From a07e5323910a6eaa51180928118393242713d186 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Jan=20Kundr=C3=A1t?= <jkt@kde.org>
Date: Tue, 18 Oct 2016 16:04:22 +0200
Subject: [PATCH] Support iteration up until a given top-level index

Change-Id: I163db82e9e354aee85c064376bbdb1215df61a1d
---
 src/UiUtils/QaimDfsIterator.cpp     |  8 +++++++-
 src/UiUtils/QaimDfsIterator.h       |  4 ++++
 tests/Misc/test_QaimDfsIterator.cpp | 40 ++++++++++++++++++++++++++-----------
 3 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/src/UiUtils/QaimDfsIterator.cpp b/src/UiUtils/QaimDfsIterator.cpp
index efb0ecd2..7277db5d 100644
--- a/src/UiUtils/QaimDfsIterator.cpp
+++ b/src/UiUtils/QaimDfsIterator.cpp
@@ -52,7 +52,8 @@ QaimDfsIterator &QaimDfsIterator::operator++()
         wentUp = true;
         // ...and because this is a while-loop, this iterator doesn't really support
         // iterating until an arbitrary particular end-iterator, just until the very
-        // end of the model.
+        // end of the model, or until an arbitrary top-level item (an index whose
+        // parent is a null, invalid QAIM).
     }
     Q_ASSERT(!m_current.isValid());
     return *this;
@@ -63,6 +64,11 @@ const QModelIndex &QaimDfsIterator::operator*() const
     return m_current;
 }
 
+const QModelIndex *QaimDfsIterator::operator->() const
+{
+    return &m_current;
+}
+
 bool QaimDfsIterator::operator!=(const QaimDfsIterator &other)
 {
     return m_current != other.m_current;
diff --git a/src/UiUtils/QaimDfsIterator.h b/src/UiUtils/QaimDfsIterator.h
index e5e61fb4..3a13b3d2 100644
--- a/src/UiUtils/QaimDfsIterator.h
+++ b/src/UiUtils/QaimDfsIterator.h
@@ -36,6 +36,7 @@ public:
     QaimDfsIterator(const QaimDfsIterator &) = default;
     QaimDfsIterator & operator++();
     const QModelIndex &operator*() const;
+    const QModelIndex *operator->() const;
     bool operator!=(const QaimDfsIterator &other);
 private:
     QModelIndex m_current;
@@ -55,4 +56,7 @@ template<> struct iterator_traits<UiUtils::QaimDfsIterator>
 };
 }
 
+Q_DECLARE_METATYPE(UiUtils::QaimDfsIterator);
+
+
 #endif
diff --git a/tests/Misc/test_QaimDfsIterator.cpp b/tests/Misc/test_QaimDfsIterator.cpp
index abbd1971..b065f0d0 100644
--- a/tests/Misc/test_QaimDfsIterator.cpp
+++ b/tests/Misc/test_QaimDfsIterator.cpp
@@ -30,23 +30,21 @@ void TestQaimDfsIterator::testQaimDfsIterator()
 {
     QFETCH(QString, order);
     QFETCH(QSharedPointer<QStandardItemModel>, model);
+    QFETCH(UiUtils::QaimDfsIterator, end);
 
     QStringList buf;
-    std::transform(UiUtils::QaimDfsIterator(model->index(0, 0, QModelIndex())),
-                   UiUtils::QaimDfsIterator(),
-                   std::back_inserter(buf),
+    auto it = UiUtils::QaimDfsIterator(model->index(0, 0, QModelIndex()));
+    std::transform(it, end, std::back_inserter(buf),
                    [](const QModelIndex &what) -> QString {
         return what.data().toString();
     }
                    );
     QCOMPARE(buf.join(QLatin1Char(' ')), order);
 
-    auto it1 = UiUtils::QaimDfsIterator(model->index(0, 0, QModelIndex()));
-    auto it2 = UiUtils::QaimDfsIterator();
     if (order.isEmpty()) {
-        QCOMPARE(std::distance(it1, it2), 0);
+        QCOMPARE(std::distance(it, end), 0);
     } else {
-        QCOMPARE(std::distance(it1, it2), order.count(QLatin1Char(' ')) + 1);
+        QCOMPARE(std::distance(it, end), order.count(QLatin1Char(' ')) + 1);
     }
 }
 
@@ -54,20 +52,21 @@ void TestQaimDfsIterator::testQaimDfsIterator_data()
 {
     QTest::addColumn<QString>("order");
     QTest::addColumn<QSharedPointer<QStandardItemModel>>("model");
+    QTest::addColumn<UiUtils::QaimDfsIterator>("end");
     QSharedPointer<QStandardItemModel> m;
 
     m.reset(new QStandardItemModel());
-    QTest::newRow("empty-model") << QString() << m;
+    QTest::newRow("empty-model") << QString() << m << UiUtils::QaimDfsIterator();
 
     m.reset(new QStandardItemModel());
     m->appendRow(new QStandardItem("a"));
-    QTest::newRow("one-item") << "a" << m;
+    QTest::newRow("one-item") << "a" << m << UiUtils::QaimDfsIterator();
 
     m.reset(new QStandardItemModel());
     m->appendRow(new QStandardItem("a"));
     m->appendRow(new QStandardItem("b"));
     m->appendRow(new QStandardItem("c"));
-    QTest::newRow("flat-list") << "a b c" << m;
+    QTest::newRow("flat-list") << "a b c" << m << UiUtils::QaimDfsIterator();
 
     m.reset(new QStandardItemModel());
     auto item3 = new QStandardItem("a.A.1");
@@ -77,7 +76,7 @@ void TestQaimDfsIterator::testQaimDfsIterator_data()
     item1->appendRow(item2);
     m->appendRow(item1);
     item1 = item2 = item3 = nullptr;
-    QTest::newRow("linear-hierarchy") << "a a.A a.A.1" << m;
+    QTest::newRow("linear-hierarchy") << "a a.A a.A.1" << m << UiUtils::QaimDfsIterator();
 
     m.reset(new QStandardItemModel());
     item3 = new QStandardItem("a.A.1");
@@ -92,7 +91,24 @@ void TestQaimDfsIterator::testQaimDfsIterator_data()
     m->appendRow(item1);
     item1 = new QStandardItem("b");
     m->appendRow(item1);
-    QTest::newRow("backtracking") << "a a.A a.A.1 a.B a.B.1 b" << m;
+    QTest::newRow("backtracking") << "a a.A a.A.1 a.B a.B.1 b" << m << UiUtils::QaimDfsIterator();
+
+    m.reset(new QStandardItemModel());
+    item3 = new QStandardItem("a.A.1");
+    item2 = new QStandardItem("a.A");
+    item2->appendRow(item3);
+    item1 = new QStandardItem("a");
+    item1->appendRow(item2);
+    item3 = new QStandardItem("a.B.1");
+    item2 = new QStandardItem("a.B");
+    item2->appendRow(item3);
+    item1->appendRow(item2);
+    m->appendRow(item1);
+    item1 = new QStandardItem("b");
+    m->appendRow(item1);
+    auto end = UiUtils::QaimDfsIterator(m->index(1, 0, QModelIndex()));
+    Q_ASSERT(end->data().toString() == "b");
+    QTest::newRow("backtracking-until-top-level") << "a a.A a.A.1 a.B a.B.1" << m << end;
 }
 
 QTEST_GUILESS_MAIN(TestQaimDfsIterator)
-- 
2.11.4.GIT