/* Event handling for GTK 3 and (in the future) GTK 4      -*- coding: utf-8 -*-

Copyright (C) 2020 Free Software Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs 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 3 of the License, or (at
your option) any later version.

GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */

#ifndef __PGTK_EVENT_H
#define __PGTK_EVENT_H

#include "config.h"
#include "gtkconfig.h"
#include <gtk/gtk.h>

G_BEGIN_DECLS
#if !defined (HAVE_GTK4) || defined (FIX_GTK_LEGACY_CONTROLLER_BUG)
/* ATTENTION *
 * If Emacs fails to compile, or throws weird
 * errors during runtime, make sure to update
 * this section with the contents of gtkeventcontrollerprivate.h
 * from the GTK version you're using
 */
#ifndef HAVE_GTK4
struct _GtkEventController
{
  GObject parent_instance;
};

struct _GtkEventControllerClass
{
  GObjectClass parent_class;

  void     (* set_widget)   (GtkEventController *controller,
                             GtkWidget          *widget);
  void     (* unset_widget) (GtkEventController *controller);
  gboolean (* handle_event) (GtkEventController *controller,
                             const GdkEvent     *event);
  void     (* reset)        (GtkEventController *controller);

  /*<private>*/

  /* Tells whether the event is filtered out, %TRUE makes
   * the event unseen by the handle_event vfunc.
   */
  gboolean (* filter_event) (GtkEventController *controller,
                             const GdkEvent     *event);
  gpointer padding[10];
};
#else
typedef enum {
  GTK_CROSSING_FOCUS,
  GTK_CROSSING_POINTER,
  GTK_CROSSING_DROP
} GtkCrossingType;

typedef enum {
  GTK_CROSSING_IN,
  GTK_CROSSING_OUT
} GtkCrossingDirection;

typedef struct _GtkCrossingData GtkCrossingData;

/**
 * GtkCrossingData:
 * @type: the type of crossing event
 * @direction: whether this is a focus-in or focus-out event
 * @mode: the crossing mode
 * @old_target: the old target
 * @old_descendent: the direct child of the receiving widget that
 *     is an ancestor of @old_target, or %NULL if @old_target is not
 *     a descendent of the receiving widget
 * @new_target: the new target
 * @new_descendent: the direct child of the receiving widget that
 *     is an ancestor of @new_target, or %NULL if @new_target is not
 *     a descendent of the receiving widget
 * @drop: the #GdkDrop if this is info for a drop operation
 *
 * The struct that is passed to gtk_event_controller_handle_crossing().
 *
 * The @old_target and @new_target fields are set to the old or new
 * focus, drop or hover location.
 */
struct _GtkCrossingData {
  GtkCrossingType type;
  GtkCrossingDirection direction;
  GdkCrossingMode mode;
  GtkWidget *old_target;
  GtkWidget *old_descendent;
  GtkWidget *new_target;
  GtkWidget *new_descendent;
  GdkDrop *drop;
};

struct _GtkEventController
{
  GObject parent_instance;
};

struct _GtkEventControllerClass
{
  GObjectClass parent_class;

  void     (* set_widget)   (GtkEventController *controller,
                             GtkWidget          *widget);
  void     (* unset_widget) (GtkEventController *controller);
  gboolean (* handle_event) (GtkEventController *controller,
                             GdkEvent            *event,
                             double              x,
                             double              y);
  void     (* reset)        (GtkEventController *controller);

  void     (* handle_crossing) (GtkEventController    *controller,
                                const GtkCrossingData *crossing,
                                double                 x,
                                double                 y);

  /*<private>*/

  /* Tells whether the event is filtered out, %TRUE makes
   * the event unseen by the handle_event vfunc.
   */
  gboolean (* filter_event) (GtkEventController *controller,
                             GdkEvent           *event);

  gpointer padding[10];
};

