Ensure items in ListView and GridViews viewport are visible.

Unrequested items and items in the cache buffer are hidden by the views.
Make these items visible again if they enter the viewport due to a
relayout.

Change-Id: I574d1513e88c31c3c01a4a20ac77c21111279d3e
Reviewed-by: Bea Lam <bea.lam@nokia.com>

2 files changed, 236 insertions, 0 deletions

diff --git a/tests/auto/qtquick2/qquickgridview/data/unrequestedItems.qml b/tests/auto/qtquick2/qquickgridview/data/unrequestedItems.qml
new file mode 100644
index 0000000000..ffd52d283e
--- /dev/null
+++ b/tests/auto/qtquick2/qquickgridview/data/unrequestedItems.qml
@@ -0,0 +1,67 @@
+import QtQuick 2.0
+
+Item {
+    width: 240
+    height: 320
+
+    Component {
+        id: myDelegate
+
+        Package {
+            Rectangle {
+                id: leftWrapper
+                objectName: "wrapper"
+                Package.name: "left"
+                height: 80
+                width: 60
+                Text {
+                    text: index
+                }
+                color: ListView.isCurrentItem ? "lightsteelblue" : "white"
+            }
+            Rectangle {
+                id: rightWrapper
+                objectName: "wrapper"
+                Package.name: "right"
+                height: 80
+                width: 60
+                Text {
+                    text: index
+                }
+                color: ListView.isCurrentItem ? "lightsteelblue" : "white"
+            }
+        }
+
+    }
+
+    VisualDataModel {
+        id: visualModel
+
+        delegate: myDelegate
+        model: testModel
+    }
+
+    GridView {
+        id: leftList
+        objectName: "leftGrid"
+        anchors {
+            left: parent.left; top: parent.top;
+            right: parent.horizontalCenter; bottom: parent.bottom
+        }
+        model: visualModel.parts.left
+        cellWidth: 60
+        cellHeight: 80
+    }
+
+    GridView {
+        id: rightList
+        objectName: "rightGrid"
+        anchors {
+            left: parent.horizontalCenter; top: parent.top;
+            right: parent.right; bottom: parent.bottom
+        }
+        model: visualModel.parts.right
+        cellWidth: 60
+        cellHeight: 80
+    }
+}
diff --git a/tests/auto/qtquick2/qquickgridview/tst_qquickgridview.cpp b/tests/auto/qtquick2/qquickgridview/tst_qquickgridview.cpp
index 9ceafffbe9..5a1f482f49 100644
--- a/tests/auto/qtquick2/qquickgridview/tst_qquickgridview.cpp
+++ b/tests/auto/qtquick2/qquickgridview/tst_qquickgridview.cpp
@@ -120,6 +120,7 @@ private slots:
     void unaligned();
     void cacheBuffer();
     void asynchronous();
+    void unrequestedVisibility();
 
 private:
     QQuickView *createView();
@@ -3747,6 +3748,174 @@ void tst_QQuickGridView::asynchronous()
     delete canvas;
 }
 
