#ifndef DRAG_H
#define DRAG_H

#include <windows.h>

/* Dragger objects implement draggable portions of the client area,
 * such as the split between two list views. HandleLButtonDown and
 * HandleSetCursor are called by relevant window procedures upon
 * WM_(NC)LBUTTONDOWN and WM_SETCURSOR. */

struct Window;

struct Dragger
{
	Window& parent;
	bool HandleLButtonDown();
	bool HandleSetCursor();
	inline Dragger(Window& parent) : parent(parent) {}
protected:
	bool IsDown() const;
	bool IsDouble(const long time, const POINT& pt);
	virtual bool InDragArea(int x, int y) const = 0;
	/* Perform drag, resizing relevant windows. */
	virtual void Drag(int x, int y) const = 0;
	/* Reset dragger to automatic position. */
	virtual void Reset() const = 0;
	/* Called after drag, when mouse button is released. */
	virtual void Done() const = 0;
private:
	bool m_bActive = false;
	long m_time0 = 0;
	POINT m_pt0 = {0, 0};
};

/* DlvDragger implements the draggable split between the data list
 * view and the episode list view. */

struct DlvDragger : public Dragger
{
	inline DlvDragger(Window& parent) : Dragger(parent) {}
private:
	bool InDragArea(int x, int y) const override;
	void Drag(int x, int y) const override;
	void Reset() const override;
	void Done() const override;
};

#endif