ProjectTree: Merge descendants of hidden Sources and Headers virtual folders

Unchecking the recently added "Show Source and Header Groups" option removes
the Sources and Headers virtual folders from the Projects tree. This patch
additionally merges descendants of these folders with identical priorities,
display names and file paths.

For example, if a project contains a folder including both source and header
files, both the Sources and Headers virtual folders will have child nodes
representing that folder. Previously, unchecking "Show Source and Header
Groups" kept both these identically named nodes in the Projects tree (one
containing sources, the other headers). With this patch, these nodes are
merged into a single node containing both sources and headers.

Change-Id: I4786eee4a528ea141a7fe117e14a050f68411890
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/libs/utils/CMakeLists.txt

@@ -71,6 +71,7 @@ add_qtc_library(Utils
     htmldocextractor.cpp htmldocextractor.h
     icon.cpp icon.h
     id.cpp id.h
+    indexedcontainerproxyconstiterator.h
     infobar.cpp infobar.h
     infolabel.cpp infolabel.h
     itemviews.cpp itemviews.h

src/libs/utils/indexedcontainerproxyconstiterator.h

@@ -0,0 +1,188 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#pragma once
+
+#include "utils_global.h"
+
+#include <QtGlobal>
+
+#include <type_traits>
+
+namespace Utils {
+
+/// A class useful for the implementation of the -> operator of proxy iterators.
+template <typename Reference>
+struct ArrowProxy {
+    Reference r;
+    Reference *operator->() {
+        return &r;
+    }
+};
+
+/// Random-access const iterator over elements of a container providing an overloaded operator[]
+/// (which may return a proxy object, like std::vector<bool>, rather than a reference).
+template <typename Container>
+class IndexedContainerProxyConstIterator
+{
+public:
+    typedef std::random_access_iterator_tag iterator_category;
+    typedef typename std::make_signed<typename Container::size_type>::type difference_type;
+    typedef typename Container::value_type value_type;
+    typedef value_type reference;
+    typedef ArrowProxy<reference> pointer;
+    typedef typename Container::size_type size_type;
+
+    IndexedContainerProxyConstIterator()
+      : m_container(nullptr), m_index(0)
+    {}
+
+    IndexedContainerProxyConstIterator(const Container &container, size_type index)
+      : m_container(&container), m_index(index)
+    {}
+
+    reference operator*() const
+    {
+        Q_ASSERT(m_container);
+        return (*m_container)[m_index];
+    }
+
+    pointer operator->() const
+    {
+        Q_ASSERT(m_container);
+        return pointer{(*m_container)[m_index]};
+    }
+
+    reference operator[](difference_type j) const
+    {
+        Q_ASSERT(m_container);
+        return (*m_container)[m_index + j];
+    }
+
+    bool operator==(const IndexedContainerProxyConstIterator &other) const
+    {
+        Q_ASSERT(m_container == other.m_container);
+        return m_index == other.m_index;
+    }
+
+    bool operator!=(const IndexedContainerProxyConstIterator &other) const
+    {
+        Q_ASSERT(m_container == other.m_container);
+        return m_index != other.m_index;
+    }
+
+    bool operator<(const IndexedContainerProxyConstIterator &other) const
+    {
+        Q_ASSERT(m_container == other.m_container);
+        return m_index < other.m_index;
+    }
+
+    bool operator<=(const IndexedContainerProxyConstIterator &other) const
+    {
+        Q_ASSERT(m_container == other.m_container);
+        return m_index <= other.m_index;
+    }
+
+    bool operator>(const IndexedContainerProxyConstIterator &other) const
+    {
+        Q_ASSERT(m_container == other.m_container);
+        return m_index > other.m_index;
+    }
+
+    bool operator>=(const IndexedContainerProxyConstIterator &other) const
+    {
+        Q_ASSERT(m_container == other.m_container);
+        return m_index >= other.m_index;
+    }
+
+    IndexedContainerProxyConstIterator &operator++()
+    {
+        ++m_index;
+        return *this;
+    }
+
+    IndexedContainerProxyConstIterator operator++(int)
+    {
+        IndexedContainerProxyConstIterator copy(*this);
+        ++m_index;
+        return copy;
+    }
+
+    IndexedContainerProxyConstIterator &operator--()
+    {
+        --m_index;
+        return *this;
+    }
+
+    IndexedContainerProxyConstIterator operator--(int)
+    {
+        IndexedContainerProxyConstIterator copy(*this);
+        --m_index;
+        return copy;
+    }
+
+    IndexedContainerProxyConstIterator &operator+=(difference_type j)
+    {
+        m_index += j;
+        return *this;
+    }
+
+    IndexedContainerProxyConstIterator &operator-=(difference_type j)
+    {
+        m_index -= j;
+        return *this;
+    }
+
+    IndexedContainerProxyConstIterator operator+(difference_type j) const
+    {
+        IndexedContainerProxyConstIterator result(*this);
+        result += j;
+        return result;
+    }
+
+    IndexedContainerProxyConstIterator operator-(difference_type j) const
+    {
+        IndexedContainerProxyConstIterator result(*this);
+        result -= j;
+        return result;
+    }
+
+    friend IndexedContainerProxyConstIterator operator+(
+            difference_type j, const IndexedContainerProxyConstIterator &other)
+    {
+        return other + j;
+    }
+
+    difference_type operator-(const IndexedContainerProxyConstIterator &other) const
+    {
+        return static_cast<difference_type>(m_index) - static_cast<difference_type>(other.m_index);
+    }
+
+private:
+    const Container *m_container;
+    size_type m_index;
+};
+
+} // namespace Utils

