add syntax sugar and fix some safety issues

src/Painter.hpp

@@ -31,6 +31,8 @@ public:
     bool text(Point &where, std::string &text);
     bool text(Box &geometry, std::string &text, PaintTextAlign align, PangoEllipsizeMode ellipsize);
 
+    bool can_paint() { if (m_cairo) return true; else return false; }
+
     void source_rgb(RGB &source_rgb);
     void fill();
 

src/Widget.cpp

@@ -1,6 +1,7 @@
 #include <algorithm>
 #include <iostream>
 #include <memory>
+#include <exception>
 #include "Widget.hpp"
 #include "Events.hpp"
 #include "Window.hpp"
@@ -21,13 +22,16 @@ void Widget::set_layout(std::shared_ptr<Layout> layout) {
 }
 
 void Widget::set_window(Window *window) {
+    if (!window)
+        throw std::logic_error{"null window value for set_window"};
+
     m_window = window;
     m_styles = m_window->get_top_level_styles();
 
     on_init();
 }
 
-bool Widget::add_child(Widget *child) {
+bool Widget::add_child(std::shared_ptr<Widget> child) {
     if (child->get_parent()) {
         return false;
     }
@@ -40,7 +44,7 @@ bool Widget::add_child(Widget *child) {
     return true;
 }
 
-void Widget::remove_child(Widget *child) {
+void Widget::remove_child(std::shared_ptr<Widget> child) {
     m_children.erase(std::remove(m_children.begin(), m_children.end(), child), m_children.end());
 }
 
@@ -97,6 +101,10 @@ void Widget::handle_repaint(WidgetRepaintRequestedEvent &event) {
         return;
 
     auto painter = m_window->get_painter();
+
+    if (!painter.can_paint())
+        return;
+
     auto cr = painter.get_cairo();
     auto event_should_do_group = event.should_do_group();
 

src/Widget.hpp

@@ -34,7 +34,7 @@ DEF_WIDGET_STYLE_PROP(background_border_radius, double, 0.0)
 
 private:
     Box m_current_geometry { 0, 0, 0, 0 };
-    std::vector<Widget*> m_children;
+    std::vector<std::shared_ptr<Widget>> m_children;
     Widget *m_parent { nullptr };
     Window *m_window { nullptr };
     std::shared_ptr<TopLevelStyles> m_styles { nullptr };
@@ -59,9 +59,9 @@ public:
     void set_current_geometry(Box current_geometry) { m_current_geometry = current_geometry; wants_full_relayout(); }
     void set_current_geometry(Box current_geometry, bool is_pure) { m_current_geometry = current_geometry; if (!is_pure) { wants_full_relayout(); } }
 
-    std::vector<Widget*> &get_children() { return m_children; }
+    std::vector<std::shared_ptr<Widget>> &get_children() { return m_children; }
-    bool add_child(Widget *child);
+    bool add_child(std::shared_ptr<Widget> child);
-    void remove_child(Widget *child);
+    void remove_child(std::shared_ptr<Widget> child);
 
     Widget *get_parent() { return m_parent; }
     void set_parent(Widget *parent) { m_parent = parent; }
@@ -97,11 +97,18 @@ public:
 
     template<typename T, class... Args>
     std::shared_ptr<T> set_layout(Args&&... args) {
-        std::shared_ptr<T> layout = std::make_shared<T>(std::forward<T>(args)...);
+        std::shared_ptr<T> layout = std::make_shared<T>(std::forward<Args>(args)...);
         set_layout(layout);
         return layout;
     }
 
