fix: screen capture for KDE on Wayland

src/core/UBApplicationController.cpp

@@ -620,6 +620,19 @@ void UBApplicationController::hideDesktop()
     emit desktopMode(false);
 }
 
+void UBApplicationController::showGlassPane(bool show)
+{
+    if (isShowingDesktop())
+    {
+        uninotesController()->drawingView()->setVisible(show);
+
+        if (show)
+        {
+            UBPlatformUtils::keepOnTop();
+        }
+    }
+}
+
 void UBApplicationController::setMirrorSourceWidget(QWidget* pWidget)
 {
     if (mMirror)

src/core/UBApplicationController.h

@@ -132,8 +132,8 @@ class UBApplicationController : public QObject
 
         // defaulting to false to match QAction triggered(bool checked = false)
         void showDesktop(bool dontSwitchFrontProcess = false);
-
         void hideDesktop();
+        void showGlassPane(bool show);
 
         void useMultiScreen(bool use);
 

src/core/UBDisplayManager.cpp

@@ -672,18 +672,13 @@ qreal UBDisplayManager::logicalDpi(ScreenRole role) const
     return scr ? scr->logicalDotsPerInch() : 96.;
 }
 
-void UBDisplayManager::grab(ScreenRole role, std::function<void (QPixmap)> callback, QRect rect) const
+void UBDisplayManager::grab(ScreenRole role, std::function<void (QPixmap)> callback, bool crop) const
 {
     QScreen* scr = screen(role);
 
     if (scr)
     {
-        if (!rect.isValid())
-        {
-            rect = QRect(QPoint(0, 0), scr->geometry().size());
-        }
-
-        UBPlatformUtils::grabScreen(scr, callback, rect);
+        UBPlatformUtils::grabScreen(scr, callback, crop);
     }
     else
     {

src/core/UBDisplayManager.h

@@ -107,7 +107,7 @@ class UBDisplayManager : public QObject
         qreal physicalDpi(ScreenRole role) const;
         qreal logicalDpi(ScreenRole role) const;
 
-        void grab(ScreenRole role, std::function<void(QPixmap)> callback, QRect rect = {}) const;
+        void grab(ScreenRole role, std::function<void(QPixmap)> callback, bool crop = false) const;
         QPixmap grabGlobal(QRect rect) const;
 
         void initScreensByRole();

src/desktop/UBDesktopAnnotationController.cpp

@@ -359,13 +359,7 @@ void UBDesktopAnnotationController::showWindow()
 
     UBDrawingController::drawingController()->setStylusTool(mDesktopStylusTool);
 
-#ifndef Q_OS_LINUX
     UBPlatformUtils::showFullScreen(mTransparentDrawingView);
-#else
-    // this is necessary to avoid hiding the panels on Unity and Cinnamon
-    // if finer control is necessary, use qgetenv("XDG_CURRENT_DESKTOP")
-    mTransparentDrawingView->show();
-#endif
     UBPlatformUtils::hideMenuBarAndDock();
 
     mDesktopPalette->appear();
@@ -470,7 +464,9 @@ void UBDesktopAnnotationController::customCapture()
 
         mDesktopPalette->disappearForCapture();
 
-        getScreenPixmap([this](QPixmap pixmap){
+        const auto grabCanCrop = UBPlatformUtils::grabCanCrop();
+
+        getScreenPixmap([this, grabCanCrop](QPixmap pixmap){
             auto finishCapture = [this](){
                 mDesktopPalette->appear();
                 mCustomCaptureClicked = false;
@@ -481,7 +477,7 @@ void UBDesktopAnnotationController::customCapture()
             QPixmap screenshot = pixmap.isNull() ? clipboardScreenshot() : pixmap;
 
             // On Wayland with xdg-desktop-portal, the user already chose the area.
-            if (UBPlatformUtils::sessionType() == UBPlatformUtils::WAYLAND && !screenshot.isNull())
+            if (grabCanCrop && !screenshot.isNull())
             {
                 emit imageCaptured(screenshot, false);
                 finishCapture();
@@ -497,7 +493,7 @@ void UBDesktopAnnotationController::customCapture()
             }
 
             finishCapture();
-        });
+        }, grabCanCrop);
     }
 }
 
@@ -519,22 +515,15 @@ void UBDesktopAnnotationController::screenCapture()
 
         QPixmap screenshot = pixmap.isNull() ? clipboardScreenshot() : pixmap;
 
-        if (UBPlatformUtils::sessionType() == UBPlatformUtils::WAYLAND && !screenshot.isNull())
-        {
-            emit imageCaptured(screenshot, false);
-            finishCapture();
-            return;
-        }
-
         emit imageCaptured(screenshot, false);
         finishCapture();
-    });
+    }, false);
 }
 
