QmlDesigner: Add UniqueName class

The class is used for generating a unique name anywhere in QmlDesigner
codebase. The role of this class is generation of next candidate name
when name is not unique. Actual checking of name uniqueness is provided
as a function param.

Also applied the new UniqueName on 1 usecase in
ContentLibraryUserModel::getUniqueLib3DQmlName

Change-Id: I777aeef7c269bed7d999695cf5fcee6a5576222b
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>

src/plugins/qmldesigner/CMakeLists.txt

@@ -46,10 +46,10 @@ add_qtc_library(QmlDesignerUtils STATIC
     hdrimage.cpp hdrimage.h
     ktximage.cpp ktximage.h
     imageutils.cpp imageutils.h
+    uniquename.cpp uniquename.h
     qmldesignerutils_global.h
 )
 
-
 target_compile_options(QmlDesignerUtils PUBLIC $<$<COMPILE_LANG_AND_ID:CXX,Clang,GNU>:-Wno-error=maybe-uninitialized>)
 target_compile_options(QmlDesignerUtils PUBLIC $<$<COMPILE_LANG_AND_ID:CXX,Clang>:-Wno-unneeded-internal-declaration>)
 

src/plugins/qmldesigner/components/contentlibrary/contentlibraryusermodel.cpp

@@ -16,6 +16,7 @@
 
 #include <utils/algorithm.h>
 #include <utils/qtcassert.h>
+#include <utils/uniquename.h>
 
 #include <QFileInfo>
 #include <QJsonArray>
@@ -314,13 +315,9 @@ QString ContentLibraryUserModel::getUniqueLib3DQmlName(const QString &defaultNam
     baseQml[0] = baseQml.at(0).toUpper();
     baseQml.prepend("My");
 
-    QString uniqueQml = baseQml;
+    QString uniqueQml = UniqueName::get(baseQml, [&] (const QString &name) {
-
+        return !itemQmls.contains(name);
-    int counter = 1;
+    });
-    while (itemQmls.contains(uniqueQml)) {
-        uniqueQml = QString("%1%2").arg(uniqueQml).arg(counter);
-        ++counter;
-    }
 
     return uniqueQml + ".qml";
 }

src/plugins/qmldesigner/utils/uniquename.cpp

@@ -0,0 +1,58 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#include "uniquename.h"
+
+#include <QRegularExpression>
+
+namespace QmlDesigner {
+
+/**
+ * @brief Gets a unique name from a give name
+ * @param oldName input name
+ * @param predicate function to check if the name is unique. Retuns true if name is unique
+ * @return a unique name
+ */
+// static
+QString UniqueName::get(const QString &oldName, std::function<bool(const QString &)> predicate)
+{
+    QString newName = oldName;
+    while (!predicate(newName))
+        newName = nextName(newName);
+
+    return newName;
+}
+
+// static
+QString UniqueName::nextName(const QString &oldName)
+{
+    static QRegularExpression rgx("\\d+$"); // matches a number at the end of a string
+
+    QString uniqueName = oldName;
+    // if the name ends with a number, increment it
+    QRegularExpressionMatch match = rgx.match(uniqueName);
+    if (match.hasMatch()) { // ends with a number
+        QString numStr = match.captured(0);
+        int num = match.captured(0).toInt();
+
+        // get number of padding zeros, ex: for "005" = 2
+        int nPaddingZeros = 0;
+        for (; nPaddingZeros < numStr.size() && numStr[nPaddingZeros] == '0'; ++nPaddingZeros);
+
+        ++num;
+
+        // if the incremented number's digits increased, decrease the padding zeros
+        if (std::fmod(std::log10(num), 1.0) == 0)
+            --nPaddingZeros;
+
+        uniqueName = oldName.mid(0, match.capturedStart())
+                     + QString('0').repeated(nPaddingZeros)
+                     + QString::number(num);
+    } else {
+        uniqueName = oldName + '1';
+    }
+
+    return uniqueName;
+}
+
+} // namespace QmlDesigner

src/plugins/qmldesigner/utils/uniquename.h

@@ -0,0 +1,19 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#pragma once
+
+#include <QString>
+
+namespace QmlDesigner {
+
+class UniqueName
+{
+public:
+    static QString get(const QString &oldName, std::function<bool(const QString &)> predicate);
+
+private:
+    static QString nextName(const QString &oldName);
+};
+
+} // namespace QmlDesigner