App: fix crash at shutdown in some conditions

src/app/app_context.cpp

@@ -26,7 +26,7 @@ AppContext::AppContext(MainWindow* wnd)
     QObject::connect(
                 m_wnd->widgetPageDocuments(), &WidgetMainControl::currentDocumentIndexChanged,
                 this, &AppContext::onCurrentDocumentIndexChanged
-    );
+        );
 }
 
 GuiApplication* AppContext::guiApp() const
@@ -41,7 +41,8 @@ TaskManager* AppContext::taskMgr() const
 
 QWidget* AppContext::pageDocuments_widgetLeftSideBar() const
 {
-    return m_wnd->widgetPageDocuments()->widgetLeftSideBar();
+    const WidgetMainControl* pageDocs = m_wnd->widgetPageDocuments();
+    return pageDocs ? pageDocs->widgetLeftSideBar() : nullptr;
 }
 
 QWidget* AppContext::widgetMain() const

src/app/commands_api.cpp

@@ -76,6 +76,15 @@ QAction* CommandContainer::findCommandAction(std::string_view name) const
     return cmd ? cmd->action() : nullptr;
 }
 
+void CommandContainer::clear()
+{
+    for (auto [name, cmd] : m_mapCommand) {
+        delete cmd;
+    }
+
+    m_mapCommand.clear();
+}
+
 void CommandContainer::addCommand_impl(std::string_view name, Command* cmd)
 {
     assert(m_appContext != nullptr);

src/app/commands_api.h

@@ -117,6 +117,8 @@ class CommandContainer {
     // The command name is implicit and found by assuming the presence of CmdType::Name class member
     template<typename CmdType, typename... Args> CmdType* addNamedCommand(Args... p);
 
+    void clear();
+
 private:
     void addCommand_impl(std::string_view name, Command* cmd);
 

src/app/commands_window.h

@@ -26,6 +26,7 @@ class CommandMainWidgetToggleFullscreen : public Command {
 class CommandLeftSidebarWidgetToggle : public Command {
 public:
     CommandLeftSidebarWidgetToggle(IAppContext* context);
+
     void execute() override;
     bool getEnabledStatus() const override;
 

src/app/mainwindow.cpp

@@ -66,6 +66,8 @@ MainWindow::MainWindow(GuiApplication* guiApp, QWidget* parent)
 
 MainWindow::~MainWindow()
 {
+    // Force deletion of Command objects as some of them are event filters of MainWindow widgets
+    m_cmdContainer.clear();
     delete m_ui;
 }
 
@@ -284,18 +286,20 @@ void MainWindow::updateCurrentPage()
         m_appContext->setCurrentPage(newPage);
 }
 
+IWidgetMainPage* MainWindow::widgetMainPage(IAppContext::Page page) const
+{
+    auto it = m_mapWidgetPage.find(page);
+    return it != m_mapWidgetPage.cend() ? it->second : nullptr;
+}
+
 WidgetMainHome* MainWindow::widgetPageHome() const
 {
-    auto it = m_mapWidgetPage.find(IAppContext::Page::Home);
-    assert(it != m_mapWidgetPage.cend());
-    return dynamic_cast<WidgetMainHome*>(it->second);
+    return dynamic_cast<WidgetMainHome*>(this->widgetMainPage(IAppContext::Page::Home));
 }
 
 WidgetMainControl* MainWindow::widgetPageDocuments() const
 {
-    auto it = m_mapWidgetPage.find(IAppContext::Page::Documents);
-    assert(it != m_mapWidgetPage.cend());
-    return dynamic_cast<WidgetMainControl*>(it->second);
+    return dynamic_cast<WidgetMainControl*>(this->widgetMainPage(IAppContext::Page::Documents));
 }
 
 } // namespace Mayo

src/app/mainwindow.h

@@ -54,6 +54,7 @@ class MainWindow : public QMainWindow {
     void updateControlsActivation();
     void updateCurrentPage();
 
+    IWidgetMainPage* widgetMainPage(IAppContext::Page page) const;
     WidgetMainHome* widgetPageHome() const;
     WidgetMainControl* widgetPageDocuments() const;