src/libs/utils/treemodel.h

@@ -26,6 +26,7 @@
 #pragma once
 
 #include "utils_global.h"
+#include "indexedcontainerproxyconstiterator.h"
 
 #include <QAbstractItemModel>
 
@@ -119,6 +120,15 @@ public:
         });
     }
 
+    using value_type = ChildType *;
+    using const_iterator = IndexedContainerProxyConstIterator<TypedTreeItem>;
+    using size_type = int;
+
+    ChildType *operator[](int index) const { return childAt(index); }
+    int size() const { return childCount(); }
+    const_iterator begin() const { return const_iterator(*this, 0); }
+    const_iterator end() const { return const_iterator(*this, size()); }
+
     template <typename Predicate>
     void forAllChildren(const Predicate &pred) const {
         const auto pred0 = [pred](TreeItem *treeItem) { pred(static_cast<ChildType *>(treeItem)); };

src/libs/utils/utils-lib.pri

@@ -150,6 +150,7 @@ HEADERS += \
     $$PWD/environmentfwd.h \
     $$PWD/genericconstants.h \
     $$PWD/globalfilechangeblocker.h \
+    $$PWD/indexedcontainerproxyconstiterator.h \
     $$PWD/benchmarker.h \
     $$PWD/displayname.h \
     $$PWD/environment.h \

src/libs/utils/utils.qbs

@@ -149,6 +149,7 @@ Project {
             "icon.h",
             "id.cpp",
             "id.h",
+            "indexedcontainerproxyconstiterator.h",
             "infobar.cpp",
             "infobar.h",
             "infolabel.cpp",

src/plugins/projectexplorer/projectmodels.cpp

@@ -61,6 +61,7 @@
 #include <QVBoxLayout>
 
 #include <functional>
+#include <iterator>
 #include <tuple>
 #include <vector>
 
@@ -69,6 +70,28 @@ using namespace Utils;
 namespace ProjectExplorer {
 namespace Internal {
 
+/// An output iterator whose assignment operator appends a clone of the operand to the list of
+/// children of the WrapperNode passed to the constructor.
+class Appender : public std::iterator<std::output_iterator_tag, void, void, void, void>
+{
+public:
+    explicit Appender(WrapperNode *parent) : m_parent(parent) {}
+
+    Appender &operator=(const WrapperNode *node)
+    {
+        if (node)
+            m_parent->appendClone(*node);
+        return *this;
+    }
+
+    Appender &operator*() { return *this; }
+    Appender &operator++() { return *this; }
+    Appender &operator++(int) { return *this; }
+
+private:
+    WrapperNode *m_parent;
+};
+
 bool compareNodes(const Node *n1, const Node *n2)
 {
     if (n1->priority() > n2->priority())
@@ -82,9 +105,7 @@ bool compareNodes(const Node *n1, const Node *n2)
 
     const int filePathResult = caseFriendlyCompare(n1->filePath().toString(),
                                  n2->filePath().toString());
-    if (filePathResult != 0)
+    return filePathResult < 0;
-        return filePathResult < 0;
-    return n1 < n2; // sort by pointer value
 }
 
 static bool sortWrapperNodes(const WrapperNode *w1, const WrapperNode *w2)
@@ -92,6 +113,71 @@ static bool sortWrapperNodes(const WrapperNode *w1, const WrapperNode *w2)
     return compareNodes(w1->m_node, w2->m_node);
 }
 
