/*
 *      fm-dnd-src.c
 *      
 *      Copyright 2009 PCMan <pcman.tw@gmail.com>
 *      
 *      This program 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.
 *      
 *      This program 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 "fm-dnd-src.h"

GtkTargetEntry fm_default_dnd_src_targets[] = 
{
	{"application/x-fmlist-ptr", GTK_TARGET_SAME_APP, FM_DND_SRC_TARGET_FM_LIST},
	{"text/uri-list", 0, FM_DND_SRC_TARGET_URI_LIST}
};

enum
{
	DATA_GET,
	N_SIGNALS
};

static void fm_dnd_src_finalize  			(GObject *object);

static void
on_drag_data_get ( GtkWidget *src_widget,
				   GdkDragContext *drag_context,
				   GtkSelectionData *sel_data,
				   guint info,
				   guint time,
				   FmDndSrc* ds );

static void
on_drag_begin ( GtkWidget *src_widget,
				GdkDragContext *drag_context,
				FmDndSrc* ds );

static void
on_drag_end ( GtkWidget *src_widget,
			  GdkDragContext *drag_context,
			  FmDndSrc* ds );

static guint signals[N_SIGNALS];


G_DEFINE_TYPE(FmDndSrc, fm_dnd_src, G_TYPE_OBJECT);


static void fm_dnd_src_class_init(FmDndSrcClass *klass)
{
	GObjectClass *g_object_class;
	FmDndSrcClass *dnd_src_class;

	g_object_class = G_OBJECT_CLASS(klass);
	g_object_class->finalize = fm_dnd_src_finalize;

	dnd_src_class = FM_DND_SRC_CLASS(klass);

	/* emitted when information of source files is needed.
	 * call fm_dnd_source_set_files() in its callback to 
	 * provide info of dragged source files. */
    signals[ DATA_GET ] =
        g_signal_new ( "data-get",
                       G_TYPE_FROM_CLASS( klass ),
                       G_SIGNAL_RUN_FIRST,
                       G_STRUCT_OFFSET ( FmDndSrcClass, data_get ),
                       NULL, NULL,
                       g_cclosure_marshal_VOID__VOID,
                       G_TYPE_NONE, 0 );
}


static void fm_dnd_src_finalize(GObject *object)
{
	FmDndSrc *ds;

	g_return_if_fail(object != NULL);
	g_return_if_fail(FM_IS_DND_SRC(object));

	ds = FM_DND_SRC(object);

	if(ds->files)
		fm_list_unref(ds->files);

	fm_dnd_src_set_widget(ds, NULL);

	G_OBJECT_CLASS(fm_dnd_src_parent_class)->finalize(object);
}


static void fm_dnd_src_init(FmDndSrc *self)
{
	
}


FmDndSrc *fm_dnd_src_new(GtkWidget* w)
{
	FmDndSrc* ds = (FmDndSrc*)g_object_new(FM_TYPE_DND_SRC, NULL);
	fm_dnd_src_set_widget(ds, w);
	return ds;
}

void fm_dnd_src_set_widget(FmDndSrc* ds, GtkWidget* w)
{
	if(w == ds->widget)
		return;
	if(ds->widget) /* there is an old widget connected */
	{
		g_signal_handlers_disconnect_by_func(ds->widget, on_drag_data_get, ds);
		g_signal_handlers_disconnect_by_func(ds->widget, on_drag_begin, ds);
		g_signal_handlers_disconnect_by_func(ds->widget, on_drag_end, ds);
	}
	ds->widget = w;
	if( w )
	{
        g_object_add_weak_pointer(G_OBJECT(w), &ds->widget);
		g_signal_connect(w, "drag-data-get", G_CALLBACK(on_drag_data_get), ds);
		g_signal_connect_after(w, "drag-begin", G_CALLBACK(on_drag_begin), ds);
		g_signal_connect_after(w, "drag-end", G_CALLBACK(on_drag_end), ds);
	}
}

void fm_dnd_src_set_files(FmDndSrc* ds, FmFileInfoList* files)
{
	ds->files = fm_list_ref(files);
}

void fm_dnd_src_set_file(FmDndSrc* ds, FmFileInfo* file)
{
	FmFileInfoList* files = fm_file_info_list_new();
	fm_list_push_tail(files, file);
	ds->files = files;
}

static void
on_drag_data_get ( GtkWidget *src_widget,
				   GdkDragContext *drag_context,
				   GtkSelectionData *sel_data,
				   guint info,
				   guint time,
				   FmDndSrc* ds )
{
    GdkAtom type;

    /*  Don't call the default handler  */
    g_signal_stop_emission_by_name( src_widget, "drag-data-get" );
    drag_context->actions = GDK_ACTION_MOVE | GDK_ACTION_COPY | GDK_ACTION_LINK;

	type = gdk_atom_intern_static_string(fm_default_dnd_src_targets[info].target);
	switch( info )
	{
	case FM_DND_SRC_TARGET_FM_LIST:
		/* just store the pointer in GtkSelection since this is used 
		 * within the same app. */
		gtk_selection_data_set(sel_data, type, 8,
								&ds->files, sizeof(gpointer));
		break;
	case FM_DND_SRC_TARGET_URI_LIST:
		{
			gchar* uri;
			GString* uri_list = g_string_sized_new( 8192 );
			GList* l;
			FmFileInfo* file;
			char* full_path;

			for( l = fm_list_peek_head_link(ds->files); l; l=l->next )
			{
				file = (FmFileInfo*)l->data;
				uri = fm_path_to_uri(file->path);
				g_string_append( uri_list, uri );
				g_free( uri );
				g_string_append( uri_list, "\r\n" );
			}
			gtk_selection_data_set ( sel_data, type, 8,
									 ( guchar* ) uri_list->str, uri_list->len + 1 );
			g_string_free( uri_list, TRUE );
		}
		break;
	}
}

static void
on_drag_begin ( GtkWidget *src_widget,
				GdkDragContext *drag_context,
				FmDndSrc* ds )
{
	/* block default handler */

    gtk_drag_set_icon_default( drag_context );

	/* FIXME: set the icon to file icon later */
	// gtk_drag_set_icon_pixbuf();

	/* ask drag source to provide list of source files. */
	g_signal_emit(ds, signals[DATA_GET], 0);
}

static void
on_drag_end ( GtkWidget *src_widget,
			  GdkDragContext *drag_context,
			  FmDndSrc* ds )
{

}