Merge remote-tracking branch 'origin/wip/qt6' into wip/cmake

Change-Id: I2963c1209316fb6755f572969f368970450d7991

2 files changed, 52 insertions, 3 deletions

diff --git a/src/qmlmodels/qqmldelegatecomponent.cpp b/src/qmlmodels/qqmldelegatecomponent.cpp
index a7e9536917..ccb0d60053 100644
--- a/src/qmlmodels/qqmldelegatecomponent.cpp
+++ b/src/qmlmodels/qqmldelegatecomponent.cpp
@@ -199,11 +199,45 @@ bool QQmlDelegateChoice::match(int row, int column, const QVariant &value) const
     The DelegateChooser is a special \l Component type intended for those scenarios where a Component is required
     by a view and used as a delegate.
     DelegateChooser encapsulates a set of \l {DelegateChoice}s.
-    These choices are used determine the delegate that will be instantiated for each
+    These choices are used to determine the delegate that will be instantiated for each
     item in the model.
     The selection of the choice is performed based on the value that a model item has for \l role,
     and also based on index.
 
+    DelegateChooser is commonly used when a view needs to display a set of delegates that are significantly
+    different from each other. For example, a typical phone settings view might include toggle switches,
+    sliders, radio buttons, and other visualizations based on the type of each setting. In this case, DelegateChooser
+    could provide an easy way to associate a different type of delegate with each setting:
+
+    \qml \QtMinorVersion
+    import QtQuick 2.\1
+    import QtQuick.Controls 2.\1
+    import Qt.labs.qmlmodels 1.0
+
+    ListView {
+        width: 200; height: 400
+
+        ListModel {
+            id: listModel
+            ListElement { type: "info"; ... }
+            ListElement { type: "switch"; ... }
+            ListElement { type: "swipe"; ... }
+            ListElement { type: "switch"; ... }
+        }
+
+        DelegateChooser {
+            id: chooser
+            role: "type"
+            DelegateChoice { roleValue: "info"; ItemDelegate { ... } }
+            DelegateChoice { roleValue: "switch"; SwitchDelegate { ... } }
+            DelegateChoice { roleValue: "swipe"; SwipeDelegate { ... } }
+        }
+
+        model: listModel
+        delegate: chooser
+    }
+    \endqml
+
     \note This type is intended to transparently work only with TableView and any DelegateModel-based view.
     Views (including user-defined views) that aren't internally based on a DelegateModel need to explicitly support
     this type of component to make it function as described.
diff --git a/src/qmlmodels/qqmldelegatemodel.cpp b/src/qmlmodels/qqmldelegatemodel.cpp
index 2216e5fb50..6c80f4a3e5 100644
--- a/src/qmlmodels/qqmldelegatemodel.cpp
+++ b/src/qmlmodels/qqmldelegatemodel.cpp
@@ -1344,6 +1344,11 @@ void QQmlDelegateModel::_q_itemsInserted(int index, int count)
     const QList<QQmlDelegateModelItem *> cache = d->m_cache;
     for (int i = 0, c = cache.count();  i < c; ++i) {
         QQmlDelegateModelItem *item = cache.at(i);
+        // layout change triggered by changing the modelIndex might have
+        // already invalidated this item in d->m_cache and deleted it.
+        if (!d->m_cache.isSharedWith(cache) && !d->m_cache.contains(item))
+            continue;
+
         if (item->modelIndex() >= index) {
             const int newIndex = item->modelIndex() + count;
             const int row = newIndex;
@@ -1487,7 +1492,7 @@ void QQmlDelegateModel::_q_itemsRemoved(int index, int count)
         QQmlDelegateModelItem *item = cache.at(i);
         // layout change triggered by removal of a previous item might have
         // already invalidated this item in d->m_cache and deleted it
-        if (!d->m_cache.contains(item))
+        if (!d->m_cache.isSharedWith(cache) && !d->m_cache.contains(item))
             continue;
 
         if (item->modelIndex() >= index + count) {
@@ -1542,6 +1547,11 @@ void QQmlDelegateModel::_q_itemsMoved(int from, int to, int count)
     const QList<QQmlDelegateModelItem *> cache = d->m_cache;
     for (int i = 0, c = cache.count();  i < c; ++i) {
         QQmlDelegateModelItem *item = cache.at(i);
+        // layout change triggered by changing the modelIndex might have
+        // already invalidated this item in d->m_cache and deleted it.
+        if (!d->m_cache.isSharedWith(cache) && !d->m_cache.contains(item))
+            continue;
+
         if (item->modelIndex() >= from && item->modelIndex() < from + count) {
             const int newIndex = item->modelIndex() - from + to;
             const int row = newIndex;
@@ -1634,6 +1644,11 @@ void QQmlDelegateModel::_q_modelReset()
         const QList<QQmlDelegateModelItem *> cache = d->m_cache;
         for (int i = 0, c = cache.count();  i < c; ++i) {
             QQmlDelegateModelItem *item = cache.at(i);
+            // layout change triggered by changing the modelIndex might have
+            // already invalidated this item in d->m_cache and deleted it.
+            if (!d->m_cache.isSharedWith(cache) && !d->m_cache.contains(item))
+                continue;
+
             if (item->modelIndex() != -1)
                 item->setModelIndex(-1, -1, -1);
         }
@@ -2639,10 +2654,10 @@ QJSValue QQmlDelegateModelGroup::get(int index)
         model->m_cacheMetaType->initializePrototype();
     QV4::ExecutionEngine *v4 = model->m_cacheMetaType->v4Engine;
     QV4::Scope scope(v4);
+    ++cacheItem->scriptRef;
     QV4::ScopedObject o(scope, v4->memoryManager->allocate<QQmlDelegateModelItemObject>(cacheItem));
     QV4::ScopedObject p(scope, model->m_cacheMetaType->modelItemProto.value());
     o->setPrototypeOf(p);
-    ++cacheItem->scriptRef;
 
     return QJSValue(v4, o->asReturnedValue());
 }