VisualBuilder: Use real GWidgets instead of pretend VBWidgets.

That first design was the wrong idea. Instead, have VBWidget instantiate
a GWidget of the appropriate type and parent it to the VBForm.
We then use a new "greedy hit-testing" mechanism in GWidget to prevent any
mouse events from reaching the VBForm's children.

To paint the grabbers above the child widgets, I added a slightly hackish
but kind of neat second_paint_event() that is called after a widget has
painted all of his children. :^)

Applications/VisualBuilder/Makefile

@@ -1,8 +1,6 @@
 OBJS = \
     VBForm.o \
     VBWidget.o \
-    VBButtonWidget.o \
-    VBWidgetFactory.o \
     main.o
 
 APP = VisualBuilder 

Applications/VisualBuilder/VBButtonWidget.cpp

@@ -1,17 +0,0 @@
-#include "VBButtonWidget.h"
-#include <SharedGraphics/StylePainter.h>
-#include <LibGUI/GPainter.h>
-
-VBButtonWidget::VBButtonWidget(VBForm& form)
-    : VBWidget(form)
-{
-}
-
-VBButtonWidget::~VBButtonWidget()
-{
-}
-
-void VBButtonWidget::paint(GPainter& painter)
-{
-    StylePainter::paint_button(painter, rect(), ButtonStyle::Normal, false);
-}

Applications/VisualBuilder/VBButtonWidget.h

@@ -1,15 +0,0 @@
-#pragma once
-
-#include "VBWidget.h"
-
-class VBButtonWidget : public VBWidget {
-public:
-    static Retained<VBButtonWidget> create(VBForm& form) { return adopt(*new VBButtonWidget(form)); }
-    virtual ~VBButtonWidget() override;
-
-    virtual void paint(GPainter&) override;
-    virtual const char* gwidget_name() const { return "GButton"; }
-
-private:
-    explicit VBButtonWidget(VBForm&);
-};

Applications/VisualBuilder/VBForm.cpp

@@ -1,23 +1,24 @@
 #include "VBForm.h"
 #include "VBWidget.h"
-#include "VBWidgetFactory.h"
 #include <LibGUI/GPainter.h>
 
 VBForm::VBForm(const String& name, GWidget* parent)
     : GWidget(parent)
+    , m_name(name)
 {
     set_fill_with_background_color(true);
     set_background_color(Color::LightGray);
+    set_greedy_for_hits(true);
 
-    auto box1 = VBWidget::create(*this);
-    box1->set_rect({ 10, 10, 61, 41 });
+    auto box1 = VBWidget::create(WidgetType::GSpinBox, *this);
+    box1->set_rect({ 10, 10, 61, 21 });
     m_widgets.append(move(box1));
 
-    auto box2 = VBWidget::create(*this);
+    auto box2 = VBWidget::create(WidgetType::GTextEditor, *this);
     box2->set_rect({ 100, 100, 161, 141 });
     m_widgets.append(move(box2));
 
-    auto button1 = VBWidgetFactory::create("GButton", *this);
+    auto button1 = VBWidget::create(WidgetType::GButton, *this);
     button1->set_rect({ 200, 50, 101, 21 });
     m_widgets.append(move(button1));
 }
@@ -36,9 +37,14 @@ void VBForm::paint_event(GPaintEvent& event)
             painter.set_pixel({ x, y }, Color::Black);
         }
     }
+}
+
+void VBForm::second_paint_event(GPaintEvent& event)
+{
+    GPainter painter(*this);
+    painter.add_clip_rect(event.rect());
 
     for (auto& widget : m_widgets) {
-        widget->paint(painter);
         if (widget->is_selected()) {
             for_each_direction([&] (Direction direction) {
                 painter.fill_rect(widget->grabber_rect(direction), Color::Black);

Applications/VisualBuilder/VBForm.h

@@ -9,6 +9,9 @@ public:
     explicit VBForm(const String& name, GWidget* parent = nullptr);
     virtual ~VBForm() override;
 
+    String name() const { return m_name; }
+    void set_name(const String& name) { m_name = name; }
+
     bool is_selected(const VBWidget&) const;
     VBWidget* widget_at(const Point&);
 
@@ -17,6 +20,7 @@ public:
 
 protected:
     virtual void paint_event(GPaintEvent&) override;
+    virtual void second_paint_event(GPaintEvent&) override;
     virtual void mousedown_event(GMouseEvent&) override;
     virtual void mousemove_event(GMouseEvent&) override;
     virtual void mouseup_event(GMouseEvent&) override;

