ILXQtTaskbarAbstractBackend: add dummy implementation

This will be used to avoid crashing panel in case no backend could be
created.
A warning message will be printed in this case.

panel/CMakeLists.txt

@@ -25,6 +25,7 @@ set(PRIV_HEADERS
     backends/ilxqttaskbarabstractbackend.h
     backends/lxqttaskbartypes.h
 
+    backends/lxqttaskbardummybackend.h
     backends/xcb/lxqttaskbarbackend_x11.h
 )
 
@@ -59,6 +60,7 @@ set(SOURCES
 
     backends/ilxqttaskbarabstractbackend.cpp
 
+    backends/lxqttaskbardummybackend.cpp
     backends/xcb/lxqttaskbarbackend_x11.cpp
 )
 

panel/backends/lxqttaskbardummybackend.cpp

@@ -0,0 +1,156 @@
+#include "lxqttaskbardummybackend.h"
+
+#include <QIcon>
+
+LXQtTaskBarDummyBackend::LXQtTaskBarDummyBackend(QObject *parent)
+    : ILXQtTaskbarAbstractBackend(parent)
+{
+
+}
+
+
+/************************************************
+ *   Windows function
+ ************************************************/
+bool LXQtTaskBarDummyBackend::supportsAction(WId, LXQtTaskBarBackendAction) const
+{
+    return false;
+}
+
+bool LXQtTaskBarDummyBackend::reloadWindows()
+{
+    return false;
+}
+
+QVector<WId> LXQtTaskBarDummyBackend::getCurrentWindows() const
+{
+    return {};
+}
+
+QString LXQtTaskBarDummyBackend::getWindowTitle(WId) const
+{
+    return QString();
+}
+
+bool LXQtTaskBarDummyBackend::applicationDemandsAttention(WId) const
+{
+    return false;
+}
+
+QIcon LXQtTaskBarDummyBackend::getApplicationIcon(WId, int) const
+{
+    return QIcon();
+}
+
+QString LXQtTaskBarDummyBackend::getWindowClass(WId) const
+{
+    return QString();
+}
+
+LXQtTaskBarWindowLayer LXQtTaskBarDummyBackend::getWindowLayer(WId) const
+{
+    return LXQtTaskBarWindowLayer::Normal;
+}
+
+bool LXQtTaskBarDummyBackend::setWindowLayer(WId, LXQtTaskBarWindowLayer)
+{
+    return false;
+}
+
+LXQtTaskBarWindowState LXQtTaskBarDummyBackend::getWindowState(WId) const
+{
+    return LXQtTaskBarWindowState::Normal;
+}
+
+bool LXQtTaskBarDummyBackend::setWindowState(WId, LXQtTaskBarWindowState, bool)
+{
+    return false;
+}
+
+bool LXQtTaskBarDummyBackend::isWindowActive(WId) const
+{
+    return false;
+}
+
+bool LXQtTaskBarDummyBackend::raiseWindow(WId, bool)
+{
+    return false;
+}
+
+bool LXQtTaskBarDummyBackend::closeWindow(WId)
+{
+    return false;
+}
+
+WId LXQtTaskBarDummyBackend::getActiveWindow() const
+{
+    return 0;
+}
+
+
+/************************************************
+ *   Workspaces
+ ************************************************/
+int LXQtTaskBarDummyBackend::getWorkspacesCount() const
+{
+    return 1; // Fake 1 workspace
+}
+
+QString LXQtTaskBarDummyBackend::getWorkspaceName(int) const
+{
+    return QString();
+}
+
+int LXQtTaskBarDummyBackend::getCurrentWorkspace() const
+{
+    return 0;
+}
+
+bool LXQtTaskBarDummyBackend::setCurrentWorkspace(int)
+{
+    return false;
+}
+
+int LXQtTaskBarDummyBackend::getWindowWorkspace(WId) const
+{
+    return 0;
+}
+
+bool LXQtTaskBarDummyBackend::setWindowOnWorkspace(WId, int)
+{
+    return false;
+}
+
+void LXQtTaskBarDummyBackend::moveApplicationToPrevNextMonitor(WId, bool, bool)
+{
+    //No-op
+}
+
+bool LXQtTaskBarDummyBackend::isWindowOnScreen(QScreen *, WId) const
+{
+    return false;
+}
+
+/************************************************
+ *   X11 Specific
+ ************************************************/
+void LXQtTaskBarDummyBackend::moveApplication(WId)
+{
+    //No-op
+}
+
+void LXQtTaskBarDummyBackend::resizeApplication(WId)
+{
+    //No-op
+}
+
+void LXQtTaskBarDummyBackend::refreshIconGeometry(WId, QRect const &)
+{
+    //No-op
+}
+
+bool LXQtTaskBarDummyBackend::isAreaOverlapped(const QRect &) const
+{
+    return false;
+}
+

