Widgets: Add widget theme (WIP)

include/Nazara/Widgets.hpp

@@ -34,11 +34,13 @@
 #include <Nazara/Widgets/ButtonWidget.hpp>
 #include <Nazara/Widgets/Canvas.hpp>
 #include <Nazara/Widgets/Config.hpp>
+#include <Nazara/Widgets/DefaultWidgetTheme.hpp>
 #include <Nazara/Widgets/Enums.hpp>
 #include <Nazara/Widgets/ImageWidget.hpp>
 #include <Nazara/Widgets/LabelWidget.hpp>
 #include <Nazara/Widgets/RichTextAreaWidget.hpp>
 #include <Nazara/Widgets/TextAreaWidget.hpp>
 #include <Nazara/Widgets/Widgets.hpp>
+#include <Nazara/Widgets/WidgetTheme.hpp>
 
 #endif // NAZARA_GLOBAL_WIDGETS_HPP

include/Nazara/Widgets/BaseWidget.hpp

@@ -19,10 +19,13 @@
 
 namespace Nz
 {
+	class BaseWidgetStyle;
 	class Canvas;
+	class WidgetTheme;
 
-	class NAZARA_WIDGETS_API BaseWidget : public Nz::Node
+	class NAZARA_WIDGETS_API BaseWidget : public Node
 	{
+		friend BaseWidgetStyle;
 		friend Canvas;
 
 		public:
@@ -70,6 +73,7 @@ namespace Nz
 			inline const Rectf& GetRenderingRect() const;
 
 			inline Vector2f GetSize() const;
+			const std::shared_ptr<WidgetTheme>& GetTheme() const;
 			inline float GetWidth() const;
 			inline std::size_t GetWidgetChildCount() const;
 
@@ -118,6 +122,7 @@ namespace Nz
 			Rectf GetScissorRect() const;
 
 			virtual bool IsFocusable() const;
+			inline bool IsInside(float x, float y) const;
 			virtual void OnFocusLost();
 			virtual void OnFocusReceived();
 			virtual bool OnKeyPressed(const WindowEvent::KeyEvent& key);
@@ -137,7 +142,7 @@ namespace Nz
 			virtual void ShowChildren(bool show);
 
 		private:
-			inline BaseWidget();
+			inline BaseWidget(std::shared_ptr<WidgetTheme> theme);
 
 			void DestroyChild(BaseWidget* widget);
 			void DestroyChildren();
@@ -158,6 +163,7 @@ namespace Nz
 			std::optional<entt::entity> m_backgroundEntity;
 			std::size_t m_canvasIndex;
 			std::shared_ptr<Sprite> m_backgroundSprite;
+			std::shared_ptr<WidgetTheme> m_theme;
 			std::vector<WidgetEntity> m_entities;
 			std::vector<std::unique_ptr<BaseWidget>> m_children;
 			entt::registry* m_registry;

include/Nazara/Widgets/BaseWidget.inl

@@ -10,8 +10,9 @@
 
 namespace Nz
 {
-	inline BaseWidget::BaseWidget() :
+	inline BaseWidget::BaseWidget(std::shared_ptr<WidgetTheme> theme) :
 	m_canvasIndex(InvalidCanvasIndex),
+	m_theme(std::move(theme)),
 	m_registry(nullptr),
 	m_canvas(nullptr),
 	m_backgroundColor(Color(230, 230, 230, 255)),
@@ -164,6 +165,11 @@ namespace Nz
 		return Vector2f(GetWidth(), GetHeight());
 	}
 
+	inline const std::shared_ptr<WidgetTheme>& BaseWidget::GetTheme() const
+	{
+		return m_theme;
+	}
+
 	inline float BaseWidget::GetWidth() const
 	{
 		return m_size.x;
@@ -179,6 +185,12 @@ namespace Nz
 		return Show(false);
 	}
 
+	inline bool BaseWidget::IsInside(float x, float y) const
+	{
+		Rectf rect(0.f, 0.f, m_size.x, m_size.y);
+		return rect.Contains(x, y);
+	}
+
 	inline bool BaseWidget::IsVisible() const
 	{
 		return m_visible;

include/Nazara/Widgets/ButtonWidget.hpp

@@ -8,9 +8,10 @@
 #define NAZARA_WIDGETS_BUTTONWIDGET_HPP
 
 #include <Nazara/Core/Color.hpp>
-#include <Nazara/Graphics/Sprite.hpp>
+#include <Nazara/Graphics/SlicedSprite.hpp>
 #include <Nazara/Graphics/TextSprite.hpp>
 #include <Nazara/Widgets/BaseWidget.hpp>
+#include <Nazara/Widgets/WidgetTheme.hpp>
 
 namespace Nz
 {
@@ -25,18 +26,7 @@ namespace Nz
 			ButtonWidget(ButtonWidget&&) = default;
 			~ButtonWidget() = default;
 
