#include<graphics.h>
#include <tchar.h>

class EasyTextBox {
private:
	int left = 0, top = 0, right = 0, bottom = 0;
	wchar_t* text = NULL;
	size_t maxlen = 0;
public:
	void create(int x1, int y1, int x2, int y2, int max) {
		maxlen = max;
		text = new wchar_t[maxlen];
		text[0] = 0;
		left = x1, top = y1, right = x2, bottom = y2;
		// 绘制用户界面
		show();
	}
	~EasyTextBox() {
		if (text != NULL) delete[] text;
	}
	wchar_t* get_text() {
		return text;
	}
	bool check(int x, int y) {
		return left <= x && x <= right && top <= y && y <= bottom;
	}
	void show() {
		// 备份环境值
		int old_line_color = getlinecolor();
		int old_bk_color = getbkcolor();
		int old_fill_color = getfillcolor();

		setlinecolor(LIGHTGRAY);
		setbkcolor(0xeeeeee);
		setfillcolor(0xeeeeee);
		fillrectangle(left, top, right, bottom);
		outtextxy(left + 10, top + 5, (LPCTSTR)(&text[0]));

		// 恢复环境值
		setlinecolor(old_line_color);
		setbkcolor(old_line_color);
		setfillcolor(old_fill_color);
	}
	void on_message() {
		// 备份环境值
		int old_line_color = getlinecolor();
		int old_bk_color = getbkcolor();
		int old_fill_color = getfillcolor();

		setlinecolor(BLACK);
		setbkcolor(WHITE);
		setfillcolor(WHITE);
		fillrectangle(left, top, right, bottom);

		int width = textwidth((LPCTSTR)text);
		int counter = 0;
		bool binput = true;

		ExMessage msg;
		while (binput) {
			// 获取消息，但不从消息队列中拿出
			while (binput && peekmessage(&msg, EX_MOUSE | EX_CHAR, false)) {
				if (msg.message == WM_LBUTTONDOWN) {
					// 如果鼠标点击文本框外面，结束文本输入
					if (msg.x < left || msg.x > right || msg.y < top || msg.y > bottom) {
						binput = false;
						break;
					}
				}
				else if (msg.message == WM_CHAR) {
					size_t len = wcslen(text);
					switch (msg.ch) {
					case '\b': {
						if (len > 0) {
							text[len - 1] = 0;
							width = textwidth((LPCTSTR)text);
							counter = 0;
							clearrectangle(left + 10 + width, top + 1, right - 1, bottom - 1);
						} 
						break;
					}
					case '\r':
					case '\n':
						binput = false;
						break;
					default:
						if (len < maxlen - 1) {
							text[len++] = msg.ch;
							text[len] = 0;

							clearrectangle(left + 10 + width + 1, top + 3, left + 10 + width + 1, bottom - 3);	// 清除画的光标
							// 重新计算文本框宽度
							width = textwidth((LPCTSTR)text);
							counter = 0;
							outtextxy(left + 10, top + 5, (LPCTSTR)text);
						}
					}
				}
				peekmessage(NULL, EX_MOUSE | EX_CHAR);
			}

			// 绘制光标（光标闪烁周期为 20ms * 32）
			counter = (counter + 1) % 32;
			if (counter < 16)
				line(left + 10 + width + 1, top + 3, left + 10 + width + 1, bottom - 3);
			else 
				clearrectangle(left + 10 + width + 1, top + 3, left + 10 + width + 1, bottom - 3);		// 擦光标

			// 延时 20ms
			Sleep(20);
		}
		clearrectangle(left + 10 + width + 1, top + 3, left + 10 + width + 1, bottom - 3);	// 擦光标

		// 恢复环境值
		setlinecolor(old_line_color);
		setbkcolor(old_bk_color);
		setfillcolor(old_fill_color);

		show();
	}
};

// 实现按钮控件
class EasyButton {
private:
	int left = 0, top = 0, right = 0, bottom = 0;
	wchar_t* text = NULL; // 控件内容
	void (*userfunc)() = NULL; // 控件消息

public:
	void create(int x1, int y1, int x2, int y2, const wchar_t* title, void(*func)()) {
		text = new wchar_t[wcslen(title) + 1];
		wcscpy_s(text, wcslen(title) + 1, title);
		left = x1, top = y1, right = x2, bottom = y2;
		userfunc = func;

		// 绘制
		show();
	}
	~EasyButton() {
		if (text != NULL) delete[] text;
	}
	bool check(int x, int y) {
		return left <= x && x <= right && top <= y && y <= bottom;
	}
	void show() {
		int old_line_color = getlinecolor();
		int old_bk_color = getbkcolor();
		int old_fill_color = getfillcolor();

		setlinecolor(BLACK); // 设置划线颜色
		setbkcolor(WHITE); // 设置背景颜色
		setfillcolor(WHITE); // 设置填充颜色
		outtextxy(left + (right - left - textwidth((LPCTSTR)text) + 1) / 2, top + (bottom - top - textheight((LPCTSTR)text) + 1) / 2, (LPCTSTR)text);
		
		setlinecolor(old_line_color);
		setbkcolor(old_bk_color);
		setfillcolor(old_fill_color);
	}

	void on_message() {
		if (userfunc != NULL) userfunc();
	}
};