/* $Id$ */

/*
 * This file is part of OpenTTD.
 * OpenTTD 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, version 2.
 * OpenTTD 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 OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file textbuf_gui.h Stuff related to the text buffer GUI. */

#ifndef TEXTBUF_GUI_H
#define TEXTBUF_GUI_H

#include "window_type.h"
#include "string_type.h"
#include "strings_type.h"
#include "core/enum_type.hpp"

/** Helper/buffer for input fields. */
struct Textbuf {
	char *buf;                ///< buffer in which text is saved
	uint16 max_bytes;         ///< the maximum size of the buffer in bytes (including terminating '\0')
	uint16 max_chars;         ///< the maximum size of the buffer in characters (including terminating '\0')
	uint16 bytes;             ///< the current size of the string in bytes (including terminating '\0')
	uint16 chars;             ///< the current size of the string in characters (including terminating '\0')
	uint16 pixels;            ///< the current size of the string in pixels
	bool caret;               ///< is the caret ("_") visible or not
	uint16 caretpos;          ///< the current position of the caret in the buffer, in bytes
	uint16 caretxoffs;        ///< the current position of the caret in pixels
};

bool HandleCaret(Textbuf *tb);

void DeleteTextBufferAll(Textbuf *tb);
bool DeleteTextBufferChar(Textbuf *tb, int delmode);
bool InsertTextBufferChar(Textbuf *tb, uint32 key);
bool InsertTextBufferClipboard(Textbuf *tb);
bool MoveTextBufferPos(Textbuf *tb, int navmode);
void InitializeTextBuffer(Textbuf *tb, char *buf, uint16 max_bytes);
void InitializeTextBuffer(Textbuf *tb, char *buf, uint16 max_bytes, uint16 max_chars);
void UpdateTextBufferSize(Textbuf *tb);

/** Flags used in ShowQueryString() call */
enum QueryStringFlags {
	QSF_NONE             =    0,
	QSF_ACCEPT_UNCHANGED = 0x01, ///< return success even when the text didn't change
	QSF_ENABLE_DEFAULT   = 0x02, ///< enable the 'Default' button ("\0" is returned)
	QSF_LEN_IN_CHARS     = 0x04, ///< the length of the string is counted in characters
};

DECLARE_ENUM_AS_BIT_SET(QueryStringFlags)


typedef void QueryCallbackProc(Window*, bool);

void ShowQueryString(StringID str, StringID caption, uint max_len, Window *parent, CharSetFilter afilter, QueryStringFlags flags);
void ShowQuery(StringID caption, StringID message, Window *w, QueryCallbackProc *callback);

/** The number of 'characters' on the on-screen keyboard. */
static const uint OSK_KEYBOARD_ENTRIES = 50;

/**
 * The number of characters has to be OSK_KEYBOARD_ENTRIES. However, these
 * have to be UTF-8 encoded, which means up to 4 bytes per character.
 * Furthermore the string needs to be '\0'-terminated.
 */
extern char _keyboard_opt[2][OSK_KEYBOARD_ENTRIES * 4 + 1];

#endif /* TEXTBUF_GUI_H */