code_twain/sane/DlgArea.h

#pragma once

#include <Windows.h>
#include <string>

#include "DlgPage.h"

// CDlgIndicator 对话框

class dlg_area: public dlg_base
{
	enum paper_unit
	{
		PAPER_UNIT_MM = 0,
		PAPER_UNIT_INCH,
		PAPER_UNIT_PIXEL,
	};
	enum drag_pos
	{
		DRAG_POS_NONE = 0,
		DRAG_POS_LT,
		DRAG_POS_MT,
		DRAG_POS_RT,
		DRAG_POS_LM,
		DRAG_POS_RM,
		DRAG_POS_LB,
		DRAG_POS_MB,
		DRAG_POS_RB,
		DRAG_POS_MOVE,
	};
	typedef struct _drag_block : RECT
	{
		drag_pos	pos;
	}DRAGRECT;
	std::wstring	paper_;
	paper_unit		unit_;
	float		paper_w_0_;
	float		paper_h_0_;
	float		paper_w_;
	float		paper_h_;
	float		dpi_;
	float		x_;
	float		y_;
	float		w_;
	float		h_;

	RECT		whole_;
	RECT		user_sel_;
	float		ratio_;		// mm / pixel
	drag_pos	drag_;
	POINT		move_;
	bool		in_set_func_;
	const wchar_t* cursor_;

	static int	area_min_pixel;

	BOOL handle_message(UINT msg, WPARAM wp, LPARAM lp) override;
	void handle_command(WORD code, WORD id, HANDLE ctrl);
	void layout(void);

	float as_mm(float v);
	float from_mm(float v);
	float as_inches(float v);
	float as_pixels(float v);
	std::wstring format_number(float v);
	void refresh_paper_info(void);
	void to_unit(paper_unit unit);
	void clear_area(void);
	void drag_blocks(std::vector<DRAGRECT>& blocks);
	float pos_2_area(int val, bool x);
	void valid_x(int& x, bool left);
	void valid_y(int& y, bool top);

	void on_unit_changed(HWND wnd);
	void on_paint(HDC hdc);
	void on_mouse_move(DWORD key, int x, int y);
	void on_lbutton_down(int x, int y);
	void on_lbutton_up(int x, int y);

public:
	dlg_area(HWND parent);
	~dlg_area();

	static float mm_2_pixel(float mm, float dpi);
	static float mm_2_inches(float mm);
	static float inches_2_pixel(float inch, float dpi);
	static float inches_2_mm(float inch);
	static float pixel_2_mm(float px, float dpi);
	static float pixel_2_inches(float px, float dpi);

public:
	void set_paper(const wchar_t* name, float width_mm, float height_mm, float dpi);
	void set_area(float x, float y, float w, float h);
	float x_in_mm(void);
	float y_in_mm(void);
	float w_in_mm(void);
	float h_in_mm(void);
};