-			inline const Color& GetColor() const;
+			void UpdateText(const AbstractTextDrawer& drawer);
-			inline const Color& GetCornerColor() const;
-			inline const Color& GetHoverColor() const;
-			inline const Color& GetHoverCornerColor() const;
-			inline const Color& GetPressColor() const;
-			inline const Color& GetPressCornerColor() const;
-
-			inline void SetColor(const Color& color, const Color& cornerColor);
-			inline void SetHoverColor(const Color& color, const Color& cornerColor);
-			inline void SetPressColor(const Color& color, const Color& cornerColor);
-
-			inline void UpdateText(const AbstractTextDrawer& drawer);
 
 			ButtonWidget& operator=(const ButtonWidget&) = delete;
 			ButtonWidget& operator=(ButtonWidget&&) = default;
@@ -51,17 +41,7 @@ namespace Nz
 			void OnMouseButtonRelease(int x, int y, Mouse::Button button) override;
 			void OnMouseExit() override;
 
-			std::shared_ptr<MaterialPass> m_gradientMaterialPass;
+			std::unique_ptr<ButtonWidgetStyle> m_style;
-			std::shared_ptr<Sprite> m_gradientSprite;
-			std::shared_ptr<TextSprite> m_textSprite;
-			entt::entity m_textEntity;
-			entt::entity m_gradientEntity;
-			Color m_color;
-			Color m_cornerColor;
-			Color m_hoverColor;
-			Color m_hoverCornerColor;
-			Color m_pressColor;
-			Color m_pressCornerColor;
 	};
 }
 

include/Nazara/Widgets/ButtonWidget.inl

@@ -7,68 +7,6 @@
 
 namespace Nz
 {
-	inline const Color& ButtonWidget::GetColor() const
-	{
-		return m_color;
-	}
-
-	inline const Color& ButtonWidget::GetCornerColor() const
-	{
-		return m_cornerColor;
-	}
-
-	inline const Color& ButtonWidget::GetHoverColor() const
-	{
-		return m_hoverColor;
-	}
-
-	inline const Color& ButtonWidget::GetHoverCornerColor() const
-	{
-		return m_hoverCornerColor;
-	}
-
-	inline const Color& ButtonWidget::GetPressColor() const
-	{
-		return m_pressColor;
-	}
-
-	inline const Color& ButtonWidget::GetPressCornerColor() const
-	{
-		return m_pressCornerColor;
-	}
-
-	inline void ButtonWidget::SetColor(const Color& color, const Color& cornerColor)
-	{
-		m_color = color;
-		m_cornerColor = cornerColor;
-
-		m_gradientSprite->SetColor(m_color);
-		m_gradientSprite->SetCornerColor(RectCorner::LeftBottom, m_cornerColor);
-		m_gradientSprite->SetCornerColor(RectCorner::RightBottom, m_cornerColor);
-	}
-
-	inline void ButtonWidget::SetHoverColor(const Color& color, const Color& cornerColor)
-	{
-		m_hoverColor = color;
-		m_hoverCornerColor = cornerColor;
-	}
-
-	inline void ButtonWidget::SetPressColor(const Color& color, const Color& cornerColor)
-	{
-		m_pressColor = color;
-		m_pressCornerColor = cornerColor;
-	}
-
-	inline void ButtonWidget::UpdateText(const AbstractTextDrawer& drawer)
-	{
-		m_textSprite->Update(drawer);
-
-		Vector2f textSize = Vector2f(m_textSprite->GetAABB().GetLengths());
-		SetMinimumSize(textSize);
-		SetPreferredSize(textSize + Vector2f(20.f, 10.f));
-
-		Layout();
-	}
 }
 
