guacamole-spice-protocol/protocols/ssh/include/terminal.h

/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is libguac-client-ssh.
 *
 * The Initial Developer of the Original Code is
 * Michael Jumper.
 * Portions created by the Initial Developer are Copyright (C) 2011
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#ifndef _SSH_GUAC_TERMINAL_H
#define _SSH_GUAC_TERMINAL_H

#include <stdbool.h>
#include <pthread.h>

#include <guacamole/client.h>

#include "types.h"
#include "display.h"
#include "buffer.h"

#define GUAC_SSH_WHEEL_SCROLL_AMOUNT 3

typedef struct guac_terminal guac_terminal;

/**
 * Handler for characters printed to the terminal. When a character is printed,
 * the current char handler for the terminal is called and given that
 * character.
 */
typedef int guac_terminal_char_handler(guac_terminal* term, char c);

/**
 * Represents a terminal emulator which uses a given Guacamole client to
 * render itself.
 */
struct guac_terminal {

    /**
     * The Guacamole client this terminal emulator will use for rendering.
     */
    guac_client* client;

    /**
     * Lock which restricts simultaneous access to this terminal via the root
     * guac_terminal_* functions.
     */
    pthread_mutex_t lock;

    /**
     * Pipe which should be written to (and read from) to provide output to
     * this terminal. Another thread should read from this pipe when writing
     * data to the terminal. It would make sense for the terminal to provide
     * this thread, but for simplicity, that logic is left to the guac
     * message handler (to give the message handler something to block with).
     */
    int stdout_pipe_fd[2];

    /**
     * Pipe which will be the source of user input. When a terminal code
     * generates synthesized user input, that data will be written to
     * this pipe.
     */
    int stdin_pipe_fd[2];

    /**
     * The relative offset of the display. A positive value indicates that
     * many rows have been scrolled into view, zero indicates that no
     * scrolling has occurred. Negative values are illegal.
     */
    int scroll_offset;

    /**
     * The width of the terminal, in characters.
     */
    int term_width;

    /**
     * The height of the terminal, in characters.
     */
    int term_height;

    /**
     * The index of the first row in the scrolling region.
     */
    int scroll_start;

    /**
     * The index of the last row in the scrolling region.
     */
    int scroll_end;

    /**
     * The current row location of the cursor.
     */
    int cursor_row;

    /**
     * The current column location of the cursor.
     */
    int cursor_col;

    /**
     * The row of the rendered cursor.
     */
    int visible_cursor_row;

    /**
     * The column of the rendered cursor.
     */
    int visible_cursor_col;

    /**
     * The row of the saved cursor (ESC 7).
     */
    int saved_cursor_row;

    /**
     * The column of the saved cursor (ESC 7).
     */
    int saved_cursor_col;

    /**
     * The attributes which will be applied to future characters.
     */
    guac_terminal_attributes current_attributes;

    /**
     * The character whose attributes dictate the default attributes
     * of all characters. When new screen space is allocated, this
     * character fills the gaps.
     */
    guac_terminal_char default_char;

    /**
     * Handler which will receive all printed characters, updating the terminal
     * accordingly.
     */
    guac_terminal_char_handler* char_handler;

    /**
     * The difference between the currently-rendered screen and the current
     * state of the terminal.
     */
    guac_terminal_display* display;

    /**
     * Current terminal display state. All characters present on the screen
     * are within this buffer. This has nothing to do with the display, which
     * facilitates transfer of a set of changes to the remote display.
     */
    guac_terminal_buffer* buffer;

    /**
     * Array of arrays of mapped characters, where the character N is located at the N-32
     * position within the array. Each element in a contained array is the corresponding Unicode
     * codepoint. If NULL, a direct mapping from Unicode is used. The entries of the main array
     * correspond to the character set in use (G0, G1, etc.)
     */
    const int* char_mapping[2];

    /**
     * The active character set. For example, 0 for G0, 1 for G1, etc.
     */
    int active_char_set;

