cursor.h

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/*
 Copyright (C) 2001-2006, William Joseph.
 All Rights Reserved.

 This file is part of GtkRadiant.

 GtkRadiant 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; either version 2 of the License, or
 (at your option) any later version.

 GtkRadiant 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 GtkRadiant; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#if !defined(INCLUDED_GTKUTIL_CURSOR_H)
#define INCLUDED_GTKUTIL_CURSOR_H

#include <glib/gmain.h>
#include <gdk/gdkevents.h>
#include <gtk/gtkwidget.h>
#include <gtk/gtkwindow.h>

#include "debugging/debugging.h"

typedef struct _GdkCursor GdkCursor;
typedef struct _GtkWidget GtkWidget;
typedef struct _GtkWindow GtkWindow;

GdkCursor* create_blank_cursor ();
void Sys_GetCursorPos (GtkWindow* window, int *x, int *y);
void Sys_SetCursorPos (GtkWindow* window, int x, int y);

class DeferredMotion
{
        guint m_handler;
        typedef void(*MotionFunction) (gdouble x, gdouble y, guint state, void* data);
        MotionFunction m_function;
        void* m_data;
        gdouble m_x;
        gdouble m_y;
        guint m_state;

        static gboolean deferred (DeferredMotion* self)
        {
            self->m_handler = 0;
            self->m_function(self->m_x, self->m_y, self->m_state, self->m_data);
            return FALSE;
        }
    public:
        DeferredMotion (MotionFunction function, void* data) :
            m_handler(0), m_function(function), m_data(data)
        {
        }
        void motion (gdouble x, gdouble y, guint state)
        {
            m_x = x;
            m_y = y;
            m_state = state;
            if (m_handler == 0) {
                m_handler = g_idle_add((GSourceFunc) deferred, this);
            }
        }
        // greebo: This is the actual callback method that gets connected via to the "motion_notify_event"
        static gboolean gtk_motion (GtkWidget *widget, GdkEventMotion *event, DeferredMotion* self)
        {
            self->motion(event->x, event->y, event->state);
            return FALSE;
        }
};

class DeferredMotionDelta
{
        int m_delta_x;
        int m_delta_y;
        guint m_motion_handler;
        typedef void (*MotionDeltaFunction) (int x, int y, void* data);
        MotionDeltaFunction m_function;
        void* m_data;

        static gboolean deferred_motion (gpointer data)
        {
            reinterpret_cast<DeferredMotionDelta*> (data)->m_function(
                    reinterpret_cast<DeferredMotionDelta*> (data)->m_delta_x,
                    reinterpret_cast<DeferredMotionDelta*> (data)->m_delta_y,
                    reinterpret_cast<DeferredMotionDelta*> (data)->m_data);
            reinterpret_cast<DeferredMotionDelta*> (data)->m_motion_handler = 0;
            reinterpret_cast<DeferredMotionDelta*> (data)->m_delta_x = 0;
            reinterpret_cast<DeferredMotionDelta*> (data)->m_delta_y = 0;
            return FALSE;
        }
    public:
        DeferredMotionDelta (MotionDeltaFunction function, void* data) :
            m_delta_x(0), m_delta_y(0), m_motion_handler(0), m_function(function), m_data(data)
        {
        }
        void flush ()
        {
            if (m_motion_handler != 0) {
                g_source_remove(m_motion_handler);
                deferred_motion(this);
            }
        }
        void motion_delta (int x, int y, unsigned int state)
        {
            m_delta_x += x;
            m_delta_y += y;
            if (m_motion_handler == 0) {
                m_motion_handler = g_idle_add(deferred_motion, this);
            }
        }
};

class FreezePointer
{
        unsigned int handle_motion;
        int recorded_x, recorded_y;
        typedef void (*MotionDeltaFunction) (int x, int y, unsigned int state, void* data);
        MotionDeltaFunction m_function;
        void* m_data;
    public:
        FreezePointer () :
            handle_motion(0), m_function(0), m_data(0)
        {
        }
        static gboolean motion_delta (GtkWidget *widget, GdkEventMotion *event, FreezePointer* self)
        {
            int current_x, current_y;
            Sys_GetCursorPos(GTK_WINDOW(widget), &current_x, &current_y);
            const int dx = current_x - self->recorded_x;
            const int dy = current_y - self->recorded_y;
            if (dx != 0 || dy != 0) {
                Sys_SetCursorPos(GTK_WINDOW(widget), self->recorded_x, self->recorded_y);
                self->m_function(dx, dy, event->state, self->m_data);
            }
            return FALSE;
        }

        void freeze_pointer (GtkWindow* window, MotionDeltaFunction function, void* data)
        {
            ASSERT_MESSAGE(m_function == 0, "can't freeze pointer");

            const GdkEventMask mask = static_cast<GdkEventMask> (GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK
                    | GDK_BUTTON_MOTION_MASK | GDK_BUTTON1_MOTION_MASK | GDK_BUTTON2_MOTION_MASK
                    | GDK_BUTTON3_MOTION_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK
                    | GDK_VISIBILITY_NOTIFY_MASK);

            GdkCursor* cursor = create_blank_cursor();
            //GdkGrabStatus status =
            gdk_pointer_grab(GTK_WIDGET(window)->window, TRUE, mask, 0, cursor, GDK_CURRENT_TIME);
            gdk_cursor_unref(cursor);

            Sys_GetCursorPos(window, &recorded_x, &recorded_y);

            Sys_SetCursorPos(window, recorded_x, recorded_y);

            m_function = function;
            m_data = data;

            handle_motion = g_signal_connect(G_OBJECT(window), "motion_notify_event", G_CALLBACK(motion_delta), this);
        }

        void unfreeze_pointer (GtkWindow* window)
        {
            g_signal_handler_disconnect(G_OBJECT(window), handle_motion);

            m_function = 0;
            m_data = 0;

            Sys_SetCursorPos(window, recorded_x, recorded_y);

            gdk_pointer_ungrab(GDK_CURRENT_TIME);
        }
};

#endif