core_window.h

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/*
 * Copyright 2012 Michael Drake <tlsa@netsurf-browser.org>
 *
 * This file is part of NetSurf, http://www.netsurf-browser.org/
 *
 * NetSurf 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 of the License.
 *
 * NetSurf 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
/**
 * \file
 * Interface to core window handling.
 *
 * This provides a generalised API for frontends to implement which
 *  allows them to provide a single implementation for general window
 *  operations on their platform.
 *
 * General core implementations (cookie manager, global history,
 *  hotlist and ssl certificate viewer) use this API to perform
 *  operations like drawing and user input in a portable way.
 */
 
#ifndef _NETSURF_CORE_WINDOW_H_
#define _NETSURF_CORE_WINDOW_H_
 
struct core_window;
struct rect;
 
/**
 * drag status passed to drag_status callback
 */
typedef enum {
        CORE_WINDOW_DRAG_NONE,
        CORE_WINDOW_DRAG_SELECTION,
        CORE_WINDOW_DRAG_TEXT_SELECTION,
        CORE_WINDOW_DRAG_MOVE
} core_window_drag_status;
 
/**
 * Callbacks to achieve various core window functionality.
 */
struct core_window_callback_table {
        /**
         * Invalidate an area of a window.
         *
         * The specified area of the window should now be considered
         *  out of date. If the area is NULL the entire window must be
         *  invalidated. It is expected that the windowing system will
         *  then subsequently cause redraw/expose operations as
         *  necessary.
         *
         * \note the frontend should not attempt to actually start the
         *  redraw operations as a result of this callback because the
         *  core redraw functions may already be threaded.
         *
         * \param[in] cw The core window to invalidate.
         * \param[in] rect area to redraw or NULL for the entire window area
         * \return NSERROR_OK on success or appropriate error code
         */
        nserror (*invalidate)(struct core_window *cw, const struct rect *rect);
 
        /**
         * Update the limits of the window
         *
         * \param[in] cw the core window object
         * \param[in] width the width in px, or negative if don't care
         * \param[in] height the height in px, or negative if don't care
         * \return NSERROR_OK on success or appropriate error code
         */
        nserror (*update_size)(struct core_window *cw, int width, int height);
 
        /**
         * Scroll the window to given scroll offsets
         *
         * Note: Core callers of this may want to look at calling
         * the `cw_helper_scroll_visible()`, rather than calling
         * this directly.
         *
         * \param[in] cw the core window object
         * \param[in] x x-scroll value to set
         * \param[in] y y-scroll value to set
         * \return NSERROR_OK on success or appropriate error code
         */
        nserror (*set_scroll)(struct core_window *cw, int x, int y);
 
        /**
         * Get the current scroll offsets
         *
         * \param[in] cw the core window object
         * \param[out] returns horizontal scroll in px
         * \param[out] returns vertical scroll in px
         * \return NSERROR_OK on success or appropriate error code
         */
        nserror (*get_scroll)(const struct core_window *cw, int *x, int *y);
 
        /**
         * Get window viewport dimensions
         *
         * \param[in] cw the core window object
         * \param[out] width to be set to viewport width in px
         * \param[out] height to be set to viewport height in px
         * \return NSERROR_OK on success or appropriate error code
         */
        nserror (*get_window_dimensions)(const struct core_window *cw,
                        int *width, int *height);
 
        /**
         * Inform corewindow owner of drag status
         *
         * \param[in] cw the core window object
         * \param[in] ds the current drag status
         * \return NSERROR_OK on success or appropriate error code
         */
        nserror (*drag_status)(struct core_window *cw,
                        core_window_drag_status ds);
};
 
 
#endif