Got rid of Map / Unmap events in favor of Expose event.

Since change 2e4d8f67a871f2033 the need for Map and Unmap events has
gone away, as now the Expose event is used to notify the application
about when it can start rendering.

The Map and Unmap events weren't really used except by QWidget to set
the WA_Mapped flag, which we now set based on the expose / unexpose.

Also guarantee that a Resize event is always sent before the first
Expose, by re-introducing an asynchronous expose event handler. Since
an expose is required before rendering to a QWindow, show a warning if
QOpenGLContext::swapBuffers() or QBackingStore::flush() if called on a
window that has not received its first expose.

Change-Id: Ia6b609aa275d5b463b5011a96f2fd9bbe52e9bc4
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>

2 files changed, 112 insertions, 0 deletions

diff --git a/tests/auto/gui/kernel/qbackingstore/qbackingstore.pro b/tests/auto/gui/kernel/qbackingstore/qbackingstore.pro
new file mode 100644
index 0000000000..cc0a2c69f7
--- /dev/null
+++ b/tests/auto/gui/kernel/qbackingstore/qbackingstore.pro
@@ -0,0 +1,9 @@
+CONFIG += testcase
+TARGET = tst_qbackingstore
+
+QT += core-private gui-private testlib
+
+SOURCES  += tst_qbackingstore.cpp
+
+mac: CONFIG += insignificant_test # QTBUG-23059
+win32: CONFIG += insignificant_test # QTBUG-24885
diff --git a/tests/auto/gui/kernel/qbackingstore/tst_qbackingstore.cpp b/tests/auto/gui/kernel/qbackingstore/tst_qbackingstore.cpp
new file mode 100644
index 0000000000..678e616b19
--- /dev/null
+++ b/tests/auto/gui/kernel/qbackingstore/tst_qbackingstore.cpp
@@ -0,0 +1,103 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** 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, Nokia gives you certain additional
+** rights. These rights are described in the Nokia 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.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <qwindow.h>
+#include <qbackingstore.h>
+#include <qpainter.h>
+
+#include <QtTest/QtTest>
+
+#include <QEvent>
+
+// For QSignalSpy slot connections.
+Q_DECLARE_METATYPE(Qt::ScreenOrientation)
+
+class tst_QBackingStore : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void flush();
+};
+
+class Window : public QWindow
+{
+public:
+    Window()
+        : backingStore(this)
+    {
+    }
+
+    void resizeEvent(QResizeEvent *)
+    {
+        backingStore.resize(size());
+    }
+
+    void exposeEvent(QExposeEvent *event)
+    {
+        QRect rect(QPoint(), size());
+
+        backingStore.beginPaint(rect);
+
+        QPainter p(backingStore.paintDevice());
+        p.fillRect(rect, Qt::white);
+        p.end();
+
+        backingStore.endPaint();
+
+        backingStore.flush(event->region().boundingRect());
+    }
+
+private:
+    QBackingStore backingStore;
+};
+
+void tst_QBackingStore::flush()
+{
+    Window window;
+    window.setGeometry(20, 20, 200, 200);
+    window.showMaximized();
+
+    QTRY_VERIFY(window.isExposed());
+}
+
+#include <tst_qbackingstore.moc>
+QTEST_MAIN(tst_QBackingStore);