1 files changed, 134 insertions, 0 deletions
diff --git a/tests/auto/client/scaling/tst_scaling.cpp b/tests/auto/client/scaling/tst_scaling.cpp
new file mode 100644
index 000000000..b4d2995ea
--- /dev/null
+++ b/tests/auto/client/scaling/tst_scaling.cpp
@@ -0,0 +1,134 @@
+// Copyright (C) 2022 David Edmundson <davidedmundson@kde.org>
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+#include "mockcompositor.h"
+#include <QtGui/QRasterWindow>
+#include <QtGui/qpa/qplatformnativeinterface.h>
+#include <QtWaylandClient/private/wayland-wayland-client-protocol.h>
+#include <QtWaylandClient/private/qwaylandwindow_p.h>
+
+using namespace MockCompositor;
+
+class tst_scaling : public QObject, private DefaultCompositor
+{
+    Q_OBJECT
+private slots:
+    void init();
+    void cleanup() { QTRY_VERIFY2(isClean(), qPrintable(dirtyMessage())); }
+    void scaledWindow();
+    void roundingPolicy_data();
+    void roundingPolicy();
+
+};
+
+void tst_scaling::init()
+{
+    setenv("QT_WAYLAND_DISABLE_WINDOWDECORATION", "1", 1);
+}
+
+void tst_scaling::scaledWindow()
+{
+    QRasterWindow window;
+    window.resize(100, 100);
+    window.show();
+    QCOMPOSITOR_TRY_VERIFY(xdgToplevel());
+
+    QSignalSpy configureSpy(exec([&] { return xdgSurface(); }), &XdgSurface::configureCommitted);
+    QSignalSpy surfaceCommitSpy(exec([&] { return surface(); }), &Surface::commit);
+
+    const QSize configureSize(100, 100);
+
+    exec([&] {
+        QVERIFY(fractionalScale());
+        fractionalScale()->send_preferred_scale(1.5 * 120);
+        xdgToplevel()->sendCompleteConfigure(configureSize);
+    });
+
+    QTRY_COMPARE(configureSpy.count(), 1);
+    QCOMPARE(window.devicePixelRatio(), 1.5);
+
+    exec([&] {
+        Buffer *buffer = xdgToplevel()->surface()->m_committed.buffer;
+        QVERIFY(buffer);
+        QCOMPARE(buffer->size(), QSize(150, 150));
+        Viewport *vp = viewport();
+        QVERIFY(vp);
+        QCOMPARE(vp->m_destination, QSize(100, 100));
+    });
+
+    // resize the window
+    window.resize(200,200);
+    QCOMPARE(window.size(), QSize(200,200));
+
+    QVERIFY(surfaceCommitSpy.wait());
+    exec([&] {
+        Buffer *buffer = xdgToplevel()->surface()->m_committed.buffer;
+        QVERIFY(buffer);
+        QCOMPARE(buffer->size(), QSize(300, 300));
+        Viewport *vp = viewport();
+        QVERIFY(vp);
+        QCOMPARE(vp->m_destination, QSize(200, 200));
+    });
+
+    // dynamic scale change
+    exec([&] {
+        QVERIFY(fractionalScale());
+        fractionalScale()->send_preferred_scale(2.5 * 120);
+    });
+    QTRY_COMPARE(window.devicePixelRatio(), 2.5);
+    QCOMPARE(window.size(), QSize(200,200));
+
+    QVERIFY(surfaceCommitSpy.wait());
+    exec([&] {
+        Buffer *buffer = xdgToplevel()->surface()->m_committed.buffer;
+        QVERIFY(buffer);
+        QCOMPARE(buffer->size(), QSize(500, 500));
+        Viewport *vp = viewport();
+        QVERIFY(vp);
+        QCOMPARE(vp->m_destination, QSize(200, 200));
+    });
+}
+
+void tst_scaling::roundingPolicy_data()
+{
+    QTest::addColumn<QSize>("windowSize");
+    QTest::addColumn<qreal>("scale");
+    QTest::addColumn<QSize>("expectedBufferSize");
+
+    QTest::newRow("1.125 - round down") << QSize(10, 10) << 1.125 << QSize(11,11);
+    QTest::newRow("1.25 - round up") << QSize(10, 10) << 1.25 << QSize(13,13);
+    QTest::newRow("1.5 - don't round") << QSize(10, 10) << 1.5 << QSize(15,15);
+}
+
+void tst_scaling::roundingPolicy()
+{
+    QFETCH(QSize, windowSize);
+    QFETCH(qreal, scale);
+    QFETCH(QSize, expectedBufferSize);
+
+
+    QRasterWindow window;
+    window.resize(windowSize);
+    window.show();
+    QCOMPOSITOR_TRY_VERIFY(xdgToplevel());
+
+    QSignalSpy surfaceCommitSpy(exec([&] { return surface(); }), &Surface::commit);
+
+    exec([&] {
+        QVERIFY(fractionalScale());
+        fractionalScale()->send_preferred_scale(scale * 120);
+        xdgToplevel()->sendCompleteConfigure();
+    });
+
+    QVERIFY(surfaceCommitSpy.wait());
+
+    exec([&] {
+        Buffer *buffer = xdgToplevel()->surface()->m_committed.buffer;
+        QVERIFY(buffer);
+        QCOMPARE(buffer->size(), expectedBufferSize);
+    });
+}
+
+
+QCOMPOSITOR_TEST_MAIN(tst_scaling)
+#include "tst_scaling.moc"