    /**
     * Whether text is being selected.
     */
    bool text_selected;

    /**
     * The row that the selection starts at.
     */
    int selection_start_row;

    /**
     * The column that the selection starts at.
     */
    int selection_start_column;

    /**
     * The row that the selection ends at.
     */
    int selection_end_row;

    /**
     * The column that the selection ends at.
     */
    int selection_end_column;

    /**
     * Whether the cursor (arrow) keys should send cursor sequences
     * or application sequences (DECCKM).
     */
    bool application_cursor_keys;

    /**
     * Whether a CR should automatically follow a LF, VT, or FF.
     */
    bool automatic_carriage_return;

};

/**
 * Creates a new guac_terminal, having the given width and height, and
 * rendering to the given client.
 */
guac_terminal* guac_terminal_create(guac_client* client,
        int width, int height);

/**
 * Resets the state of the given terminal, as if it were just allocated.
 */
void guac_terminal_reset(guac_terminal* term);

/**
 * Frees all resources associated with the given terminal.
 */
void guac_terminal_free(guac_terminal* term);

/**
 * Writes the given string of characters to the terminal.
 */
int guac_terminal_write(guac_terminal* term, const char* c, int size);

/**
 * Sets the character at the given row and column to the specified value.
 */
int guac_terminal_set(guac_terminal* term, int row, int col, int codepoint);

/**
 * Clears the given region within a single row.
 */
int guac_terminal_clear_columns(guac_terminal* term,
        int row, int start_col, int end_col);

/**
 * Clears the given region from right-to-left, top-to-bottom, replacing
 * all characters with the current background color and attributes.
 */
int guac_terminal_clear_range(guac_terminal* term,
        int start_row, int start_col,
        int end_row, int end_col);

/**
 * Scrolls the terminal's current scroll region up by one row.
 */
int guac_terminal_scroll_up(guac_terminal* term,
        int start_row, int end_row, int amount);

/**
 * Scrolls the terminal's current scroll region down by one row.
 */
int guac_terminal_scroll_down(guac_terminal* term,
        int start_row, int end_row, int amount);

/**
 * Commits the current cursor location, updating the visible cursor
 * on the screen.
 */
void guac_terminal_commit_cursor(guac_terminal* term);

/**
 * Scroll down the display by the given amount, replacing the new space with
 * data from the buffer. If not enough data is available, the maximum
 * amount will be scrolled.
 */
void guac_terminal_scroll_display_down(guac_terminal* terminal, int amount);

/**
 * Scroll up the display by the given amount, replacing the new space with data
 * from either the buffer or the terminal buffer.  If not enough data is
 * available, the maximum amount will be scrolled.
 */
void guac_terminal_scroll_display_up(guac_terminal* terminal, int amount);

/**
 * Marks the start of text selection at the given row and column.
 */
void guac_terminal_select_start(guac_terminal* terminal, int row, int column);

/**
 * Updates the end of text selection at the given row and column.
 */
void guac_terminal_select_update(guac_terminal* terminal, int row, int column);

/**
 * Ends text selection, removing any highlight. Character data is stored in the
 * string buffer provided.
 */
void guac_terminal_select_end(guac_terminal* terminal, char* string);

/* LOW-LEVEL TERMINAL OPERATIONS */

/**
 * Copies the given range of columns to a new location, offset from
 * the original by the given number of columns.
 */
void guac_terminal_copy_columns(guac_terminal* terminal, 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_copy_rows(guac_terminal* terminal,
        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_set_columns(guac_terminal* terminal, int row,
        int start_column, int end_column, guac_terminal_char* character);

/**
 * Resize the terminal to the given dimensions.
 */
void guac_terminal_resize(guac_terminal* term, int width, int height);

/**
 * Flushes all pending operations within the given guac_terminal.
 */
void guac_terminal_flush(guac_terminal* terminal);

#endif