#endif
#endif
struct _EmacsGtkEventHandler
{
#if !defined (HAVE_GTK4) || defined (FIX_GTK_LEGACY_HANDLER_BUG)
  GtkEventController parent_instance;
#else
  GObject parent_instance;
#endif
#ifdef HAVE_GTK4
  // FIXME stupid hack
  gchar padding[1280];
#endif
  GtkWidget *widget;
  gboolean (*key_down) (GtkWidget *w, GdkEvent *ev, struct frame *frame);
  gboolean (*key_up) (GtkWidget *w, GdkEvent *ev, struct frame *f);
  gboolean (*button_down) (GtkWidget *w, GdkEvent *ev, struct frame *f);
  gboolean (*button_up) (GtkWidget *w, GdkEvent *ev, struct frame *f);
  gboolean (*window_state_event) (GtkWidget *w, GdkEvent *ev, struct frame *f);
  gboolean (*delete_event) (GtkWidget *w, GdkEvent *ev, struct frame *f);
  gboolean (*map_event) (GtkWidget *w, GdkEvent *ev, struct frame *f);
  gboolean (*size_allocate) (GtkWidget *w, GdkEvent *ev, struct frame *f);
#ifndef HAVE_GTK4
  gboolean (*scroll_event) (GtkWidget *w, GdkEvent *ev, struct frame *f);
#else
  gboolean (*scroll_event) (GtkEventControllerScroll *widget,
			    gdouble dx,
			    gdouble dy,
			    struct frame *_);
  gboolean (*long_press_event) (struct frame *f, gdouble ex, gdouble ey);
#endif
#ifndef HAVE_GTK4
  gboolean (*selection_lost) (GtkWidget *w, GdkEventSelection *ev, struct frame *f);
#endif
  gboolean (*configure) (GtkWidget *w, GdkEvent *ev, struct frame *f);
#ifndef HAVE_GTK4
  gboolean (*expose) (GtkWidget *w, GdkEventExpose *ev, gpointer ignored);
#endif
  gboolean (*focus_in) (GtkWidget *w, GdkEvent *ev, gpointer frame_ptr);
  gboolean (*focus_out) (GtkWidget *w, GdkEvent *ev, gpointer frame_ptr);
#ifdef HAVE_GTK4
  gboolean (*enter_notify) (GtkWidget *w, GdkEvent *ev, gpointer frame_ptr);
  gboolean (*leave_notify) (GtkWidget *w, GdkEvent *ev, gpointer frame_ptr);
  gboolean (*motion_notify) (GtkWidget *w, GdkEvent *ev, gpointer frame_ptr);
  void (*enter) (GtkWidget *w, GdkCrossingMode cm, struct frame *f);
  void (*leave) (GtkWidget *w, GdkCrossingMode cm, struct frame *f);
#ifndef FIX_GTK_LEGACY_HANDLER_BUG
  GtkEventControllerLegacy *legacy;
#endif
#ifdef HAVE_GTK4
  GtkEventControllerScroll *scroll;
  GtkEventControllerMotion *focus;
  GtkGesture *drag;
  GtkGesture *lpress;
  gdouble dsy, dsx;
  bool_bf s_flag;
  bool_bf hq_flag;
  bool_bf se_blocked;
#endif
#endif
};

#define EMACS_TYPE_GTK_EVENT_HANDLER (emacs_gtk_event_handler_get_type ())

G_DECLARE_FINAL_TYPE (EmacsGtkEventHandler,
		      emacs_gtk_event_handler,
		      EMACS,
#if !defined (HAVE_GTK4) || defined (FIX_GTK_LEGACY_HANDLER_BUG)
		      GTK_EVENT_HANDLER
#else
		      G_OBJECT
#endif
		      ,
#if !defined (HAVE_GTK4) || defined (FIX_GTK_LEGACY_HANDLER_BUG)
		      GtkEventController
#else
		      GObject
#endif
		      )

EmacsGtkEventHandler *emacs_gtk_event_handler_new (struct frame *f);

void
emacs_gtk_event_handler_set_widget (EmacsGtkEventHandler *handler, GtkWidget *w);

#ifdef HAVE_GTK4
void
emacs_gtk_event_handler_toggle_scroll_evs (EmacsGtkEventHandler *handler,
					   bool enable);
#endif
G_END_DECLS

#endif /* __PGTK_EVENT_H */