Gui: offer possibility to editing view provider to handle "Select All" command

src/Gui/View3DInventorViewer.cpp

@@ -227,7 +227,12 @@ public:
         else if (event->type() == QEvent::KeyPress) {
             auto ke = static_cast<QKeyEvent*>(event);  // NOLINT
             if (ke->matches(QKeySequence::SelectAll)) {
-                static_cast<View3DInventorViewer*>(obj)->selectAll();
+                auto* viewer3d = static_cast<View3DInventorViewer*>(obj);
+                auto* editingVP = viewer3d->getEditingViewProvider();
+                if(!editingVP || !editingVP->selectAll())
+                {
+                    viewer3d->selectAll();
+                }
                 return true;
             }
         }
@@ -1088,6 +1093,12 @@ bool View3DInventorViewer::isEditingViewProvider() const
     return this->editViewProvider != nullptr;
 }
 
+/// return currently editing view provider
+ViewProvider* View3DInventorViewer::getEditingViewProvider() const
+{
+    return this->editViewProvider;
+}
+
 /// display override mode
 void View3DInventorViewer::setOverrideMode(const std::string& mode)
 {

src/Gui/View3DInventorViewer.h

@@ -220,6 +220,8 @@ public:
     void setEditingViewProvider(Gui::ViewProvider* vp, int ModNum);
     /// return whether a view provider is edited
     bool isEditingViewProvider() const;
+    /// return currently editing view provider
+    ViewProvider* getEditingViewProvider() const;
     /// reset from edit mode
     void resetEditingViewProvider();
     void setupEditingRoot(SoNode *node=nullptr, const Base::Matrix4D *mat=nullptr);

src/Gui/ViewProvider.h

@@ -462,6 +462,9 @@ public:
     virtual void getTaskViewContent(std::vector<Gui::TaskView::TaskContent*>&) const {}
     //@}
 
+    /// is called when the provider is in edit and a "Select All" command was issued
+    /// Provider shall return 'false' is it ignores the command, 'true' otherwise
+    virtual bool selectAll() { return false; }
     /// is called when the provider is in edit and a key event occurs. Only ESC ends edit.
     virtual bool keyPressed(bool pressed, int key);
     /// Is called by the tree if the user double clicks on the object. It returns the string

src/Mod/Sketcher/Gui/ViewProviderSketch.cpp

@@ -2588,6 +2588,12 @@ void ViewProviderSketch::updateColor()
     editCoinManager->updateColor();
 }
 
+bool ViewProviderSketch::selectAll()
+{
+    // TODO: eventually implement "select all" logic
+    return true;
+}
+
 bool ViewProviderSketch::doubleClicked()
 {
     Gui::Application::Instance->activeDocument()->setEdit(this);

src/Mod/Sketcher/Gui/ViewProviderSketch.h

@@ -656,6 +656,9 @@ public:
     {
         return nullptr;
     }
+    /// is called when the provider is in edit and a "Select All" command was issued
+    /// Provider shall return 'false' is it ignores the command, 'true' otherwise
+    bool selectAll() override;
     /// is called by the tree if the user double clicks on the object
     bool doubleClicked() override;
     /// is called when the Provider is in edit and the mouse is moved