Layouts (#189)

* Layout WIP

* Widgets/BoxLayout: Fix layout algorithm

* Widgets/BoxLayout: Fix box layout algorithm for good

* SDK/Widgets: Remove padding

* Sdk/Widgets: Make use of minimum/preferred size

* Sdk/TextAreaWidget: Add Minimum/PreferredSize to TextArea

* Sdk/Widgets: Add height/width variants of get/set fixed, maximum, minimum and preferred size methods

* Sdk/BoxLayout: Remove useless code

* Sdk/TextAreaWidget: Fix compilation

* Widgets/TextAreaWidget: Fix cursor position

SDK/include/NDK/BaseWidget.inl

@@ -13,11 +13,13 @@ namespace Ndk
 	m_canvas(nullptr),
 	m_backgroundColor(Nz::Color(230, 230, 230, 255)),
 	m_cursor(Nz::SystemCursor_Default),
-	m_contentSize(50.f, 50.f),
+	m_size(50.f, 50.f),
+	m_maximumSize(std::numeric_limits<float>::infinity()),
+	m_minimumSize(0.f),
+	m_preferredSize(-1),
 	m_widgetParent(nullptr),
 	m_visible(true)
 	{
-		SetPadding(5.f, 5.f, 5.f, 5.f);
 	}
 
 	template<typename T, typename... Args>
@@ -64,6 +66,20 @@ namespace Ndk
 		SetPosition(GetPosition(Nz::CoordSys_Local).x, (parentSize.y - mySize.y) / 2.f);
 	}
 
+	template<typename F>
+	inline void BaseWidget::ForEachWidgetChild(F iterator)
+	{
+		for (const auto& child : m_children)
+			iterator(child.get());
+	}
+
+	template<typename F>
+	inline void BaseWidget::ForEachWidgetChild(F iterator) const
+	{
+		for (const auto& child : m_children)
+			iterator(static_cast<const BaseWidget*>(child.get()));
+	}
+
 	inline const Nz::Color& BaseWidget::GetBackgroundColor() const
 	{
 		return m_backgroundColor;
@@ -79,24 +95,69 @@ namespace Ndk
 		return m_cursor;
 	}
 
-	inline const BaseWidget::Padding& BaseWidget::GetPadding() const
+	inline float BaseWidget::GetHeight() const
 	{
-		return m_padding;
+		return m_size.y;
 	}
 
-	inline Nz::Vector2f BaseWidget::GetContentOrigin() const
+	inline float BaseWidget::GetMaximumHeight() const
 	{
-		return { m_padding.left, m_padding.top };
+		return m_maximumSize.y;
 	}
 
-	inline const Nz::Vector2f& BaseWidget::GetContentSize() const
+	inline Nz::Vector2f BaseWidget::GetMaximumSize() const
 	{
-		return m_contentSize;
+		return m_maximumSize;
+	}
+
+	inline float BaseWidget::GetMaximumWidth() const
+	{
+		return m_maximumSize.x;
+	}
+
+	inline float BaseWidget::GetMinimumHeight() const
+	{
+		return m_minimumSize.y;
+	}
+
+	inline Nz::Vector2f BaseWidget::GetMinimumSize() const
+	{
+		return m_minimumSize;
+	}
+
+	inline float BaseWidget::GetMinimumWidth() const
+	{
+		return m_minimumSize.x;
+	}
+
+	inline float BaseWidget::GetPreferredHeight() const
+	{
+		return m_preferredSize.y;
+	}
+
+	inline Nz::Vector2f BaseWidget::GetPreferredSize() const
+	{
+		return m_preferredSize;
+	}
+
+	inline float BaseWidget::GetPreferredWidth() const
+	{
+		return m_preferredSize.x;
 	}
 
 	inline Nz::Vector2f BaseWidget::GetSize() const
 	{
-		return Nz::Vector2f(m_contentSize.x + m_padding.left + m_padding.right, m_contentSize.y + m_padding.top + m_padding.bottom);
+		return Nz::Vector2f(GetWidth(), GetHeight());
+	}
+
+	inline float BaseWidget::GetWidth() const
+	{
+		return m_size.x;
+	}
+
+	inline std::size_t BaseWidget::GetWidgetChildCount() const
+	{
+		return m_children.size();
 	}
 
 	inline bool BaseWidget::IsVisible() const
@@ -104,22 +165,79 @@ namespace Ndk
 		return m_visible;
 	}
 
-	inline void BaseWidget::SetContentSize(const Nz::Vector2f& size)
+	inline void BaseWidget::SetFixedHeight(float fixedHeight)
 	{
-		NotifyParentResized(size);
-		m_contentSize = size;
-
-		Layout();
+		SetMaximumHeight(fixedHeight);
+		SetMinimumHeight(fixedHeight);
 	}
 
-	inline void BaseWidget::SetPadding(float left, float top, float right, float bottom)
+	inline void BaseWidget::SetFixedSize(const Nz::Vector2f& fixedSize)
 	{
-		m_padding.left = left;
-		m_padding.top = top;
-		m_padding.bottom = bottom;
-		m_padding.right = right;
+		SetMaximumSize(fixedSize);
+		SetMinimumSize(fixedSize);
+	}
 
-		Layout();
+	inline void BaseWidget::SetFixedWidth(float fixedWidth)
+	{
+		SetMaximumWidth(fixedWidth);
+		SetMinimumWidth(fixedWidth);
+	}
+
+	inline void BaseWidget::SetMaximumHeight(float maximumHeight)
+	{
+		Nz::Vector2f maximumSize = GetMaximumSize();
+		maximumSize.y = maximumHeight;
+
+		SetMaximumSize(maximumSize);
+	}
+
+	inline void BaseWidget::SetMaximumSize(const Nz::Vector2f& maximumSize)
+	{
+		m_maximumSize = maximumSize;
+
+		Nz::Vector2f size = GetSize();
+		if (size.x > m_maximumSize.x || size.y > m_maximumSize.y)
+			Resize(size); //< Will clamp automatically
+	}
+
+	inline void BaseWidget::SetMaximumWidth(float maximumWidth)
+	{
+		Nz::Vector2f maximumSize = GetMaximumSize();
+		maximumSize.x = maximumWidth;
+
+		SetMaximumSize(maximumSize);
+	}
+
+	inline void BaseWidget::SetMinimumHeight(float minimumHeight)
+	{
+		Nz::Vector2f minimumSize = GetMinimumSize();
+		minimumSize.y = minimumHeight;
+
+		SetMinimumSize(minimumSize);
+	}
+
+	inline void BaseWidget::SetMinimumSize(const Nz::Vector2f& minimumSize)
+	{
+		m_minimumSize = minimumSize;
+
+		Nz::Vector2f size = GetSize();
+		if (size.x < m_minimumSize.x || size.y < m_minimumSize.y)
+			Resize(size); //< Will clamp automatically
+	}
+
+	inline void BaseWidget::SetMinimumWidth(float minimumWidth)
+	{
+		Nz::Vector2f minimumSize = GetMinimumSize();
+		minimumSize.x = minimumWidth;
+
+		SetMinimumSize(minimumSize);
+	}
+
+	inline void BaseWidget::SetPreferredSize(const Nz::Vector2f& preferredSize)
+	{
+		m_preferredSize = preferredSize;
+
+		Resize(m_preferredSize);
 	}
 
 	inline bool BaseWidget::IsRegisteredToCanvas() const