evince/libview/ev-view-accessible.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8; c-indent-level: 8 -*- */
/* this file is part of evince, a gnome document viewer
 *
 *  Copyright (C) 2004 Red Hat, Inc
 *
 * Evince 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.
 *
 * Evince 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include <config.h>
#include <glib/gi18n-lib.h>

#include "ev-view-accessible.h"
#include "ev-view-private.h"

#define EV_TYPE_VIEW_ACCESSIBLE      (ev_view_accessible_get_type ())
#define EV_VIEW_ACCESSIBLE(obj)      (G_TYPE_CHECK_INSTANCE_CAST ((obj), EV_TYPE_VIEW_ACCESSIBLE, EvViewAccessible))
#define EV_IS_VIEW_ACCESSIBLE(obj)   (G_TYPE_CHECK_INSTANCE_TYPE ((obj), EV_TYPE_VIEW_ACCESSIBLE))

static GType ev_view_accessible_get_type (void);

enum {
	ACTION_SCROLL_UP,
	ACTION_SCROLL_DOWN,
	LAST_ACTION
};

static const gchar *const ev_view_accessible_action_names[] = 
{
	N_("Scroll Up"),
	N_("Scroll Down"),
	NULL
};

static const gchar *const ev_view_accessible_action_descriptions[] = 
{
	N_("Scroll View Up"),
	N_("Scroll View Down"),
	NULL
};

typedef struct {
	/* Action */
	gchar *action_descriptions[LAST_ACTION];
	guint action_idle_handler;  
	GtkScrollType idle_scroll;	 
} EvViewAccessiblePriv;

typedef GtkAccessibleClass EvViewAccessibleClass;

#define EV_VIEW_ACCESSIBLE_GET_PRIVATE(inst) (G_TYPE_INSTANCE_GET_PRIVATE ((inst), EV_TYPE_VIEW_ACCESSIBLE, EvViewAccessiblePriv))

static void
ev_view_accessible_finalize (GObject *object)
{
	EvViewAccessiblePriv *priv = EV_VIEW_ACCESSIBLE_GET_PRIVATE (object);
	int i;
	
	if (priv->action_idle_handler)
		g_source_remove (priv->action_idle_handler);
	for (i = 0; i < LAST_ACTION; i++)	
		g_free (priv->action_descriptions [i]);
}

static void ev_view_accessible_class_init (EvViewAccessibleClass *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);

  object_class->finalize = ev_view_accessible_finalize;

  g_type_class_add_private (klass, sizeof (EvViewAccessiblePriv));
}

static gchar*
ev_view_accessible_get_text (AtkText *text,
                     gint    start_pos,
                     gint    end_pos)
{
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return NULL;

  return NULL;
}

static gunichar 
ev_view_accessible_get_character_at_offset (AtkText *text,
                                    gint     offset)
{
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return '\0';

  return '\0';
}

static gchar*
ev_view_accessible_get_text_before_offset (AtkText	    *text,
				   gint		    offset,
				   AtkTextBoundary  boundary_type,
				   gint		    *start_offset,
				   gint		    *end_offset)
{
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return NULL;

  return NULL;
}

static gchar*
ev_view_accessible_get_text_at_offset (AtkText          *text,
                               gint             offset,
                               AtkTextBoundary  boundary_type,
                               gint             *start_offset,
                               gint             *end_offset)
{
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return NULL;

  return NULL;
}

static gchar*
ev_view_accessible_get_text_after_offset  (AtkText	    *text,
				   gint		    offset,
				   AtkTextBoundary  boundary_type,
				   gint		    *start_offset,
				   gint		    *end_offset)
{
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return NULL;

  return NULL;
}

static gint
ev_view_accessible_get_character_count (AtkText *text)
{
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return 0;

  return 0;
}

static gint
ev_view_accessible_get_caret_offset (AtkText *text)
{
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return 0;
 
  return 0;
}

static gboolean
ev_view_accessible_set_caret_offset (AtkText *text, gint offset)
{
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return FALSE;

  return FALSE;
}

static AtkAttributeSet*
ev_view_accessible_get_run_attributes (AtkText *text,
			       gint    offset,
                               gint    *start_offset,
                               gint    *end_offset)
{
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return NULL;
 
  return NULL;
}

static AtkAttributeSet*
ev_view_accessible_get_default_attributes (AtkText *text)
{
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return NULL;

  return NULL;
}
  
static void
ev_view_accessible_get_character_extents (AtkText *text,
				  gint    offset,
		                  gint    *x,
                    		  gint 	  *y,
                                  gint 	  *width,
                                  gint 	  *height,
			          AtkCoordType coords)
{
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return;