 #include <Nazara/Widgets/DebugOff.hpp>

include/Nazara/Widgets/Canvas.hpp

@@ -20,7 +20,7 @@ namespace Nz
 		friend BaseWidget;
 
 		public:
-			inline Canvas(entt::registry& registry, EventHandler& eventHandler, CursorControllerHandle cursorController, UInt32 renderMask);
+			Canvas(entt::registry& registry, EventHandler& eventHandler, CursorControllerHandle cursorController, UInt32 renderMask);
 			Canvas(const Canvas&) = delete;
 			Canvas(Canvas&&) = delete;
 			inline ~Canvas();

include/Nazara/Widgets/Canvas.inl

@@ -8,33 +8,6 @@
 
 namespace Nz
 {
-	inline Canvas::Canvas(entt::registry& registry, Nz::EventHandler& eventHandler, Nz::CursorControllerHandle cursorController, UInt32 renderMask) :
-	m_renderMask(renderMask),
-	m_keyboardOwner(InvalidCanvasIndex),
-	m_hoveredWidget(InvalidCanvasIndex),
-	m_mouseOwner(InvalidCanvasIndex),
-	m_registry(registry),
-	m_cursorController(cursorController)
-	{
-		m_canvas = this;
-		m_widgetParent = nullptr;
-
-		// Register ourselves as a widget to handle cursor change
-		RegisterToCanvas();
-
-		// Connect to every meaningful event
-		m_keyPressedSlot.Connect(eventHandler.OnKeyPressed, this, &Canvas::OnEventKeyPressed);
-		m_keyReleasedSlot.Connect(eventHandler.OnKeyReleased, this, &Canvas::OnEventKeyReleased);
-		m_mouseButtonPressedSlot.Connect(eventHandler.OnMouseButtonPressed, this, &Canvas::OnEventMouseButtonPressed);
-		m_mouseButtonReleasedSlot.Connect(eventHandler.OnMouseButtonReleased, this, &Canvas::OnEventMouseButtonRelease);
-		m_mouseEnteredSlot.Connect(eventHandler.OnMouseEntered, this, &Canvas::OnEventMouseEntered);
-		m_mouseLeftSlot.Connect(eventHandler.OnMouseLeft, this, &Canvas::OnEventMouseLeft);
-		m_mouseMovedSlot.Connect(eventHandler.OnMouseMoved, this, &Canvas::OnEventMouseMoved);
-		m_mouseWheelMovedSlot.Connect(eventHandler.OnMouseWheelMoved, this, &Canvas::OnEventMouseWheelMoved);
-		m_textEnteredSlot.Connect(eventHandler.OnTextEntered, this, &Canvas::OnEventTextEntered);
-		m_textEditedSlot.Connect(eventHandler.OnTextEdited, this, &Canvas::OnEventTextEdited);
-	}
-
 	inline Canvas::~Canvas()
 	{
 		// Destroy children explicitly because they signal us when getting destroyed, and that can't happen after our own destruction

include/Nazara/Widgets/DefaultWidgetTheme.hpp

@@ -0,0 +1,69 @@
+// Copyright (C) 2021 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
+// This file is part of the "Nazara Engine - Widgets module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#pragma once
+
+#ifndef NAZARA_WIDGETS_DEFAULTWIDGETTHEME_HPP
+#define NAZARA_WIDGETS_DEFAULTWIDGETTHEME_HPP
+
+#include <Nazara/Graphics/SlicedSprite.hpp>
+#include <Nazara/Graphics/TextSprite.hpp>
+#include <Nazara/Widgets/WidgetTheme.hpp>
+#include <entt/entt.hpp>
+
+namespace Nz
+{
+	class DefaultDefaultButtonWidgetStyle;
+
+	class NAZARA_WIDGETS_API DefaultWidgetTheme : public WidgetTheme
+	{
+		public:
+			DefaultWidgetTheme();
+			DefaultWidgetTheme(const DefaultWidgetTheme&) = delete;
+			DefaultWidgetTheme(DefaultWidgetTheme&&) = default;
+			~DefaultWidgetTheme() = default;
+
+			std::unique_ptr<ButtonWidgetStyle> CreateStyle(ButtonWidget* buttonWidget) const override;
+
+			DefaultWidgetTheme& operator=(const DefaultWidgetTheme&) = delete;
+			DefaultWidgetTheme& operator=(DefaultWidgetTheme&&) = default;
+
+		private:
+			std::shared_ptr<Material> m_buttonMaterial;
+			std::shared_ptr<Material> m_pressedButtonMaterial;
+	};
+
+	class NAZARA_WIDGETS_API DefaultButtonWidgetStyle : public ButtonWidgetStyle
+	{
+		public:
+			DefaultButtonWidgetStyle(ButtonWidget* buttonWidget, std::shared_ptr<Material> defaultMaterial, std::shared_ptr<Material> pressedMaterial);
+			DefaultButtonWidgetStyle(const DefaultButtonWidgetStyle&) = delete;
+			DefaultButtonWidgetStyle(DefaultButtonWidgetStyle&&) = default;
+			~DefaultButtonWidgetStyle() = default;
+
+			void Layout(const Vector2f& size) override;
+
+			void OnHoverBegin() override;
+			void OnHoverEnd() override;
+			void OnPress() override;
+			void OnRelease() override;
+
+			void UpdateText(const AbstractTextDrawer& drawer) override;
+
+			DefaultButtonWidgetStyle& operator=(const DefaultButtonWidgetStyle&) = delete;
+			DefaultButtonWidgetStyle& operator=(DefaultButtonWidgetStyle&&) = default;
+
+		private:
+			std::shared_ptr<Material> m_defaultMaterial;
+			std::shared_ptr<Material> m_pressedMaterial;
+			std::shared_ptr<SlicedSprite> m_sprite;
+			std::shared_ptr<TextSprite> m_textSprite;
+			entt::entity m_textEntity;
+			entt::entity m_gradientEntity;
+	};
+}
+
+#include <Nazara/Widgets/DefaultWidgetTheme.inl>
+
+#endif // NAZARA_WIDGETS_DEFAULTWIDGETTHEME_HPP