+    template<typename T, class... Args>
+    std::shared_ptr<T> add_child(Args&&... args) {
+        std::shared_ptr<T> child = std::make_shared<T>(std::forward<Args>(args)...);
+        add_child(child);
+        return child;
+    }
+
     virtual ~Widget() {};
 protected:
     WidgetType m_type { WidgetType::Widget };

src/Window.cpp

@@ -13,7 +13,7 @@
 
 namespace Raven {
 
-void Window::set_main_widget(Widget *main_widget) {
+void Window::set_main_widget(std::shared_ptr<Widget> main_widget) {
     m_main_widget = main_widget;
     m_main_widget->set_window(this);
     m_main_widget->set_current_geometry(m_current_geometry);

src/Window.hpp

@@ -13,7 +13,7 @@ class Window {
 private:
     Widget *m_focused_widget { nullptr };
     Widget *m_active_widget { nullptr };
-    Widget *m_main_widget { nullptr };
+    std::shared_ptr<Widget> m_main_widget { nullptr };
     Box m_current_geometry { 0, 0, 800, 600 };
     Painter m_painter {};
     std::shared_ptr<TopLevelStyles> m_top_level_styles = std::make_shared<TopLevelStyles>(this);
@@ -31,8 +31,8 @@ public:
     Widget *get_active_widget() { return m_active_widget; }
     void set_active_widget(Widget *active_widget) { m_active_widget = active_widget; }
 
-    Widget *get_main_widget() { return m_main_widget; }
+    std::shared_ptr<Widget> get_main_widget() { return m_main_widget; }
-    void set_main_widget(Widget *main_widget);
+    void set_main_widget(std::shared_ptr<Widget> main_widget);
 
     std::shared_ptr<TopLevelStyles> get_top_level_styles() { return m_top_level_styles; }
 
@@ -48,6 +48,13 @@ public:
 
     bool spawn_window();
     void run(bool block);
+
+    template<typename T, class... Args>
+    std::shared_ptr<T> set_main_widget(Args&&... args) {
+        std::shared_ptr<T> widget = std::make_shared<T>(std::forward<Args>(args)...);
+        set_main_widget(widget);
+        return widget;
+    }
 };
 
 }

src/main.cpp

@@ -8,42 +8,34 @@
 #include "src/DocumentLayout.hpp"
 
 int main() {
-    Raven::Widget new_row { Raven::ControlWidgetType::NewRow };
     Raven::Window window {};
 
-    Raven::Widget main_widget {};
+    auto main_widget = window.set_main_widget<Raven::Widget>();
-    Raven::Button add_button {"add"};
+    main_widget->set_layout<Raven::DocumentLayout>(6.0);
-    Raven::Button subtract_button {"subtract"};
+
-    Raven::Label label {"0"};
+    auto add_button = main_widget->add_child<Raven::Button>("add");
+    auto subtract_button = main_widget->add_child<Raven::Button>("subtract");
+    main_widget->add_child<Raven::Widget>(Raven::ControlWidgetType::NewRow);
+    auto label = main_widget->add_child<Raven::Label>("0");
 
     int number = 0;
 
     window.spawn_window();
 
-    add_button.set_current_geometry(Raven::Box(0, 0, 100, 30));
+    add_button->set_current_geometry(Raven::Box(0, 0, 100, 30));
-    subtract_button.set_current_geometry(Raven::Box(0, 0, 100, 30));
+    subtract_button->set_current_geometry(Raven::Box(0, 0, 100, 30));
-    label.set_current_geometry(Raven::Box(0, 0, 100, 20));
+    label->set_current_geometry(Raven::Box(0, 0, 100, 20));
 
-    main_widget.set_layout<Raven::DocumentLayout>(6.0);
+    add_button->on_click = [&]() {
-
-    window.set_main_widget(&main_widget);
-
-    add_button.on_click = [&]() {
         number++;
-        label.set_text(std::to_string(number));
+        label->set_text(std::to_string(number));
     };
 
-    subtract_button.on_click = [&]() {
+    subtract_button->on_click = [&]() {
         number--;
-        label.set_text(std::to_string(number));
+        label->set_text(std::to_string(number));
     };
 
-    main_widget.add_child(&add_button);
-    main_widget.add_child(&subtract_button);
-    main_widget.add_child(&new_row);
-    main_widget.add_child(&label);
-
-
     window.run(true);
     return 0;
 }