 
-void UBDesktopAnnotationController::getScreenPixmap(std::function<void(QPixmap)> callback)
+void UBDesktopAnnotationController::getScreenPixmap(std::function<void(QPixmap)> callback, bool crop)
 {
-    UBApplication::displayManager->grab(ScreenRole::Control, callback);
+    UBApplication::displayManager->grab(ScreenRole::Control, callback, crop);
 }
 
 

src/desktop/UBDesktopAnnotationController.h

@@ -99,7 +99,7 @@ class UBDesktopAnnotationController : public QObject
         void restoreUniboard();
 
     protected:
-        void getScreenPixmap(std::function<void (QPixmap)> callback);
+        void getScreenPixmap(std::function<void (QPixmap)> callback, bool crop);
 
         UBBoardView* mTransparentDrawingView;       
         std::shared_ptr<UBGraphicsScene> mTransparentDrawingScene;

src/frameworks/CMakeLists.txt

@@ -23,10 +23,14 @@ target_sources(openboard PRIVATE
 
 if(CMAKE_SYSTEM_NAME STREQUAL Linux)
     target_sources(openboard PRIVATE
-        UBDesktopPortal.cpp
-        UBDesktopPortal.h
-        UBPipewireSink.cpp
-        UBPipewireSink.h
+        linux/UBScreenCastDesktopPortalWrapper.cpp
+        linux/UBScreenCastDesktopPortalWrapper.h
+        linux/UBScreenshotDesktopPortalWrapper.cpp
+        linux/UBScreenshotDesktopPortalWrapper.h
+        linux/UBDesktopPortalTokenGenerator.cpp
+        linux/UBDesktopPortalTokenGenerator.h
+        linux/UBPipewireSink.cpp
+        linux/UBPipewireSink.h
         UBPlatformUtils_linux.cpp
     )
 endif()

src/frameworks/UBPlatformUtils.h

@@ -213,7 +213,8 @@ class UBPlatformUtils
         static void setFrontProcess();
         static void showFullScreen(QWidget * pWidget);
         static void showOSK(bool show);
-        static void grabScreen(QScreen* screen, std::function<void(QPixmap)> callback, QRect rect = {});
+        static void grabScreen(QScreen* screen, std::function<void(QPixmap)> callback, bool crop = false);
+        static bool grabCanCrop();
 
 #ifdef Q_OS_OSX
         static void SetMacLocaleByIdentifier(const QString& id);

src/frameworks/UBPlatformUtils_linux.cpp

@@ -36,7 +36,7 @@
 
 #include <unistd.h>
 
-#include "frameworks/UBDesktopPortal.h"
+#include "frameworks/linux/UBScreenshotDesktopPortalWrapper.h"
 #include "frameworks/UBFileSystemUtils.h"
 #include "core/UBApplication.h"
 #include "core/UBDisplayManager.h"
@@ -45,6 +45,40 @@
 
 static OnboardListener* listener = nullptr;
 
+// utility function to detect desktop environment
+enum DesktopEnvironment
+{
+    UNKNOWN,
+    GNOME,
+    KDE,
+    OTHER
+};
+
+static DesktopEnvironment desktopEnvironment()
+{
+    static DesktopEnvironment desktop{UNKNOWN};
+
+    if (desktop == UNKNOWN)
+    {
+        const auto xdgCurrentDesktop{QProcessEnvironment::systemEnvironment().value("XDG_CURRENT_DESKTOP", "")};
+
+        if (xdgCurrentDesktop.compare("gnome", Qt::CaseInsensitive) == 0)
+        {
+            desktop = GNOME;
+        }
+        else if (xdgCurrentDesktop.compare("kde", Qt::CaseInsensitive) == 0)
+        {
+            desktop = KDE;
+        }
+        else
+        {
+            desktop = OTHER;
+        }
+    }
+
+    return desktop;
+}
+
 void UBPlatformUtils::init()
 {
     initializeKeyboardLayouts();
@@ -535,28 +569,33 @@ void UBPlatformUtils::showOSK(bool show)
     }
 }
 
-void UBPlatformUtils::grabScreen(QScreen* screen, std::function<void (QPixmap)> callback, QRect rect)
+void UBPlatformUtils::grabScreen(QScreen* screen, std::function<void (QPixmap)> callback, bool crop)
 {
     if (sessionType() == WAYLAND)
     {
-        UBDesktopPortal* portal = new UBDesktopPortal;
+        auto* portal = new UBScreenshotDesktopPortalWrapper;
 
-        QObject::connect(portal, &UBDesktopPortal::screenGrabbed, portal, [portal,callback](QPixmap screenshot){
+        QObject::connect(portal, &UBScreenshotDesktopPortalWrapper::screenGrabbed, portal, [portal,callback](QPixmap screenshot){
             callback(screenshot);
             portal->deleteLater();
         });
 