+void tst_QQuickGridView::unrequestedVisibility()
+{
+    TestModel model;
+    for (int i = 0; i < 30; i++)
+        model.addItem("Item" + QString::number(i), QString::number(i));
+
+    QQuickView *canvas = new QQuickView(0);
+    canvas->setGeometry(0,0,240,320);
+
+    QDeclarativeContext *ctxt = canvas->rootContext();
+    ctxt->setContextProperty("testModel", &model);
+    ctxt->setContextProperty("testWrap", QVariant(false));
+
+    QString filename(TESTDATA("unrequestedItems.qml"));
+    canvas->setSource(QUrl::fromLocalFile(filename));
+
+    canvas->show();
+
+    qApp->processEvents();
+
+    QQuickGridView *leftview = findItem<QQuickGridView>(canvas->rootObject(), "leftGrid");
+    QTRY_VERIFY(leftview != 0);
+
+    QQuickGridView *rightview = findItem<QQuickGridView>(canvas->rootObject(), "rightGrid");
+    QTRY_VERIFY(rightview != 0);
+
+    QQuickItem *leftContent = leftview->contentItem();
+    QTRY_VERIFY(leftContent != 0);
+
+    QQuickItem *rightContent = rightview->contentItem();
+    QTRY_VERIFY(rightContent != 0);
+
+    rightview->setCurrentIndex(12);
+
+    QTRY_COMPARE(leftview->contentY(), 0.0);
+    QTRY_COMPARE(rightview->contentY(), 240.0);
+
+    QQuickItem *item;
+
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 1));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 1));
+    QCOMPARE(item->isVisible(), false);
+
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 11));
+    QCOMPARE(item->isVisible(), false);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 11));
+    QCOMPARE(item->isVisible(), true);
+
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 9));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 10));
+    QCOMPARE(item->isVisible(), false);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 3));
+    QCOMPARE(item->isVisible(), false);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 4));
+    QCOMPARE(item->isVisible(), true);
+
+    rightview->setCurrentIndex(0);
+
+    QTRY_COMPARE(leftview->contentY(), 0.0);
+    QTRY_COMPARE(rightview->contentY(), 0.0);
+
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 1));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 1));
+    QTRY_COMPARE(item->isVisible(), true);
+
+    QVERIFY(!findItem<QQuickItem>(leftContent, "wrapper", 11));
+    QVERIFY(!findItem<QQuickItem>(rightContent, "wrapper", 11));
+
+    leftview->setCurrentIndex(12);
+
+    QTRY_COMPARE(leftview->contentY(), 240.0);
+    QTRY_COMPARE(rightview->contentY(), 0.0);
+
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 1));
+    QTRY_COMPARE(item->isVisible(), false);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 1));
+    QCOMPARE(item->isVisible(), true);
+
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 11));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 11));
+    QCOMPARE(item->isVisible(), false);
+
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 3));
+    QCOMPARE(item->isVisible(), false);
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 4));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 9));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 10));
+    QCOMPARE(item->isVisible(), false);
+
+    model.moveItems(19, 1, 1);
+    QTRY_COMPARE(QQuickItemPrivate::get(leftview)->polishScheduled, false);
+
+    QTRY_VERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 1));
+    QCOMPARE(item->isVisible(), false);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 1));
+    QCOMPARE(item->isVisible(), true);
+
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 11));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 11));
+    QCOMPARE(item->isVisible(), false);
+
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 3));
+    QCOMPARE(item->isVisible(), false);
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 4));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 9));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 10));
+    QCOMPARE(item->isVisible(), false);
+
+    model.moveItems(3, 4, 1);
+    QTRY_COMPARE(QQuickItemPrivate::get(leftview)->polishScheduled, false);
+
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 1));
+    QCOMPARE(item->isVisible(), false);
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 2));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 9));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 10));
+    QCOMPARE(item->isVisible(), false);
+
+    model.moveItems(4, 5, 1);
+    QTRY_COMPARE(QQuickItemPrivate::get(leftview)->polishScheduled, false);
+
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 1));
+    QCOMPARE(item->isVisible(), false);
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 2));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 9));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 10));
+    QCOMPARE(item->isVisible(), false);
+
+    model.moveItems(9, 10, 1);
+    QTRY_COMPARE(QQuickItemPrivate::get(leftview)->polishScheduled, false);
+
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 1));
+    QCOMPARE(item->isVisible(), false);
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 2));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 9));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 10));
+    QCOMPARE(item->isVisible(), false);
+
+    model.moveItems(10, 9, 1);
+    QTRY_COMPARE(QQuickItemPrivate::get(leftview)->polishScheduled, false);
+
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 1));
+    QCOMPARE(item->isVisible(), false);
+    QVERIFY(item = findItem<QQuickItem>(leftContent, "wrapper", 2));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 9));
+    QCOMPARE(item->isVisible(), true);
+    QVERIFY(item = findItem<QQuickItem>(rightContent, "wrapper", 10));
+    QCOMPARE(item->isVisible(), false);
+
+    delete canvas;
+}
+
 /*
    Find an item with the specified objectName.  If index is supplied then the
    item must also evaluate the {index} expression equal to index