include/Nazara/Widgets/DefaultWidgetTheme.inl

@@ -0,0 +1,13 @@
+// Copyright (C) 2021 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
+// This file is part of the "Nazara Engine - Widgets module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Widgets/DefaultWidgetTheme.hpp>
+#include <Nazara/Widgets/WidgetTheme.hpp>
+#include <Nazara/Widgets/Debug.hpp>
+
+namespace Nz
+{
+}
+
+#include <Nazara/Widgets/DebugOff.hpp>

include/Nazara/Widgets/WidgetTheme.hpp

@@ -0,0 +1,84 @@
+// Copyright (C) 2021 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
+// This file is part of the "Nazara Engine - Widgets module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#pragma once
+
+#ifndef NAZARA_WIDGETS_WIDGETTHEME_HPP
+#define NAZARA_WIDGETS_WIDGETTHEME_HPP
+
+#include <Nazara/Graphics/Sprite.hpp>
+#include <Nazara/Math/Vector2.hpp>
+#include <Nazara/Renderer/Texture.hpp>
+#include <Nazara/Widgets/BaseWidget.hpp>
+
+namespace Nz
+{
+	class AbstractTextDrawer;
+	class ButtonWidget;
+	class ButtonWidgetStyle;
+
+	class NAZARA_WIDGETS_API WidgetTheme
+	{
+		public:
+			WidgetTheme() = default;
+			WidgetTheme(const WidgetTheme&) = delete;
+			WidgetTheme(WidgetTheme&&) = default;
+			virtual ~WidgetTheme();
+
+			virtual std::unique_ptr<ButtonWidgetStyle> CreateStyle(ButtonWidget* buttonWidget) const = 0;
+
+			WidgetTheme& operator=(const WidgetTheme&) = delete;
+			WidgetTheme& operator=(WidgetTheme&&) = default;
+
+		private:
+	};
+
+	class NAZARA_WIDGETS_API BaseWidgetStyle
+	{
+		public:
+			inline BaseWidgetStyle(BaseWidget* widget);
+			BaseWidgetStyle(const BaseWidgetStyle&) = delete;
+			BaseWidgetStyle(BaseWidgetStyle&&) = default;
+			virtual ~BaseWidgetStyle();
+
+			inline entt::entity CreateEntity();
+			inline void DestroyEntity(entt::entity entity);
+
+			inline entt::registry& GetRegistry();
+			inline const entt::registry& GetRegistry() const;
+			UInt32 GetRenderMask() const;
+
+			BaseWidgetStyle& operator=(const BaseWidgetStyle&) = delete;
+			BaseWidgetStyle& operator=(BaseWidgetStyle&&) = default;
+
+		private:
+			BaseWidget* m_widgetOwner;
+	};
+
+	class NAZARA_WIDGETS_API ButtonWidgetStyle : public BaseWidgetStyle
+	{
+		public:
+			using BaseWidgetStyle::BaseWidgetStyle;
+			ButtonWidgetStyle(const ButtonWidgetStyle&) = delete;
+			ButtonWidgetStyle(ButtonWidgetStyle&&) = default;
+			~ButtonWidgetStyle() = default;
+
+			virtual void Layout(const Vector2f& size) = 0;
+
+			virtual void OnHoverBegin();
+			virtual void OnHoverEnd();
+			virtual void OnPress();
+			virtual void OnRelease();
+
+			virtual void UpdateText(const AbstractTextDrawer& drawer) = 0;
+
+			ButtonWidgetStyle& operator=(const ButtonWidgetStyle&) = delete;
+			ButtonWidgetStyle& operator=(ButtonWidgetStyle&&) = default;
+
+	};
+}
+
+#include <Nazara/Widgets/WidgetTheme.inl>
+
+#endif // NAZARA_WIDGETS_WIDGETTHEME_HPP

