileutils)
 #include "tst_fileutils.moc"