  return;
} 

static gint 
ev_view_accessible_get_offset_at_point (AtkText *text,
                                gint x,
                                gint y,
			        AtkCoordType coords)
{ 
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return -1;

  return -1;
}

static gint
ev_view_accessible_get_n_selections (AtkText              *text)
{
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return -1;
    
  return -1;
}

static gchar*
ev_view_accessible_get_selection (AtkText *text,
			  gint    selection_num,
                          gint    *start_pos,
                          gint    *end_pos)
{
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return NULL;

  return NULL;
}

static gboolean
ev_view_accessible_add_selection (AtkText *text,
                          gint    start_pos,
                          gint    end_pos)
{
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return FALSE;

  return FALSE;
}

static gboolean
ev_view_accessible_remove_selection (AtkText *text,
                             gint    selection_num)
{
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return FALSE;

  return FALSE;
}

static gboolean
ev_view_accessible_set_selection (AtkText *text,
			  gint	  selection_num,
                          gint    start_pos,
                          gint    end_pos)
{
  GtkWidget *widget;

  widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (text));
  if (widget == NULL)
    /* State is defunct */
    return FALSE;

  return FALSE;
}


static void ev_view_accessible_text_iface_init (AtkTextIface * iface)
{
	g_return_if_fail (iface != NULL);

	iface->get_text = ev_view_accessible_get_text;
	iface->get_character_at_offset = ev_view_accessible_get_character_at_offset;
	iface->get_text_before_offset = ev_view_accessible_get_text_before_offset;
	iface->get_text_at_offset = ev_view_accessible_get_text_at_offset;
	iface->get_text_after_offset = ev_view_accessible_get_text_after_offset;
	iface->get_caret_offset = ev_view_accessible_get_caret_offset;
	iface->set_caret_offset = ev_view_accessible_set_caret_offset;
	iface->get_character_count = ev_view_accessible_get_character_count;
	iface->get_n_selections = ev_view_accessible_get_n_selections;
	iface->get_selection = ev_view_accessible_get_selection;
	iface->add_selection = ev_view_accessible_add_selection;
	iface->remove_selection = ev_view_accessible_remove_selection;
	iface->set_selection = ev_view_accessible_set_selection;
	iface->get_run_attributes = ev_view_accessible_get_run_attributes;
	iface->get_default_attributes = ev_view_accessible_get_default_attributes;
	iface->get_character_extents = ev_view_accessible_get_character_extents;
	iface->get_offset_at_point = ev_view_accessible_get_offset_at_point;
	return;
}

static gboolean
ev_view_accessible_idle_do_action (gpointer data)
{
	EvViewAccessiblePriv* priv = EV_VIEW_ACCESSIBLE_GET_PRIVATE (data);
	
	ev_view_scroll (EV_VIEW (gtk_accessible_get_widget (GTK_ACCESSIBLE (data))),
			priv->idle_scroll,
			FALSE);
	priv->action_idle_handler = 0;
	return FALSE;
}

static gboolean
ev_view_accessible_action_do_action (AtkAction *action,
                                     gint       i)
{
	EvViewAccessiblePriv* priv = EV_VIEW_ACCESSIBLE_GET_PRIVATE (action);
	
	if (gtk_accessible_get_widget (GTK_ACCESSIBLE (action)) == NULL)
		return FALSE;

	if (priv->action_idle_handler)
		return FALSE;
	
	switch (i) {
		case ACTION_SCROLL_UP:
			priv->idle_scroll = GTK_SCROLL_PAGE_BACKWARD;
			break;
		case ACTION_SCROLL_DOWN:
			priv->idle_scroll = GTK_SCROLL_PAGE_FORWARD;
			break;
		default:
			return FALSE;
	}
	priv->action_idle_handler = g_idle_add (ev_view_accessible_idle_do_action, 
						action);
	return TRUE;
}

static gint
ev_view_accessible_action_get_n_actions (AtkAction *action)
{
        return LAST_ACTION;
}

static const gchar *
ev_view_accessible_action_get_description (AtkAction *action,
                                           gint       i)
{
  EvViewAccessiblePriv* priv = EV_VIEW_ACCESSIBLE_GET_PRIVATE (action);

  if (i < 0 || i >= LAST_ACTION) 
    return NULL;

  if (priv->action_descriptions[i])
    return priv->action_descriptions[i];
  else
    return ev_view_accessible_action_descriptions[i];
}

