/*      _______   __   __   __   ______   __   __   _______   __   __
 *     / _____/\ / /\ / /\ / /\ / ____/\ / /\ / /\ / ___  /\ /  |\/ /\
 *    / /\____\// / // / // / // /\___\// /_// / // /\_/ / // , |/ / /
 *   / / /__   / / // / // / // / /    / ___  / // ___  / // /| ' / /
 *  / /_// /\ / /_// / // / // /_/_   / / // / // /\_/ / // / |  / /
 * /______/ //______/ //_/ //_____/\ /_/ //_/ //_/ //_/ //_/ /|_/ /
 * \______\/ \______\/ \_\/ \_____\/ \_\/ \_\/ \_\/ \_\/ \_\/ \_\/
 *
 * Copyright (c) 2004, 2005, 2006, 2007 Olof Naessén and Per Larsson
 *
 *                                                         Js_./
 * Per Larsson a.k.a finalman                          _RqZ{a<^_aa
 * Olof Naessén a.k.a jansem/yakslem                _asww7!uY`>  )\a//
 *                                                 _Qhm`] _f "'c  1!5m
 * Visit: http://guichan.darkbits.org             )Qk<P ` _: :+' .'  "{[
 *                                               .)j(] .d_/ '-(  P .   S
 * License: (BSD)                                <Td/Z <fP"5(\"??"\a.  .L
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#ifndef GCN_GUI_HPP
#define GCN_GUI_HPP

#include <list>
#include <deque>

#include "guisan/keyevent.hpp"
#include "guisan/mouseevent.hpp"
#include "guisan/mouseinput.hpp"
#include "guisan/platform.hpp"

namespace gcn
{
	class FocusHandler;
	class Graphics;
	class Input;
	class KeyListener;
	class Widget;

	// The following comment will appear in the doxygen main page.
	/**
	 * @mainpage
	 * @section Introduction
	 * This documentation is mostly intended as a reference to the API. If you want to get started with Guichan, we suggest you check out the programs in the examples directory of the Guichan release.
	 * @n
	 * @n
	 * This documentation is, and will always be, work in progress. If you find any errors, typos or inconsistencies, or if you feel something needs to be explained in more detail - don't hesitate to tell us.
	 */

	/**
	 * Gui core class. Contains a special widget called the top widget.
	 * If you want to be able to have more then one Widget in your Gui,
	 * the top widget should be a Container.
	 *
	 * NOTE: For the Gui to function properly you need to set a Graphics
	 *       object to use and an Input object to use.
	 */
	class GCN_CORE_DECLSPEC Gui
	{
	public:

		/**
		 * Constructor.
		 */
		Gui();

		/**
		 * Destructor.
		 */
		virtual ~Gui();

		/**
		 * Sets the top Widget.
		 *
		 * @param top the top Widget.
		 */
		virtual void setTop(Widget* top);

		/**
		 * Gets the top Widget.
		 *
		 * @return the top widget. NULL if no top widget has been set.
		 */
		[[nodiscard]] virtual Widget* getTop() const;

		/**
		 * Sets the Graphics object to use for drawing.
		 *
		 * @param graphics the Graphics object to use for drawing.
		 * @see SDLGraphics, OpenGLGraphics, AllegroGraphics
		 */
		virtual void setGraphics(Graphics* graphics);

		/**
		 * Gets the Graphics object used for drawing.
		 *
		 *  @return the Graphics object used for drawing. NULL if no
		 *          Graphics object has been set.
		 */
		[[nodiscard]] virtual Graphics* getGraphics() const;

		/**
		 * Sets the Input object to use for input handling.
		 *
		 * @param input the Input object to use for input handling.
		 * @see SDLInput, AllegroInput
		 */
		virtual void setInput(Input* input);

		/**
		 * Gets the Input object being used for input handling.
		 *
		 *  @return the Input object used for handling input. NULL if no
		 *          Input object has been set.
		 */
		[[nodiscard]] virtual Input* getInput() const;

		/**
		 * Performs the Gui logic. By calling this function all logic
		 * functions down in the Gui heirarchy will be called.
		 * What performs in Logic can be just about anything like
		 * adjusting a Widgets size or doing some calculations.
		 *
		 * NOTE: Logic also deals with user input (Mouse and Keyboard)
		 *       for Widgets.
		 */
		virtual void logic();

		/**
		 * Draws the Gui. By calling this funcion all draw functions
		 * down in the Gui hierarchy will be called.
		 */
		virtual void draw();

		/**
		 * Focus none of the Widgets in the Gui.
		 */
		virtual void focusNone();

		/**
		 * Toggles the use of the tab key to focus Widgets.
		 * By default, tabbing is enabled.
		 *
		 * @param tabbing set to false if you want to disable tabbing.
		 */
		virtual void setTabbingEnabled(bool tabbing);

		/**
		 * Checks if tabbing is enabled.
		 *
		 * @return true if tabbing is enabled.
		 */
		virtual bool isTabbingEnabled();

		/**
		 * Adds a global KeyListener to the Gui.
		 *
		 * @param keyListener a KeyListener to add.
		 */
		virtual void addGlobalKeyListener(KeyListener* keyListener);

		/**
		 * Remove global KeyListener from the Gui.
		 *
		 * @param keyListener a KeyListener to remove.
		 * @throws Exception if the KeyListener hasn't been added.
		 */
		virtual void removeGlobalKeyListener(KeyListener* keyListener);

	protected:
		/**
		 * Handles all mouse input.
		 *
		 * @since 0.6.0
		 */
		virtual void handleMouseInput();

