Set all attached section properties before emitting change signals.

If we have bindings to the section properties, e.g. implementing manual
section header creation, we want previousSection, section and
nextSection to be set before emitting the change signals to prevent
different results each time the binding is run.

Change-Id: Id3a0b4a53419681f35102c9e7c620b5c6112ebb0
Reviewed-by: Martin Jones <martin.jones@jollamobile.com>

4 files changed, 50 insertions, 8 deletions

diff --git a/src/quick/items/qquickitemview_p.h b/src/quick/items/qquickitemview_p.h
index 318f5361b5..17d150f480 100644
--- a/src/quick/items/qquickitemview_p.h
+++ b/src/quick/items/qquickitemview_p.h
@@ -324,6 +324,21 @@ public:
         }
     }
 
+    void setSections(const QString &prev, const QString &sect, const QString &next) {
+        bool prevChanged = prev != m_prevSection;
+        bool sectChanged = sect != m_section;
+        bool nextChanged = next != m_nextSection;
+        m_prevSection = prev;
+        m_section = sect;
+        m_nextSection = next;
+        if (prevChanged)
+            Q_EMIT prevSectionChanged();
+        if (sectChanged)
+            Q_EMIT sectionChanged();
+        if (nextChanged)
+            Q_EMIT nextSectionChanged();
+    }
+
     void emitAdd() { Q_EMIT add(); }
     void emitRemove() { Q_EMIT remove(); }
 
diff --git a/src/quick/items/qquicklistview.cpp b/src/quick/items/qquicklistview.cpp
index c55f9ef696..d6754ddfd1 100644
--- a/src/quick/items/qquicklistview.cpp
+++ b/src/quick/items/qquicklistview.cpp
@@ -487,7 +487,7 @@ QString QQuickListViewPrivate::sectionAt(int modelIndex)
         return item->attached->section();
 
     QString section;
-    if (sectionCriteria) {
+    if (sectionCriteria && modelIndex >= 0 && modelIndex < itemCount) {
         QString propValue = model->stringValue(modelIndex, sectionCriteria->property());
         section = sectionCriteria->sectionString(propValue);
     }
@@ -565,19 +565,19 @@ FxViewItem *QQuickListViewPrivate::newViewItem(int modelIndex, QQuickItem *item)
     // initialise attached properties
     if (sectionCriteria) {
         QString propValue = model->stringValue(modelIndex, sectionCriteria->property());
-        listItem->attached->setSection(sectionCriteria->sectionString(propValue));
+        QString section = sectionCriteria->sectionString(propValue);
+        QString prevSection;
+        QString nextSection;
         if (modelIndex > 0) {
             if (FxViewItem *item = itemBefore(modelIndex))
-                listItem->attached->setPrevSection(item->attached->section());
+                prevSection = item->attached->section();
             else
-                listItem->attached->setPrevSection(sectionAt(modelIndex-1));
+                prevSection = sectionAt(modelIndex-1);
         }
         if (modelIndex < model->count()-1) {
-            if (FxViewItem *item = visibleItem(modelIndex+1))
-                listItem->attached->setNextSection(static_cast<QQuickListViewAttached*>(item->attached)->section());
-            else
-                listItem->attached->setNextSection(sectionAt(modelIndex+1));
+            nextSection = sectionAt(modelIndex+1);
         }
+        listItem->attached->setSections(prevSection, section, nextSection);
     }
 
     return listItem;
diff --git a/tests/auto/quick/qquicklistview/data/listview-sections.qml b/tests/auto/quick/qquicklistview/data/listview-sections.qml
index d5b8a4400d..e9fb83910a 100644
--- a/tests/auto/quick/qquicklistview/data/listview-sections.qml
+++ b/tests/auto/quick/qquicklistview/data/listview-sections.qml
@@ -1,6 +1,7 @@
 import QtQuick 2.0
 
 Rectangle {
+    property bool sectionsInvalidOnCompletion
     width: 240
     height: 320
     color: "#ffffff"
@@ -9,6 +10,26 @@ Rectangle {
             id: myDelegate
             Item {
                 id: wrapper
+
+                function validateInitialSections() {
+                    var invalid = false
+                    if (index == 0) {
+                        invalid |= wrapper.ListView.previousSection != ""
+                    }
+                    if (index == model.count - 1) {
+                        invalid |= wrapper.ListView.nextSection != ""
+                    }
+                    if (index % 5 == 0 && index > 0) {
+                        invalid |= wrapper.ListView.previousSection != Number(wrapper.ListView.section) - 1
+                    } else if ((index + 1) % 5 == 0 && index < model.count - 1) {
+                        invalid |= wrapper.ListView.nextSection != Number(wrapper.ListView.section) + 1
+                    } else if (index > 0 && index < model.count - 1) {
+                        invalid |= wrapper.ListView.previousSection != wrapper.ListView.section
+                        invalid |= wrapper.ListView.nextSection != wrapper.ListView.section
+                    }
+                    sectionsInvalidOnCompletion |= invalid
+                }
+
                 objectName: "wrapper"
                 height: ListView.previousSection != ListView.section ? 40 : 20;
                 width: 240
@@ -49,6 +70,10 @@ Rectangle {
                     visible: wrapper.ListView.previousSection != wrapper.ListView.section ? true : false
                     Text { text: wrapper.ListView.section }
                 }
+                ListView.onPreviousSectionChanged: validateInitialSections()
+                ListView.onNextSectionChanged: validateInitialSections()
+                ListView.onSectionChanged: validateInitialSections()
+                Component.onCompleted: validateInitialSections()
             }
         }
     ]
diff --git a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
index fb0b1c95ca..d888ba2b5c 100644
--- a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
+++ b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
@@ -1956,6 +1956,8 @@ void tst_QQuickListView::sections(const QUrl &source)
         QCOMPARE(next->text().toInt(), (i+1)/5);
     }
 
+    QVERIFY(!listview->property("sectionsInvalidOnCompletion").toBool());
+
     QSignalSpy currentSectionChangedSpy(listview, SIGNAL(currentSectionChanged()));
 
     // Remove section boundary