Improve performance on touch event delivery.

We continuously constructed and sorted the paint ordered items for every
touch event (and paint), even though the list in most cases is identical
to the childItems list, and when it is different it rarely changes.

Detect when we can just use the childItems list directly, and otherwise
cache the ordered items list.

Change-Id: I5db0f19fc021d0c95aa6f8372ae47e6ce138d5ad
Reviewed-by: Michael Brasser <michael.brasser@nokia.com>

4 files changed, 141 insertions, 1 deletions

diff --git a/tests/auto/declarative/qquickitem/data/order.1.qml b/tests/auto/declarative/qquickitem/data/order.1.qml
new file mode 100644
index 0000000000..963288b257
--- /dev/null
+++ b/tests/auto/declarative/qquickitem/data/order.1.qml
@@ -0,0 +1,7 @@
+import QtQuick 2.0
+
+Item {
+    Item { objectName: "1" }
+    Item { objectName: "2" }
+    Item { objectName: "3" }
+}
diff --git a/tests/auto/declarative/qquickitem/data/order.2.qml b/tests/auto/declarative/qquickitem/data/order.2.qml
new file mode 100644
index 0000000000..5609c77e28
--- /dev/null
+++ b/tests/auto/declarative/qquickitem/data/order.2.qml
@@ -0,0 +1,7 @@
+import QtQuick 2.0
+
+Item {
+    Item { objectName: "1" }
+    Item { objectName: "2"; z: 1.0 }
+    Item { objectName: "3" }
+}
diff --git a/tests/auto/declarative/qquickitem/qquickitem.pro b/tests/auto/declarative/qquickitem/qquickitem.pro
index c1c7b825f9..f484bae014 100644
--- a/tests/auto/declarative/qquickitem/qquickitem.pro
+++ b/tests/auto/declarative/qquickitem/qquickitem.pro
@@ -4,5 +4,9 @@ SOURCES += tst_qquickitem.cpp
 
 macx:CONFIG -= app_bundle
 
+testDataFiles.files = data
+testDataFiles.path = .
+DEPLOYMENT += testDataFiles
+
 CONFIG += parallel_test
-QT += core-private gui-private declarative-private widgets testlib
+QT += core-private gui-private v8-private declarative-private widgets testlib
diff --git a/tests/auto/declarative/qquickitem/tst_qquickitem.cpp b/tests/auto/declarative/qquickitem/tst_qquickitem.cpp
index a5f908ce86..01f9240016 100644
--- a/tests/auto/declarative/qquickitem/tst_qquickitem.cpp
+++ b/tests/auto/declarative/qquickitem/tst_qquickitem.cpp
@@ -43,10 +43,13 @@
 
 #include "qquickitem.h"
 #include "qquickcanvas.h"
+#include "qquickview.h"
 #include <QtWidgets/QGraphicsSceneMouseEvent>
 #include "private/qquickfocusscope_p.h"
+#include "private/qquickitem_p.h"
 #include <QDebug>
 #include <QTimer>
+#include "../shared/util.h"
 
 class TestItem : public QQuickItem
 {
@@ -131,8 +134,15 @@ private slots:
     void hoverEvent();
     void hoverEventInParent();
 
+    void paintOrder_data();
+    void paintOrder();
+
 private:
 
+    enum PaintOrderOp {
+        NoOp, Append, Remove, StackBefore, StackAfter, SetZ
+    };
+
     void ensureFocus(QWindow *w) {
         w->show();
         w->requestActivateWindow();
@@ -1064,6 +1074,118 @@ void tst_qquickitem::hoverEventInParent()
     delete canvas;
 }
 
