Correctly update flickable visibleArea.heightRatio when geometry changes

Without this fix the visibleArea.heightRatio and widthRatio values
were only updated on geometry changes when flicking was active.

So when setting the flickable geometry to the content geometry and
thereby disabling flicking the ratios were not updated.

This could for example cause wrong scrollbar renderings.

The ratios are now also calculated directly after accessing the
visibleArea property for the first time.

The new autotest covers both problems.

Change-Id: I54ba606524557fb328a198c312c1f65eb125c5a3
Reviewed-by: Alan Alpert <aalpert@blackberry.com>

2 files changed, 94 insertions, 0 deletions

diff --git a/tests/auto/quick/qquickflickable/data/ratios.qml b/tests/auto/quick/qquickflickable/data/ratios.qml
new file mode 100644
index 0000000000..1291cada72
--- /dev/null
+++ b/tests/auto/quick/qquickflickable/data/ratios.qml
@@ -0,0 +1,71 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.0
+
+Rectangle {
+  width: 400
+  height: 400
+
+  property bool forceNoFlicking: true
+  property double heightRatioIs: flickable.visibleArea.heightRatio
+  property double heightRatioShould: flickable.height / flickable.contentHeight
+  property double widthRatioIs: flickable.visibleArea.widthRatio
+  property double widthRatioShould: flickable.height / flickable.contentWidth
+
+  Flickable {
+    id: flickable
+    flickableDirection: Flickable.AutoFlickDirection
+    width: forceNoFlicking ? contentItem.width   /* so xflick() returns false */ : 20
+    height: forceNoFlicking ? contentItem.height /* likewise */ : 20
+    contentHeight: contentItem.height
+    contentWidth: contentItem.width
+    clip: true
+
+    Rectangle {
+      id: contentItem
+      color: "red"
+      width: 300
+      height: 300
+    }
+  }
+}
+
diff --git a/tests/auto/quick/qquickflickable/tst_qquickflickable.cpp b/tests/auto/quick/qquickflickable/tst_qquickflickable.cpp
index 3575dfa012..a8055b3467 100644
--- a/tests/auto/quick/qquickflickable/tst_qquickflickable.cpp
+++ b/tests/auto/quick/qquickflickable/tst_qquickflickable.cpp
@@ -67,6 +67,7 @@ private slots:
     void create();
     void horizontalViewportSize();
     void verticalViewportSize();
+    void visibleAreaRatiosUpdate();
     void properties();
     void boundsBehavior();
     void rebound();
@@ -158,6 +159,28 @@ void tst_qquickflickable::verticalViewportSize()
     delete obj;
 }
 
+void tst_qquickflickable::visibleAreaRatiosUpdate()
+{
+    QQmlEngine engine;
+    QQmlComponent c(&engine, testFileUrl("ratios.qml"));
+    QQuickItem *obj = qobject_cast<QQuickItem*>(c.create());
+
+    QVERIFY(obj != 0);
+    // check initial ratio values
+    QCOMPARE(obj->property("heightRatioIs").toDouble(), obj->property("heightRatioShould").toDouble());
+    QCOMPARE(obj->property("widthRatioIs").toDouble(), obj->property("widthRatioShould").toDouble());
+    // change flickable geometry so that flicking is enabled (content size > flickable size)
+    obj->setProperty("forceNoFlicking", false);
+    QCOMPARE(obj->property("heightRatioIs").toDouble(), obj->property("heightRatioShould").toDouble());
+    QCOMPARE(obj->property("widthRatioIs").toDouble(), obj->property("widthRatioShould").toDouble());
+    // change flickable geometry so that flicking is disabled (content size == flickable size)
+    obj->setProperty("forceNoFlicking", true);
+    QCOMPARE(obj->property("heightRatioIs").toDouble(), obj->property("heightRatioShould").toDouble());
+    QCOMPARE(obj->property("widthRatioIs").toDouble(), obj->property("widthRatioShould").toDouble());
+
+    delete obj;
+}
+
 void tst_qquickflickable::properties()
 {
     QQmlEngine engine;