guacamole-spice-protocol/src/common/guac_cursor.h

/*
 * Copyright (C) 2014 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_COMMON_CURSOR_H
#define GUAC_COMMON_CURSOR_H

#include "guac_surface.h"

#include <cairo/cairo.h>
#include <guacamole/client.h>
#include <guacamole/socket.h>
#include <guacamole/user.h>

/**
 * The default size of the cursor image buffer.
 */
#define GUAC_COMMON_CURSOR_DEFAULT_SIZE 64*64*4

/**
 * Cursor object which maintains and synchronizes the current mouse cursor
 * state across all users of a specific client.
 */
typedef struct guac_common_cursor {

    /**
     * The client to maintain the mouse cursor for.
     */
    guac_client* client;

    /**
     * The cursor layer. This layer will be available to all connected users,
     * but will be visible only to those users who are not moving the mouse.
     */
    guac_layer* layer;

    /**
     * The width of the cursor image, in pixels.
     */
    int width;

    /**
     * The height of the cursor image, in pixels.
     */
    int height;

    /**
     * Arbitrary image data buffer, backing the Cairo surface used to store
     * the cursor image.
     */
    unsigned char* image_buffer;

    /**
     * The size of the image data buffer, in bytes.
     */
    int image_buffer_size;

    /**
     * The current cursor image, if any. If the mouse cursor has not yet been
     * set, this will be NULL.
     */
    cairo_surface_t* surface;

    /**
     * The X coordinate of the hotspot of the mouse cursor.
     */
    int hotspot_x;

    /**
     * The Y coordinate of the hotspot of the mouse cursor.
     */
    int hotspot_y;

    /**
     * The last user to move the mouse, or NULL if no user has moved the
     * mouse yet.
     */
    guac_user* user;

    /**
     * The X coordinate of the current mouse cursor location.
     */
    int x;

    /**
     * The Y coordinate of the current mouse cursor location.
     */
    int y;

} guac_common_cursor;

/**
 * Allocates a new cursor object which maintains and synchronizes the current
 * mouse cursor state across all users of the given client.
 *
 * @param client The client for which this object shall maintain the mouse
 *               cursor.
 */
guac_common_cursor* guac_common_cursor_alloc(guac_client* client);

/**
 * Frees the given cursor.
 *
 * @param cursor The cursor to free.
 */
void guac_common_cursor_free(guac_common_cursor* cursor);

/**
 * Sends the current state of this cursor across the given socket, including
 * the current cursor image. The resulting cursor on the remote display will
 * be visible.
 *
 * @param cursor
 *     The cursor to send.
 *
 * @param user
 *     The user receiving the updated cursor.
 *
 * @param socket
 *     The socket over which the updated cursor should be sent.
 */
void guac_common_cursor_dup(guac_common_cursor* cursor, guac_user* user,
        guac_socket* socket);

/**
 * Moves the mouse cursor, marking the given user as the most recent user of
 * the mouse. The remote mouse cursor will be hidden for this user and shown
 * for all others.
 *
 * @param cursor The cursor being moved.
 * @param user The user that moved the cursor.
 * @param x The new X coordinate of the cursor.
 * @param y The new Y coordinate of the cursor.
 */
void guac_common_cursor_move(guac_common_cursor* cursor, guac_user* user,
        int x, int y);

/**
 * Sets the cursor image to the given raw image data. This raw image data must
 * be in 32-bit ARGB format, having 8 bits per color component, where the
 * alpha component is stored in the high-order 8 bits, and blue is stored
 * in the low-order 8 bits.
 *
 * @param cursor The cursor to set the image of.
 * @param hx The X coordinate of the hotspot of the new cursor image.
 * @param hy The Y coordinate of the hotspot of the new cursor image.
 * @param data A pointer to raw 32-bit ARGB image data.
 * @param width The width of the given image data, in pixels.
 * @param height The height of the given image data, in pixels.
 * @param stride The number of bytes in a single row of image data.
 */
void guac_common_cursor_set_argb(guac_common_cursor* cursor, int hx, int hy,
    unsigned const char* data, int width, int height, int stride);

/**
 * Sets the cursor image to the contents of the given surface. The entire
 * contents of the surface are used, and the dimensions of the resulting
 * cursor will be the dimensions of the given surface.
 *
 * @param cursor The cursor to set the image of.
 * @param hx The X coordinate of the hotspot of the new cursor image.
 * @param hy The Y coordinate of the hotspot of the new cursor image.
 * @param surface The surface containing the cursor image.
 */
void guac_common_cursor_set_surface(guac_common_cursor* cursor, int hx, int hy,
    guac_common_surface* surface);

/**
 * Set the cursor of the remote display to the embedded "pointer" graphic. The
 * pointer graphic is a black arrow with white border.
 *
 * @param cursor The cursor to set the image of.
 */
void guac_common_cursor_set_pointer(guac_common_cursor* cursor);

/**
 * Set the cursor of the remote display to the embedded "dot" graphic. The dot
 * graphic is a small black square with white border.
 *
 * @param cursor The cursor to set the image of.
 */
void guac_common_cursor_set_dot(guac_common_cursor* cursor);

/**
 * Sets the cursor of the remote display to the embedded "I-bar" graphic. The
 * I-bar graphic is a small black "I" shape with white border, used to indicate
 * the presence of selectable or editable text.
 *
 * @param cursor
 *     The cursor to set the image of.
 */
void guac_common_cursor_set_ibar(guac_common_cursor* cursor);

/**
 * Sets the cursor of the remote display to the embedded transparent (blank)
 * graphic, effectively hiding the mouse cursor.
 *
 * @param cursor
 *     The cursor to set the image of.
 */
void guac_common_cursor_set_blank(guac_common_cursor* cursor);

/**
 * Removes the given user, such that future synchronization will not occur.
 * This is necessary when a user leaves the connection. If a user leaves the
 * connection and this is not called, the corresponding guac_user and socket
 * may cease to be valid, and future synchronization attempts will segfault.
 *
 * @param cursor The cursor to remove the user from.
 * @param user The user to remove.
 */
void guac_common_cursor_remove_user(guac_common_cursor* cursor,
        guac_user* user);

#endif