fix(@desktop/general): Changing System Appearance on the fly is not working

This is corresponding dotherside part of the issue 1725.

So far we had kind of a memory leak, cause objects added to the filter were not
deleted ever. When the app is closing, it just removes filters, but doesn't
delete them.

I faced a logical issue, that we were sending qmlengine pointer to the
installEventFilter method, instead object which may or may not rely on the
qqmlengine instance, that is fixed also.

Fixes: #1725

vendor/DOtherSide/lib/CMakeLists.txt

@@ -20,7 +20,8 @@ macro(add_target name type)
         include/DOtherSide/DosIQAbstractItemModelImpl.h
         include/DOtherSide/DosQAbstractItemModel.h
         include/DOtherSide/Utils.h
-        include/DOtherSide/DosDockClicker.h
+        include/DOtherSide/StatusEvents/StatusDockShowAppEvent.h
+        include/DOtherSide/StatusEvents/StatusOSThemeEvent.h
         include/DOtherSide/DOtherSideStatusWindow.h
         include/DOtherSide/DOtherSideSingleInstance.h
         src/DOtherSide.cpp
@@ -31,7 +32,8 @@ macro(add_target name type)
         src/DosQObjectImpl.cpp
         src/DosQAbstractItemModel.cpp
         src/DosQQuickImageProvider.cpp
-        src/DosDockClicker.cpp
+        src/StatusEvents/StatusDockShowAppEvent.cpp
+        src/StatusEvents/StatusOSThemeEvent.cpp
         src/DOtherSideStatusWindow.cpp
         src/DOtherSideSingleInstance.cpp
     )

vendor/DOtherSide/lib/include/DOtherSide/DOtherSide.h

@@ -82,11 +82,11 @@ DOS_API void DOS_CALL dos_qguiapplication_delete(void);
 
 DOS_API void DOS_CALL dos_qguiapplication_icon(const char *filename);
 
-DOS_API void dos_qguiapplication_installEventFilter(DosQQmlApplicationEngine *vptr);
+DOS_API void dos_qguiapplication_installEventFilter(DosStatusEventObject *vptr);
 
 DOS_API void dos_qapplication_clipboard_setText(const char* text);
 
-DOS_API void dos_qapplication_installEventFilter(DosQQmlApplicationEngine *vptr);
+DOS_API void dos_qapplication_installEventFilter(DosStatusEventObject *vptr);
 
 /// @}
 
@@ -993,6 +993,11 @@ DOS_API void DOS_CALL dos_singleinstance_delete(DosSingleInstance *vptr);
 
 /// @}
 
+/// Status event object
+DOS_API DosStatusEventObject* dos_statusevent_create_showAppEvent(DosQQmlApplicationEngine* vptr);
+DOS_API DosStatusEventObject* dos_statusevent_create_osThemeEvent(DosQQmlApplicationEngine* vptr);
+DOS_API void dos_statusevent_delete(DosStatusEventObject* vptr);
+
 #ifdef __cplusplus
 }
 #endif

vendor/DOtherSide/lib/include/DOtherSide/DOtherSideTypes.h

@@ -98,6 +98,9 @@ typedef void DosPixmap;
 /// A pointer to SingleInstance
 typedef void DosSingleInstance;
 
+/// A pointer to a status event object which is actualy a QObject
+typedef void DosStatusEventObject;
+
 /// A pixmap callback to be supplied to an image provider
 /// \param id Image source id
 /// \param width pointer to the width of the image

vendor/DOtherSide/lib/include/DOtherSide/DosDockClicker.h

@@ -1,27 +0,0 @@
-#ifndef DOCKCLICKER_H
-#define DOCKCLICKER_H
-
-#include <QObject>
-
-#include <QQmlApplicationEngine>
-#include "DOtherSideTypes.h"
-
-class DockClicker : public QObject
-{
-    Q_OBJECT
-
-private:
-    Qt::ApplicationState _prevAppState;
-    QQmlApplicationEngine* _engine;
-
-protected:
-    bool eventFilter(QObject *obj, QEvent *event) override;
-
-public:
-    DockClicker(DosQQmlApplicationEngine *vptr) {
-        auto engine = static_cast<QQmlApplicationEngine *>(vptr);
-        _engine = engine;
-    }
-};
-
-#endif // DOCKCLICKER_H

