guacamole-spice-protocol/src/terminal/buffer.h

/*
 * Copyright (C) 2013 Glyptodon LLC
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */


#ifndef _GUAC_TERMINAL_BUFFER_H
#define _GUAC_TERMINAL_BUFFER_H

#include "config.h"

#include "types.h"

/**
 * A single variable-length row of terminal data.
 */
typedef struct guac_terminal_buffer_row {

    /**
     * Array of guac_terminal_char representing the contents of the row.
     */
    guac_terminal_char* characters;

    /**
     * The length of this row in characters. This is the number of initialized
     * characters in the buffer, usually equal to the number of characters
     * in the screen width at the time this row was created.
     */
    int length;

    /**
     * The number of elements in the characters array. After the length
     * equals this value, the array must be resized.
     */
    int available;

} guac_terminal_buffer_row;

/**
 * A buffer containing a constant number of arbitrary-length rows.
 * New rows can be appended to the buffer, with the oldest row replaced with
 * the new row.
 */
typedef struct guac_terminal_buffer {

    /**
     * The character to assign to newly-allocated cells.
     */
    guac_terminal_char default_character;

    /**
     * Array of buffer rows. This array functions as a ring buffer.
     * When a new row needs to be appended, the top reference is moved down
     * and the old top row is replaced.
     */
    guac_terminal_buffer_row* rows;

    /**
     * The row to replace when adding a new row to the buffer.
     */
    int top;

    /**
     * The number of rows currently stored in the buffer.
     */
    int length;

    /**
     * The number of rows in the buffer. This is the total capacity
     * of the buffer.
     */
    int available;

} guac_terminal_buffer;

/**
 * Allocates a new buffer having the given maximum number of rows. New character cells will
 * be initialized to the given character.
 */
guac_terminal_buffer* guac_terminal_buffer_alloc(int rows, guac_terminal_char* default_character);

/**
 * Frees the given buffer.
 */
void guac_terminal_buffer_free(guac_terminal_buffer* buffer);

/**
 * Returns the row at the given location. The row returned is guaranteed to be at least the given
 * width.
 */
guac_terminal_buffer_row* guac_terminal_buffer_get_row(guac_terminal_buffer* buffer, int row, int width);

/**
 * Copies the given range of columns to a new location, offset from
 * the original by the given number of columns.
 */
void guac_terminal_buffer_copy_columns(guac_terminal_buffer* buffer, int row,
        int start_column, int end_column, int offset);

/**
 * Copies the given range of rows to a new location, offset from the
 * original by the given number of rows.
 */
void guac_terminal_buffer_copy_rows(guac_terminal_buffer* buffer,
        int start_row, int end_row, int offset);

/**
 * Sets the given range of columns within the given row to the given
 * character.
 */
void guac_terminal_buffer_set_columns(guac_terminal_buffer* buffer, int row,
        int start_column, int end_column, guac_terminal_char* character);

#endif