include/Nazara/Widgets/WidgetTheme.inl

@@ -0,0 +1,36 @@
+// Copyright (C) 2021 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
+// This file is part of the "Nazara Engine - Widgets module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Widgets/WidgetTheme.hpp>
+#include <Nazara/Widgets/Debug.hpp>
+
+namespace Nz
+{
+	inline BaseWidgetStyle::BaseWidgetStyle(BaseWidget* widget) :
+	m_widgetOwner(widget)
+	{
+	}
+
+	inline entt::entity BaseWidgetStyle::CreateEntity()
+	{
+		return m_widgetOwner->CreateEntity();
+	}
+
+	inline void BaseWidgetStyle::DestroyEntity(entt::entity entity)
+	{
+		m_widgetOwner->DestroyEntity(entity);
+	}
+
+	inline entt::registry& BaseWidgetStyle::GetRegistry()
+	{
+		return m_widgetOwner->GetRegistry();
+	}
+
+	inline const entt::registry& BaseWidgetStyle::GetRegistry() const
+	{
+		return m_widgetOwner->GetRegistry();
+	}
+}
+
+#include <Nazara/Widgets/DebugOff.hpp>

src/Nazara/Widgets/BaseWidget.cpp

@@ -29,7 +29,7 @@ namespace Nz
 	* This will also register the widget to the canvas owning the top-most widget.
 	*/
 	BaseWidget::BaseWidget(BaseWidget* parent) :
-	BaseWidget()
+	BaseWidget(parent->GetTheme())
 	{
 		NazaraAssert(parent, "Invalid parent");
 		NazaraAssert(parent->GetCanvas(), "Parent has no canvas");
@@ -46,6 +46,15 @@ namespace Nz
 	 */
 	BaseWidget::~BaseWidget()
 	{
+		if (m_registry)
+		{
+			for (WidgetEntity& entity : m_entities)
+			{
+				if (m_registry->valid(entity.handle))
+					m_registry->destroy(entity.handle);
+			}
+		}
+
 		UnregisterFromCanvas();
 	}
 

src/Nazara/Widgets/ButtonWidget.cpp

@@ -6,7 +6,9 @@
 #include <Nazara/Graphics/BasicMaterial.hpp>
 #include <Nazara/Graphics/Material.hpp>
 #include <Nazara/Graphics/MaterialPass.hpp>
+#include <Nazara/Graphics/SlicedSprite.hpp>
 #include <Nazara/Graphics/Components/GraphicsComponent.hpp>
+#include <Nazara/Utility/AbstractTextDrawer.hpp>
 #include <Nazara/Utility/Components/NodeComponent.hpp>
 #include <Nazara/Widgets/Canvas.hpp>
 #include <Nazara/Widgets/Widgets.hpp>
@@ -15,31 +17,20 @@
 namespace Nz
 {
 	ButtonWidget::ButtonWidget(BaseWidget* parent) :
-	BaseWidget(parent),
+	BaseWidget(parent)
-	m_color { 74, 74, 74 },
-	m_cornerColor { 180, 180, 180 },
-	m_hoverColor { 128, 128, 128 },
-	m_hoverCornerColor { 180, 180, 180 },
-	m_pressColor { 180, 180, 180 },
-	m_pressCornerColor { 74, 74, 74 }
 	{
-		entt::registry& registry = GetRegistry();
+		m_style = GetTheme()->CreateStyle(this);
-		UInt32 renderMask = GetCanvas()->GetRenderMask();
 
-		m_gradientSprite = std::make_shared<Sprite>(Widgets::Instance()->GetOpaqueMaterial());
+		Layout();
-		m_gradientSprite->SetColor(m_color);
+	}
-		m_gradientSprite->SetCornerColor(RectCorner::LeftBottom, m_cornerColor);
-		m_gradientSprite->SetCornerColor(RectCorner::RightBottom, m_cornerColor);
 
