Refactor item model mapping and proxies

- Introduced new handler for item models. Instance of this is
  owned by item model proxies.
- Introduced abstract mapping class to enable moving a lot of
  duplicate code to the new handler.
- Changed ownership handling of mapping objects to be in line
  with proxies and axes, though there is no default mapping
  at this time. Need to reconsider the default case more.
- Made item model const so it is clear that we do not own it.

The documentation is not yet up to date.

Change-Id: Ie961da29340743fdaa9293d7d4ace9577def9102
Reviewed-by: Tomi Korpipää <tomi.korpipaa@digia.com>

2 files changed, 6 insertions, 3 deletions

diff --git a/examples/barchart/main.cpp b/examples/barchart/main.cpp
index 0f1a8252..ca9c3260 100644
--- a/examples/barchart/main.cpp
+++ b/examples/barchart/main.cpp
@@ -296,8 +296,7 @@ int main(int argc, char **argv)
 
     // We don't need to initialize the mapping object in any way, as it defaults
     // to row/column support and uses the Qt::DisplayRole role for value role by default.
-    QItemModelBarDataMapping mapping;
-    QItemModelBarDataProxy *proxy = new QItemModelBarDataProxy(tableWidget->model(), &mapping);
+    QItemModelBarDataProxy *proxy = new QItemModelBarDataProxy(tableWidget->model(), new QItemModelBarDataMapping);
     chart->setActiveDataProxy(proxy);
 
     ChartDataGenerator *generator = new ChartDataGenerator(chart, tableWidget);
diff --git a/examples/qmlbarchart/qml/qmlbarchart/main.qml b/examples/qmlbarchart/qml/qmlbarchart/main.qml
index 44ad36ca..781e7517 100644
--- a/examples/qmlbarchart/qml/qmlbarchart/main.qml
+++ b/examples/qmlbarchart/qml/qmlbarchart/main.qml
@@ -27,12 +27,15 @@ Item {
     height: 600
     visible: true
 
+
     Item {
         id: dataView
         width: parent.width - tableView.width
         height: parent.height
         anchors.right: parent.right;
 
+        property point storedSelection: Qt.point(-1, -1)
+
         BarDataMapping {
             id: valueMapping
             rowRole: "year"
@@ -138,7 +141,7 @@ Item {
 
             onDataResolved: {
                 // Can't select a bar until data has been resolved from model to proxy
-                //selectedBarPos = Qt.point(0, 5)
+                selectedBarPos = dataView.storedSelection
             }
         }
 
@@ -177,6 +180,7 @@ Item {
                 text = "Show Income"
                 testchart.valueAxis = expensesAxis
             }
+            dataView.storedSelection = testchart.selectedBarPos
         }
     }