-        portal->grabScreen(screen, rect);
+        portal->grabScreen(screen, crop);
     }
     else
     {
         // see https://doc.qt.io/qt-6.2/qtwidgets-desktop-screenshot-example.html
         // for using window id 0
-        QPixmap pixmap = screen->grabWindow(0, rect.x(), rect.y(), rect.width(), rect.height());
+        QPixmap pixmap = screen->grabWindow(0);
         callback(pixmap);
     }
 }
 
+bool UBPlatformUtils::grabCanCrop()
+{
+    return sessionType() == WAYLAND && desktopEnvironment() == GNOME;
+}
+
 UBPlatformUtils::SessionType UBPlatformUtils::sessionType()
 {
     /*
@@ -596,7 +635,9 @@ void UBPlatformUtils::keepOnTop()
                 return;
             }
 
-            auto path = "/" + result.arguments().first().toString();
+            const auto kdeSesionVersion = QProcessEnvironment::systemEnvironment().value("KDE_SESSION_VERSION", "0").toInt();
+            const auto prefix = kdeSesionVersion <= 5 ? "/" : "/Scripting/Script";
+            const auto path = prefix + result.arguments().first().toString();
 
             QDBusInterface script("org.kde.KWin", path);
             script.call("run");

src/frameworks/UBPlatformUtils_mac.mm

@@ -752,8 +752,14 @@ click menu item (nbItems - 4)\n\
     }
 }
 
-void UBPlatformUtils::grabScreen(QScreen* screen, std::function<void (QPixmap)> callback, QRect rect)
+void UBPlatformUtils::grabScreen(QScreen* screen, std::function<void (QPixmap)> callback, bool crop)
 {
-    QPixmap pixmap = screen->grabWindow(0, rect.x(), rect.y(), rect.width(), rect.height());
+    Q_UNUSED(crop)
+    QPixmap pixmap = screen->grabWindow(0);
     callback(pixmap);
 }
+
+bool UBPlatformUtils::grabCanCrop()
+{
+    return false;
+}

src/frameworks/UBPlatformUtils_win.cpp

@@ -495,8 +495,14 @@ void UBPlatformUtils::showOSK(bool show)
     }
 }
 
-void UBPlatformUtils::grabScreen(QScreen* screen, std::function<void (QPixmap)> callback, QRect rect)
+void UBPlatformUtils::grabScreen(QScreen* screen, std::function<void (QPixmap)> callback, bool crop)
 {
-    QPixmap pixmap = screen->grabWindow(0, rect.x(), rect.y(), rect.width(), rect.height());
+    Q_UNUSED(crop)
+    QPixmap pixmap = screen->grabWindow(0);
     callback(pixmap);
 }
+
+bool UBPlatformUtils::grabCanCrop()
+{
+    return false;
+}

src/frameworks/frameworks.pri

@@ -25,22 +25,24 @@ SOURCES      += src/frameworks/UBGeometryUtils.cpp \
 win32 {
 
     SOURCES  += src/frameworks/UBPlatformUtils_win.cpp
-}            
+}
 
 
-macx {                
+macx {
 
     OBJECTIVE_SOURCES  += src/frameworks/UBPlatformUtils_mac.mm
-                
-}       
+
+}
 
 
 linux-g++* {
-    HEADERS  += src/frameworks/UBDesktopPortal.h \
-                src/frameworks/UBPipewireSink.h
+    HEADERS  += src/frameworks/linux/UBScreenCastDesktopPortalWrapper.h \
+                src/frameworks/linux/UBScreenshotDesktopPortalWrapper.h \
+                src/frameworks/linux/UBPipewireSink.h
     SOURCES  += src/frameworks/UBPlatformUtils_linux.cpp \
-                src/frameworks/UBDesktopPortal.cpp \
-                src/frameworks/UBPipewireSink.cpp
+                src/frameworks/linux/UBScreenCastDesktopPortalWrapper.cpp \
+                src/frameworks/linux/UBScreenshotDesktopPortalWrapper.cpp \
+                src/frameworks/linux/UBPipewireSink.cpp
 
     CONFIG += link_pkgconfig
     PKGCONFIG += libpipewire-0.3

src/frameworks/linux/UBDesktopPortalTokenGenerator.cpp

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2015-2026 Département de l'Instruction Publique (DIP-SEM)
+ *
+ * This file is part of OpenBoard.
+ *
+ * OpenBoard is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3 of the License,
+ * with a specific linking exception for the OpenSSL project's
+ * "OpenSSL" library (or with modified versions of it that use the
+ * same license as the "OpenSSL" library).
+ *
+ * OpenBoard is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with OpenBoard. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#include "UBDesktopPortalTokenGenerator.h"
+
+#include <QRandomGenerator>
+
+
+QString UBDesktopPortalTokenGenerator::generateToken()
+{
+    const auto randomValue = QRandomGenerator::global()->generate();
+    return "OB_" + QString::number(randomValue, 16);
+}