-		m_gradientEntity = CreateEntity();
+	void ButtonWidget::UpdateText(const AbstractTextDrawer& drawer)
-		registry.emplace<NodeComponent>(m_gradientEntity).SetParent(this);
+	{
-		registry.emplace<GraphicsComponent>(m_gradientEntity).AttachRenderable(m_gradientSprite, renderMask);
+		m_style->UpdateText(drawer);
 
-		m_textSprite = std::make_shared<TextSprite>(Widgets::Instance()->GetTransparentMaterial());
+		Vector2f size(drawer.GetBounds().GetLengths());
-
+		SetMinimumSize(size);
-		m_textEntity = CreateEntity();
+		SetPreferredSize(size + Vector2f(20.f, 10.f));
-		registry.emplace<NodeComponent>(m_textEntity).SetParent(this);
-		registry.emplace<GraphicsComponent>(m_textEntity).AttachRenderable(m_textSprite, renderMask);
 
 		Layout();
 	}
@@ -47,49 +38,35 @@ namespace Nz
 	void ButtonWidget::Layout()
 	{
 		BaseWidget::Layout();
-
+		m_style->Layout(GetSize());
-		Vector2f size = GetSize();
-		m_gradientSprite->SetSize(size);
-
-		entt::registry& registry = GetRegistry();
-
-		Boxf textBox = m_textSprite->GetAABB();
-		registry.get<NodeComponent>(m_textEntity).SetPosition(size.x / 2.f - textBox.width / 2.f, size.y / 2.f - textBox.height / 2.f);
 	}
 
 	void ButtonWidget::OnMouseButtonPress(int /*x*/, int /*y*/, Mouse::Button button)
 	{
 		if (button == Mouse::Left)
-		{
+			m_style->OnPress();
-			m_gradientSprite->SetColor(m_pressColor);
-			m_gradientSprite->SetCornerColor(RectCorner::LeftBottom, m_pressCornerColor);
-			m_gradientSprite->SetCornerColor(RectCorner::RightBottom, m_pressCornerColor);
-		}
 	}
 
-	void ButtonWidget::OnMouseButtonRelease(int /*x*/, int /*y*/, Mouse::Button button)
+	void ButtonWidget::OnMouseButtonRelease(int x, int y, Mouse::Button button)
 	{
 		if (button == Mouse::Left)
 		{
-			m_gradientSprite->SetColor(m_hoverColor);
+			m_style->OnRelease();
-			m_gradientSprite->SetCornerColor(RectCorner::LeftBottom, m_hoverCornerColor);
-			m_gradientSprite->SetCornerColor(RectCorner::RightBottom, m_hoverCornerColor);
 
-			OnButtonTrigger(this);
+			// If user clicks inside button and holds it outside, a release mouse button event will be triggered outside of the widget
+			// we don't want this to trigger the button, so double-check
+			if (IsInside(x, y))
+				OnButtonTrigger(this);
 		}
 	}
 
 	void ButtonWidget::OnMouseEnter()
 	{
-		m_gradientSprite->SetColor(m_hoverColor);
+		m_style->OnHoverBegin();
-		m_gradientSprite->SetCornerColor(RectCorner::LeftBottom, m_hoverCornerColor);
-		m_gradientSprite->SetCornerColor(RectCorner::RightBottom, m_hoverCornerColor);
 	}
 
 	void ButtonWidget::OnMouseExit()
 	{
-		m_gradientSprite->SetColor(m_color);
+		m_style->OnHoverEnd();
-		m_gradientSprite->SetCornerColor(RectCorner::LeftBottom, m_cornerColor);
-		m_gradientSprite->SetCornerColor(RectCorner::RightBottom, m_cornerColor);
 	}
 }

src/Nazara/Widgets/Canvas.cpp

@@ -3,11 +3,40 @@
 // For conditions of distribution and use, see copyright notice in Config.hpp
 
