Add XdgOutput client support

XdgOutput is an extension of wl_output with the benefit of having the
logical size of a screen as an explicit parameter, instead of clients
inferring it from modeSize / scale. This is useful as it allows
compositors to implement fractional scaling whilst clients can still
fill the screen.

In the future XdgOutputV2 will support a more useful name and ID that
we can use.

[ChangeLog][QPA plugin] Added support for xdg-output-unstable-v1

Change-Id: I2e1e64ad6cb497a1cbb7b7b170f28ac92231c2c4
Reviewed-by: Pier Luigi Fiorini <pierluigi.fiorini@liri.io>
Reviewed-by: Johan Helsing <johan.helsing@qt.io>

5 files changed, 65 insertions, 7 deletions

diff --git a/src/client/client.pro b/src/client/client.pro
index 593e8daf6..45bbb976b 100644
--- a/src/client/client.pro
+++ b/src/client/client.pro
@@ -28,6 +28,7 @@ WAYLANDCLIENTSOURCES += \
             ../extensions/qt-key-unstable-v1.xml \
             ../extensions/qt-windowmanager.xml \
             ../3rdparty/protocol/text-input-unstable-v2.xml \
+            ../3rdparty/protocol/xdg-output-unstable-v1.xml \
 
 WAYLANDCLIENTSOURCES_SYSTEM += \
             ../3rdparty/protocol/wayland.xml \
diff --git a/src/client/qwaylanddisplay.cpp b/src/client/qwaylanddisplay.cpp
index 03e4e3a2c..40ceafd96 100644
--- a/src/client/qwaylanddisplay.cpp
+++ b/src/client/qwaylanddisplay.cpp
@@ -276,6 +276,11 @@ void QWaylandDisplay::registry_global(uint32_t id, const QString &interface, uin
         // make a roundtrip here since we need to receive the events sent by
         // qt_hardware_integration before creating windows
         forceRoundTrip();
+    } else if (interface == QLatin1String("zxdg_output_manager_v1")) {
+        mXdgOutputManager.reset(new QtWayland::zxdg_output_manager_v1(registry, id, 1));
+        for (auto *screen : qAsConst(mScreens))
+            screen->initXdgOutput(xdgOutputManager());
+        forceRoundTrip();
     }
 
     mGlobals.append(RegistryGlobal(id, interface, version, registry));
diff --git a/src/client/qwaylanddisplay_p.h b/src/client/qwaylanddisplay_p.h
index 8570eba03..aee1ed45f 100644
--- a/src/client/qwaylanddisplay_p.h
+++ b/src/client/qwaylanddisplay_p.h
@@ -76,6 +76,7 @@ class QPlatformScreen;
 namespace QtWayland {
     class qt_surface_extension;
     class zwp_text_input_manager_v2;
+    class zxdg_output_manager_v1;
 }
 
 namespace QtWaylandClient {
@@ -143,6 +144,8 @@ public:
     QWaylandTouchExtension *touchExtension() const { return mTouchExtension.data(); }
     QtWayland::zwp_text_input_manager_v2 *textInputManager() const { return mTextInputManager.data(); }
     QWaylandHardwareIntegration *hardwareIntegration() const { return mHardwareIntegration.data(); }
+    QtWayland::zxdg_output_manager_v1 *xdgOutputManager() const { return mXdgOutputManager.data(); }
+
 
     struct RegistryGlobal {
         uint32_t id;
@@ -214,6 +217,7 @@ private:
     QScopedPointer<QWaylandWindowManagerIntegration> mWindowManagerIntegration;
     QScopedPointer<QtWayland::zwp_text_input_manager_v2> mTextInputManager;
     QScopedPointer<QWaylandHardwareIntegration> mHardwareIntegration;
+    QScopedPointer<QtWayland::zxdg_output_manager_v1> mXdgOutputManager;
     QSocketNotifier *mReadNotifier = nullptr;
     int mFd;
     int mWritableNotificationFd;
diff --git a/src/client/qwaylandscreen.cpp b/src/client/qwaylandscreen.cpp
index 37fe5f323..892ef974b 100644
--- a/src/client/qwaylandscreen.cpp
+++ b/src/client/qwaylandscreen.cpp
@@ -58,6 +58,23 @@ QWaylandScreen::QWaylandScreen(QWaylandDisplay *waylandDisplay, int version, uin
     , mWaylandDisplay(waylandDisplay)
     , mOutputName(QStringLiteral("Screen%1").arg(id))
 {
+    if (auto *xdgOutputManager = waylandDisplay->xdgOutputManager())
+        initXdgOutput(xdgOutputManager);
+}
+
+QWaylandScreen::~QWaylandScreen()
+{
+    if (zxdg_output_v1::isInitialized())
+        zxdg_output_v1::destroy();
+}
+
+void QWaylandScreen::initXdgOutput(QtWayland::zxdg_output_manager_v1 *xdgOutputManager)
+{
+    Q_ASSERT(xdgOutputManager);
+    if (zxdg_output_v1::isInitialized())
+        return;
+
+    zxdg_output_v1::init(xdgOutputManager->get_xdg_output(wl_output::object()));
 }
 