+/// Appends to `dest` clones of children of `first` and `second`, removing duplicates (recursively).
+///
+/// \param first, second
+///   Nodes with children sorted by sortWrapperNodes.
+/// \param dest
+///   Node to which to append clones of children of `first` and `second`, with duplicates removed.
+static void appendMergedChildren(const WrapperNode *first, const WrapperNode *second, WrapperNode *dest)
+{
+    setUnionMerge(first->begin(), first->end(),
+                  second->begin(), second->end(),
+                  Appender(dest),
+                  [dest](const WrapperNode *childOfFirst, const WrapperNode *childOfSecond)
+                  -> const WrapperNode * {
+                      if (childOfSecond->hasChildren()) {
+                          if (childOfFirst->hasChildren()) {
+                              WrapperNode *mergeResult = new WrapperNode(childOfFirst->m_node);
+                              dest->appendChild(mergeResult);
+                              appendMergedChildren(childOfFirst, childOfSecond, mergeResult);
+                              // mergeResult has already been appended to the parent's list of
+                              // children -- there's no need for the Appender to do it again.
+                              // That's why we return a null pointer.
+                              return nullptr;
+                          } else {
+                              return childOfSecond;
+                          }
+                      } else {
+                          return childOfFirst;
+                      }
+                  },
+                  sortWrapperNodes);
+}
+
+/// Given a node `parent` with children sorted by the criteria defined in sortWrapperNodes(), merge
+/// any children that are equal according to those criteria.
+static void mergeDuplicates(WrapperNode *parent)
+{
+    // We assume all descendants of 'parent' are sorted
+    int childIndex = 0;
+    while (childIndex + 1 < parent->childCount()) {
+        const WrapperNode *child = parent->childAt(childIndex);
+        const WrapperNode *nextChild = parent->childAt(childIndex + 1);
+        Q_ASSERT_X(!sortWrapperNodes(nextChild, child), __func__, "Children are not sorted");
+        if (!sortWrapperNodes(child, nextChild)) {
+            // child and nextChild must have the same priorities, display names and folder paths.
+            // Replace them by a single node 'mergeResult` containing the union of their children.
+            auto mergeResult = new WrapperNode(child->m_node);
+            parent->insertChild(childIndex, mergeResult);
+            appendMergedChildren(child, nextChild, mergeResult);
+            // Now we can remove the original children
+            parent->removeChildAt(childIndex + 2);
+            parent->removeChildAt(childIndex + 1);
+        } else {
+            ++childIndex;
+        }
+    }
+}
+
+void WrapperNode::appendClone(const WrapperNode &node)
+{
+    WrapperNode *clone = new WrapperNode(node.m_node);
+    appendChild(clone);
+    for (const WrapperNode *child : node)
+        clone->appendClone(*child);
+}
+
 FlatModel::FlatModel(QObject *parent)
     : TreeModel<WrapperNode, WrapperNode>(new WrapperNode(nullptr), parent)
 {
@@ -393,6 +479,8 @@ void FlatModel::saveExpandData()
 
 void FlatModel::addFolderNode(WrapperNode *parent, FolderNode *folderNode, QSet<Node *> *seen)
 {
+    bool hasHiddenSourcesOrHeaders = false;
+
     for (Node *node : folderNode->nodes()) {
         if (m_filterGeneratedFiles && node->isGenerated())
             continue;
@@ -403,8 +491,10 @@ void FlatModel::addFolderNode(WrapperNode *parent, FolderNode *folderNode, QSet<
             if (!m_showSourceGroups) {
                 if (subFolderNode->isVirtualFolderType()) {
                     auto vnode = static_cast<VirtualFolderNode *>(subFolderNode);
-                    if (vnode->isSourcesOrHeaders())
+                    if (vnode->isSourcesOrHeaders()) {
                         isHidden = true;
+                        hasHiddenSourcesOrHeaders = true;
+                    }
                 }
             }
             if (!isHidden && !seen->contains(subFolderNode)) {
@@ -423,6 +513,11 @@ void FlatModel::addFolderNode(WrapperNode *parent, FolderNode *folderNode, QSet<
             }
         }
     }
+
+    if (hasHiddenSourcesOrHeaders) {
+        parent->sortChildren(&sortWrapperNodes);
+        mergeDuplicates(parent);
+    }
 }
 
 bool FlatModel::trimEmptyDirectories(WrapperNode *parent)

src/plugins/projectexplorer/projectmodels.h

@@ -52,6 +52,8 @@ class WrapperNode : public Utils::TypedTreeItem<WrapperNode>
 public:
     explicit WrapperNode(Node *node) : m_node(node) {}
     Node *m_node = nullptr;
+
+    void appendClone(const WrapperNode &node);
 };
 
 class FlatModel : public Utils::TreeModel<WrapperNode, WrapperNode>

src/plugins/projectexplorer/projectnodes.h

@@ -361,7 +361,7 @@ public:
     void setIsSourcesOrHeaders(bool on) { m_isSourcesOrHeaders = on; }
 
 private:
-    bool m_isSourcesOrHeaders; // "Sources" or "Headers"
+    bool m_isSourcesOrHeaders = false; // "Sources" or "Headers"
 };
 