panel/backends/lxqttaskbardummybackend.h

@@ -0,0 +1,82 @@
+#ifndef LXQTTASKBARDUMMYBACKEND_H
+#define LXQTTASKBARDUMMYBACKEND_H
+
+#include "ilxqttaskbarabstractbackend.h"
+
+class LXQtTaskBarDummyBackend : public ILXQtTaskbarAbstractBackend
+{
+    Q_OBJECT
+
+public:
+    explicit LXQtTaskBarDummyBackend(QObject *parent = nullptr);
+
+    // Backend
+    bool supportsAction(WId windowId, LXQtTaskBarBackendAction action) const override;
+
+    // Windows
+    bool reloadWindows() override;
+
+    QVector<WId> getCurrentWindows() const override;
+
+    QString getWindowTitle(WId windowId) const override;
+
+    bool applicationDemandsAttention(WId windowId) const override;
+
+    QIcon getApplicationIcon(WId windowId, int fallbackDevicePixels) const override;
+
+    QString getWindowClass(WId windowId) const override;
+
+    LXQtTaskBarWindowLayer getWindowLayer(WId windowId) const override;
+    bool setWindowLayer(WId windowId, LXQtTaskBarWindowLayer layer) override;
+
+    LXQtTaskBarWindowState getWindowState(WId windowId) const override;
+    bool setWindowState(WId windowId, LXQtTaskBarWindowState state, bool set = true) override;
+
+    bool isWindowActive(WId windowId) const override;
+    bool raiseWindow(WId windowId, bool onCurrentWorkSpace) override;
+
+    bool closeWindow(WId windowId) override;
+
+    WId getActiveWindow() const override;
+
+    // Workspaces
+    int getWorkspacesCount() const override;
+    QString getWorkspaceName(int idx) const override;
+
+    int getCurrentWorkspace() const override;
+    bool setCurrentWorkspace(int idx) override;
+
+    int getWindowWorkspace(WId windowId) const override;
+    bool setWindowOnWorkspace(WId windowId, int idx) override;
+
+    void moveApplicationToPrevNextMonitor(WId windowId, bool next, bool raiseOnCurrentDesktop) override;
+
+    bool isWindowOnScreen(QScreen *screen, WId windowId) const override;
+
+    // X11 Specific
+    void moveApplication(WId windowId) override;
+    void resizeApplication(WId windowId) override;
+
+    void refreshIconGeometry(WId windowId, const QRect &geom) override;
+
+    // Panel internal
+    bool isAreaOverlapped(const QRect& area) const override;
+
+signals:
+    void reloaded();
+
+    // Windows
+    void windowAdded(WId windowId);
+    void windowRemoved(WId windowId);
+    void windowPropertyChanged(WId windowId, int prop);
+
+    // Workspaces
+    void workspacesCountChanged();
+    void workspaceNameChanged(int idx);
+    void currentWorkspaceChanged(int idx);
+
+    // TODO: needed?
+    void activeWindowChanged(WId windowId);
+};
+
+#endif // LXQTTASKBARDUMMYBACKEND_H

panel/lxqtpanelapplication.cpp

@@ -36,6 +36,7 @@
 #include "lxqtpanelapplication_p.h"
 #include <LXQt/Settings>
 
+#include "backends/lxqttaskbardummybackend.h"
 #include "backends/xcb/lxqttaskbarbackend_x11.h"
 
 #include <chrono>
@@ -47,8 +48,13 @@ ILXQtTaskbarAbstractBackend *createWMBackend()
     if(qGuiApp->nativeInterface<QNativeInterface::QX11Application>())
         return new LXQtTaskbarX11Backend;
 
-    Q_ASSERT_X(false, "createWMBackend()", "Only X11 supported!");
-    return nullptr;
+    qWarning() << "\n"
+               << "ERROR: Could not create a backend for window managment operations.\n"
+               << "Only X11 supported!\n"
+               << "Falling back to dummy backend. Some functions will not be available.\n"
+               << "\n";
+
+    return new LXQtTaskBarDummyBackend;
 }
 
 LXQtPanelApplicationPrivate::LXQtPanelApplicationPrivate(LXQtPanelApplication *q)