static const gchar *
ev_view_accessible_action_get_name (AtkAction *action,
                                    gint       i)
{
  if (i < 0 || i >= LAST_ACTION) 
    return NULL;

  return ev_view_accessible_action_names[i];
}

static gboolean
ev_view_accessible_action_set_description (AtkAction   *action,
                                           gint         i,
                                           const gchar *description)
{
  EvViewAccessiblePriv* priv = EV_VIEW_ACCESSIBLE_GET_PRIVATE (action);
  gchar *old_description;

  if (i < 0 || i >= LAST_ACTION) 
    return FALSE;

  old_description = priv->action_descriptions[i];
  priv->action_descriptions[i] = g_strdup (description);
  g_free (old_description);

  return TRUE;
}

static void ev_view_accessible_action_iface_init (AtkActionIface * iface)
{
	iface->do_action = ev_view_accessible_action_do_action;
	iface->get_n_actions = ev_view_accessible_action_get_n_actions;
	iface->get_description = ev_view_accessible_action_get_description;
	iface->get_name = ev_view_accessible_action_get_name;
	iface->set_description = ev_view_accessible_action_set_description;
}

GType ev_view_accessible_get_type (void)
{
	static GType type = 0;

	if (G_UNLIKELY (type == 0)) {
		GTypeInfo tinfo = {
			0,	/* class size */
			(GBaseInitFunc) NULL,	/* base init */
			(GBaseFinalizeFunc) NULL,	/* base finalize */
			(GClassInitFunc) ev_view_accessible_class_init,	/* class init */
			(GClassFinalizeFunc) NULL,	/* class finalize */
			NULL,	/* class data */
			0,	/* instance size */
			0,	/* nb preallocs */
 			(GInstanceInitFunc) NULL,	/* instance init */
			NULL	/* value table */
		};

		const GInterfaceInfo atk_text_info = {
			(GInterfaceInitFunc)
			    ev_view_accessible_text_iface_init,
			(GInterfaceFinalizeFunc) NULL,
			NULL
		};

		const GInterfaceInfo atk_action_info = {
			(GInterfaceInitFunc)
			    ev_view_accessible_action_iface_init,
			(GInterfaceFinalizeFunc) NULL,
			NULL
		};
	        /*
    	         * Figure out the size of the class and instance
		 * we are deriving from
    		 */
		AtkObjectFactory *factory;
		GType derived_type;
	        GTypeQuery query;
    		GType derived_atk_type;	    

    		derived_type = g_type_parent (EV_TYPE_VIEW);
		factory = atk_registry_get_factory (atk_get_default_registry (), 
                                        	    derived_type);
    		derived_atk_type = atk_object_factory_get_accessible_type (factory);

	        g_type_query (derived_atk_type, &query);
    		tinfo.class_size = query.class_size;
		tinfo.instance_size = query.instance_size;
 
    		type = g_type_register_static (derived_atk_type, "EvViewAccessible",
					       &tinfo, 0);
		g_type_add_interface_static (type, ATK_TYPE_TEXT,
					     &atk_text_info);
		g_type_add_interface_static (type, ATK_TYPE_ACTION,
					     &atk_action_info);
	}

	return type;
}

static AtkObject *ev_view_accessible_new(GObject * obj)
{
	AtkObject *accessible;
	
	g_return_val_if_fail(EV_IS_VIEW (obj), NULL);

	accessible = g_object_new (ev_view_accessible_get_type (), NULL);
	atk_object_initialize (accessible, obj);

	atk_object_set_name (ATK_OBJECT (accessible), _("Document View"));
	atk_object_set_role (ATK_OBJECT (accessible), ATK_ROLE_UNKNOWN);

	return accessible;
}

typedef AtkObjectFactory      EvViewAccessibleFactory;
typedef AtkObjectFactoryClass EvViewAccessibleFactoryClass;

static void ev_view_accessible_factory_init (EvViewAccessibleFactory *factory)
{
}

static GType ev_view_accessible_factory_get_accessible_type(void)
{
	return ev_view_accessible_get_type();
}

static AtkObject *ev_view_accessible_factory_create_accessible (GObject * obj)
{
	return ev_view_accessible_new(obj);
}

static void ev_view_accessible_factory_class_init (AtkObjectFactoryClass * klass)
{
	klass->create_accessible = ev_view_accessible_factory_create_accessible;
	klass->get_accessible_type =
	    ev_view_accessible_factory_get_accessible_type;
}

G_DEFINE_TYPE (EvViewAccessibleFactory, ev_view_accessible_factory, ATK_TYPE_OBJECT_FACTORY)