Introduce X11 default screen property in Application

This spares unnecessary looping through all available X11 screens.

autotests/integration/desktop_window_x11_test.cpp

@@ -124,7 +124,7 @@ void X11DesktopWindowTest::testDesktopWindow()
     auto cmCookie = xcb_create_colormap_checked(c.data(), XCB_COLORMAP_ALLOC_NONE, colormapId, rootWindow(), visualId);
     QVERIFY(!xcb_request_check(c.data(), cmCookie));
 
-    const uint32_t values[] = {XCB_PIXMAP_NONE, defaultScreen()->black_pixel, colormapId};
+    const uint32_t values[] = {XCB_PIXMAP_NONE, kwinApp()->x11DefaultScreen()->black_pixel, colormapId};
     auto cookie = xcb_create_window_checked(c.data(), 32, w, rootWindow(),
                       windowGeometry.x(),
                       windowGeometry.y(),

autotests/integration/scene_qpainter_test.cpp

@@ -327,7 +327,7 @@ void SceneQPainterTest::testX11Window()
     QVERIFY(!xcb_connection_has_error(c.data()));
     const QRect windowGeometry(0, 0, 100, 200);
     xcb_window_t w = xcb_generate_id(c.data());
-    uint32_t value = defaultScreen()->white_pixel;
+    uint32_t value = kwinApp()->x11DefaultScreen()->white_pixel;
     xcb_create_window(c.data(), XCB_COPY_FROM_PARENT, w, rootWindow(),
                       windowGeometry.x(),
                       windowGeometry.y(),

autotests/integration/xwaylandserver_test.cpp

@@ -129,6 +129,7 @@ void XwaylandServerTest::testCrash()
     QTRY_VERIFY(!client);
     QTRY_VERIFY(!unmanaged);
     QCOMPARE(kwinApp()->x11Connection(), nullptr);
+    QCOMPARE(kwinApp()->x11DefaultScreen(), nullptr);
     QCOMPARE(kwinApp()->x11RootWindow(), XCB_WINDOW_NONE);
     QCOMPARE(kwinApp()->x11ScreenNumber(), -1);
 }

libkwineffects/kwinglobals.h

@@ -167,38 +167,6 @@ KWIN_EXPORT xcb_timestamp_t xTime()
     return qApp->property("x11Time").value<xcb_timestamp_t>();
 }
 
-inline
-KWIN_EXPORT xcb_screen_t *defaultScreen()
-{
-    xcb_connection_t *c = connection();
-    if (!c) {
-        return nullptr;
-    }
-    int screen = qApp->property("x11ScreenNumber").toInt();
-    for (xcb_screen_iterator_t it = xcb_setup_roots_iterator(xcb_get_setup(c));
-            it.rem;
-            --screen, xcb_screen_next(&it)) {
-        if (screen == 0) {
-            return it.data;
-        }
-    }
-    return nullptr;
-}
-
-inline
-KWIN_DEPRECATED_EXPORT int displayWidth()
-{
-    xcb_screen_t *screen = defaultScreen();
-    return screen ? screen->width_in_pixels : 0;
-}
-
-inline
-KWIN_DEPRECATED_EXPORT int displayHeight()
-{
-    xcb_screen_t *screen = defaultScreen();
-    return screen ? screen->height_in_pixels : 0;
-}
-
 /**
  * Short wrapper for a cursor image provided by the Platform.
  * @since 5.9

main.h

@@ -162,6 +162,13 @@ public:
         return m_connection;
     }
 
+    /**
+     * @returns the X11 default screen
+     */
+    xcb_screen_t *x11DefaultScreen() const {
+        return m_defaultScreen;
+    }
+
 #ifdef KWIN_BUILD_ACTIVITIES
     bool usesKActivities() const {
         return m_useKActivities;
@@ -224,6 +231,13 @@ protected:
     void setX11Connection(xcb_connection_t *c) {
         m_connection = c;
     }
+    /**
+     * Inheriting classes should use this method to set the default screen
+     * before accessing any X11 specific code pathes.
+     */
+    void setX11DefaultScreen(xcb_screen_t *screen) {
+        m_defaultScreen = screen;
+    }
     void destroyAtoms();
     void destroyPlatform();
 