 #include <Nazara/Widgets/Canvas.hpp>
+#include <Nazara/Widgets/DefaultWidgetTheme.hpp>
 #include <limits>
 #include <Nazara/Widgets/Debug.hpp>
 
 namespace Nz
 {
+	Canvas::Canvas(entt::registry& registry, Nz::EventHandler& eventHandler, Nz::CursorControllerHandle cursorController, UInt32 renderMask) :
+	BaseWidget(std::make_shared<DefaultWidgetTheme>()),
+	m_renderMask(renderMask),
+	m_keyboardOwner(InvalidCanvasIndex),
+	m_hoveredWidget(InvalidCanvasIndex),
+	m_mouseOwner(InvalidCanvasIndex),
+	m_registry(registry),
+	m_cursorController(cursorController)
+	{
+		m_canvas = this;
+		m_widgetParent = nullptr;
+
+		// Register ourselves as a widget to handle cursor change
+		RegisterToCanvas();
+
+		// Connect to every meaningful event
+		m_keyPressedSlot.Connect(eventHandler.OnKeyPressed, this, &Canvas::OnEventKeyPressed);
+		m_keyReleasedSlot.Connect(eventHandler.OnKeyReleased, this, &Canvas::OnEventKeyReleased);
+		m_mouseButtonPressedSlot.Connect(eventHandler.OnMouseButtonPressed, this, &Canvas::OnEventMouseButtonPressed);
+		m_mouseButtonReleasedSlot.Connect(eventHandler.OnMouseButtonReleased, this, &Canvas::OnEventMouseButtonRelease);
+		m_mouseEnteredSlot.Connect(eventHandler.OnMouseEntered, this, &Canvas::OnEventMouseEntered);
+		m_mouseLeftSlot.Connect(eventHandler.OnMouseLeft, this, &Canvas::OnEventMouseLeft);
+		m_mouseMovedSlot.Connect(eventHandler.OnMouseMoved, this, &Canvas::OnEventMouseMoved);
+		m_mouseWheelMovedSlot.Connect(eventHandler.OnMouseWheelMoved, this, &Canvas::OnEventMouseWheelMoved);
+		m_textEnteredSlot.Connect(eventHandler.OnTextEntered, this, &Canvas::OnEventTextEntered);
+		m_textEditedSlot.Connect(eventHandler.OnTextEdited, this, &Canvas::OnEventTextEdited);
+	}
+
 	std::size_t Canvas::RegisterWidget(BaseWidget* widget)
 	{
 		WidgetEntry box;

