LibGUI+VisualBuilder: Support custom editing widgets for property values.

Implemented this by letting GAbstractViews provide a GModelEditingDelegate
for a given index, which then knows how to create and setup a custom widget
appropriate for the data type being edited.

DevTools/VisualBuilder/VBPropertiesWindow.cpp

@@ -1,9 +1,55 @@
 #include "VBPropertiesWindow.h"
+#include "VBWidgetPropertyModel.h"
 #include <LibGUI/GBoxLayout.h>
+#include <LibGUI/GComboBox.h>
+#include <LibGUI/GModelEditingDelegate.h>
 #include <LibGUI/GTableView.h>
 #include <LibGUI/GTextBox.h>
 #include <LibGUI/GWidget.h>
 
+class BoolValuesModel final : public GModel {
+public:
+    virtual int row_count(const GModelIndex&) const override { return 2; }
+    virtual int column_count(const GModelIndex&) const override { return 1; }
+    virtual void update() override {}
+    virtual GVariant data(const GModelIndex& index, Role role) const override
+    {
+        if (role != Role::Display)
+            return {};
+        switch (index.row()) {
+        case 0:
+            return "false";
+        case 1:
+            return "true";
+        }
+        ASSERT_NOT_REACHED();
+    }
+};
+
+class BoolModelEditingDelegate : public GModelEditingDelegate {
+public:
+    BoolModelEditingDelegate() {}
+    virtual ~BoolModelEditingDelegate() override {}
+
+    virtual GWidget* create_widget() override
+    {
+        auto* combo = new GComboBox(nullptr);
+        combo->set_only_allow_values_from_model(true);
+        combo->set_model(adopt(*new BoolValuesModel));
+        combo->on_return_pressed = [this] { commit(); };
+        combo->on_change = [this](auto&) { commit(); };
+        return combo;
+    }
+    virtual GVariant value() const override { return static_cast<const GComboBox*>(widget())->text() == "true"; }
+    virtual void set_value(const GVariant& value) override { static_cast<GComboBox*>(widget())->set_text(value.to_string()); }
+    virtual void will_begin_editing() override
+    {
+        auto& combo = *static_cast<GComboBox*>(widget());
+        combo.select_all();
+        combo.open();
+    }
+};
+
 VBPropertiesWindow::VBPropertiesWindow()
 {
     set_title("Properties");
@@ -18,6 +64,19 @@ VBPropertiesWindow::VBPropertiesWindow()
     m_table_view = new GTableView(widget);
     m_table_view->set_headers_visible(false);
     m_table_view->set_editable(true);
+
+    m_table_view->aid_create_editing_delegate = [this](auto& index) -> OwnPtr<GModelEditingDelegate> {
+        if (!m_table_view->model())
+            return nullptr;
+        auto type_index = m_table_view->model()->index(index.row(), VBWidgetPropertyModel::Column::Type);
+        auto type = m_table_view->model()->data(type_index, GModel::Role::Custom).to_int();
+        switch ((GVariant::Type)type) {
+        case GVariant::Type::Bool:
+            return make<BoolModelEditingDelegate>();
+        default:
+            return make<GStringModelEditingDelegate>();
+        }
+    };
 }
 
 VBPropertiesWindow::~VBPropertiesWindow()

DevTools/VisualBuilder/VBWidgetPropertyModel.cpp

@@ -24,6 +24,8 @@ String VBWidgetPropertyModel::column_name(int column) const
         return "Name";
     case Column::Value:
         return "Value";
+    case Column::Type:
+        return "Type";
     default:
         ASSERT_NOT_REACHED();
     }
@@ -39,6 +41,12 @@ GModel::ColumnMetadata VBWidgetPropertyModel::column_metadata(int column) const
 
 GVariant VBWidgetPropertyModel::data(const GModelIndex& index, Role role) const
 {
+    if (role == Role::Custom) {
+        auto& property = *m_widget.m_properties[index.row()];
+        if (index.column() == Column::Type)
+            return (int)property.value().type();
+        return {};
+    }
     if (role == Role::Display) {
         auto& property = *m_widget.m_properties[index.row()];
         switch (index.column()) {
@@ -46,6 +54,8 @@ GVariant VBWidgetPropertyModel::data(const GModelIndex& index, Role role) const
             return property.name();
         case Column::Value:
             return property.value();
+        case Column::Type:
+            return to_string(property.value().type());
         }
         ASSERT_NOT_REACHED();
     }
@@ -54,6 +64,8 @@ GVariant VBWidgetPropertyModel::data(const GModelIndex& index, Role role) const
         switch (index.column()) {
         case Column::Name:
             return Color::Black;
+        case Column::Type:
+            return Color::Blue;
         case Column::Value:
             return property.is_readonly() ? Color(Color::MidGray) : Color(Color::Black);
         }

DevTools/VisualBuilder/VBWidgetPropertyModel.h

@@ -10,6 +10,7 @@ public:
     enum Column {
         Name = 0,
         Value,
+        Type,
         __Count
     };