vendor/DOtherSide/lib/include/DOtherSide/StatusEvents/StatusDockShowAppEvent.h

@@ -0,0 +1,24 @@
+#ifndef STATUS_DOCK_SHOW_APP_EVENT_H
+#define STATUS_DOCK_SHOW_APP_EVENT_H
+
+#include "../DOtherSideTypes.h"
+
+#include <QObject>
+#include <QQmlApplicationEngine>
+
+class StatusDockShowAppEvent : public QObject
+{
+    Q_OBJECT
+
+public:
+    StatusDockShowAppEvent(DosQQmlApplicationEngine* vptr, QObject* parent = nullptr);
+
+protected:
+    bool eventFilter(QObject* obj, QEvent* event) override;
+
+private:
+    Qt::ApplicationState m_prevAppState;
+    QQmlApplicationEngine* m_engine;
+};
+
+#endif

vendor/DOtherSide/lib/include/DOtherSide/StatusEvents/StatusOSThemeEvent.h

@@ -0,0 +1,23 @@
+#ifndef STATUS_OS_THEME_EVENT_H
+#define STATUS_OS_THEME_EVENT_H
+
+#include "../DOtherSideTypes.h"
+
+#include <QObject>
+#include <QQmlApplicationEngine>
+
+class StatusOSThemeEvent : public QObject
+{
+    Q_OBJECT
+
+public:
+    StatusOSThemeEvent(DosQQmlApplicationEngine* vptr, QObject* parent = nullptr);
+
+protected:
+    bool eventFilter(QObject* obj, QEvent* event) override;
+
+private:
+    QQmlApplicationEngine* m_engine;
+};
+
+#endif

vendor/DOtherSide/lib/src/DOtherSide.cpp

@@ -57,10 +57,12 @@
 #include "DOtherSide/DosQAbstractItemModel.h"
 #include "DOtherSide/DosQDeclarative.h"
 #include "DOtherSide/DosQQuickImageProvider.h"
-#include "DOtherSide/DosDockClicker.h"
 #include "DOtherSide/DOtherSideStatusWindow.h"
 #include "DOtherSide/DOtherSideSingleInstance.h"
 
+#include "DOtherSide/StatusEvents/StatusDockShowAppEvent.h"
+#include "DOtherSide/StatusEvents/StatusOSThemeEvent.h"
+
 namespace {
 
 void register_meta_types()
@@ -155,7 +157,8 @@ void dos_qguiapplication_exec()
 
 void dos_qguiapplication_quit()
 {
-    qGuiApp->quit();
+    // This way we will be safe for quitting the app (avoid potential crashes).
+    QMetaObject::invokeMethod(qGuiApp, "quit", Qt::QueuedConnection);
 }
 
 void dos_qguiapplication_icon(const char *filename)
@@ -163,10 +166,10 @@ void dos_qguiapplication_icon(const char *filename)
     qGuiApp->setWindowIcon(QIcon(filename));
 }
 
-void dos_qguiapplication_installEventFilter(::DosQQmlApplicationEngine *vptr)
+void dos_qguiapplication_installEventFilter(::DosStatusEventObject* vptr)
 {
-    DockClicker *dockClicker = new DockClicker(vptr);
+    auto qobject = static_cast<QObject*>(vptr);
-    qGuiApp->installEventFilter(dockClicker);
+    qGuiApp->installEventFilter(qobject);
 }
 
 void dos_qapplication_create()
@@ -196,13 +199,14 @@ void dos_qapplication_icon(const char *filename)
 
 void dos_qapplication_quit()
 {
-    qApp->quit();
+    // This way we will be safe for quitting the app (avoid potential crashes).
+    QMetaObject::invokeMethod(qApp, "quit", Qt::QueuedConnection);
 }
 
-void dos_qapplication_installEventFilter(::DosQQmlApplicationEngine *vptr)
+void dos_qapplication_installEventFilter(::DosStatusEventObject* vptr)
 {
-    DockClicker *dockClicker = new DockClicker(vptr);
+    auto qobject = static_cast<QObject*>(vptr);
-    qApp->installEventFilter(dockClicker);
+    qApp->installEventFilter(qobject);
 }
 