src/Nazara/Widgets/DefaultWidgetTheme.cpp

@@ -0,0 +1,121 @@
+// Copyright (C) 2021 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
+// This file is part of the "Nazara Engine - Widgets module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Widgets/DefaultWidgetTheme.hpp>
+#include <Nazara/Graphics/BasicMaterial.hpp>
+#include <Nazara/Graphics/Material.hpp>
+#include <Nazara/Graphics/MaterialPass.hpp>
+#include <Nazara/Graphics/Components/GraphicsComponent.hpp>
+#include <Nazara/Utility/Components/NodeComponent.hpp>
+#include <Nazara/Widgets/ButtonWidget.hpp>
+#include <Nazara/Widgets/Canvas.hpp>
+#include <Nazara/Widgets/Widgets.hpp>
+#include <Nazara/Widgets/Debug.hpp>
+
+namespace Nz
+{
+	namespace
+	{
+		const UInt8 ButtonImage[] = {
+			#include <Nazara/Widgets/Resources/DefaultStyle/Button.png.h>
+		};
+
+		const UInt8 ButtonPressedImage[] = {
+			#include <Nazara/Widgets/Resources/DefaultStyle/ButtonPressed.png.h>
+		};
+	}
+
+	DefaultWidgetTheme::DefaultWidgetTheme()
+	{
+		TextureParams texParams;
+		texParams.renderDevice = Graphics::Instance()->GetRenderDevice();
+		texParams.loadFormat = PixelFormat::RGBA8_SRGB;
+
+		// Button material
+		{
+			std::shared_ptr<MaterialPass> buttonMaterialPass = std::make_shared<MaterialPass>(BasicMaterial::GetSettings());
+			buttonMaterialPass->EnableDepthBuffer(true);
+			buttonMaterialPass->EnableDepthWrite(false);
+
+			m_buttonMaterial = std::make_shared<Material>();
+			m_buttonMaterial->AddPass("ForwardPass", buttonMaterialPass);
+
+			BasicMaterial buttonBasicMat(*buttonMaterialPass);
+			buttonBasicMat.SetDiffuseMap(Texture::LoadFromMemory(ButtonImage, sizeof(ButtonImage), texParams));
+		}
+
+		// Button (pressed) material
+		{
+			std::shared_ptr<MaterialPass> buttonMaterialPass = std::make_shared<MaterialPass>(BasicMaterial::GetSettings());
+			buttonMaterialPass->EnableDepthBuffer(true);
+			buttonMaterialPass->EnableDepthWrite(false);
+
+			m_pressedButtonMaterial = std::make_shared<Material>();
+			m_pressedButtonMaterial->AddPass("ForwardPass", buttonMaterialPass);
+
+			BasicMaterial buttonBasicMat(*buttonMaterialPass);
+			buttonBasicMat.SetDiffuseMap(Texture::LoadFromMemory(ButtonPressedImage, sizeof(ButtonPressedImage), texParams));
+		}
+	}
+
+	std::unique_ptr<ButtonWidgetStyle> DefaultWidgetTheme::CreateStyle(ButtonWidget* buttonWidget) const
+	{
+		return std::make_unique<DefaultButtonWidgetStyle>(buttonWidget, m_buttonMaterial, m_pressedButtonMaterial);
+	}
+
+	DefaultButtonWidgetStyle::DefaultButtonWidgetStyle(ButtonWidget* buttonWidget, std::shared_ptr<Material> defaultMaterial, std::shared_ptr<Material> pressedMaterial) :
+	ButtonWidgetStyle(buttonWidget),
+	m_defaultMaterial(std::move(defaultMaterial)),
+	m_pressedMaterial(std::move(pressedMaterial))
+	{
+		auto& registry = GetRegistry();
+		UInt32 renderMask = GetRenderMask();
+
+		m_sprite = std::make_shared<SlicedSprite>(m_defaultMaterial);
+
+		m_gradientEntity = CreateEntity();
+		registry.emplace<NodeComponent>(m_gradientEntity).SetParent(buttonWidget);
+		registry.emplace<GraphicsComponent>(m_gradientEntity).AttachRenderable(m_sprite, renderMask);
+
+		m_textSprite = std::make_shared<TextSprite>(Widgets::Instance()->GetTransparentMaterial());
+
+		m_textEntity = CreateEntity();
+		registry.emplace<NodeComponent>(m_textEntity).SetParent(buttonWidget);
+		registry.emplace<GraphicsComponent>(m_textEntity).AttachRenderable(m_textSprite, renderMask);
+	}
+
+	void DefaultButtonWidgetStyle::Layout(const Vector2f& size)
+	{
+		m_sprite->SetSize(size);
+
+		entt::registry& registry = GetRegistry();
+
+		Boxf textBox = m_textSprite->GetAABB();
+		registry.get<NodeComponent>(m_textEntity).SetPosition(size.x / 2.f - textBox.width / 2.f, size.y / 2.f - textBox.height / 2.f);
+	}
+
+	void DefaultButtonWidgetStyle::OnHoverBegin()
+	{
+	}
+
+	void DefaultButtonWidgetStyle::OnHoverEnd()
+	{
+		m_sprite->SetMaterial(m_defaultMaterial);
+	}
+
+	void DefaultButtonWidgetStyle::OnPress()
+	{
+		m_sprite->SetMaterial(m_pressedMaterial);
+	}
+
+	void DefaultButtonWidgetStyle::OnRelease()
+	{
+		m_sprite->SetMaterial(m_defaultMaterial);
+	}
+
+	void DefaultButtonWidgetStyle::UpdateText(const AbstractTextDrawer& drawer)
+	{
+		m_textSprite->Update(drawer);
+	}
+}

src/Nazara/Widgets/WidgetTheme.cpp

@@ -0,0 +1,35 @@
+// Copyright (C) 2021 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
+// This file is part of the "Nazara Engine - Widgets module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Widgets/WidgetTheme.hpp>
+#include <Nazara/Widgets/Canvas.hpp>
+#include <Nazara/Widgets/Debug.hpp>
+
+namespace Nz
+{
+	WidgetTheme::~WidgetTheme() = default;
+
+	BaseWidgetStyle::~BaseWidgetStyle() = default;
+
+	UInt32 BaseWidgetStyle::GetRenderMask() const
+	{
+		return m_widgetOwner->GetCanvas()->GetRenderMask();
+	}
+
+	void ButtonWidgetStyle::OnHoverBegin()
+	{
+	}
+
+	void ButtonWidgetStyle::OnHoverEnd()
+	{
+	}
+
+	void ButtonWidgetStyle::OnPress()
+	{
+	}
+
+	void ButtonWidgetStyle::OnRelease()
+	{
+	}
+}