@@ -246,6 +260,7 @@ private:
     xcb_timestamp_t m_x11Time = XCB_TIME_CURRENT_TIME;
     xcb_window_t m_rootWindow = XCB_WINDOW_NONE;
     xcb_connection_t *m_connection = nullptr;
+    xcb_screen_t *m_defaultScreen = nullptr;
 #ifdef KWIN_BUILD_ACTIVITIES
     bool m_useKActivities = true;
 #endif

main_x11.cpp

@@ -208,6 +208,19 @@ void ApplicationX11::lostSelection()
     quit();
 }
 
+
+static xcb_screen_t *findXcbScreen(xcb_connection_t *connection, int screen)
+{
+    for (xcb_screen_iterator_t it = xcb_setup_roots_iterator(xcb_get_setup(connection));
+            it.rem;
+            --screen, xcb_screen_next(&it)) {
+        if (screen == 0) {
+            return it.data;
+        }
+    }
+    return nullptr;
+}
+
 void ApplicationX11::performStartup()
 {
     crashChecking();
@@ -215,6 +228,7 @@ void ApplicationX11::performStartup()
     if (Application::x11ScreenNumber() == -1) {
         Application::setX11ScreenNumber(QX11Info::appScreen());
     }
+    setX11DefaultScreen(findXcbScreen(x11Connection(), x11ScreenNumber()));
 
     owner.reset(new KWinSelectionOwner(Application::x11ScreenNumber()));
     connect(owner.data(), &KSelectionOwner::failedToClaimOwnership, []{

plugins/platforms/x11/standalone/screens_xrandr.cpp

@@ -78,7 +78,7 @@ bool XRandRScreens::event(xcb_generic_event_t *event)
 
     // update default screen
     auto *xrrEvent = reinterpret_cast<xcb_randr_screen_change_notify_event_t*>(event);
-    xcb_screen_t *screen = defaultScreen();
+    xcb_screen_t *screen = kwinApp()->x11DefaultScreen();
     if (xrrEvent->rotation & (XCB_RANDR_ROTATION_ROTATE_90 | XCB_RANDR_ROTATION_ROTATE_270)) {
         screen->width_in_pixels = xrrEvent->height;
         screen->height_in_pixels = xrrEvent->width;
@@ -96,7 +96,7 @@ bool XRandRScreens::event(xcb_generic_event_t *event)
 
 QSize XRandRScreens::displaySize() const
 {
-    xcb_screen_t *screen = defaultScreen();
+    xcb_screen_t *screen = kwinApp()->x11DefaultScreen();
     if (!screen) {
         return Screens::size();
     }

plugins/platforms/x11/standalone/x11cursor.cpp

@@ -165,7 +165,7 @@ xcb_cursor_t X11Cursor::createCursor(const QByteArray &name)
         return XCB_CURSOR_NONE;
     }
     xcb_cursor_context_t *ctx;
-    if (xcb_cursor_context_new(connection(), defaultScreen(), &ctx) < 0) {
+    if (xcb_cursor_context_new(kwinApp()->x11Connection(), kwinApp()->x11DefaultScreen(), &ctx) < 0) {
         return XCB_CURSOR_NONE;
     }
     xcb_cursor_t cursor = xcb_cursor_load_cursor(ctx, name.constData());

plugins/scenes/xrender/scene_xrender.cpp

@@ -162,7 +162,7 @@ void X11XRenderBackend::init(bool createOverlay)
         xcb_render_create_picture(connection(), m_front, m_overlayWindow->window(), m_format, 0, nullptr);
     } else {
         // create XRender picture for the root window
-        m_format = XRenderUtils::findPictFormat(defaultScreen()->root_visual);
+        m_format = XRenderUtils::findPictFormat(kwinApp()->x11DefaultScreen()->root_visual);
         if (m_format == 0) {
             setFailed("Failed to find XRender format for root window");
             return; // error

workspace.cpp

@@ -79,8 +79,8 @@ extern bool is_multihead;
 