+void tst_qquickitem::paintOrder_data()
+{
+    QTest::addColumn<QUrl>("source");
+    QTest::addColumn<int>("op");
+    QTest::addColumn<QVariant>("param1");
+    QTest::addColumn<QVariant>("param2");
+    QTest::addColumn<QStringList>("expected");
+
+    QTest::newRow("test 1 noop") << QUrl::fromLocalFile(TESTDATA("order.1.qml"))
+        << int(NoOp) << QVariant() << QVariant()
+        << (QStringList() << "1" << "2" << "3");
+    QTest::newRow("test 1 add") << QUrl::fromLocalFile(TESTDATA("order.1.qml"))
+        << int(Append) << QVariant("new") << QVariant()
+        << (QStringList() << "1" << "2" << "3" << "new");
+    QTest::newRow("test 1 remove") << QUrl::fromLocalFile(TESTDATA("order.1.qml"))
+        << int(Remove) << QVariant(1) << QVariant()
+        << (QStringList() << "1" << "3");
+    QTest::newRow("test 1 stack before") << QUrl::fromLocalFile(TESTDATA("order.1.qml"))
+        << int(StackBefore) << QVariant(2) << QVariant(1)
+        << (QStringList() << "1" << "3" << "2");
+    QTest::newRow("test 1 stack after") << QUrl::fromLocalFile(TESTDATA("order.1.qml"))
+        << int(StackAfter) << QVariant(0) << QVariant(1)
+        << (QStringList() << "2" << "1" << "3");
+    QTest::newRow("test 1 set z") << QUrl::fromLocalFile(TESTDATA("order.1.qml"))
+        << int(SetZ) << QVariant(1) << QVariant(qreal(1.))
+        << (QStringList() << "1" << "3" << "2");
+
+    QTest::newRow("test 2 noop") << QUrl::fromLocalFile(TESTDATA("order.2.qml"))
+        << int(NoOp) << QVariant() << QVariant()
+        << (QStringList() << "1" << "3" << "2");
+    QTest::newRow("test 2 add") << QUrl::fromLocalFile(TESTDATA("order.2.qml"))
+        << int(Append) << QVariant("new") << QVariant()
+        << (QStringList() << "1" << "3" << "new" << "2");
+    QTest::newRow("test 2 remove 1") << QUrl::fromLocalFile(TESTDATA("order.2.qml"))
+        << int(Remove) << QVariant(1) << QVariant()
+        << (QStringList() << "1" << "3");
+    QTest::newRow("test 2 remove 2") << QUrl::fromLocalFile(TESTDATA("order.2.qml"))
+        << int(Remove) << QVariant(2) << QVariant()
+        << (QStringList() << "1" << "2");
+    QTest::newRow("test 2 stack before 1") << QUrl::fromLocalFile(TESTDATA("order.2.qml"))
+        << int(StackBefore) << QVariant(1) << QVariant(0)
+        << (QStringList() << "1" << "3" << "2");
+    QTest::newRow("test 2 stack before 2") << QUrl::fromLocalFile(TESTDATA("order.2.qml"))
+        << int(StackBefore) << QVariant(2) << QVariant(0)
+        << (QStringList() << "3" << "1" << "2");
+    QTest::newRow("test 2 stack after 1") << QUrl::fromLocalFile(TESTDATA("order.2.qml"))
+        << int(StackAfter) << QVariant(0) << QVariant(1)
+        << (QStringList() << "1" << "3" << "2");
+    QTest::newRow("test 2 stack after 2") << QUrl::fromLocalFile(TESTDATA("order.2.qml"))
+        << int(StackAfter) << QVariant(0) << QVariant(2)
+        << (QStringList() << "3" << "1" << "2");
+    QTest::newRow("test 1 set z") << QUrl::fromLocalFile(TESTDATA("order.1.qml"))
+        << int(SetZ) << QVariant(2) << QVariant(qreal(2.))
+        << (QStringList() << "1" << "2" << "3");
+}
+
+void tst_qquickitem::paintOrder()
+{
+    QFETCH(QUrl, source);
+    QFETCH(int, op);
+    QFETCH(QVariant, param1);
+    QFETCH(QVariant, param2);
+    QFETCH(QStringList, expected);
+
+    QQuickView view;
+    view.setSource(source);
+
+    QQuickItem *root = qobject_cast<QQuickItem*>(view.rootObject());
+    QVERIFY(root);
+
+    switch (op) {
+        case Append: {
+                QQuickItem *item = new QQuickItem(root);
+                item->setObjectName(param1.toString());
+            }
+            break;
+        case Remove: {
+                QQuickItem *item = root->childItems().at(param1.toInt());
+                delete item;
+            }
+            break;
+        case StackBefore: {
+                QQuickItem *item1 = root->childItems().at(param1.toInt());
+                QQuickItem *item2 = root->childItems().at(param2.toInt());
+                item1->stackBefore(item2);
+            }
+            break;
+        case StackAfter: {
+                QQuickItem *item1 = root->childItems().at(param1.toInt());
+                QQuickItem *item2 = root->childItems().at(param2.toInt());
+                item1->stackAfter(item2);
+            }
+            break;
+        case SetZ: {
+                QQuickItem *item = root->childItems().at(param1.toInt());
+                item->setZ(param2.toReal());
+            }
+            break;
+        default:
+            break;
+    }
+
+    QList<QQuickItem*> list = QQuickItemPrivate::get(root)->paintOrderChildItems();
+
+    QStringList items;
+    for (int i = 0; i < list.count(); ++i)
+        items << list.at(i)->objectName();
+
+    QCOMPARE(items, expected);
+}
+
+
 QTEST_MAIN(tst_qquickitem)
 
 #include "tst_qquickitem.moc"