BansheeEngine/BansheeEngine/Include/BsGUISpace.h

#pragma once

#include "BsPrerequisites.h"
#include "BsGUIElementBase.h"

namespace BansheeEngine
{
	/**
	 * @brief	GUI element that may be inserted into layouts in order to make
	 *			a space of a fixed size.
	 */
	class BS_EXPORT GUIFixedSpace : public GUIElementBase
	{
	public:
		GUIFixedSpace(UINT32 size)
			:mSize(size)
		{ }

		~GUIFixedSpace();

		/**
		 * @brief	Returns the size of the space in pixels.
		 */
		UINT32 getSize() const { return mSize; }

		/**
		 * @brief	Changes the size of the space to the specified value, in pixels.
		 */
		void setSize(UINT32 size) { mSize = size; _markContentAsDirty(); }

		/**
		 * @copydoc	GUIElementBase::_getType
		 */
		Type _getType() const { return GUIElementBase::Type::FixedSpace; }

		/**
		 * @copydoc	GUIElementBase::_getOptimalSize
		 */
		virtual Vector2I _getOptimalSize() const override { return Vector2I(getSize(), getSize()); }

		/**
		 * @copydoc	GUIElementBase::_calculateLayoutSizeRange
		 */
		virtual LayoutSizeRange _calculateLayoutSizeRange() const override;

		/**
		 * @copydoc	GUIElementBase::_getPadding
		 */
		virtual const RectOffset& _getPadding() const  override
		{
			static RectOffset padding;

			return padding;
		}

		/**
		 * @brief	Creates a new fixed space GUI element.
		 */
		static GUIFixedSpace* create(UINT32 size);

		/**
		 * @brief	Destroys the space and removes it from its parent.
		 */
		static void destroy(GUIFixedSpace* space);

	protected:
		UINT32 mSize;
	};

	/**
	 * @brief	GUI element that may be inserted into layouts to make a space of
	 *			a flexible size. The space will expand only if there is room and
	 *			other elements are not squished because of it. If multiple flexible
	 *			spaces are in a layout, their sizes will be shared equally.
	 *
	 * @note	e.g. If you had a horizontal layout with a button, and you wanted to
	 *			align that button to the right of the layout, you would insert a flexible
	 *			space before the button in the layout.
	 */
	class BS_EXPORT GUIFlexibleSpace : public GUIElementBase
	{
	public:
		GUIFlexibleSpace() {}
		~GUIFlexibleSpace();

		/**
		 * @copydoc	GUIElementBase::_getType
		 */
		Type _getType() const override { return GUIElementBase::Type::FlexibleSpace; }

		/**
		 * @copydoc	GUIElementBase::_getOptimalSize
		 */
		virtual Vector2I _getOptimalSize() const override { return Vector2I(0, 0); }

		/**
		 * @copydoc	GUIElementBase::_calculateLayoutSizeRange
		 */
		virtual LayoutSizeRange _calculateLayoutSizeRange() const override;

		/**
		 * @copydoc	GUIElementBase::_getPadding
		 */
		virtual const RectOffset& _getPadding() const override
		{
			static RectOffset padding;

			return padding;
		}

		/**
		 * @brief	Creates a new flexible space GUI element.
		 */
		static GUIFlexibleSpace* create();

		/**
		 * @brief	Destroys the space and removes it from its parent.
		 */
		static void destroy(GUIFlexibleSpace* space);
	};
}