 ColorMapper::ColorMapper(QObject *parent)
     : QObject(parent)
-    , m_default(defaultScreen()->default_colormap)
+    , m_default(kwinApp()->x11DefaultScreen()->default_colormap)
-    , m_installed(defaultScreen()->default_colormap)
+    , m_installed(kwinApp()->x11DefaultScreen()->default_colormap)
 {
 }
 

xwl/clipboard.cpp

@@ -61,7 +61,7 @@ Clipboard::Clipboard(xcb_atom_t atom, QObject *parent)
                       10, 10,
                       0,
                       XCB_WINDOW_CLASS_INPUT_OUTPUT,
-                      Xwayland::self()->xcbScreen()->root_visual,
+                      XCB_COPY_FROM_PARENT,
                       XCB_CW_EVENT_MASK,
                       clipboardValues);
     registerXfixes();

xwl/dnd.cpp

@@ -68,7 +68,7 @@ Dnd::Dnd(xcb_atom_t atom, QObject *parent)
                       8192, 8192,           // TODO: get current screen size and connect to changes
                       0,
                       XCB_WINDOW_CLASS_INPUT_OUTPUT,
-                      Xwayland::self()->xcbScreen()->root_visual,
+                      XCB_COPY_FROM_PARENT,
                       XCB_CW_EVENT_MASK,
                       dndValues);
     registerXfixes();

xwl/drag_x.cpp

@@ -304,7 +304,7 @@ WlVisit::WlVisit(AbstractClient *target, XToWlDrag *drag)
                       8192, 8192,           // TODO: get current screen size and connect to changes
                       0,
                       XCB_WINDOW_CLASS_INPUT_OUTPUT,
-                      Xwayland::self()->xcbScreen()->root_visual,
+                      XCB_COPY_FROM_PARENT,
                       XCB_CW_EVENT_MASK,
                       dndValues);
 

xwl/transfer.cpp

@@ -293,7 +293,7 @@ TransferXtoWl::TransferXtoWl(xcb_atom_t selection, xcb_atom_t target, qint32 fd,
                       10, 10,
                       0,
                       XCB_WINDOW_CLASS_INPUT_OUTPUT,
-                      Xwayland::self()->xcbScreen()->root_visual,
+                      XCB_COPY_FROM_PARENT,
                       XCB_CW_EVENT_MASK,
                       values);
     // convert selection

xwl/xwayland.cpp

@@ -281,13 +281,13 @@ void Xwayland::createX11Connection()
         return;
     }
 
-    xcb_screen_iterator_t iter = xcb_setup_roots_iterator(xcb_get_setup(connection));
+    xcb_screen_t *screen = xcb_setup_roots_iterator(xcb_get_setup(connection)).data;
-    m_xcbScreen = iter.data;
+    Q_ASSERT(screen);
-    Q_ASSERT(m_xcbScreen);
 
     m_app->setX11Connection(connection);
+    m_app->setX11DefaultScreen(screen);
     m_app->setX11ScreenNumber(0);
-    m_app->setX11RootWindow(defaultScreen()->root);
+    m_app->setX11RootWindow(screen->root);
 
     m_app->createAtoms();
     m_app->installNativeX11EventFilter();
@@ -313,11 +313,11 @@ void Xwayland::destroyX11Connection()
 
     xcb_disconnect(m_app->x11Connection());
 
-    m_xcbScreen = nullptr;
     m_xcbConnectionFd = -1;
     m_xfixes = nullptr;
 
     m_app->setX11Connection(nullptr);
+    m_app->setX11DefaultScreen(nullptr);
     m_app->setX11ScreenNumber(-1);
     m_app->setX11RootWindow(XCB_WINDOW_NONE);
 

xwl/xwayland.h

@@ -28,8 +28,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <xcb/xproto.h>
 
-class xcb_screen_t;
-
 namespace KWin
 {
 class ApplicationWaylandAbstract;
@@ -48,9 +46,6 @@ public:
     Xwayland(ApplicationWaylandAbstract *app, QObject *parent = nullptr);
     ~Xwayland() override;
 
-    xcb_screen_t *xcbScreen() const {
-        return m_xcbScreen;
-    }
     const xcb_query_extension_reply_t *xfixes() const {
         return m_xfixes;
     }
@@ -115,7 +110,6 @@ private:
     int m_displayFileDescriptor = -1;
     int m_xcbConnectionFd = -1;
     QProcess *m_xwaylandProcess = nullptr;
-    xcb_screen_t *m_xcbScreen = nullptr;
     const xcb_query_extension_reply_t *m_xfixes = nullptr;
     DataBridge *m_dataBridge = nullptr;
     QSocketNotifier *m_socketNotifier = nullptr;