 QWaylandDisplay * QWaylandScreen::display() const
@@ -77,9 +94,13 @@ QString QWaylandScreen::model() const
 
 QRect QWaylandScreen::geometry() const
 {
-    // Scale geometry for QScreen. This makes window and screen
-    // geometry be in the same coordinate system.
-    return QRect(mGeometry.topLeft(), mGeometry.size() / mScale);
+    if (zxdg_output_v1::isInitialized()) {
+        return mXdgGeometry;
+    } else {
+        // Scale geometry for QScreen. This makes window and screen
+        // geometry be in the same coordinate system.
+        return QRect(mGeometry.topLeft(), mGeometry.size() / mScale);
+    }
 }
 
 int QWaylandScreen::depth() const
@@ -184,7 +205,6 @@ void QWaylandScreen::output_mode(uint32_t flags, int width, int height, int refr
         return;
 
     QSize size(width, height);
-
     if (size != mGeometry.size())
         mGeometry.setSize(size);
 
@@ -247,8 +267,25 @@ void QWaylandScreen::output_done()
         QWindowSystemInterface::handleScreenOrientationChange(screen(), m_orientation);
         mTransform = -1;
     }
-    QWindowSystemInterface::handleScreenGeometryChange(screen(), geometry(), geometry());
     QWindowSystemInterface::handleScreenRefreshRateChange(screen(), refreshRate());
+    if (!zxdg_output_v1::isInitialized())
+        QWindowSystemInterface::handleScreenGeometryChange(screen(), geometry(), geometry());
+}
+
+
+void QWaylandScreen::zxdg_output_v1_logical_position(int32_t x, int32_t y)
+{
+    mXdgGeometry.moveTopLeft(QPoint(x, y));
+}
+
+void QWaylandScreen::zxdg_output_v1_logical_size(int32_t width, int32_t height)
+{
+    mXdgGeometry.setSize(QSize(width, height));
+}
+
+void QWaylandScreen::zxdg_output_v1_done()
+{
+    QWindowSystemInterface::handleScreenGeometryChange(screen(), geometry(), geometry());
 }
 
 }
diff --git a/src/client/qwaylandscreen_p.h b/src/client/qwaylandscreen_p.h
index 39b72bc24..6e4ed94f7 100644
--- a/src/client/qwaylandscreen_p.h
+++ b/src/client/qwaylandscreen_p.h
@@ -55,6 +55,8 @@
 #include <QtWaylandClient/qtwaylandclientglobal.h>
 
 #include <QtWaylandClient/private/qwayland-wayland.h>
+#include <QtWaylandClient/private/qwayland-xdg-output-unstable-v1.h>
+
 
 QT_BEGIN_NAMESPACE
 
@@ -63,10 +65,13 @@ namespace QtWaylandClient {
 class QWaylandDisplay;
 class QWaylandCursor;
 
-class Q_WAYLAND_CLIENT_EXPORT QWaylandScreen : public QPlatformScreen, QtWayland::wl_output
+class Q_WAYLAND_CLIENT_EXPORT QWaylandScreen : public QPlatformScreen, QtWayland::wl_output, QtWayland::zxdg_output_v1
 {
 public:
     QWaylandScreen(QWaylandDisplay *waylandDisplay, int version, uint32_t id);
+    ~QWaylandScreen() override;
+
+    void initXdgOutput(QtWayland::zxdg_output_manager_v1 *xdgOutputManager);
 
     QWaylandDisplay *display() const;
 
@@ -97,7 +102,7 @@ public:
 #endif
 
     uint32_t outputId() const { return m_outputId; }
-    ::wl_output *output() { return object(); }
+    ::wl_output *output() { return QtWayland::wl_output::object(); }
 
     static QWaylandScreen *waylandScreenFromWindow(QWindow *window);
     static QWaylandScreen *fromWlOutput(::wl_output *output);
@@ -113,11 +118,17 @@ private:
     void output_scale(int32_t factor) override;
     void output_done() override;
 
+    // XdgOutput
+    void zxdg_output_v1_logical_position(int32_t x, int32_t y) override;
+    void zxdg_output_v1_logical_size(int32_t width, int32_t height) override;
+    void zxdg_output_v1_done() override;
+
     int m_outputId;
     QWaylandDisplay *mWaylandDisplay = nullptr;
     QString mManufacturer;
     QString mModel;
     QRect mGeometry;
+    QRect mXdgGeometry;
     int mScale = 1;
     int mDepth = 32;
     int mRefreshRate = 60000;