 // Documentation inside.

tests/auto/utils/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_subdirectory(ansiescapecodehandler)
 add_subdirectory(fileutils)
 add_subdirectory(fuzzymatcher)
+add_subdirectory(indexedcontainerproxyconstiterator)
 add_subdirectory(persistentsettings)
 add_subdirectory(qtcprocess)
 add_subdirectory(settings)

tests/auto/utils/indexedcontainerproxyconstiterator/CMakeLists.txt

@@ -0,0 +1,4 @@
+add_qtc_test(tst_utils_indexedcontainerproxyconstiterator
+  DEPENDS Utils
+  SOURCES tst_indexedcontainerproxyconstiterator.cpp
+)

tests/auto/utils/indexedcontainerproxyconstiterator/indexedcontainerproxyconstiterator.pro

@@ -0,0 +1,4 @@
+QTC_LIB_DEPENDS += utils
+include(../../qttest.pri)
+
+SOURCES += tst_indexedcontainerproxyconstiterator.cpp

tests/auto/utils/indexedcontainerproxyconstiterator/indexedcontainerproxyconstiterator.qbs

@@ -0,0 +1,7 @@
+import qbs
+
+QtcAutotest {
+    name: "IndexedContainerProxyConstIterator autotest"
+    Depends { name: "Utils" }
+    files: "tst_indexedcontainerproxyconstiterator.cpp"
+}

tests/auto/utils/indexedcontainerproxyconstiterator/tst_indexedcontainerproxyconstiterator.cpp