Applications/VisualBuilder/VBWidget.cpp

@@ -1,16 +1,51 @@
 #include "VBWidget.h"
 #include "VBForm.h"
 #include <LibGUI/GPainter.h>
+#include <LibGUI/GLabel.h>
+#include <LibGUI/GButton.h>
+#include <LibGUI/GSpinBox.h>
+#include <LibGUI/GTextEditor.h>
 
-VBWidget::VBWidget(VBForm& form)
-    : m_form(form)
+static GWidget* build_gwidget(WidgetType type, GWidget* parent)
 {
+    switch (type) {
+    case WidgetType::GWidget:
+        return new GWidget(parent);
+    case WidgetType::GLabel:
+        return new GLabel(parent);
+    case WidgetType::GButton:
+        return new GButton(parent);
+    case WidgetType::GSpinBox:
+        return new GSpinBox(parent);
+    case WidgetType::GTextEditor:
+        return new GTextEditor(GTextEditor::Type::MultiLine, parent);
+    default:
+        ASSERT_NOT_REACHED();
+        return nullptr;
+    }
+}
+
+VBWidget::VBWidget(WidgetType type, VBForm& form)
+    : m_type(type)
+    , m_form(form)
+{
+    m_gwidget = build_gwidget(type, &form);
 }
 
 VBWidget::~VBWidget()
 {
 }
 
+Rect VBWidget::rect() const
+{
+    return m_gwidget->relative_rect();
+}
+
+void VBWidget::set_rect(const Rect& rect)
+{
+    m_gwidget->set_relative_rect(rect);
+}
+
 bool VBWidget::is_selected() const
 {
     return m_form.is_selected(*this);
@@ -22,21 +57,21 @@ Rect VBWidget::grabber_rect(Direction direction) const
     int half_grabber_size = grabber_size / 2;
     switch (direction) {
     case Direction::Left:
-        return { m_rect.x() - half_grabber_size, m_rect.center().y() - half_grabber_size, grabber_size, grabber_size };
+        return { rect().x() - half_grabber_size, rect().center().y() - half_grabber_size, grabber_size, grabber_size };
     case Direction::UpLeft:
-        return { m_rect.x() - half_grabber_size, m_rect.y() - half_grabber_size, grabber_size, grabber_size };
+        return { rect().x() - half_grabber_size, rect().y() - half_grabber_size, grabber_size, grabber_size };
     case Direction::Up:
-        return { m_rect.center().x() - half_grabber_size, m_rect.y() - half_grabber_size, grabber_size, grabber_size };
+        return { rect().center().x() - half_grabber_size, rect().y() - half_grabber_size, grabber_size, grabber_size };
     case Direction::UpRight:
-        return { m_rect.right() - half_grabber_size, m_rect.y() - half_grabber_size, grabber_size, grabber_size };
+        return { rect().right() - half_grabber_size, rect().y() - half_grabber_size, grabber_size, grabber_size };
     case Direction::Right:
-        return { m_rect.right() - half_grabber_size, m_rect.center().y() - half_grabber_size, grabber_size, grabber_size };
+        return { rect().right() - half_grabber_size, rect().center().y() - half_grabber_size, grabber_size, grabber_size };
     case Direction::DownLeft:
-        return { m_rect.x() - half_grabber_size, m_rect.bottom() - half_grabber_size, grabber_size, grabber_size };
+        return { rect().x() - half_grabber_size, rect().bottom() - half_grabber_size, grabber_size, grabber_size };
     case Direction::Down:
-        return { m_rect.center().x() - half_grabber_size, m_rect.bottom() - half_grabber_size, grabber_size, grabber_size };
+        return { rect().center().x() - half_grabber_size, rect().bottom() - half_grabber_size, grabber_size, grabber_size };
     case Direction::DownRight:
-        return { m_rect.right() - half_grabber_size, m_rect.bottom() - half_grabber_size, grabber_size, grabber_size };
+        return { rect().right() - half_grabber_size, rect().bottom() - half_grabber_size, grabber_size, grabber_size };
     default:
         ASSERT_NOT_REACHED();
     }
@@ -51,9 +86,3 @@ Direction VBWidget::grabber_at(const Point& position) const
     });
     return found_grabber;
 }
-
-void VBWidget::paint(GPainter& painter)
-{
-    painter.fill_rect(m_rect, Color::White);
-    painter.draw_rect(m_rect, Color::Black);
-}

Applications/VisualBuilder/VBWidget.h

@@ -6,6 +6,7 @@
 #include <AK/Weakable.h>
 
 class GPainter;
+class GWidget;
 class VBForm;
 
 enum class Direction { None, Left, UpLeft, Up, UpRight, Right, DownRight, Down, DownLeft };
@@ -22,27 +23,35 @@ inline void for_each_direction(Callback callback)
     callback(Direction::DownLeft);
 }
 
