LibGUI: Add AbstractView "edit triggers" to improve editing control

This API allows the embedder of a view to decide which actions upon
the view will begin editing the current item.

To maintain the old behavior, we will begin editing when an item is
either double-clicked, or when the "edit key" (return) is pressed.

Libraries/LibGUI/AbstractTableView.cpp

@@ -248,8 +248,10 @@ void AbstractTableView::doubleclick_event(MouseEvent& event)
     if (!model())
         return;
     if (event.button() == MouseButton::Left) {
-        if (!selection().is_empty())
-            activate_or_edit_selected();
+        if (is_editable() && edit_triggers() & EditTrigger::DoubleClicked)
+            begin_editing(cursor_index());
+        else
+            activate(cursor_index());
     }
 }
 

Libraries/LibGUI/AbstractView.cpp

@@ -362,15 +362,10 @@ void AbstractView::doubleclick_event(MouseEvent& event)
     else if (!m_selection.contains(index))
         set_selection(index);
 
-    activate_or_edit_selected();
-}
-
-void AbstractView::activate_or_edit_selected()
-{
-    if (is_editable())
-        begin_editing(selection().first());
+    if (is_editable() && edit_triggers() & EditTrigger::DoubleClicked)
+        begin_editing(cursor_index());
     else
-        activate_selected();
+        activate(cursor_index());
 }
 
 void AbstractView::context_menu_event(ContextMenuEvent& event)
@@ -449,4 +444,9 @@ void AbstractView::set_cursor(ModelIndex index, SelectionUpdate selection_update
     }
 }
 
+void AbstractView::set_edit_triggers(unsigned triggers)
+{
+    m_edit_triggers = triggers;
+}
+
 }

Libraries/LibGUI/AbstractView.h

@@ -67,6 +67,16 @@ public:
     bool is_editable() const { return m_editable; }
     void set_editable(bool editable) { m_editable = editable; }
 
+    enum EditTrigger {
+        None = 0,
+        DoubleClicked = 1 << 0,
+        EditKeyPressed = 1 << 1,
+        AnyKeyPressed = 1 << 2,
+    };
+
+    unsigned edit_triggers() const { return m_edit_triggers; }
+    void set_edit_triggers(unsigned);
+
     bool is_multi_select() const { return m_multi_select; }
     void set_multi_select(bool);
 
@@ -128,7 +138,6 @@ protected:
     void set_hovered_index(const ModelIndex&);
     void activate(const ModelIndex&);
     void activate_selected();
-    void activate_or_edit_selected();
     void update_edit_widget_position();
 
     bool m_editable { false };
@@ -150,6 +159,7 @@ private:
     OwnPtr<ModelEditingDelegate> m_editing_delegate;
     ModelSelection m_selection;
     ModelIndex m_cursor_index;
+    unsigned m_edit_triggers { EditTrigger::DoubleClicked | EditTrigger::EditKeyPressed };
     bool m_activates_on_selection { false };
     bool m_multi_select { true };
 };

Libraries/LibGUI/TableView.cpp

@@ -165,7 +165,10 @@ void TableView::keydown_event(KeyEvent& event)
     if (!model())
         return;
     if (event.key() == KeyCode::Key_Return) {
-        activate_or_edit_selected();
+        if (is_editable() && edit_triggers() & EditTrigger::EditKeyPressed)
+            begin_editing(cursor_index());
+        else
+            activate(cursor_index());
         return;
     }
     return AbstractTableView::keydown_event(event);