@@ -0,0 +1,209 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include <utils/indexedcontainerproxyconstiterator.h>
+
+#include <QtTest>
+
+#include <string>
+#include <vector>
+
+using namespace Utils;
+
+class tst_IndexedContainerProxyConstIterator : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void initTestCase();
+    void testConstruction();
+    void testDereference();
+    void testIndexing();
+    void testComparisons();
+    void testIncrement();
+    void testDecrement();
+    void testPlus();
+    void testMinus();
+    void testIteration();
+
+private:
+    using StringContainer = std::vector<std::string>;
+    using StringIterator = IndexedContainerProxyConstIterator<StringContainer>;
+    StringContainer strings;
+
+    using BoolContainer = std::vector<bool>;
+    using BoolIterator = IndexedContainerProxyConstIterator<BoolContainer>;
+    BoolContainer bools;
+};
+
+void tst_IndexedContainerProxyConstIterator::initTestCase()
+{
+    strings = {"abc", "defgh", "ijk"};
+    bools = {false, true, false};
+}
+
+void tst_IndexedContainerProxyConstIterator::testConstruction()
+{
+    StringIterator strIt(strings, 0);
+    QCOMPARE(*strIt, "abc");
+
+    StringIterator strIt2(strings, 1);
+    QCOMPARE(*strIt2, "defgh");
+
+    BoolIterator boolIt(bools, 0);
+    QCOMPARE(*boolIt, false);
+
+    BoolIterator boolIt2(bools, 1);
+    QCOMPARE(*boolIt2, true);
+}
+
+void tst_IndexedContainerProxyConstIterator::testDereference()
+{
+    StringIterator strIt(strings, 0);
+    QCOMPARE(*strIt, "abc");
+    QCOMPARE(strIt->length(), 3);
+
+    BoolIterator boolIt(bools, 0);
+    QCOMPARE(*boolIt, false);
+}
+
+void tst_IndexedContainerProxyConstIterator::testIndexing()
+{
+    StringIterator strIt(strings, 0);
+    QCOMPARE(strIt[2], "ijk");
+
+    BoolIterator boolIt(bools, 0);
+    QCOMPARE(boolIt[2], false);
+}
+
+void tst_IndexedContainerProxyConstIterator::testComparisons()
+{
+    StringIterator strIt(strings, 0);
+    StringIterator strIt2(strings, 0);
+    StringIterator strIt3(strings, 1);
+
+    QVERIFY(strIt == strIt);
+    QVERIFY(!(strIt != strIt));
+    QVERIFY(!(strIt < strIt));
+    QVERIFY(strIt <= strIt);
+    QVERIFY(!(strIt > strIt));
+    QVERIFY(strIt >= strIt);
+
+    QVERIFY(strIt == strIt2);
+    QVERIFY(!(strIt != strIt2));
+    QVERIFY(!(strIt < strIt2));
+    QVERIFY(strIt <= strIt2);
+    QVERIFY(!(strIt > strIt2));
+    QVERIFY(strIt >= strIt2);
+
+    QVERIFY(!(strIt == strIt3));
+    QVERIFY(strIt != strIt3);
+    QVERIFY(strIt < strIt3);
+    QVERIFY(strIt <= strIt3);
+    QVERIFY(!(strIt > strIt3));
+    QVERIFY(!(strIt >= strIt3));
+
+    QVERIFY(!(strIt3 == strIt));
+    QVERIFY(strIt3 != strIt);
+    QVERIFY(!(strIt3 < strIt));
+    QVERIFY(!(strIt3 <= strIt));
+    QVERIFY(strIt3 > strIt);
+    QVERIFY(strIt3 >= strIt);
+}
+
+void tst_IndexedContainerProxyConstIterator::testIncrement()
+{
+    StringIterator strIt(strings, 0);
+    QCOMPARE(*(++strIt), "defgh");
+    QCOMPARE(*(strIt++), "defgh");
+    QCOMPARE(*strIt, "ijk");
+
+    BoolIterator boolIt(bools, 0);
+    QCOMPARE(*(++boolIt), true);
+    QCOMPARE(*(boolIt++), true);
+    QCOMPARE(*boolIt, false);
+}
+
+void tst_IndexedContainerProxyConstIterator::testDecrement()
+{
+    StringIterator strIt(strings, 3);
+    QCOMPARE(*(--strIt), "ijk");
+    QCOMPARE(*(strIt--), "ijk");
+    QCOMPARE(*strIt, "defgh");
+
+    BoolIterator boolIt(bools, 3);
+    QCOMPARE(*(--boolIt), false);
+    QCOMPARE(*(boolIt--), false);
+    QCOMPARE(*boolIt, true);
+}
+
+void tst_IndexedContainerProxyConstIterator::testPlus()
+{
+    StringIterator strIt(strings, 1);
+    QCOMPARE(*(strIt + 1), "ijk");
+    QCOMPARE(*(1 + strIt), "ijk");
+    strIt += 1;
+    QCOMPARE(*strIt, "ijk");
+
+    BoolIterator boolIt(bools, 1);
+    QCOMPARE(*(boolIt + 1), false);
+    QCOMPARE(*(1 + boolIt), false);
+    boolIt += 1;
+    QCOMPARE(*boolIt, false);
+}
+
+void tst_IndexedContainerProxyConstIterator::testMinus()
+{
+    StringIterator strIt(strings, 1);
+    QCOMPARE(*(strIt - 1), "abc");
+    strIt -= 1;
+    QCOMPARE(*strIt, "abc");
+
+    BoolIterator boolIt(bools, 1);
+    QCOMPARE(*(boolIt - 1), false);
+    boolIt -= 1;
+    QCOMPARE(*boolIt, false);
+}
+
+void tst_IndexedContainerProxyConstIterator::testIteration()
+{
+    StringIterator strBegin(strings, 0);
+    StringIterator strEnd(strings, strings.size());
+    StringContainer stringsCopy;
+    for (StringIterator it = strBegin; it != strEnd; ++it)
+        stringsCopy.push_back(*it);
+    QCOMPARE(stringsCopy, strings);
+
+    BoolIterator boolBegin(bools, 0);
+    BoolIterator boolEnd(bools, bools.size());
+    BoolContainer boolsCopy;
+    for (BoolIterator it = boolBegin; it != boolEnd; ++it)
+        boolsCopy.push_back(*it);
+    QCOMPARE(boolsCopy, bools);
+}
+
+QTEST_MAIN(tst_IndexedContainerProxyConstIterator)
+
+#include "tst_indexedcontainerproxyconstiterator.moc"

tests/auto/utils/utils.pro

@@ -4,6 +4,7 @@ SUBDIRS = \
     fileutils \
     ansiescapecodehandler \
     fuzzymatcher \
+    indexedcontainerproxyconstiterator \
     persistentsettings \
     qtcprocess \
     settings \

tests/auto/utils/utils.qbs

@@ -6,6 +6,7 @@ Project {
         "fileutils/fileutils.qbs",
         "ansiescapecodehandler/ansiescapecodehandler.qbs",
         "fuzzymatcher/fuzzymatcher.qbs",
+        "indexedcontainerproxyconstiterator/indexedcontainerproxyconstiterator.qbs",
         "persistentsettings/persistentsettings.qbs",
         "qtcprocess/qtcprocess.qbs",
         "settings/settings.qbs",