 ::DosQQmlApplicationEngine *dos_qqmlapplicationengine_create()
@@ -1313,3 +1317,21 @@ bool dos_singleinstance_isfirst(DosSingleInstance *vptr)
     }
     return false;
 }
+
+::DosStatusEventObject* dos_statusevent_create_showAppEvent(::DosQQmlApplicationEngine* vptr)
+{
+    auto engine = static_cast<QQmlApplicationEngine*>(vptr);
+    return new StatusDockShowAppEvent(engine);
+}
+
+::DosStatusEventObject* dos_statusevent_create_osThemeEvent(::DosQQmlApplicationEngine* vptr)
+{
+    auto engine = static_cast<QQmlApplicationEngine*>(vptr);
+    return new StatusOSThemeEvent(engine);
+}
+
+void dos_statusevent_delete(DosStatusEventObject* vptr)
+{
+    auto qobject = static_cast<QObject*>(vptr);
+    qobject->deleteLater();
+}

vendor/DOtherSide/lib/src/DosDockClicker.cpp

@@ -1,27 +0,0 @@
-#include "DOtherSide/DosDockClicker.h"
-
-#include <QQuickWindow>
-#include <QCoreApplication>
-
-
-bool DockClicker::eventFilter(QObject *obj, QEvent *event)
-{
-#ifdef Q_OS_MACOS
-    if (obj == qApp) {
-        if (event->type() == QEvent::ApplicationStateChange) {
-            auto ev = static_cast<QApplicationStateChangeEvent*>(event);
-            if (_prevAppState == Qt::ApplicationActive && ev->applicationState() == Qt::ApplicationActive) {
-                QObject *topLevel = _engine->rootObjects().value(0);
-                QQuickWindow *window = qobject_cast<QQuickWindow *>(topLevel);
-                window->setVisible(true);
-                window->showNormal();
-            }
-            _prevAppState = ev->applicationState();
-            return true;
-        } else {
-            return false;
-        }
-    }
-#endif // Q_OS_MACOS
-    return QObject::eventFilter(obj, event);
-}

vendor/DOtherSide/lib/src/StatusEvents/StatusDockShowAppEvent.cpp

@@ -0,0 +1,45 @@
+#include "DOtherSide/StatusEvents/StatusDockShowAppEvent.h"
+
+#include <QQuickWindow>
+
+
+/*
+    Code here is exactly the same as it was before, logic is not changed. I only 
+    put it in another form, nothing else. To match an improved flow for 
+    installing filters.
+*/
+
+StatusDockShowAppEvent::StatusDockShowAppEvent(DosQQmlApplicationEngine* vptr, 
+    QObject* parent)
+    : QObject(parent) 
+{
+    m_engine = static_cast<QQmlApplicationEngine*>(vptr);
+}
+
+bool StatusDockShowAppEvent::eventFilter(QObject* obj, QEvent* event)
+{
+#ifdef Q_OS_MACOS
+    if (event->type() == QEvent::ApplicationStateChange) 
+    {
+        auto ev = static_cast<QApplicationStateChangeEvent*>(event);
+        if (m_prevAppState == Qt::ApplicationActive 
+            && ev->applicationState() == Qt::ApplicationActive) 
+        {
+            QObject* topLevelObj = m_engine->rootObjects().value(0);
+            if(topLevelObj && topLevelObj->objectName() == "mainWindow")
+            {
+                QQuickWindow* window = qobject_cast<QQuickWindow *>(topLevelObj);
+                if(window)
+                {
+                    window->setVisible(true);
+                    window->showNormal();
+                    return true;
+                }
+            }
+        }
+        m_prevAppState = ev->applicationState();
+    }
+#endif
+
+    return QObject::eventFilter(obj, event);
+}

vendor/DOtherSide/lib/src/StatusEvents/StatusOSThemeEvent.cpp

@@ -0,0 +1,29 @@
+#include "DOtherSide/StatusEvents/StatusOSThemeEvent.h"
+
+#include <QQuickWindow>
+
+StatusOSThemeEvent::StatusOSThemeEvent(DosQQmlApplicationEngine* vptr, QObject* parent)
+    : QObject(parent) 
+{
+    m_engine = static_cast<QQmlApplicationEngine*>(vptr);
+}
+
+bool StatusOSThemeEvent::eventFilter(QObject *obj, QEvent *event)
+{
+    if (event->type() == QEvent::PaletteChange ||
+        event->type() == QEvent::ApplicationPaletteChange)
+    {
+        QObject* topLevelObj = m_engine->rootObjects().value(0);
+        if(topLevelObj && topLevelObj->objectName() == "mainWindow")
+        {
+            QQuickWindow* window = qobject_cast<QQuickWindow *>(topLevelObj);
+            if(window)
+            {
+                QMetaObject::invokeMethod(window, "changeThemeFromOutside");
+                return true;
+            }
+        }
+    }
+
+    return QObject::eventFilter(obj, event);
+}