/*
	Copyright 2006-2014 The QElectroTech Team
	This file is part of QElectroTech.
	
	QElectroTech is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 2 of the License, or
	(at your option) any later version.
	
	QElectroTech is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.
	
	You should have received a copy of the GNU General Public License
	along with QElectroTech.  If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef ELEMENTPRIMITIVEDECORATOR_H
#define ELEMENTPRIMITIVEDECORATOR_H
#include <QGraphicsObject>
#include "qet.h"
class ElementEditionCommand;
class ElementScene;
class CustomElementPart;

/**
	This class represents a decorator rendered above selected items so users
	can manipulate (move, resize, ...) them.
	
	The implementation considers four kinds of bounding rects:
	  - the actual, effective bounding rect as returned by the boundingRect() method
	  - the original bounding rect, i.e. the rect containing all selected items at
	      the beginning of operations (or after a command object was generated)
	  - the new bounding rect, after the user moved or resized items
	  - the former bounding rect, due to implementation details
*/
class ElementPrimitiveDecorator : public QGraphicsObject {
	Q_OBJECT
	
	public:
	ElementPrimitiveDecorator(QGraphicsItem * = 0);
	virtual ~ElementPrimitiveDecorator();
	
	enum { Type = UserType + 2200 };
	
	// methods
	QRectF internalBoundingRect() const;
	virtual QRectF boundingRect () const;
	virtual void paint(QPainter *, const QStyleOptionGraphicsItem *, QWidget * = 0);
	virtual int type() const { return Type; }
	void setItems(const QList<QGraphicsItem *> &);
	void setItems(const QList<CustomElementPart *> &);
	QList<CustomElementPart *> items() const;
	QList<QGraphicsItem *> graphicsItems() const;
	
	public slots:
	void adjust();
	
	signals:
	void actionFinished(ElementEditionCommand *);
	
	protected:
	void hoverMoveEvent(QGraphicsSceneHoverEvent *);
	void mousePressEvent(QGraphicsSceneMouseEvent *);
	void mouseDoubleClickEvent(QGraphicsSceneMouseEvent *);
	void mouseMoveEvent(QGraphicsSceneMouseEvent *);
	void mouseReleaseEvent(QGraphicsSceneMouseEvent *);
	void keyPressEvent(QKeyEvent *);
	void keyReleaseEvent(QKeyEvent *);
	QPointF deltaForRoundScaling(const QRectF &, const QRectF &, qreal);
	QPointF snapConstPointToGrid(const QPointF &) const;
	void snapPointToGrid(QPointF &) const;
	bool mustSnapToGrid(QGraphicsSceneMouseEvent *);
	QET::ScalingMethod scalingMethod(QGraphicsSceneMouseEvent *);
	
	private:
	void init();
	void saveOriginalBoundingRect();
	void adjustEffectiveBoundingRect();
	void startMovement();
	void applyMovementToRect(int, const QPointF &, QRectF &);
	CustomElementPart *singleItem() const;
	void translateItems(const QPointF &);
	void scaleItems(const QRectF &, const QRectF &);
	QRectF getSceneBoundingRect(QGraphicsItem *) const;
	void drawSquares(QPainter *, const QStyleOptionGraphicsItem *, QWidget *);
	void drawResizeSquare(QPainter *, const QStyleOptionGraphicsItem *, QWidget *, const QRectF &);
	void drawGenericSquare(QPainter *, const QStyleOptionGraphicsItem *, QWidget *, const QRectF &, const QColor &, const QColor &);
	QList<QRectF> getResizingSquares();
	QRectF getGenericSquare(const QPointF &);
	int resizingSquareAtPos(const QPointF &);
	
	// attributes
	private:
	QList<CustomElementPart *> decorated_items_;
	QRectF effective_bounding_rect_; ///< actual, effective bounding rect -- never shrinks
	QRectF original_bounding_rect_; ///< original bounding rect
	QRectF modified_bounding_rect_; ///< new bounding rect, after the user moved or resized items
	
	/**
		Index of the square leading the current operation (resizing, etc.) or -1 if no
		operation is occurring, -2 for a move operation.
	*/
	int current_operation_square_;
	int grid_step_x_;              ///< Grid horizontal step
	int grid_step_y_;              ///< Grid horizontal step
	QPointF first_pos_;            ///< First point involved within the current resizing operation
	QPointF latest_pos_;           ///< Latest point involved within the current resizing operation
	QPointF mouse_offset_;         ///< Offset between the mouse position and the point to be snapped to grid when moving selection
	bool moving_by_keys_;          ///< Whether we are currently moving our decorated items using the arrow keys
	QPointF keys_movement_;           ///< Movement applied to our decorated items using the arrow keys
};

#endif