LibGUI: Move index_at_event_position() up to GAbstractView

It's now an abstract (pure virtual) public method in GAbstractView that
individual widgets have to implement. This will allow us to move more
selection-related logic into GAbstractView in order to share it between
implementations.

Libraries/LibGUI/GAbstractColumnView.cpp

@@ -396,6 +396,13 @@ GModelIndex GAbstractColumnView::index_at_event_position(const Point& position,
     return {};
 }
 
+GModelIndex GAbstractColumnView::index_at_event_position(const Point& position) const
+{
+    bool is_toggle;
+    auto index = index_at_event_position(position, is_toggle);
+    return is_toggle ? GModelIndex() : index;
+}
+
 int GAbstractColumnView::item_count() const
 {
     if (!model())

Libraries/LibGUI/GAbstractColumnView.h

@@ -68,6 +68,9 @@ public:
 
     void scroll_into_view(const GModelIndex&, Orientation);
 
+    virtual GModelIndex index_at_event_position(const Point&, bool& is_toggle) const;
+    virtual GModelIndex index_at_event_position(const Point&) const override;
+
 protected:
     virtual ~GAbstractColumnView() override;
     explicit GAbstractColumnView(GWidget* parent);
@@ -81,7 +84,6 @@ protected:
     virtual void leave_event(CEvent&) override;
     virtual void context_menu_event(GContextMenuEvent&) override;
 
-    virtual GModelIndex index_at_event_position(const Point&, bool& is_toggle) const;
     virtual void toggle_index(const GModelIndex&) {}
 
     void paint_headers(GPainter&);

Libraries/LibGUI/GAbstractView.h

@@ -54,6 +54,7 @@ public:
     virtual void did_update_selection();
 
     virtual Rect content_rect(const GModelIndex&) const { return {}; }
+    virtual GModelIndex index_at_event_position(const Point&) const = 0;
     void begin_editing(const GModelIndex&);
     void stop_editing();
 

Libraries/LibGUI/GColumnsView.h

@@ -35,11 +35,11 @@ public:
     int model_column() const { return m_model_column; }
     void set_model_column(int column) { m_model_column = column; }
 
+    virtual GModelIndex index_at_event_position(const Point&) const override;
+
 private:
     GColumnsView(GWidget* parent = nullptr);
     virtual ~GColumnsView();
-
-    GModelIndex index_at_event_position(const Point&) const;
     void push_column(GModelIndex& parent_index);
     void update_column_sizes();
 

Libraries/LibGUI/GItemView.h

@@ -48,6 +48,8 @@ public:
     int model_column() const { return m_model_column; }
     void set_model_column(int column) { m_model_column = column; }
 
+    virtual GModelIndex index_at_event_position(const Point&) const override;
+
 private:
     explicit GItemView(GWidget* parent);
 
@@ -64,7 +66,6 @@ private:
 
     int item_count() const;
     Rect item_rect(int item_index) const;
-    GModelIndex index_at_event_position(const Point&) const;
     Vector<int> items_intersecting_rect(const Rect&) const;
     void update_content_size();
     void get_item_rects(int item_index, const Font&, const GVariant& item_text, Rect& item_rect, Rect& icon_rect, Rect& text_rect) const;

Libraries/LibGUI/GListView.h

@@ -51,7 +51,7 @@ public:
 
     Point adjusted_position(const Point&) const;
 
-    GModelIndex index_at_event_position(const Point&) const;
+    virtual GModelIndex index_at_event_position(const Point&) const override;
     virtual Rect content_rect(const GModelIndex&) const override;
 
     int model_column() const { return m_model_column; }