+enum class WidgetType {
+    None,
+    GWidget,
+    GButton,
+    GLabel,
+    GSpinBox,
+    GTextEditor,
+};
+
 class VBWidget : public Retainable<VBWidget>, public Weakable<VBWidget> {
 public:
-    static Retained<VBWidget> create(VBForm& form) { return adopt(*new VBWidget(form)); }
-    virtual ~VBWidget();
+    static Retained<VBWidget> create(WidgetType type, VBForm& form) { return adopt(*new VBWidget(type, form)); }
+    ~VBWidget();
 
     bool is_selected() const;
 
-    Rect rect() const { return m_rect; }
-    void set_rect(const Rect& rect) { m_rect = rect; }
+    Rect rect() const;
+    void set_rect(const Rect&);
 
     Rect grabber_rect(Direction) const;
     Direction grabber_at(const Point&) const;
 
-    virtual void paint(GPainter&);
-
-    virtual const char* gwidget_name() const { return "GWidget"; }
+    GWidget* gwidget() { return m_gwidget; }
 
 protected:
-    explicit VBWidget(VBForm&);
+    VBWidget(WidgetType, VBForm&);
 
 private:
+    WidgetType m_type { WidgetType::None };
     VBForm& m_form;
-    Rect m_rect;
+    GWidget* m_gwidget { nullptr };
 };

Applications/VisualBuilder/VBWidgetFactory.cpp

@@ -1,9 +0,0 @@
-#include "VBWidgetFactory.h"
-#include "VBButtonWidget.h"
-
-Retained<VBWidget> VBWidgetFactory::create(const String& widget_name, VBForm& form)
-{
-    if (widget_name == "GButton")
-        return VBButtonWidget::create(form);
-    return VBWidget::create(form);
-}

Applications/VisualBuilder/VBWidgetFactory.h

@@ -1,12 +0,0 @@
-#pragma once
-
-#include <AK/AKString.h>
-#include <AK/Retained.h>
-
-class VBForm;
-class VBWidget;
-
-class VBWidgetFactory {
-public:
-    static Retained<VBWidget> create(const String& widget_name, VBForm&);
-};

Applications/VisualBuilder/main.cpp

@@ -46,7 +46,7 @@ int main(int argc, char** argv)
     app.set_menubar(move(menubar));
 
     auto* window = new GWindow;
-    window->set_title("Form1");
+    window->set_title(form1->name());
     window->set_rect(20, 200, 640, 400);
     window->set_main_widget(form1);
     window->set_should_exit_event_loop_on_close(true);

LibGUI/GWidget.cpp

@@ -115,6 +115,7 @@ void GWidget::handle_paint_event(GPaintEvent& event)
             child->event(local_event);
         }
     }
+    second_paint_event(event);
 }
 
 void GWidget::set_layout(OwnPtr<GLayout>&& layout)
@@ -207,6 +208,10 @@ void GWidget::paint_event(GPaintEvent&)
 {
 }
 
+void GWidget::second_paint_event(GPaintEvent&)
+{
+}
+
 void GWidget::show_event(GShowEvent&)
 {
 }
@@ -282,6 +287,8 @@ Rect GWidget::screen_relative_rect() const
 
 GWidget::HitTestResult GWidget::hit_test(int x, int y)
 {
+    if (is_greedy_for_hits())
+        return { this, x, y };
     for (int i = children().size() - 1; i >= 0; --i) {
         if (!children()[i]->is_widget())
             continue;

LibGUI/GWidget.h

@@ -56,6 +56,9 @@ public:
     virtual void leave_event(CEvent&);
     virtual void child_event(CChildEvent&) override;
 
+    // This is called after children have been painted.
+    virtual void second_paint_event(GPaintEvent&);
+
     Rect relative_rect() const { return m_relative_rect; }
     Point relative_position() const { return m_relative_rect.location(); }
 
@@ -147,6 +150,9 @@ public:
 
     bool spans_entire_window_horizontally() const;
 
+    bool is_greedy_for_hits() const { return m_greedy_for_hits; }
+    void set_greedy_for_hits(bool b) { m_greedy_for_hits = b; }
+
 private:
     virtual bool is_widget() const final { return true; }
 
@@ -173,6 +179,7 @@ private:
 
     bool m_fill_with_background_color { false };
     bool m_visible { true };
+    bool m_greedy_for_hits { false };
 
     CElapsedTimer m_click_clock;
 };