		/**
		 * Handles key input.
		 *
		 * @since 0.6.0
		 */
		virtual void handleKeyInput();

		/**
		 * Handles mouse moved input.
		 *
		 * @param mouseInput the mouse input to handle.
		 * @since 0.6.0
		 */
		virtual void handleMouseMoved(const MouseInput& mouseInput);

		/**
		 * Handles mouse pressed input.
		 *
		 * @param mouseInput the mouse input to handle.
		 * @since 0.6.0
		 */
		virtual void handleMousePressed(const MouseInput& mouseInput);

		/**
		 *
		 * Handles mouse wheel moved down input.
		 *
		 * @param mouseInput the mouse input to handle.
		 * @since 0.6.0
		 */
		virtual void handleMouseWheelMovedDown(const MouseInput& mouseInput);

		/**
		 * Handles mouse wheel moved up input.
		 *
		 * @param mouseInput the mouse input to handle.
		 * @since 0.6.0
		 */
		virtual void handleMouseWheelMovedUp(const MouseInput& mouseInput);

		/**
		 * Handles mouse released input.
		 *
		 * @param mouseInput the mouse input to handle.
		 * @since 0.6.0
		 */
		virtual void handleMouseReleased(const MouseInput& mouseInput);

		/**
		 * Handles modal focus. Modal focus needs to be checked at 
		 * each logic iteration as it might be necessary to distribute
		 * mouse entered or mouse exited events.
		 *
		 * @since 0.8.0
		 */
		virtual void handleModalFocus();

		/**
		 * Handles modal mouse input focus. Modal mouse input focus needs 
		 * to be checked at each logic iteration as it might be necessary to 
		 * distribute mouse entered or mouse exited events.
		 *
		 * @since 0.8.0
		 */
		virtual void handleModalMouseInputFocus();

		/**
		 * Handles modal focus gained. If modal focus has been gaind it might 
		 * be necessary to distribute mouse entered or mouse exited events.
		 *
		 * @since 0.8.0
		 */
		virtual void handleModalFocusGained();

		/**
		 * Handles modal mouse input focus gained. If modal focus has been gaind 
		 * it might be necessary to distribute mouse entered or mouse exited events.
		 *
		 * @since 0.8.0
		 */
		virtual void handleModalFocusReleased();

		/**
		 * Distributes a mouse event.
		 *
		 * @param type The type of the event to distribute,
		 * @param button The button of the event (if any used) to distribute.
		 * @param x The x coordinate of the event.
		 * @param y The y coordinate of the event.
		 * @param fource indicates whether the distribution should be forced or not.
		 *               A forced distribution distributes the event even if a widget
		 *               is not enabled, not visible, another widget has modal
		 *               focus or another widget has modal mouse input focus. 
		 *               Default value is false.
		 * @param toSourceOnly indicates whether the distribution should be to the
		 *                     source widget only or to it's parent's mouse listeners
		 *                     as well.
		 *
		 * @since 0.6.0
		 */
		virtual void distributeMouseEvent(Widget* source,
										  int type,
										  int button,
										  int x,
										  int y,
										  bool force = false,
										  bool toSourceOnly = false);

		/**
		 * Distributes a key event.
		 *
		 * @param keyEvent the key event to distribute.

		 * @since 0.6.0
		 */
		virtual void distributeKeyEvent(KeyEvent& keyEvent);

		/**
		 * Distributes a key event to the global key listeners.
		 *
		 * @param keyEvent the key event to distribute.
		 *
		 * @since 0.6.0
		 */
		virtual void distributeKeyEventToGlobalKeyListeners(KeyEvent& keyEvent);

		/**
		 * Gets the widget at a certain position.
		 *
		 * @return the widget at a certain position.
		 * @since 0.6.0
		 */
		virtual Widget* getWidgetAt(int x, int y);

		/**
		 * Gets the source of the mouse event.
		 *
		 * @return the source widget of the mouse event.
		 * @since 0.6.0
		 */
		virtual Widget* getMouseEventSource(int x, int y);

		/**
		 * Gets the source of the key event.
		 *
		 * @return the source widget of the key event.
		 * @since 0.6.0
		 */
		virtual Widget* getKeyEventSource();

		Widget* mTop;
		Graphics* mGraphics;
		Input* mInput;
		FocusHandler* mFocusHandler;

		bool mTabbing;

		typedef std::list<KeyListener*> KeyListenerList;
		typedef KeyListenerList::iterator KeyListenerListIterator;

		KeyListenerList mKeyListeners;

		// Current input state
		bool mShiftPressed;
		bool mMetaPressed;
		bool mControlPressed;
		bool mAltPressed;

		// Last mouse state
		unsigned int mLastMousePressButton;
		int mLastMousePressTimeStamp;
		int mLastMouseX;
		int mLastMouseY;
		int mClickCount;
		int mLastMouseDragButton;

		// Widget with mouse stack
		std::deque<Widget*> mWidgetWithMouseQueue;
	};
}

#endif // end GCN_GUI_HPP

/* yakslem  - "Women, it's a constant struggle."
 * finalman - "Yes, but sometimes they succeed with their guesses."
 * yaklsem  - "...eh...I was talking about love."
 * finalman - "Oh...ok..."
 * An awkward silence followed.
 */